1
|
Qaeed MA, Hendi A, Thahe AA, Al-Maaqar SM, Osman AM, Ismail A, Mindil A, Eid AA, Aqlan F, Al-Nahari EG, Obaid AS, Warsi MK, Saif AA, AL-Farga A. Effect of Different Ratios of Mentha spicata Aqueous Solution Based on a Biosolvent on the Synthesis of AgNPs for Inhibiting Bacteria. Journal of Nanomaterials 2023; 2023:1-10. [DOI: 10.1155/2023/3599501] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Our work was devoted to studying the effect of different concentrations of Mentha spicata aqueous extract on the green synthesis of silver nanoparticles (AgNPs) in order to obtain the most effective of these concentrations for bacteria inhibitory activity. Different concentrations of the aqueous M. spicata extract (0.25, 0.50, 0.75, and 1.00 mM) were used as biological solvent to synthesize AgNPs by means of the reduction method. The crystal structure and morphology of the NPs were characterized UV–vis spectra, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The inhibition effect of AgNPs on Escherichia coli was studied to determine the minimum inhibitory concentration (MIC). The dark yellow color of the M. spicata extract aqueous solution indicates the successful synthesis of the AgNPs. UV spectra of the NPs show a gradual increase in absorption with increasing concentration of aqueous M. spicata extract solution from 0.25 to 1.00 mM, accompanied by a shift in the wavelength from 455 to 479 nm along with a change in the nanoparticle size from 31 to 9 nm. The tests also showed a high activity of the particles against bacteria (E. coli) ranging between 15.6 and 62.5 µg/ml. From the AgNPs, it was confirmed that aqueous M. spicata extract is an effective biosolvent for the synthesis of different sizes of AgNPs according to the solvent concentration. The AgNPs also proved effectual for the killing of bacteria.
Collapse
Affiliation(s)
- Motahher A. Qaeed
- Department of Physics, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Abdulmajeed Hendi
- Department of Physics, IRC Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Asad A. Thahe
- Department of Medical Physics, College of Applied Science, University of Fallujah, Fallujah, Iraq
| | - Saleh M. Al-Maaqar
- Faculty of Education, Department of Biology, Al-Baydha University, Al-Baydha, Yemen
| | - Abdalghaffar M. Osman
- Department of Chemistry, IRC Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - A. Ismail
- Department of Physics, University of Hafr Al Batin, Hafr Al Batin 31991, Saudi Arabia
| | - A. Mindil
- Department of Physics, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Alharthi A. Eid
- Department of Physics, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Faisal Aqlan
- Department of Chemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - E. G. Al-Nahari
- Department of Physics, Center of Excellence in Development of Non-Profit Organizations, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Ahmed. S. Obaid
- Department of Physics, College of Science, University of Anbar, Ramadi, Iraq
| | - Mohiuddin Khan Warsi
- Department of Biochemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Ala’eddin A. Saif
- Department of Physics, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Ammar AL-Farga
- Department of Biochemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| |
Collapse
|
2
|
Qaeed MA, Hendi A, Obaid AS, Thahe AA, Osman AM, Ismail A, Mindil A, Eid AA, Aqlan F, Osman NMA, Al-Farga A, Al-Maaqar SM, Saif AA. The effect of different aqueous solutions ratios of Ocimum basilicum utilized in AgNPs synthesis on the inhibition of bacterial growth. Sci Rep 2023; 13:5866. [PMID: 37041159 PMCID: PMC10088745 DOI: 10.1038/s41598-023-31221-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 03/08/2023] [Indexed: 04/13/2023] Open
Abstract
This study examined the effect of varying concentrations of Ocimum basilicum aqueous extract, which was done via the green synthesis of Silver nanoparticles (AgNPs), on the identification of the most effective concentration for bacteria inhibitory activity. Different concentrations of the aqueous Ocimum basilicum extract (0.25, 0.50, 0.75 and 1.00 mM) were used as reducing and stabilizing agent to synthesize AgNPs by means of the reduction method. The crystal structure and morphology of the NPs were characterized UV-Vis spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of AgNPs was studied against E. coli ATCC 35218 using well diffusion, MIC, MBC, and time-kill curve. The dark yellow color of the Ocimum basilicum aqueous solution indicates the successful synthesis process of the AgNPs. UV-spectra of the AgNPs display a gradual increase of absorption in sequence with concentration increase of aqueous Ocimum basilicum extract solution from 0.25 to 1.00 mM. This, in turn, led to a shift in the wavelength from 488 to 497 nm, along with a change in the nanoparticle size from 52 to 8 nm. The tests also showed a high activity of the particles against bacteria (E. coli), ranging between 15.6 and 62.5 µg/ml. Based on AgNPs, it was confirmed that an aqueous Ocimum basilicum extract can be used as an effective, reducing and stabilizing agent for the synthesis of different sizes of AgNPs based on the solvent concentration. The AgNPs also proved to be effective in inhibiting and killing bacteria.
Collapse
Affiliation(s)
- Motahher A Qaeed
- Physics Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Abdulmajeed Hendi
- Physics Department and IRC Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
| | - Ahmed S Obaid
- Physics Department, College of Science, University of Anbar, Ramadi, Iraq
| | - Asad A Thahe
- Department of Medical Physics College of Applied Science, University of Fallujah, Fallujah, Iraq
| | - Abdalghaffar M Osman
- Chemistry Department and IRC Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
| | - A Ismail
- Department of Physics, University of Hafr Al Batin, Hafar Al-Batin, 31991, Saudi Arabia
| | - A Mindil
- Physics Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Alharthi A Eid
- Physics Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Faisal Aqlan
- Chemistry Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Nadir M A Osman
- Chemistry Department, College of Chemicals and Materials, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia
| | - Ammar Al-Farga
- Department of Biochemistry, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Saleh M Al-Maaqar
- Department of Biology, Faculty of Education, Albaydha University, Albaydha, Yemen.
| | - Ala'eddin A Saif
- Physics Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| |
Collapse
|
3
|
Osman AM, Hendi A, Osman NMA. Multiwalled Carbon Nanotubes-Modified Metallic Electrode Prepared Using Chemical Vapor Deposition as Sequential Injection Analysis Detector for Determination of Ascorbic Acid. Nanomaterials (Basel) 2023; 13:1264. [PMID: 37049357 PMCID: PMC10096536 DOI: 10.3390/nano13071264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/31/2023] [Accepted: 03/31/2023] [Indexed: 06/19/2023]
Abstract
A carbon nanotubes modified silver electrode (CNTs-Ag) was prepared via catalytic chemical vapor deposition and characterized. The morphology, crystallinity, elemental composition, and other quality parameters of the prepared electrode were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman techniques. The characterization results revealed the modification of the silver metal surface with CNTs of good characteristics. A sequential injection analysis (SIA) system was developed for studying the reaction of ascorbic acid with KIO3 using the prepared CNTs-Ag electrode. Electrodes were polarized with both direct current (DC) and periodic square wave (SW). Various experimental conditions affecting the differential electrolytic potentiometric (DEP) peak such as current density, SW bias value, and flow rate were appraised. Under the optimum conditions, good linear responses for ascorbic acid were obtained in the range of 60.0-850.0 µM for both types of polarization with detection limits of 14.0-19.0 µM. The results obtained showed that the periodic polarization method was more sensitive than DC polarization and the electrode response was faster. Ascorbic acid in pharmaceutical tablets was determined with satisfactory results using this method. The prepared CNTs-based electrode exhibited good performance for a long period of use. The method is simple, rapid, and inexpensive for routine analysis.
Collapse
Affiliation(s)
- Abdalghaffar M. Osman
- Chemistry Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
- Interdisciplinary Research Center (IRC) for Advanced Materials, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Abdulmajeed Hendi
- Physics Department, Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
- Interdisciplinary Research Center (IRC) for Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Nadir M. A. Osman
- Chemistry Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| |
Collapse
|
4
|
Hendi AH, Osman AM, Khan I, Saleh TA, Kandiel TA, Qahtan TF, Hossain MK. Visible Light-Driven Photoelectrocatalytic Water Splitting Using Z-Scheme Ag-Decorated MoS 2/RGO/NiWO 4 Heterostructure. ACS Omega 2020; 5:31644-31656. [PMID: 33344816 PMCID: PMC7745211 DOI: 10.1021/acsomega.0c03985] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/13/2020] [Indexed: 05/23/2023]
Abstract
Herein, we have successfully constructed a solid-state Z-scheme photosystem with enhanced light absorption capacity by combining the optoelectrical properties of AgNPs with those of the MoS2/RGO/NiWO4 (Ag-MRGON) heterostructure. The Ag-MRGON Z-scheme system demonstrates improved photo-electrochemical (PEC) water-splitting performance in terms of applied bias photon-to-current conversion efficiency (ABPE), which is 0.52%, and 17.3- and 4.3-times better than those of pristine MoS2 and MoS2/NiWO4 photoanodes, respectively. The application of AgNPs as an optical property enhancer and RGO as an electron mediator improved the photocurrent density of Ag-MRGON to 3.5 mA/cm2 and suppressed the charge recombination to attain the photostability of ∼2 h. Moreover, the photocurrent onset potential of the Ag-MRGON heterojunction (i.e., 0.61 VRHE) is cathodically shifted compared to those of NiWO4 (0.83 VRHE), MoS2 (0.80 VRHE), and MoS2/NiWO4 heterojunction (0.73 VRHE). The improved PEC water-splitting performance in terms of ABPE, photocurrent density, and onset potential is attributed to the facilitated charge transfer through the RGO mediator, the plasmonic effect of AgNPs, and the proper energy band alignments with the thermodynamic potentials of hydrogen and oxygen evolution.
