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Zondagh LS, Joubert J, Omoruyi S, Mentor S, Malan SF, Ekpo OE, Fisher D. Multifunctional edaravone‐N‐benzyl pyridinium derivatives: AChE inhibition kinetics,
in vitro
neuroprotective activities and BBB permeability studies. Alzheimers Dement 2021. [DOI: 10.1002/alz.053939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Sarel F Malan
- University of the Western Cape Cape Town South Africa
| | - Okobi E Ekpo
- University of the Western Cape Cape Town South Africa
| | - David Fisher
- University of the Western Cape Cape Town South Africa
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Omolaja AA, Pearce B, Omoruyi SI, Badmus JA, Ismail E, Marnewick J, Botha S, Benjeddou M, Ekpo OE, Hussein AA. The potential of chalcone-capped gold nanoparticles for the management of diabetes mellitus. Surfaces and Interfaces 2021; 25:101251. [DOI: 10.1016/j.surfin.2021.101251] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
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Mzezewa SC, Omoruyi SI, Zondagh LS, Malan SF, Ekpo OE, Joubert J. Design, synthesis, and evaluation of 3,7-substituted coumarin derivatives as multifunctional Alzheimer's disease agents. J Enzyme Inhib Med Chem 2021; 36:1607-1621. [PMID: 34281458 PMCID: PMC8291583 DOI: 10.1080/14756366.2021.1913137] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Multitarget directed ligands (MTDLs) are emerging as promising treatment options for Alzheimer's disease (AD). Coumarin derivatives serve as a good starting point for designing MTDLs due to their inherent inhibition of monoamine oxidase (MAO) and cholinesterase enzymes, which are complicit in AD's complex pathophysiology. A preliminary series of 3,7-substituted coumarin derivatives were synthesised and evaluated for enzyme inhibitory activity, cytotoxicity as well as neuroprotective ability. The results indicated that the compounds are weak cholinesterase inhibitors with five compounds demonstrating relatively potent inhibition and selectivity towards MAO-B with IC50 values between 0.014 and 0.498 hx00B5;µM. Significant neuroprotective effects towards MPP+-compromised SH-SY5Y neuroblastoma cells were also observed, with no inherent cytotoxicity at 10 µM for all compounds. The overall results demonstrated that substitution of the phenylethyloxy moiety at the 7-position imparted superior general activity to the derivatives, with the propargylamine substitution at the 3-position, in particular, displaying the best MAO-B selectivity and neuroprotection.
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Affiliation(s)
- Sheunopa C Mzezewa
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Sylvester I Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Luke S Zondagh
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Sarel F Malan
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
| | - Okobi E Ekpo
- Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa
| | - Jacques Joubert
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Bellville, South Africa
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Omoruyi SI, Ibrakaw AS, Ekpo OE, Boatwright JS, Cupido CN, Hussein AA. Neuroprotective Activities of Crossyne flava Bulbs and Amaryllidaceae Alkaloids: Implications for Parkinson's Disease. Molecules 2021; 26:molecules26133990. [PMID: 34208814 PMCID: PMC8272225 DOI: 10.3390/molecules26133990] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/13/2021] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Parkinson’s disease (PD) is one of the most common neurodegenerative diseases and affects approximately 6.3 million people worldwide. To date, the treatment of PD remains a challenge, as available treatment options are known to be associated with serious side effects; hence, the search for new treatment strategies is critical. Extracts from the Amaryllidaceae plant family as well as their alkaloids have been reported to have neuroprotective potentials. This study, therefore, investigated the biological activities of Crossyne flava and its isolated alkaloids in an in vitro MPP+ (1-methyl-4-phenylpyridinium) PD model using SH-SY5Y cells. The effects of the total extract as well as the four compounds isolated from Crossyne flava (i.e., pancratinine B (1), bufanidrine (2), buphanisine (3), and epibuphanisine (4)) were evaluated for cell viability, neuroprotection, levels of reactive oxygen species (ROS), adenosine triphosphate activity (ATP), and caspase 3/7 activity in SH-SY5Y cells. The results obtained showed that pre-treatment with both the extract and the isolated compounds was effective in protecting the SH-SY5Y cells from MPP+-induced neurotoxicity and inhibited ROS generation, ATP depletion as well as apoptosis induction in the SH-SY5Y cells. The results of this study show that the Amaryllidaceae plant family may be a source of novel compounds for the treatment of neurodegenerative diseases, which validates the reported traditional uses.