Collapse
Affiliation(s)
- Abdulmajeed H. Hendi
- Physics
Department, King Fahd University of Petroleum
and Minerals, Dhahran 31261, Saudi Arabia
| | - Abdalghaffar M. Osman
- Chemistry
Department, King Fahd University of Petroleum
and Minerals, Dhahran 31261, Saudi Arabia
| | - Ibrahim Khan
- Center
for Integrative Petroleum Research (CIPR), College of Petroleum Engineering
& Geoscience (CPG), King Fahd University
of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Tawfik A. Saleh
- Chemistry
Department, King Fahd University of Petroleum
and Minerals, Dhahran 31261, Saudi Arabia
| | - Tarek A. Kandiel
- Chemistry
Department, King Fahd University of Petroleum
and Minerals, Dhahran 31261, Saudi Arabia
| | - Talal F. Qahtan
- Department
of Mechanical Engineering, College of Engineering, Prince Sattam Bin Abdulaziz University, Alkharj 11942, Saudi Arabia
| | - Mohammad K. Hossain
- Center
of Research Excellence in Renewable Energy Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| |
Collapse
|
5
|
Loutfy SA, Metwally SA, Abo-Shadi MA, Abdel Fattah NF, Osman AM, Moneer MM, Helal AM. Presence of Oncogenic Viruses: Clinical Relevance Among Egyptian Familial and Non-Familial Breast Cancer. Tumori 2020. [DOI: 10.1177/0300891620914134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Presenting Author: Loutfy SA Introduction: Oncogenic viruses including Mouse Mammary Tumor Virus (MMTV), Adenovirus (ADV), Polyomavirus (PoV), Human Papillomavirus (HPV), and Epstein–Barr virus (EBV) are one of the leading probable direct causes of Breast cancer (BC) worldwide. According to the National population-based registry program in Egypt (2008-2011) accounting for 32% of all female cancers. The present study aimed at evaluating the presence of these five oncogenic viruses among Egyptian familial and non-familial BC patients and their impact on the clinical course of the disease. Patients & Methods: The current study was conducted on 20 cases of BC patients without treatment and 10 healthy women as a control, aged between 18-45 years. Fresh frozen tissue and blood were obtained from BC patients, whereas only blood was obtained from control. All samples were subjected to qualitative and quantitative PCR assays to measure viral loads. The results were correlated to the clinicopathological parameters of breast cancer disease. Results: MMTV, ADV, PoV, HPV and EBV DNAs have been detected in 11 (55%),13 (65 %),8 (40%), 0 (0%) and 0 (0%) respectively, of 20 blood BC patients using qualitative PCR. PCR assay. Upon screening of 13 fresh frozen tissues, MMTV, ADV, PoV, HPV and EBV DNAs were present in 12(92%), 12(92%), 2(15.3%), 11(84.6%), and 11 (84.6) respectively of BC patients using quantitative PCR assay. Regarding viral load, ADV and HPV DNAs appeared to be the most replicative viruses out of all tested oncogenic viruses where their load ranged between 40 and 130,000 copies/ml. None of the tested viruses was detected in the control group. The presence of DNA of the 5 tested viruses was not associated with any clinicopathological parameters except larger tumor size was more common among BC patients with positive MMTV results. Conclusion: MMTV and ADV were the most common viruses present in tissue and blood of BC patients, tissue specimens are better for viral detection especially for EBV and papillomaviruses. The presence of oncogenic viral infection among young BC females could be considered as one of the risk external factor and could affect the path of BC disease and its prognosis.
Collapse
Affiliation(s)
- SA Loutfy
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
- Nanotechnology Research Center, British University, Cairo, Egypt
| | - SA Metwally
- Microbiology & Immunology Department, Faculty of Pharmacy for girls, Al-Azhar University, Cairo, Egypt
| | - MA Abo-Shadi
- Microbiology & Immunology Department, Faculty of Pharmacy for girls, Al-Azhar University, Cairo, Egypt
| | - NF Abdel Fattah
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - AM Osman
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - MM Moneer
- Breast surgical oncology, General Organization of Teaching hospital, Cairo, Egypt
| | - AM Helal
- Medical Oncology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| |
Collapse
|
6
|
Osman AM, Mirghani YA. Thyroid Dysfunctions in Sudanese Patients with Vitiligo. Sud Jnl Med Sci 2010. [DOI: 10.4314/sjms.v5i1.56027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
7
|
Abstract
OBJECTIVE Vitiligo is a chronic skin disease that causes loss of pigment, resulting in irregular pale patches of skin. The disease has profound psychological consequences. These effects range from mild embarrassment to a severe loss of self-confidence and social anxiety, especially for those who have lesions on exposed skin. The study sought to determine the psychological impact of vitiligo in Sudanese patients. METHOD This study is a cross-sectional, clinical-epidemiological and hospital-based study, undertaken in Khartoum Dermatologic Hospital (KDH). The data was collected between June 2007 and November 2007. 111 adult patients were enrolled sequentially during the study period and they were tested using the 12-item General Health Questionnaire (GHQ-12). RESULTS Psychological disturbances as a consequence of vitiligo were found in 36 (31 %) adult patients. Patients with mild psychological disturbances were found in 20 of these patients and severe disturbances in 16. CONCLUSION Psychological consequences are common in patients with vitiligo.
Collapse
Affiliation(s)
- A M Osman
- University of Juba, Omduman-Sudan, Sudan.
| | | | | |
Collapse
|
8
|
Abdel Hameed AA, Khoder MI, Yuosra S, Osman AM, Ghanem S. Diurnal distribution of airborne bacteria and fungi in the atmosphere of Helwan area, Egypt. Sci Total Environ 2009; 407:6217-22. [PMID: 19786293 DOI: 10.1016/j.scitotenv.2009.08.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 08/17/2009] [Accepted: 08/24/2009] [Indexed: 05/22/2023]
Abstract
Airborne bacterial and fungal composition in an industrial town of Helwan, Egypt, was studied using a slit impactor sampler during the period from March 2006 to February 2007. Airborne bacterial concentrations were usually higher than fungi. Bacteria and fungi had similar diurnal variation patterns. Airborne microorganisms reached their concentration peaks in the evening and gradually decreased during the night time. The hourly concentration peaks of the bacteria and fungi appeared at 20:00h. A significant difference (P < or =0.05) was found between the hourly mean concentrations of airborne fungi in winter compared to other seasons. Fungi concentrations were significantly higher (P< or =0.05) on working weekdays than weekends. Aspergillus, Penicillium, Alternaria and Cladosporium were the most predominant airborne fungal genera. Aspergillus showed double peak patterns whereas Penicillium, Alternaria and Cladosporium showed one peak pattern. The diurnal variations of the bacteria and fungi could be divided into four periods: 1) the morning maximum concentration (6:00h-10:00h), 2) midday to afternoon pattern (10:00h-16:00h), 3) the evening concentration peak (18:00h-20:00h) and 4) the gradual decrease of night time concentration (22:00h-24:00h). Geographical location, human activity, growth cycle of organisms and meteorological factors were the main criteria controlling the temporal variations of the air microorganisms in the Wadi Hof area.
Collapse
Affiliation(s)
- A A Abdel Hameed
- Air Pollution Dept., National Research Centre, Dokki, Giza, Egypt.
| | | | | | | | | |
Collapse
|
9
|
Osman AM, Elkordufani Y, Abdullah MA. The Socio-demography and Clinical Profile of Vitiligo in Sudan. Sud Jnl Med Sci 2009. [DOI: 10.4314/sjms.v3i4.38550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
10
|
Abdel-Nasser AM, Mahmoud MH, El Mansoury TM, Osman AM. Anti-CCP2 is an adjunct to, not a surrogate for, rheumatoid factor in the diagnosis of rheumatoid arthritis: diagnostic utility of anti-CCP2 antibodies in Egyptian patients with rheumatoid arthritis. Scand J Rheumatol 2008; 37:329-36. [PMID: 18666028 DOI: 10.1080/03009740802116208] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVES To examine the diagnostic utility of the second generation of anti-cyclic citrullinated peptide (anti-CCP2) antibodies versus rheumatoid factor (RF) in rheumatoid arthritis (RA), and to study the association between anti-CCP2 and RA disease parameters. METHODS Fifty consecutive Egyptian patients with RA, 37 patients with other rheumatic diseases, and 10 healthy controls were recruited for testing for anti-CCP2 and immunoglobulin M (IgM) rheumatoid factor (RF). Assessment measures included the Disease Activity Score (DAS28) for disease activity, the Health Assessment Questionnaire - Disability Index (HAQ-DI) for disability and the Short Erosion Narrowing Score (SENS) for radiological damage. RESULTS The sensitivities of anti-CCP2 and IgM-RF in RA patients were 70% and 52%, with specificities of 91.5% and 89.4%, respectively. There was 73.2% agreement between anti-CCP2 and RF for all groups tested (kappa = 0.42, p<0.001) but agreement was only 66% for RA patients (kappa = 0.31, p<0.05). Anti-CCP2 had superior diagnostic properties [sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)] than RF, but using both RF and anti-CCP2 enhanced the sensitivity to 78%, when either test was positive, and the specificity to 100%, with a PPV of 1, when both tests were positive. Anti-CCP2 titre was significantly correlated with disease severity [rheumatoid nodules, rheumatoid factor (RF), and radiological damage] and HAQ-DI (p<0.05) but not with parameters of disease activity. CONCLUSION Anti-CCP2 has superior diagnostic and prognostic properties in RA compared with RF. It should not replace RF as a serological test; however, since using both tests modestly increases sensitivity and markedly enhances specificity, so that diagnosis of RA is highly probable when both tests are positive.
Collapse
Affiliation(s)
- A M Abdel-Nasser
- Department of Rheumatology and Rehabilitation, Minia University, Egypt.
| | | | | | | |
Collapse
|
11
|
Osman AM, van Noort PCM. Comparison of key enzymes in the zebra mussel, Dreissena polymorpha, the earthworm Allolobophora chlorotica and Chironomus riparius larvae. Ecotoxicol Environ Saf 2007; 67:212-7. [PMID: 17052754 DOI: 10.1016/j.ecoenv.2006.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 05/24/2006] [Indexed: 05/12/2023]
Abstract
The levels of the enzymes, glutathione S-transferase, catalase, NAD(P)H-cytochrome c reductases, and DT-diaphorase were determined and compared in the tissues of three invertebrates commonly used in monitoring environmental quality: a freshwater mussel, Dreissena polymorpha, the earthworm Allolobophora chlorotica and the fourth instar of Chironomus riparius. It was found that the activities of GST, catalase, and NAD(P)-cytochrome c reductases were comparable in A. chlorotica and C. riparius, whereas comparatively a higher GST and a lower catalase activity was determined in the mussel tissues. DT-diaphorase was not detectable in A. chlorotica and the C. riparius larvae tissues, whereas this enzyme is present in the gills and the rest of soft mussel tissues (soft mussel tissues minus gills). It is suggested that the relatively low catalase activity observed in the tissues of the latter organism might be compensated by the presence of the antixidant role of DT-diaphorase. In addition, the inducibility of DT-diaphorase in D. polymorpha, by butylated hydroxyanisole (BHA) and lead (Pb) was investigated. Despite the bioaccumulation of both BHA (5.2+/-0.14 microgg(-1) wet weight) and Pb (233.7+/-0.95 mgkg(-1) dry weight) in the soft mussel tissues, the mussel DT-diaphorase was not induced. Although the activity of NADPH-cytochrome c (P-450) reductase was also not affected by these reagents, its activity was 2-fold higher in the gills than the rest of soft mussel tissues.
Collapse
Affiliation(s)
- A M Osman
- Scion, Private Bag 3020, Rotorua, New Zealand.
| | | |
Collapse
|
12
|
Osman AM, Wong KKY, Fernyhough A. ABTS radical-driven oxidation of polyphenols: Isolation and structural elucidation of covalent adducts. Biochem Biophys Res Commun 2006; 346:321-9. [PMID: 16756947 DOI: 10.1016/j.bbrc.2006.05.118] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Accepted: 05/18/2006] [Indexed: 11/23/2022]
Abstract
The formation of covalent adducts obtained from the reaction of the polyphenols, trans-3,3',4',5,7-pentahydroxyflavan (catechin) and 1,3,5-trihydroxybenzene (phloroglucinol), with ABTS radicals is reported. Two adducts derived from (+)-catechin and three adducts from phloroglucinol were isolated and identified using reversed-phase high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS). The molecular masses of the (+)-catechin-derived adducts (I(c) and II(c)) were found to be 802 and 559 Da, respectively, whereas the masses of phloroglucinol-derived adducts (I(p), II(p), and III(p)) were 638, 395, and 381 Da, respectively. The initially formed adducts (I(c), I(p)) were unstable and degraded to secondary adducts (II(c), II(p), and III(p)) releasing part of the ABTS molecule. The structures of these adducts were elucidated by interpreting the results of MS/MS analysis of prominent ions generated by both positive and negative ion ESI-MS. The adducts were found to scavenge ABTS radicals, an observation that could explain the complex kinetic behaviour manifested by the reactions of ABTS radicals with polyphenols. A mechanism, which accounts for both the formation of the adducts and the degradation products of ABTS radicals, is proposed.
Collapse
Affiliation(s)
- A M Osman
- Scion, Private Bag 3020, Rotorua, New Zealand.
| | | | | |
Collapse
|
13
|
Osman AM, Wong KKY, Hill SJ, Fernyhough A. Isolation and the characterization of the degradation products of the mediator ABTS-derived radicals formed upon reaction with polyphenols. Biochem Biophys Res Commun 2006; 340:597-603. [PMID: 16376855 DOI: 10.1016/j.bbrc.2005.12.051] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 12/06/2005] [Indexed: 11/20/2022]
Abstract
Two degradation products were obtained from the incubation of the widely used 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS, radical cations with the polyphenols, (+)-catechin, (-)-epicatechin, and phloroglucinol in acetate buffer (pH 5). The products were purified by reversed-phase chromatography and characterized by UV-visible detection, mass spectrometry, and (1)H NMR spectroscopy. The data allowed us to identify the degradation products as 3-ethyl-6-sulfonate benzothiazolinone imine and the corresponding sulfoxide, 3-ethyl-6-sulfonate benzothiazolone. Elemental composition strongly supported the proposed structures. Our results unequivocally demonstrated that ABTS radicals are not as stable as usually claimed because they could be degraded upon interaction with polyphenols, in addition to being reduced by these antioxidants back to the parent compound. Therefore, it is concluded that caution must be exercised in using ABTS radicals as a basis for the evaluation of antioxidant capacities of pure compounds and/or complex mixtures.
Collapse
Affiliation(s)
- A M Osman
- Scion, Private Bag 3020, Rotorua, New Zealand.
| | | | | | | |
Collapse
|
14
|
Osman AM, van den Heuvel H, van Noort PCM. Differential responses of biomarkers in tissues of a freshwater mussel,Dreissena polymorpha, to the exposure of sediment extracts with different levels of contamination. J Appl Toxicol 2006; 27:51-9. [PMID: 17186575 DOI: 10.1002/jat.1183] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this study, zebra mussels, D. polymorpha, were exposed to extracts of sediments obtained from two sites, a contaminated lake (Ketelmeer, Km) and a relatively clean lake (Drontenmeer, Dm). The main objective of this work was to investigate whether six selected biomarkers could discriminate between the two sediments. The selected biomarkers included phase I enzymes such as DT-diaphorase, NADPH-cytochrome c reductase, NADH-cytochrome c reductase, a phase II enzyme (glutathione S-transferase, GST), an antioxidant enzyme, catalase, and the total glutathione, reduced (GSH) and oxidized (GSSG). After a short (24 h) and a long-term (7 days) exposure, the levels of these biomarkers were measured in gills and the rest of soft mussel tissues (soft mussel tissue minus gills) and compared with control values. A decrease of GST level by 20% (P = 0.004) and a 4-fold decrease of total glutathione concentration relative to the control, were observed in the gills of mussels exposed to the more contaminated Km extract. No significant differences in the GST activities were observed in the gills of control and Dm extract-treated mussels (P = 0.23). Although the levels of catalase and NADH-cytochrome c reductase were, in the short-term exposure, unaffected, both activities were, in the long-term exposure, reduced in the gills of the mussels exposed to the contaminated Km extract, compared with control values, by 43% and 20%, respectively. The activities of DT-diaphorase and NADPH-cytochrome c reductase remained unaffected in all exposure conditions. However, the level of NADPH-cytochrome c reductase was found higher in gills than in the rest of soft mussel tissues. This difference in the ratio of the two reductases between the two tissues could account for the observed differential responses of the biomarkers.
Collapse
Affiliation(s)
- A M Osman
- Scion, Private Bag 3020, New Zealand.
| | | | | |
Collapse
|
15
|
Osman AM, Rotteveel S, den Besten PJ, van Noort PCM. In vivo exposure ofDreissena polymorpha mussels to the quinones menadione and lawsone: menadione is more toxic to mussels than lawsone. J Appl Toxicol 2004; 24:135-41. [PMID: 15052609 DOI: 10.1002/jat.963] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The principal aim of this study was to assess whether the two quinones, menadione (2-methyl-1,4-naphthoquinone) and lawsone (2-hydroxy-1,4-naphthoquinone), elicit differential toxicity in mussels as has been reported for higher organisms. Therefore, the effects of short-term (48 h) and long-term (20 days) exposure of the two quinones at concentrations of 0.56 and 1 mg l(-1) to zebra mussels, Dreissena polymorpha, under laboratory conditions were studied. After the short-term exposure, the specific activities of the two-electron quinone oxidoreductase (DT-diaphorase) and the one-electron catalysing quinone reductases NADPH-cytochrome c reductase and NADH-cytochrome c reductase were determined in the gills and the rest of the soft tissues (soft mussel tissues minus the gills) of both treated and control mussels. At the higher concentrations of menadione and lawsone used, a significant reduction of the activity of NADPH-cytochrome c reductase in the gills and in the rest of the soft mussel tissues (by 33-34% and 31-43%, respectively) was observed. The activities of DT-diaphorase and NADH-cytochrome c reductase were not significantly affected. Interestingly, DT-diaphorase was observed in the gills, an organ requiring protection against antioxidants. Furthermore, a single-cell electrophoretic assay (comet assay) performed with gill cells to assess DNA damage by the quinones did not show any significant difference between the treated and the control organisms. This indicates that the formation of reactive species by the quinone metabolism in vivo in the mussels was possibly suppressed through the concerted action of DT-diaphorase and antioxidant enzymes. The results of in vitro experiments with gill extracts confirmed the protective role of DT-diaphorase. The rate of the two-electron quinone reduction was found to be five times that of the one-electron quinone reduction. The results of the long-term exposure unambiguously demonstrated that in mussels menadione, unlike in higher organisms, is more toxic than lawsone. The lack of detectability of xanthine oxidase in the mussel tissues could explain the comparatively lower toxicity of lawsone in the invertebtrate, lending support to a previous suggestion that xanthine oxidase might be responsible for the mechanism of toxicity of lawsone in higher organisms in vivo.
Collapse
Affiliation(s)
- A M Osman
- Institute for Inland Water Management and Waste Water Treatment, PO Box 17, 8200 AA Lelystad, The Netherlands.
| | | | | | | |
Collapse
|
16
|
Osman AM, Den Besten PJ, van Noort PCM. Menadione enhances oxyradical formation in earthworm extracts: vulnerability of earthworms to quinone toxicity. Aquat Toxicol 2003; 65:101-109. [PMID: 12932705 DOI: 10.1016/s0166-445x(03)00118-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
NAD(P)H-cytochrome c reductase activities have been determined in the earthworms, L. rubellus and A. chlorotica, extracts. Menadione (0.35 mM, maximum concentration tested) was found to stimulate the rates of NADPH- and NADH-dependent cytochrome c reduction by three- and twofold, respectively. Superoxide dismutase (SOD) inhibited completely this menadione-mediated stimulation, suggesting that *O2- is involved in the redox cycling of menadione. However, SOD had no effect on the basal activity (activity in the absence of quinone) in the case of NADH-dependent cytochrome c reduction, whereas it partially inhibited the basal activity of NADPH-cytochrome c reduction. This indicates direct electron transfer in the former case and the formation of superoxide anion in the latter. DT-diaphorase, measured as the dicumarol-inhibitable part of menadione reductase activity, was not detectable in the earthworms' extracts. In contrast, it was found that DT-diaphorase represents about 70% of the menadione reductase activities in the freshwater mussel, Dreissena polymorpha. The results of this work suggest that earthworms, compared with mussels, could be more vulnerable to oxidative stress from quinones due to lack, or very low level of DT-diaphorase, an enzyme considered to play a significant role in the detoxification of quinones. On the contrary, mussels have efficient DT-diaphorase, which catalyzes two-electron reduction of menadione directly to hydroquinone, thus circumventing the formation of semiquinone.