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Affiliation(s)
- Sylvester I. Omoruyi
- Department of Chemistry, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa;
| | - Abobaker S. Ibrakaw
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Cape Town, Robert Sobukwe Road, Bellville 7535, South Africa; (A.S.I.); (J.S.B.)
| | - Okobi E. Ekpo
- Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates;
| | - James S. Boatwright
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Cape Town, Robert Sobukwe Road, Bellville 7535, South Africa; (A.S.I.); (J.S.B.)
| | - Christopher N. Cupido
- Department of Botany, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa;
| | - Ahmed A. Hussein
- Department of Chemistry, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa;
- Correspondence: ; Tel.: +27-21-959-6193; Fax: +27-21-959-3055
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Badmus JA, Ekpo OE, Sharma JR, Sibuyi NRS, Meyer M, Hussein AA, Hiss DC. An Insight into the Mechanism of Holamine- and Funtumine-Induced Cell Death in Cancer Cells. Molecules 2020; 25:molecules25235716. [PMID: 33287388 PMCID: PMC7730674 DOI: 10.3390/molecules25235716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/11/2020] [Accepted: 10/16/2020] [Indexed: 12/12/2022] Open
Abstract
Holamine and funtumine, steroidal alkaloids with strong and diverse pharmacological activities are commonly found in the Apocynaceae family of Holarrhena. The selective anti-proliferative and cell cycle arrest effects of holamine and funtumine on cancer cells have been previously reported. The present study evaluated the anti-proliferative mechanism of action of these two steroidal alkaloids on cancer cell lines (HT-29, MCF-7 and HeLa) by exploring the mitochondrial depolarization effects, reactive oxygen species (ROS) induction, apoptosis, F-actin perturbation, and inhibition of topoisomerase-I. The apoptosis-inducing effects of the compounds were studied by flow cytometry using the APOPercentageTM dye and Caspase-3/7 Glo assay kit. The two compounds showed a significantly greater cytotoxicity in cancer cells compared to non-cancer (normal) fibroblasts. The observed antiproliferative effects of the two alkaloids presumably are facilitated through the stimulation of apoptosis. The apoptotic effect was elicited through the modulation of mitochondrial function, elevated ROS production, and caspase-3/7 activation. Both compounds also induced F-actin disorganization and inhibited topoisomerase-I activity. Although holamine and funtumine appear to have translational potential for the development of novel anticancer agents, further mechanistic and molecular studies are recommended to fully understand their anticancer effects.
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Affiliation(s)
- Jelili A. Badmus
- Department of Medical Biosciences, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.A.B.); (O.E.E.)
| | - Okobi E. Ekpo
- Department of Medical Biosciences, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.A.B.); (O.E.E.)
| | - Jyoti R. Sharma
- DSI/Mintek-Nanotechnology Innovation Centre-BioLabels Node, Department of Biotechnology, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.R.S.); (N.R.S.S.); (M.M.)
| | - Nicole Remaliah S. Sibuyi
- DSI/Mintek-Nanotechnology Innovation Centre-BioLabels Node, Department of Biotechnology, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.R.S.); (N.R.S.S.); (M.M.)
| | - Mervin Meyer
- DSI/Mintek-Nanotechnology Innovation Centre-BioLabels Node, Department of Biotechnology, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.R.S.); (N.R.S.S.); (M.M.)
| | - Ahmed A. Hussein
- Department of Chemistry, Cape Peninsula University of Technology, 7535 Bellville, Western Cape, South Africa;
| | - Donavon C. Hiss
- Department of Medical Biosciences, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.A.B.); (O.E.E.)