Collapse
Affiliation(s)
- A M Osman
- Institute for Inland Water management and Waste Water Treatment (RIZA), P.O. Box 17, 8200 AA Lelystad, The Netherlands.
| | | | | |
Collapse
|
17
|
Osman AM, van Noort PCM. Evidence for redox cycling of lawsone (2-hydroxy-1,4-naphthoquinone) in the presence of the hypoxanthine/xanthine oxidase system. J Appl Toxicol 2003; 23:209-12. [PMID: 12884402 DOI: 10.1002/jat.908] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study reports that lawsone (2-hydroxy-1,4-naphthoquinone) undergoes redox cycling in the presence of the hypoxanthine/xanthine oxidase system. The rate of cytochrome c reduction obtained in the presence of 80 microM lawsone was almost three times the rate of cytochrome c reduction measured in its absence. This increase in the rate of cytochrome c reduction was partially inhibited by superoxide dismutase, suggesting the involvement of O(2)(.-) in this process. It is remarkable to note that, even though lawsone is considered to be a non-redox-cycling quinone in vitro, this quinone was shown to be more toxic in vivo in rats than menadione, causing haemolytic anemia of an oxidative nature and renal damage. The view that this quinone is a non-redox-cycling quinone was based on the inability of one-electron-transferring flavoenzymes such as NADPH-cytochrome c reductase to reduce this naphthoquinone. Our finding that lawsone, like menadione, undergoes redox cycling in the presence of the hypoxanthine/xanthine oxidase system could explain the observed oxidative damage of tissues inflicted by this quinone in rats in vivo. Such an observation therefore reconciles the in vivo toxicity results of this naphthoquinone with those of in vitro experiments.
Collapse
Affiliation(s)
- A M Osman
- Institute for Inland Water Management and Waste Water Treatment (RIZA), PO Box 17, 8200 AA Lelystad, The Netherlands.
| | | |
Collapse
|
18
|
El-Gendy SD, Osman AM, Al-Sherbiny MM. Epidemiology and immunodiagnosis of schistosomiasis haematobium in low endemic area in Egypt. J Egypt Soc Parasitol 2003; 29:229-46. [PMID: 12561903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
A survey was performed in Behbeet village in Giza governorate including 370 individuals (172 males and 198 females) representing 10% of the house holds. Clinical, stool, urine and serological tests accompanied by a questionnaire were applied to all participants to find out the prevalence, intensity of infection of S. haematobium, underlying sociodemographic factors, morbidity indicators and the awareness and treatment status among the infected population. It was revealed that the overall prevalence of S. haematobium based on the detection of eggs in urine was 18.1% while the prevalence of antibodies to S. haematobium species specific microsomal antigen was 57.6% detected by enzyme-linked immuno-transfer blot (EITB). The highest age specific prevalence and intensity of infection were detected among school children in the early teenage. Males were at a higher risk of contracting infection than females with a sex ratio of 2.5:1. Occupational and recreational water contact were significantly more frequent among the egg positives than the negative ones. Present history of haematuria and microhaematuria detected by reagent strips had the strongest association with S. haematobium infection followed by leucocyturia and dysuria. Microhaematuria had the strongest negative predictive value (85.7%) in discrimination between egg positive and negative groups while its positive predictive value was the highest (92.9%) when seropositives and negatives were discriminated. Less than half of the infected population were aware of having the disease (43.3% and 41.8% among the egg positives and seropositives, respectively) and lower percentages reported receiving previous treatment for schistosomiasis. No significant differences were detected between groups (P>0.05). Culturally appropriate and effective health education of the population, and training of the staff of rural health units to improve diagnostic and outreach skills are recommended.
Collapse
Affiliation(s)
- S D El-Gendy
- Department of Community Medicine, Benha Faculty of Medicine, Zagazig University, Egypt
| | | | | |
Collapse
|
19
|
Sayed-Ahmed MM, Khattab MM, Gad MZ, Osman AM. Increased plasma endothelin-1 and cardiac nitric oxide during doxorubicin-induced cardiomyopathy. Pharmacol Toxicol 2001; 89:140-4. [PMID: 11589785 DOI: 10.1034/j.1600-0773.2001.d01-148.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The major limiting factor in long-term administration of doxorubicin is the development of cumulative dose-dependent cardiomyopathy and congestive heart failure. Although several mechanisms have been suggested to explain the exact cause of doxorubicin-induced cardiomyopathy, the role of the vascular endothelium-derived vasoactive mediators in the pathophysiology of this toxic effect is still unknown. Accordingly, the present study has been initiated to investigate whether the changes in plasma level of endothelin-1 and nitric oxide along with cardiac nitric oxide are associated with the development of doxorubicin-induced cardiomyopathy. Doxorubicin was injected with a single dose of 5 mg/kg and every other day with a dose of 5 mg/kg, intraperitoneally, to have four cumulative doses of, 10, 15, 20 and 25 mg/kg in five separate groups of male rats. An additional group receiving a single dose of 20 mg/kg and one receiving normal saline were also included in the study. Twenty-four hr after the last dose, the animals were sacrificed and the plasma levels of endothelin-1 and nitric oxide in addition to cardiac nitric oxide were determined. The results show that doxorubicin caused a statistically significant increase of 85%, 76% and 97% in plasma endothelin-1 at a cumulative dose levels of 10, 15 and 20 mg/kg, respectively. However, the level of plasma nitric oxide remained unchanged. Furthermore, doxorubicin treatment resulted in a significant dose-dependent increase in serum lactate dehydrogenase and creatine phosphokinase. In contrast, the increase in nitric oxide production in cardiac tissue by doxorubicin was not dose-dependent with the maximum increase (81%) at a cumulative dose of 10 mg/kg. It is worth mentioning that plasma endothelin-1 and cardiac nitric oxide were significantly increased at 24 hr after the single dose of 20 mg/kg doxorubicin. The increase of plasma endothelin-1 and cardiac nitric oxide with the cardiomyopathy enzymatic indices, may point to the conclusion that both endothelin-1 and cardiac nitric oxide are increased during the development of doxorubicin-induced cardiomyopathy.
Collapse
|
20
|
Bauer C, Osman AM, Cercignani G, Gialluca N, Paolini M. A unified theory of enzyme kinetics based upon the systematic analysis of the variations of k(cat), K(M), and k(cat)/K(M) and the relevant DeltaG(0 not equal) values-possible implications in chemotherapy and biotechnology. Biochem Pharmacol 2001; 61:1049-55. [PMID: 11301037 DOI: 10.1016/s0006-2952(01)00579-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To elucidate the kinetic properties of critical enzymatic situations that have previously escaped classification, we performed a systematic analysis of all the possible variations of the kinetic constants k(cat,) K(M,) and k(sp) = k(cat)/K(M,) encompassing all aspects of enzymology. The equation gives a total of thirteen theoretically possible cases, comprising the reference case plus 12 different sets of variations, which can be divided into six principal cases and six specular ones. The six relevant cases are examined individually in the context of each of the main chapters of enzymology, i.e. as regards mechanism of action, specificity of substrate and isoenzyme, reversible and irreversible inhibition, and mutation of residues (enzyme evolution and enzyme engineering). Some critical cases where k(sp) does not hold as a specificity index are classified for the first time. Interestingly, the six possible cases correspond to the five known cases of reversible inhibition (competitive, non-competitive, incompetitive, mixed competitive/non-competitive, and mixed incompetitive/non-competitive) plus an additional case of biphasic nature (activation-inhibition), which is crucial for a full understanding of specificity and which leads us to propose some modification to the definition of enzyme specificity. The systematic approach to enzymology outlined herein could find practical applications in various sectors of biotechnology, including chemotherapy.
Collapse
Affiliation(s)
- C Bauer
- Department of Physiology and Biochemistry, Biochemistry Unit, University of Pisa, via S. Maria 55, I-56126 Pisa, Italy
| | | | | | | | | |
Collapse
|
21
|
Osman AM, Laane C, Hilhorst R. Enhanced sensitivity of Cypridina luciferin analogue (CLA) chemiluminescence for the detection of *O2(-) with non-ionic detergents. LUMINESCENCE 2001; 16:45-50. [PMID: 11180658 DOI: 10.1002/bio.609] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Superoxide anion-triggered chemiluminescence of Cypridina luciferin analogue (CLA), 2-methyl-6-phenyl-3,7-dohydroimidazo[1,2-alpha]pyrazin-3-one, is enhanced by non-ionic detergents such as Tween 20, Triton X-100 and Tween 80. At the concentration of 0.6% (v/v) the largest increase (2.7-fold) of CLA light intensity was obtained with Tween 20, followed by Tween 80 and Triton X-100. Using this detergent-amplified CLA chemiluminescence, the detection limits of xanthine and xanthine oxidase were examined at pH 7.4 and reinvestigated at pH 5.5. At pH 5.5, concentrations of xanthine and xanthine oxidase as low as 5 nmol/L and 3.85 x 10(-7) U/mL, respectively, could be accurately determined, whereas, under the experimental conditions used, at pH 7.4 the lowest concentrations of xanthine and xanthine oxidase detectable were 10 nmol/L and 3.85 x 10(-6) U/mL. The lowest detectable values of xanthine and xanthine oxidase obtained at pH 5.5 are about 400 and 10 times lower than those previously reported. The detection limit of xanthine (5 nmol/L) by this chemiluminescent-based method is about 200 and 20 times more sensitive than the determination of xanthine by enzymatic means or by HPLC with detection limits of 1 micromol/L and 0.1 micromol/L, respectively. Our data suggest that this chemiluminescent probe can detect concentrations of superoxide anion below the nanomolar range.
Collapse
Affiliation(s)
- A M Osman
- Department of Biomolecular Sciences, Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | | | | |
Collapse
|
22
|
Osman AM, Zomer G, Laane C, Hilhorst R. Comparative studies of the chemiluminescent horseradish peroxidase-catalysed peroxidation of acridan (GZ-11) and luminol reactions: effect of pH and scavengers of reactive oxygen species on the light intensity of these systems. LUMINESCENCE 2000; 15:189-97. [PMID: 10862148 DOI: 10.1002/1522-7243(200005/06)15:3<189::aid-bio585>3.0.co;2-a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this study, the chemiluminescent horseradish peroxidase/H(2)O(2)-catalysed oxidation of acridan (GZ-11) substrate was compared with the well-characterized light-producing luminol reaction. p-Iodophenol and p-phenylphenol were used as enhancers, respectively, for the luminol and acridan reactions. These two light-producing systems showed significant differences in relation to the effect of pH, as well as the effect of scavengers of reactive oxygen species, on the light intensity. Light production measured could be as low as pH 2.6 in the acridan reaction, whereas light emission was not detected in the luminol system below pH 5.6. In contrast with the luminol system, it was found that superoxide dismutase does not inhibit the light intensity of the acridan system. This suggests that superoxide anion does not participate in the mechanism of the light-emitting steps of the acridan reaction. Addition of hydroxyl radical scavengers, mannitol and benzoate, to the acridan reaction medium had no appreciable effect on the chemiluminescent intensity, indicating that hydroxyl radicals do not interfere in light-emitting steps. In addition, the peroxidation of the acridan substrate was found to be very slow at pH 5.6 in the absence of the enhancer, p-phenylphenol, whereas in its presence a rapid degradation of the acridan substrate was observed. Therefore, it is suggested that the enhancer might be initially oxidized by the HRP/H(2)O(2) system, resulting in the formation of the enhancer radical, which could be the actual oxidizing agent of the acridan substrate. Together, the data presented in this paper indicate that the chemiluminescent horseradish peroxidase-catalysed peroxidation of acridan (GZ-11) is more specific than the luminol reaction for the reactive oxygen species involved in the light-emitting steps, i. e, H(2)O(2).
Collapse
Affiliation(s)
- A M Osman
- Department of Biomolecular Sciences, Wageningen University, The Netherlands
| | | | | | | |
Collapse
|
23
|
Sayed-Ahmed MM, Shouman SA, Rezk BM, Khalifa MH, Osman AM, El-Merzabani MM. Propionyl-L-carnitine as potential protective agent against adriamycin-induced impairment of fatty acid beta-oxidation in isolated heart mitochondria. Pharmacol Res 2000; 41:143-50. [PMID: 10623482 DOI: 10.1006/phrs.1999.0583] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Propionyl-L-carnitine (PLC), a natural short-chain derivative of L-carnitine, has been tested in this study as a potential protective agent against adriamycin (ADR)-induced cardiotoxicity in isolated rat heart myocytes and mitochondria. In cardiac myocytes, ADR (0.5 mM) caused a significant (70%) inhibition of palmitate oxidation, whereas, PLC (5 mM) induced a significant (49%) stimulation. Addition of PLC to ADR-incubated myocytes induced 79% reversal of ADR-induced inhibition of palmitate oxidation. In isolated rat heart mitochondria, ADR produced concentration-dependent inhibition of both palmitoyl-CoA and palmitoyl-carnitine oxidation, while PLC caused a more than 2.5-fold increase in both substrates. Preincubation of mitochondria with 5 mM PLC caused complete reversal of ADR-induced inhibition in the oxidation of both substrates. Also ADR induced concentration-dependent inhibition of CPT I which is parallel to the inhibition of its substrate palmitoyl-CoA. In rat heart slices, ADR induced a significant (65%) decrease in adenosine triphosphate (ATP) and this effect is reduced to 17% only by PLC. Results of this study revealed that ADR induced its cardiotoxicity by inhibition of CPT I and beta-oxidation of long-chain fatty acids with the consequent depletion of ATP in cardiac tissues, and that PLC can be used as a protective agent against ADR-induced cardiotoxicity.
Collapse
Affiliation(s)
- M M Sayed-Ahmed
- Pharmacology Unit, Cancer Biology Department, National Cancer Institute, Fum El-Khalig, Kasr El-Aini Street, Cairo, Egypt
| | | | | | | | | | | |
Collapse
|
24
|
Abstract
Nephrotoxicity is a dose-limiting factor in the use of cisplatin against solid tumours. Methimazole, an antithyroid drug containing a free SH group, has a nephroprotective potential against chemically-induced nephrotoxicity. We tried to explore the nephrotoxic effect of the experimentally therapeutic dose of cisplatin (7 mg kg(-1), i.p.), particularly on the nuclear level of kidney cells in male albino rats, as well as the possible protective effect of methimazole. Furthermore, the drug interaction regarding the oncolytic effect of cisplatin was examined in Ehrlich ascites carcinoma (EAC)-bearing mice. A single dose of cisplatin caused kidney damage, 6 days after injection, manifested by 219% increase in serum creatinine, 384% increase in blood urea nitrogen and 170% increase in kidney content of lipid peroxides. Kidney DNA showed clear fragmentations detected by gel electrophoresis. However, kidney reduced glutathione was unchanged at that time period. Histological examination of kidney confirmed the toxic effect of cisplatin. Methimazole (40 mg kg(-1), i.p., 30 min before cisplatin injection) significantly protected the kidney from the nephrotoxic effect of cisplatin as judged from the biochemical parameters investigated as well as the histopathological examination. On the other hand, the survival data in EAC-bearing mice treated with both drugs indicated the persistence of an effective cytotoxic action. This study points to a promising use of this combination and necessitates further experimental and clinical studies. 2000 Academic Press@p$hr Copyright 2000 Academic Press.
Collapse
Affiliation(s)
- AM Osman
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Nasr City, Cairo, Egypt
| | | | | | | | | | | | | |
Collapse
|
25
|
Saad AH, Abdelbaky A, Osman AM, Abdallah KF, Salem D. Possible role of Schistosoma mansoni infection in male hypogonadism. J Egypt Soc Parasitol 1999; 29:307-23. [PMID: 10605485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Schistosomiasis has been suggested to decrease the reproductive potential or castrate both invertebrate and vertebrate hosts. Furthermore, schistosomiasis may cause anatomic anomalies of the reproductive organs responsible for permanent or reversible infertility. To specify the effect of schistosomiasis on gonadal functions, production of testosterone (TS), leutinizing hormone (LH) and estradiol (E2) in Egyptian men infected with schistosomiasis were studied. All participants were tested for the following parameters: Clinical examination and diagnostic, semen, haematological and liver function tests and blood level of IL-2. The mean TS levels were at the lowest limit of normal range for liver cirrhotic patients. Mean E2 levels were increased in all patients, but patients with liver cirrhosis-related schistosomiasis had higher E2 levels. Linear regression analysis showed that the sex hormone levels correlated best with the patient's liver function parameters. The present data suggest that a sex hormone imbalance plays a role in patients with liver cirrhosis due to the inhibitory effects of schistosomiasis on gonadal functions.
Collapse
Affiliation(s)
- A H Saad
- Department of Zoology, Faculty of Science, Cairo University, Egypt
| | | | | | | | | |
Collapse
|
26
|
Al-Sherbiny MM, Osman AM, Hancock K, Deelder AM, Tsang VC. Application of immunodiagnostic assays: detection of antibodies and circulating antigens in human schistosomiasis and correlation with clinical findings. Am J Trop Med Hyg 1999; 60:960-6. [PMID: 10403328 DOI: 10.4269/ajtmh.1999.60.960] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In an initial cross-sectional survey, serum, urine, and stool samples were collected from 370 participants representing about 10% of the population (n = 4,438) in Behbeet village, 50 km south of Cairo, Egypt, an area well known to be endemic solely for Schistosoma haematobium. Diagnosis was approached in two parallel ways. The first approach, which simulated actual conditions in many endemic areas in Egypt, was based on physical examination and urine and stool microscopic analysis. The second approach was based on two advanced immunodiagnostic assay systems. One system detected antibodies to species-specific microsomal antigens, the other detected circulating schistosomal antigens. Microsomal antigens from S. haematobium and S. mansoni were used to detect antibodies in the Falcon assay screening test (FAST)-ELISA and the enzyme-linked immunoelectrotransfer blot (EITB). Circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) were quantified in serum and urine samples in a sandwich ELISA using monoclonal antibodies. Parasitologically, the prevalence of S. haematobium was 7.01% in females and 25.82% in males, giving an overall prevalence of 15.8%. The combination of urine CCA and serum CAA for detecting circulating antigens and the combination of the S. haematobium adult worm microsomal antigens (HAMA) FAST-ELISA and the HAMA EITB for detecting antibodies significantly improved the sensitivity of detecting S. haematobium circulating antigens and antibodies. Also, including a medical examination as an integral part of field studies and correlating immunodiagnostic results with other clinical and investigational data allowed us to calculate an accurate estimation of S. haematobium prevalence in this area of low endemicity.
Collapse
Affiliation(s)
- M M Al-Sherbiny
- Zoology Department, Faculty of Science, Cairo University, Egypt
| | | | | | | | | |
Collapse
|
27
|
Abstract
Biopharmacological evaluations of the protective effects of L-carnitine (a naturally occurring quaternary ammonium compound) against doxorubicin-induced metabolic damage were carried out in isolated cardiac myocytes and in isolated rat heart mitochondria. Perfusion of the heart with DOX (0.5 mM) caused a significant 70% inhibition of palmitate oxidation in cardiac myocytes, while L-carnitine (5 mM) perfusion caused stimulation which accounted for 37%. Perfusion of the heart with L-carnitine after 10-min perfusion with DOX (0.5 mM) caused 88% reversal of DOX-induced inhibition of palmitate oxidation in cardiac cells. In rat heart mitochondria, DOX has no effect on either palmitate oxidation or acyl-CoA synthetase activity, whereas Enoximone (c-AMP-dependent phosphodiesterase inhibitor), caused a significant inhibition of palmitate oxidation and acyl-CoA activity (40 and 27%, respectively). The oxidation of palmitoyl-CoA, an index of carnitine palmitoyltransferse reaction was significantly inhibited by DOX as a function of DOX concentration. Preincubation of mitochondria with L-carnitine caused reversal of DOX-induced inhibition of palmitoyl-CoA oxidation depending on the concentration of L-carnitine. Moreover, L-carnitine treatment did not interfere with the cytotoxic effect of doxorubicin against the growth of solid Ehrlich carcinoma. The findings of this study may suggest that inhibition of fatty acid oxidation in the heart is at least a part of doxorubicin cardiotoxicity and that L-carnitine can be used to prevent the doxorubcin-induced cardiac metabolic damage without interfering with its antitumour activities.