- Correspondence:
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Ibrakaw AS, Omoruyi SI, Ekpo OE, Hussein AA. Neuroprotective Activities of Boophone haemanthoides (Amaryllidaceae) Extract and Its Chemical Constituents. Molecules 2020; 25:molecules25225376. [PMID: 33212961 PMCID: PMC7698425 DOI: 10.3390/molecules25225376] [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] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 11/12/2020] [Accepted: 11/12/2020] [Indexed: 12/23/2022] Open
Abstract
Parkinson’s disease (PD) is a neurodegenerative condition that progresses as age increases, and some of its major symptoms include tremor and postural and movement-related difficulties. To date, the treatment of PD remains a challenge because available drugs only treat the symptoms of the disease or possess serious side effects. In light of this, new treatment options are needed; hence, this study investigates the neuroprotective effects of an organic Boophone haemanthoides extract (BHE) and its bioactive compounds using an in vitro model of PD involving the toxin 1-methyl-4-phenylpyridinium (MPP+) and SH-SY5Y neuroblastoma cells. A total of seven compounds were isolated from BHE, viz distichamine (1), 1α,3α-diacetylnerbowdine (2), hippadine (3), stigmast-4-ene-3,6-dione (4), cholest-4-en-3-one (5), tyrosol (6), and 3-hydroxy-1-(4′-hydroxyphenyl)-1-propanone (7). Six compounds (1, 2, 4, 5, 6 and 7) were investigated, and five showed neuroprotection alongside the BHE. This study gives insight into the bioactivity of the non-alkaloidal constituents of Amaryllidaceae, since the isolated compounds and the BHE showed improved cell viability, increased ATP generation in the cells as well as inhibition of MPP+-induced apoptosis. Together, these findings support the claim that the Amaryllidaceae plant family could be a potential reserve of bioactive compounds for the discovery of neuroprotective agents.
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Affiliation(s)
- Abobaker S. Ibrakaw
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Cape Town, Robert Sobukwe Road, Bellville 7535, South Africa;
| | - Sylvester I. Omoruyi
- Department of Chemistry, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa;
| | - Okobi E. Ekpo
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Robert Sobukwe Road, Bellville 7535, South Africa;
| | - Ahmed A. Hussein
- Department of Chemistry, Cape Peninsula University of Technology, Symphony Road, Bellville 7535, South Africa;
- Correspondence: ; Tel.: +27-21-959-6193; Fax: +27-21-959-3055
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Egunlusi AO, Malan SF, Omoruyi SI, Ekpo OE, Joubert J. 4-Oxatricyclo[5.2.1.0 2,6]dec-8-ene-3,5-dione Derivatives as NMDA Receptor- and VGCC Blockers with Neuroprotective Potential. Molecules 2020; 25:E4552. [PMID: 33027964 PMCID: PMC7582567 DOI: 10.3390/molecules25194552] [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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/30/2020] [Indexed: 11/30/2022] Open
Abstract
The impact of excitotoxicity mediated by N-methyl-D-aspartate (NMDA) receptor overactivation and voltage gated calcium channel (VGCC) depolarization is prominent among the postulated processes involved in the development of neurodegenerative disorders. NGP1-01, a polycyclic amine, has been shown to be neuroprotective through modulation of the NMDA receptor and VGCC, and attenuation of MPP+-induced neurotoxicity. Recently, we reported on the calcium modulating effects of tricycloundecene derivatives, structurally similar to NGP1-01, on the NMDA receptor and VGCC of synaptoneurosomes. In the present study, we investigated novel 4-oxatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione derivatives for their cytotoxicity, neuroprotective effects via attenuation of MPP+-induced neurotoxicity and calcium influx inhibition abilities through the NMDA receptor and VGCC using neuroblastoma SH-SY5Y cells. All compounds, in general, showed low or no toxicity against neuroblastoma cells at 10-50 µM concentrations. At 10 µM, all compounds significantly attenuated MPP+-induced neurotoxicity as evident by the enhancement in cell viability between 23.05 ± 3.45% to 53.56 ± 9.29%. In comparison to known active compounds, the derivatives demonstrated mono or dual calcium modulating effect on the NMDA receptor and/or VGCC. Molecular docking studies using the NMDA receptor protein structure indicated that the compounds are able to bind in a comparable manner to the crystallographic pose of MK-801 inside the NMDA ion channel. The biological characteristics, together with results from in silico studies, suggest that these compounds could act as neuroprotective agents for the purpose of halting or slowing down the degenerative processes in neuronal cells.