Collapse
Affiliation(s)
- M M Sayed-Ahmed
- Pharmacology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | | | | | | |
Collapse
|
28
|
Osman AM, Posthumus MA, Veeger C, van Bladeren PJ, Laane C, Rietjens IM. Conversion of pentahalogenated phenols by microperoxidase-8/H2O2 to benzoquinone-type products. Chem Res Toxicol 1998; 11:1319-25. [PMID: 9815192 DOI: 10.1021/tx980037l] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study reports the microperoxidase-8 (MP8)/H2O2-catalyzed dehalogenation of pentafluorophenol and pentachlorophenol, compounds whose toxic effects and persistence in the environment are well documented. The primary products of this dehalogenation reaction appear to be the corresponding tetrahalo-p-benzoquinones. Under the conditions used, the fluorinated phenol and its intermediate products are more susceptible to degradation than the corresponding chlorinated analogue and its products. The main degradation products of tetrachloro-p-benzoquinone and tetrafluoro-p-benzoquinone were identified as trichlorohydroxy-p-benzoquinone and trifluorohydroxy-p-benzoquinone, respectively. This secondary conversion of tetrafluoro-p-benzoquinone and tetrachloro-p-benzoquinone was not mediated by MP8, but was driven by H2O2. Evidence is presented for a mechanism where H2O2 molecules and not hydroxide anions are the reactive nucleophilic species attacking the tetrahalo-p-benzoquinones. In addition to the formation of the trihalohydroxy-p-benzoquinones, the formation of adducts of the tetrahalo-p-benzoquinone products with ethanol, present in the incubation medium, was observed. The adduct from the reaction of tetrachloro-p-benzoquinone with ethanol was isolated and identified as trichloroethoxyquinone. Thus, the present paper describes a system in which the formation of tetrahalo-p-benzoquinone-type products by an oxidative heme-based catalyst could be unequivocally demonstrated.
Collapse
Affiliation(s)
- A M Osman
- Department of Biomolecular Sciences, Laboratory of Biochemistry, Agricultural University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
29
|
Osman AM. Ticks infesting sheep and goats in the Sudan. Parassitologia 1997; 39:139-42. [PMID: 9530698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Very little work has been carried out on ticks infesting small ruminants in the Sudan. Of some 70 tick species recorded in the Sudan, 34 species of different genera were collected from sheep and goats, two belonging to the genus Amblyomma, seven to the genus Hyalomma, 22 to the genus Rhipicephalus and three to the genus Boophilus. Nevertheless, their distribution, the seasonal abundance and population dynamics are poorly studied. Particularly, the peculiar distribution of A. lepidum and A. variegatum in the Nuba mountains needs further study. The variable climatic conditions of the country and the importance of the animal wealth in the national economy are all factors that call for more efforts to study the tick problem in this country.
Collapse
Affiliation(s)
- A M Osman
- Ministry of Animal Resources, Khartoum, Sudan
| |
Collapse
|
30
|
Osman AM. Major tick-borne diseases of sheep and goats in the Sudan. Parassitologia 1997; 39:143-4. [PMID: 9530699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tick-borne diseases of sheep and goats have not been thoroughly investigated in the Sudan. Heartwater, the most important of the group, was reported only in the early '60s and malignant theileriosis of sheep in the mid '80s. Other tick-borne diseases of sheep and goats like anaplasmosis, Q fever, Nairobi sheep disease and babesiosis are expected to be present although the vector which transmit Nairobi sheep disease, Rhipicephalus appendiculatus is confined to a very narrow stretch on the Southern border with Zaire, Uganda and Kenya.
Collapse
Affiliation(s)
- A M Osman
- Ministry of Animal Resources, Khartoum, Sudan
| |
Collapse
|
31
|
Osman AM, Boeren S, Veeger C, Rietjens IM. MP8-dependent oxidative dehalogenation: evidence for the direct formation of 1,4-benzoquinone from 4-fluorophenol by a peroxidase-type of reaction pathway. Chem Biol Interact 1997; 104:147-64. [PMID: 9212781 DOI: 10.1016/s0009-2797(97)00021-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The present study shows that MP8 in the presence of H2O2 is able to catalyze the rupture of the stable carbon-fluorine bond of 4-fluorophenol, used as a model substrate for the oxidative dehalogenation reaction. 1,4-Benzoquinone was shown to be the primary reaction product. It is also demonstrated that there was significant [18O] incorporation into the product, 1,4-benzoquinone, from 18O-labelled H2(18)O but not from H2(18)O2. This implies that water participates in the reaction mechanism, and acts as a source for the oxygen atom inserted into the product. It also suggests that the reaction is not a result of direct oxygen transfer from H2O2 through the heme catalyst to the product. Furthermore, ascorbic acid, known to efficiently block MP8-catalyzed peroxidase-type conversions, inhibits the MP8-dependent dehalogenation reaction, most likely because of its ability to reduce the phenoxy radical back to the parent substrate. This observation together with the above-mentioned incorporation of oxygen from the solvent into the benzoquinone product indicates that MP8 dehalogenates 4-fluorophenol and converts it to 1,4-benzoquinone in a peroxidase- and not a P-450-type of reaction mechanism. Overall, our results indicate that the oxidative dehalo genation of para-halogenated phenols, resulting in the formation of benzoquinones, is not specific only for cytochrome P-450 enzymes. Hemoproteins exhibiting peroxidase activity could also play a role in the metabolism of these xenobiotics, resulting in the formation of electrophilic reactive benzoquinone type metabolites.
Collapse
Affiliation(s)
- A M Osman
- Department of Biochemistry, Agricultural University, Wageningen, The Netherlands
| | | | | | | |
Collapse
|
32
|
Osman AM, Boeren S, Boersma MG, Veeger C, Rietjens IM. Microperoxidase/H2O2-mediated alkoxylating dehalogenation of halophenol derivatives in alcoholic media. Proc Natl Acad Sci U S A 1997; 94:4295-9. [PMID: 9113983 PMCID: PMC20716 DOI: 10.1073/pnas.94.9.4295] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The results of this study report the H2O2-driven microperoxidase-8 (MP8)-catalyzed dehalogenation of halophenols such as 4-fluorophenol, 4-chlorophenol, 4-bromophenol, and 2-fluorophenol in alcoholic solvents. In methanol, the conversion of the para-halophenols and 2-fluorophenol to, respectively, 4-methoxyphenol and 2-methoxyphenol, as the major dehalogenated products is observed. In ethanol, 4-ethoxyphenol is the principal dehalogenated product formed from 4-fluorophenol. Two mechanisms are suggested for this MP8-dependent alkoxylating dehalogenation reaction. In one of these mechanisms the oxene resonant form of compound I of MP8 is suggested to react with methanol forming a cofactor-peroxide-alkyl intermediate. This intermediate reacts with the reactive pi-electrons of the substrate, leading to the formation of the alkoxyphenols and the release of the fluorine substituent as fluoride anion.
Collapse
Affiliation(s)
- A M Osman
- Department of Biochemistry, Agricultural University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | | | | | | | | |
Collapse
|
33
|
Zhang J, Hu X, Osman AM, Rydström J. Effects of metal ions on the substrate-specificity and activity of proton-pumping nicotinamide nucleotide transhydrogenase from Escherichia coli. Biochim Biophys Acta 1997; 1319:331-9. [PMID: 9131054 DOI: 10.1016/s0005-2728(96)00171-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nicotinamide nucleotide transhydrogenase catalyzes the reversible reduction of NADP+ by NADH and a concomitant proton translocation. It was demonstrated (Glavas, N.A. and Bragg, P.D. (1995) Biochim. Biophys. Acta 1231, 297-303) that the Escherichia coli transhydrogenase also catalyzed a reduction of the NAD-analogue 3-acetylpyridine-NAD+ (AcPyAD+) by NADH at low pH and in the absence of (added) NADP(H) and high salt concentrations The mechanism of this reaction has as yet not been explained. In the present study, the E. coli transhydrogenase was purified by affinity chromatography through the NADP(H)-site, rendering the pure enzyme free of NADP(H). Using this preparation it was confirmed that the enzyme readily catalyzes the above reaction. Inhibitors specific for the NADP(H)-site, e.g., palmitoyl-Coenzyme A and adenosine-2'-monophosphate-5'-diphosphoribose, strongly inhibited the reduction of AcPyAD+ by NADH, whereas an inhibitor of the NAD(H)-site, adenosine 5'-diphosphoribose, was less inhibitory. This suggests that a lack of metal ions or other ions at low pH induces an unspecific interaction of the NADP(H)-site with AcPyAD+ or NADH, presumably NADH, producing a cyclic reduction of AcPyAD+ by NADH via NAD(H) bound in the NADP(H) site. A stimulation of reduction of AcPyAD+ by NADPH by Mg2+ present during reconstitution of transhydrogenase in phospholipid vesicles was observed, but it is presently unclear whether this effect is related to that seen with the detergent-dispersed enzyme.
Collapse
Affiliation(s)
- J Zhang
- Department of Biochemistry and Biophysics, Chalmers University of Technology, Göteborg, Sweden
| | | | | | | |
Collapse
|
34
|
Osman AM, Khalil ZH, Koraiem AIM, Abu Elhamd RM, El-Aal RM. Heterocyclic halide moieties in the synthesis and study of some conjugated oxazine methine cyanine dyes. J CHEM SCI 1997. [DOI: 10.1007/bf02871157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
35
|
Amr MM, Abbas EZ, El-Samra M, El Batanuoni M, Osman AM. Neuropsychiatric syndromes and occupational exposure to zinc phosphide in Egypt. Environ Res 1997; 73:200-206. [PMID: 9311548 DOI: 10.1006/enrs.1997.3736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Eighty-six workers exposed to zinc phosphide (Zn3P2) pesticide were studied for evidence of neuropsychiatric manifestations. They were evaluated clinically, by electroencephalography (EEG), and, in some cases, by electromyography (EMG). All were males (mean age, 35.8 years; mean duration of exposure to zinc phosphide, 11.3 years). Most presented with one (or more) neuropsychiatric symptom(s), including fear of poisoning, anxiety, impotence, and easy fatigue. About half showed evidence of neuropsychiatric signs, including hyperreflexia, polyneuropathy, lumber radiculopathy, and cervical myelopathy, as well as anxious mood, impaired attention, and psychomotor stimulation. EEG recordings showed abnormal findings in 17.4% of the subjects. The mean age in that group was 39.1 years; mean duration of exposure to Zn3P2 was 15.1 years. EMG studies showed evidence of partial denervation of the anterior tibial group of muscles and flexor digiti minimi in 2 of the 30 workers (6.7%) who underwent EMG examination. Serum levels of zinc (Zn) and cadmium (Ca) were significantly higher in exposed workers than in controls (P < 0.005). Serum copper (Cu), iron (Fe), phosphorus (P), and magnesium (Mg) were significantly lower in exposed workers than in controls. Electrophoretic pattern of globulin showed that gammaglobulin fraction was significantly increased (P < 0.005); alpha2 and beta-globulin were decreased (P < 0.005) in exposed workers. Lipoprotein pattern showed that the total lipids, B-lipoprotein, and B/alpha ratio were significantly increased (P < 0.005) in exposed workers; the alpha1 lipoprotein was decreased. Triglycerides and cholesterol were significantly increased (P < 0.001), and phospholipids and phospholipid/cholesterol ratio were significantly decreased (P < 0.005) in exposed workers compared to controls. The study findings indicated that exposure to Zn3P2 not only caused mild acute and subacute liver cell damage, but also affected renal function and perhaps B-cells of the pancreas. A total of 68.6% of the exposed workers had chest symptoms; only 24.4% presented with chest or cardiac signs. Ventilatory functions were abnormal in 70% of the exposed workers; abnormal ECG findings were present in 12.8%.
Collapse
Affiliation(s)
- M M Amr
- Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | | | | | | |
Collapse
|
36
|
Osman AM, Koerts J, Boersma MG, Boeren S, Veeger C, Rietjens IM. Microperoxidase/H2O2-catalyzed aromatic hydroxylation proceeds by a cytochrome-P-450-type oxygen-transfer reaction mechanism. Eur J Biochem 1996; 240:232-8. [PMID: 8797858 DOI: 10.1111/j.1432-1033.1996.0232h.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The mechanism of aromatic hydroxylation of aniline and phenol derivatives in a H2O2-driven microperoxidase-8(MP8)-catalyzed reaction was investigated. It was shown that the reaction was not inhibited by the addition of scavengers of superoxide anion or hydroxyl radicals, which demonstrates that the reaction mechanism differs from that of the aromatic hydroxylation catalyzed by a horseradish peroxidase/ dihydroxyfumarate system. Additional experiments with 18O-labelled H2 18O2 demonstrated that the oxygen incorporated into aniline to give 4-aminophenol originates from H2O2. Furthermore, it was found that the addition of ascorbic acid efficiently blocks all peroxidase-type reactions that can be catalyzed by the MP8/H2O2 system, but does not inhibit the aromatic hydroxylation of aniline and phenol derivatives. Together, these observations exclude reaction mechanisms for the aromatic hydroxylation that proceed through peroxidase-type mechanisms in which the oxygen incorporated into the substrate originates from O2 or H2O. The mechanism instead seems to proceed by an initial attack of the high-valent iron-oxo intermediate of MP8 on the pi-electrons of the aromatic ring of the substrate leading to product formation by a cytochrome-P-450-type of sigma-O-addition or oxygen-rebound mechanism. This implies that MP8, which has a histidyl and not a cysteinate fifth axial ligand, is able to react by a cytochrome-P-450-like oxygen-transfer reaction mechanism.
Collapse
Affiliation(s)
- A M Osman
- Department of Biochemistry, Agricultural University, Wageningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
37
|
Osman AM, Jacobs DE, Fisher MA, Pilkington JG, Jones PA. Effect of sub-lethal doses of albendazole on the fecundity of Dictyocaulus viviparus. Res Vet Sci 1996; 61:92-3. [PMID: 8819203 DOI: 10.1016/s0034-5288(96)90119-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
During an evaluation of the efficacy of prolonged low-dose albendazole therapy on nematode infections in calves, it was observed that a dose-rate of 2 mg kg-1 given daily for 10 days was highly effective at expelling Dictyocaulus viviparus, but smaller doses suppressed the faecal output of larvae without killing the lungworms. A more detailed study with four experimentally infected calves given 1 mg kg-1 day-1 for 10 days showed that faecal output of larvae ceased after six to eight days but resumed four to six days after the withdrawal of the drug. The albendazole-induced sterility was therefore reversible. A subsidiary study showed that the strain of parasite used was fully susceptible to albendazole.
Collapse
Affiliation(s)
- A M Osman
- Department of Pathology and Infectious Diseases, Royal Veterinary College (University of London), Hatfield, Hertfordshire
| | | | | | | | | |
Collapse
|
38
|
al-Harbi MM, Osman AM, al-Gharably NM, al-Bekairi AM, al-Shabanah OA, Sabah DM, Raza M. Effect of desferrioxamine on cisplatin-induced nephrotoxicity in normal rats. Chemotherapy 1995; 41:448-54. [PMID: 8529435 DOI: 10.1159/000239381] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Biochemical and histological evaluations of the effects of the iron chelator desferrioxamine on the nephrotoxicity induced by cisplatin in normal rats were carried out. A single dose of cisplatin (7.5 mg/kg, intravenously) caused nephrotoxicity that manifested biochemically as an elevation of blood urea nitrogen, serum creatinine and an increase in the kidney weight as a percent of body weight. Moreover, severe decreases in serum calcium and albumin were observed. Histopathological examination of kidney tissue revealed tubular necrosis with sloughing of tubular epithelium. Desferrioxamine treatment (250 mg/kg, intraperitoneally) 30 min before cisplatin administration does not protect the kidney from the damaging effects of cisplatin. A greater increase in blood urea nitrogen, serum creatinine and kidney weight was observed with significant tubular necrosis and a mild lymphocytic infiltrate. Desferrioxamine pretreatment decreased the lipid peroxidation induced by cisplatin but at the same time increased nonprotein sulfhydryl (-SH) concentrations in the kidney tissue. The findings of this study suggest that lipid peroxidation is not the main cause of cisplatin-induced nephrotoxicity and that desferrioxamine which was useful for prevention of cardiac and hematological damage induced by doxorubicin, aggrevated the cisplatin-induced nephrotoxicity. More investigations are needed to establish a definite assessment of its selectivity.
Collapse
Affiliation(s)
- M M al-Harbi
- Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | | | | | | | | | | | | |
Collapse
|
39
|
al-Shabanah OA, Osman AM, al-Harbi MM, al-Bekairi AM, al-Gharably NM, Aziz SA. Diltiazem potentiation of doxorubicin cytotoxicity and cellular uptake in Ehrlich ascites carcinoma cells. Chemotherapy 1995; 41:368-77. [PMID: 8521739 DOI: 10.1159/000239369] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The calcium channel blocker diltiazem, which possesses coronary vasodilator activity, greatly enhanced the cytotoxicity of doxorubicin in Ehrlich ascites carcinoma cells. 20% of the doxorubicin-treated tumor-bearing animals (2 mg/kg, every other day, three doses) survived, with a mean survival time of 35 days. However, pretreatment with diltiazem increased survival to 70% with a mean survival time of 43 days. Diltiazem treatment increased the intracellular level of doxorubicin, and there was a good correlation between the high cellular level of doxorubicin and its cytotoxic activity. In tumor-bearing animals pretreated with diltiazem, doxorubicin showed a pronounced inhibitory effect on cellular DNA, RNA content and acid phosphatase activity of tumor cells. In addition, there was a marked increase in cellular cholesterol and lipid contents. This study may suggest the benefit of using diltiazem to potentiate the cytotoxic effect of doxorubicin, allowing its dose and consequently the serious side effects to be reduced.
Collapse
Affiliation(s)
- O A al-Shabanah
- Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | | | | | | | | | | |
Collapse
|
40
|
Osman AM, Saad SF, Saad SY, el-Aaser AB, el-Merzabani MM. Pharmacokinetic profile of methotrexate and 5-fluorouracil in normal and bilharzial-infested mice. Chemotherapy 1994; 40:227-31. [PMID: 8082409 DOI: 10.1159/000239197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The pharmacokinetics of two commonly used anticancer drugs, methotrexate (MTX) and 5-fluorouracil (5-FU), were investigated in normal and bilharzial-infested mice. Liver glucose-6-phosphatase activity and antipyrine clearance were used as parameters of liver function. Liver glucose-6-phosphatase activity was significantly reduced in bilharzial-infested mice compared with the normal controls. Bilharzial infestation caused a significant reduction in the elimination (beta) and clearance rate (Cl) of antipyrine, whereas its elimination half-life (t1/2 beta) was increased in comparison with the normal controls. A similar pattern was also obtained after MTX and 5-FU administration in bilharzial mice, compared to controls. These results indicate that hepatic bilharziasis causes a significant reduction in the hepatic clearance and elimination of MTX and 5-FU, whereas their areas under the concentration-time curve were significantly increased. These findings may have to be considered in the treatment of bilharzial cancer patients.
Collapse
Affiliation(s)
- A M Osman
- Cancer Biology Department, National Cancer Institute, Cairo, Egypt
| | | | | | | | | |
Collapse
|
41
|
Osman AM, Jacobs DE, Plummer JM. In vivo effect of sublethal concentrations of albendazole metabolites on the structure of the reproductive organs of Dictyocaulus viviparus. J Helminthol 1994; 68:161-6. [PMID: 7930459 DOI: 10.1017/s0022149x00013705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Dictyocaulus viviparus were harvested from calves treated daily with albendazole at dose-rates sub-lethal to this parasite and from matched untreated calves. Male and female reproductive tracts from the worms were examined by light and transmission electron microscopy. A first description of the testis of this nematode is provided. Cell division in the germinal zone of both male and female worms was arrested by in vivo exposure to albendazole metabolites and the cytoplasmic threads connecting the germinal cells to the rachis disappeared. In male worms from treated calves, the rachis was absent from the growth zone and severe ultrastructural damage of spermatogonia, spermatocytes and spermatozoa was apparent. In female worms, the rachis remained intact in the growth zone, obvious abnormalities being confined to the germinal zone, where the cytoplasm of the oogonia was disrupted and few nuclei seen, and to the uteri and ovijector which contained only undifferentiated ova. The detrimental effects of albendazole metabolites on male and female worms were quickly reversed after withdrawal of medication.
Collapse
Affiliation(s)
- A M Osman
- Department of Pathology and Infectious Diseases, Royal Veterinary College (University of London), Hatfield, Herts, UK
| | | | | |
Collapse
|
42
|
al-Shabanah OA, Osman AM, al-Harbi MM, al-Gharably NM, al-Bekairi AM. Enhancement of doxorubicin-induced cytotoxicity by hyperthermia in Ehrlich ascites cells. Chemotherapy 1994; 40:188-94. [PMID: 8205937 DOI: 10.1159/000239191] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hyperthermia (HPT) at 43 degrees C for 30 min increased the cytotoxic activity of doxorubicin against the growth of Ehrlich ascites carcinoma cells. There was more delay in tumor growth with 89% inhibition in the tumor volume and 90% increase in the survival of the tumor-bearing animals compared to control group. Combination of HPT with doxorubicin showed a more pronounced inhibitory effect on tumor content of DNA, RNA, protein, cholesterol, total lipid and acid phosphatase activity. HPT did not significantly affect the doxorubicin uptake into tumor cells, but it has some inhibitory effect on some vital components. Along with other results, our data suggest the benefit of using HPT to enhance the cytotoxic activity of doxorubicin with a consequent reduction of doxorubicin dose and hence a decrease of its serious side effects.
Collapse
Affiliation(s)
- O A al-Shabanah
- Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | | | | | | | | |
Collapse
|
43
|
al-Gharably NM, Osman AM, al-Shabanah OA, al-Bekairi AM, al-Harbi MM. Potentiation of doxorubicin cytotoxicity by the calcium channel blocker verapamil in Ehrlich ascites cells. Chemotherapy 1993; 39:410-5. [PMID: 8222869 DOI: 10.1159/000238986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The calcium channel blocker verapamil increased the intracellular level of doxorubicin in Ehrlich ascites cells. The high cellular drug level was directly related to the enhancement of the cytotoxicity of the antitumor agent. Tumor-bearing mice pretreated with verapamil showed a 2.3-fold increase in long-term survival effect of doxorubicin together with a pronounced inhibitory effect on tumor DNA, RNA and protein content. This study suggests the possible novel use of verapamil to enhance the antitumor activity of doxorubicin, allowing its dose, and consequently the serious side effects, to be reduced.
Collapse
Affiliation(s)
- N M al-Gharably
- Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | | | | | | | | |
Collapse
|
44
|
Abstract
A considerable amount of evidence suggests that, under conditions of high discriminability, subjects are able to process multiple elements in a visual display simultaneously when searching for a single target among distractors. Relatively little emphasis, however has been placed on the question of whether subjects can search for and detect multiple targets simultaneously. This latter question is the focus of the present report. In two experiments, we compare performance in single-target and multiple-target detection tasks in order to investigate whether or not multiple targets can be detected simultaneously. In Experiment 1, subjects searched for one or two targets that were defined by color. In Experiment 2, subjects searched for a color and/or a letter target. When the two targets were presented in the same location (e.g., a red X when Target 1 was red and Target 2 was an X), they seemed to be detected simultaneously. Implications for object-based processing of visual information are discussed.
Collapse
Affiliation(s)
- C M Moore
- Department of Psychology, University of California, San Diego, La Jolla 92093-0109
| | | |
Collapse
|
45
|
Mossa MA, Osman AM, el-Sayed M, el-Aaser AA, Ismael N, el-Merzabani MM. Distribution and toxicity of 5-fluorouracil after intraperitoneal and anal submucosal administration. J Pharm Belg 1992; 47:129-34. [PMID: 1328594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The correlation of 5-fluorouracil (5-FU) distribution and its toxicity had been investigated in Albino rats. H3-5-FU was administrated either by intraperitoneal (I.P.) or anal submucosal (A.sm.) route. 5-FU was promptly distributed in different organs with marked accumulation in the pelvic area after A.sm. and in liver and kidney after I.P. administration. Acute toxicity (L.D. 50) was stronger after I.P. (63 mg/kg compared with 80 mg/kg after A.sm.). Side effects expressed in elevation of transaminase and alkaline phosphatase and increase in liver tissue glucose-6-phosphatase and total white blood count were much pronounced after I.P. administration. The results suggest the possibility of using A.sm. route for administration.
Collapse
|
46
|
al-Harbi MM, al-Gharably NM, al-Shabanah OA, al-Bekairi AM, Osman AM, Tawfik HN. Prevention of doxorubicin-induced myocardial and haematological toxicities in rats by the iron chelator desferrioxamine. Cancer Chemother Pharmacol 1992; 31:200-4. [PMID: 1464156 DOI: 10.1007/bf00685548] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Biochemical and histopathological evaluations of the protective effects of the iron-chelator desferrioxamine against the cardiac and haematological toxicities of doxorubicin in normal rats were carried out. A single dose of doxorubicin (15 mg/kg, i.v.) caused myocardial damage that manifested biochemically as an elevation of serum cardiac enzyme [glutamic oxaloacetic transaminase (GOT), lactic dehydrogenase (LDH) and creatine phosphokinase (CPK)] and cardiac isoenzyme levels and histopathologically as a swelling and separation of cardiac muscle fibers. Doxorubicin caused severe leucopenia and decreases in red blood cell counts and haemoglobin concentrations at 72 h after its administration. Desferrioxamine treatment (250 mg/kg, i.p.) carried out 30 min before doxorubicin administration protected the heart and blood elements from the toxic effects of doxorubicin as indicated by the recovery of levels of cardiac enzymes and isoenzymes and of red blood cell counts to normal values and by the absence of significant myocardial lesions. The findings of this study suggest that desferrioxamine can potentially be used clinically to prevent doxorubicin-induced cardiac and haematological toxicities.
Collapse
Affiliation(s)
- M M al-Harbi
- Department of Pharmacology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | | | | | | | | | | |
Collapse
|
47
|
Osman AM, Del Corso A, Mohamed AS, Ipata PL, Mura U. Liver purine nucleoside phosphorylase in Camelus dromedarius: purification and properties. Comp Biochem Physiol B 1990; 97:177-82. [PMID: 2123764 DOI: 10.1016/0305-0491(90)90198-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. Purine nucleoside phosphorylase (purine nucleoside:orthophosphate ribosyl transferase, EC 2.4.2.1) was purified to electrophoretic homogeneity from the liver of Camelus dromedarius. 2. The enzyme appears to be a dimer with a 44,000 subunit mol. wt and displays non-linear kinetics with concave downward curvature in double reciprocal plots with respect to both inosine and orthophosphate as variable substrates. 3. The effect of thiol compounds on the enzyme activity and of pH on kinetic parameters is reported.
Collapse
Affiliation(s)
- A M Osman
- Department of Physiology and Biochemistry, University of Pisa, Italy
| | | | | | | | | |
Collapse
|
48
|
Del Corso A, Barsacchi D, Osman AM, Mohamed AS, Tozzi MG, Camici M, Mura U. Lens aldo-keto reductase of Camelus dromedarius: purification and properties. Biochim Biophys Acta 1989; 993:116-20. [PMID: 2679888 DOI: 10.1016/0304-4165(89)90150-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Aldo-keto reductase has been purified 13,000-fold from the lens of the camel (Camelus dromedarius) to a specific activity of 85 U/mg protein. The enzyme is a monomeric protein, exhibiting a Mr = 40,000 upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Camel lens aldo-keto reductase shows a broad substrate specificity, which is strictly dependent on NADPH, and is insensitive to inhibition by Sorbinil and valproate. Aldoses with a carbon chain with more than four residues, as well as glucuronate, are not reduced by the enzyme. On the basis of substrate specificity and sensitivity to inhibition, camel lens aldo-keto reductase appears to be distinct from the so far described aldose, aldehyde and carbonyl reductases.
Collapse
Affiliation(s)
- A Del Corso
- Department of Physiology and Biochemistry, University of Pisa, Italy
| | | | | | | | | | | | | |
Collapse
|
49
|
Del Corso A, Osman AM, Mohamed AS, Camici M, Barsacchi D, Tozzi MG, Mura U. NADPH-dependent reduction of glyceraldehyde: a unusually high activity in the lens of the camel (Camelus dromedarius). Boll Soc Ital Biol Sper 1989; 65:235-42. [PMID: 2504255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The enzymes of the polyol pathway, namely aldose reductase and sorbitol dehydrogenase, were measured in camel lens extracts. A NADPH-dependent glyceraldehyde and erythrose reductase activity 25 times higher than that of calf lens was observed in camel lens. A preliminary comparison between this enzyme activity present in the camel and aldose reductase of calf lens is reported.
Collapse
|
50
|
el-Merzabani MM, el-Aaser AA, Osman AM, Ismael N, Abu el-Ela F. Potentiation of therapeutic effect of methanesulphonate and protection against its organ cytotoxicity by vitamin C in Ehrlich ascites carcinoma bearing mice. J Pharm Belg 1989; 44:109-16. [PMID: 2550606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effect of vitamin C upon the therapeutic index and side effects produced by methanesulfonate of aminoglycols (drug 864T, NSC 140117) had been evaluated in a laboratory system. The antitumor action of 864T, vitamin C and their combination were evaluated in Ehrlich ascites carcinoma (EAC) cells in vivo. Tissue toxicity was assessed using liver and intestinal DNA, RNA, protein contents and their synthesis as parameters. In addition, G-6-pase, 5-Nase and Alk, pase activity levels in both tissues were also measured. Drug 864T (200 mg/kg) produced 50 percent long-term survivors in tumor bearing mice in addition to 10 percent early mortality while in combination with vitamin C (250 mg/kg x 6), there was 80 percent long term survivors with no mortality related to drug toxicity. No toxicity, in all the parameters used, was observed when 864T was given in combination with vitamin C. Drug 864T alone produced a significant decrease in protein content of both liver and intestinal tissue while in combination with vitamin C normal levels were maintained. In addition, all the parameters used were either elevated or decreased by 864T treatment and returned to normal levels in combination with vitamin C. This study proved that vitamin C may be useful not only to potentiate the effect of anticancer drug 864T on the Ehrlich ascites carcinoma but also to antagonize the side effects of the drug.
Collapse
|