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Affiliation(s)
- Ayodeji O. Egunlusi
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| | - Sarel F. Malan
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
| | - Sylvester I. Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (S.I.O.); (O.E.E.)
| | - Okobi E. Ekpo
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (S.I.O.); (O.E.E.)
| | - Jacques Joubert
- Pharmaceutical Chemistry, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa; (A.O.E.); (S.F.M.)
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Enogieru AB, Omoruyi SI, Ekpo OE. Aqueous leaf extract of Sutherlandia frutescens attenuates ROS-induced apoptosis and loss of mitochondrial membrane potential in MPP+-treated SH-SY5Y cells. TROP J PHARM RES 2020. [DOI: 10.4314/tjpr.v19i3.13] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Purpose: To investigate the neuroprotective activity of the aqueous extract of Sutherlandia frutescens (SF) against 1-methyl-4-phenylpyridinium (MPP+)-induced toxicity in SH-SY5Y neuroblastoma cells.
Methods: SH-SY5Y neuroblastoma cells were divided into different treatment groups: untreated cells, cells treated with MPP+ alone (2 mM), cells pretreated with SF (20 μg) prior to MPP+ (2 mM) treatment and cells treated with SF (20 μg) alone. Twenty-four hours after treatment with MPP+, cell viability was assessed by MTT assay, and changes in cell morphology, intracellular reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP) as well as caspases 3/7 and 9 activities were determined.
Results: Treatment of SH-SY5Y cells with MPP+ alone significantly altered cellular morphology, increased ROS production (p = 0.005), induced a significant loss of MMP (p = 0.0011) and caused significant apoptotic cell death, via the activation of caspases 3/7 and 9 (p ≤ 0.0359). These effects were however significantly (p ≤ 0.0359) attenuated in cells pre-treated with the aqueous leaf extract of SF, indicating the possible neuroprotective activity of the SF extract.
Conclusion: The results of this study suggest that the aqueous leaf extract of SF may be neuroprotective against MPP+-induced toxicity via apoptotic cell death and inhibition of ROS production. Further mechanistic studies are required to validate the results of the present study using additional PD models, different extract preparations and active compounds derived from SF.
Keywords: Parkinson’s disease, MPP+, Sutherlandia frutescens, Reactive oxygen species, Apoptosis, Neurodegeneration
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Zindo FT, Malan SF, Omoruyi SI, Enogieru AB, Ekpo OE, Joubert J. Design, synthesis and evaluation of pentacycloundecane and hexacycloundecane propargylamine derivatives as multifunctional neuroprotective agents. Eur J Med Chem 2019; 163:83-94. [DOI: 10.1016/j.ejmech.2018.11.051] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/09/2018] [Accepted: 11/21/2018] [Indexed: 01/15/2023]
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Denya I, Malan SF, Enogieru AB, Omoruyi SI, Ekpo OE, Kapp E, Zindo FT, Joubert J. Design, synthesis and evaluation of indole derivatives as multifunctional agents against Alzheimer's disease. Medchemcomm 2018; 9:357-370. [PMID: 30108930 DOI: 10.1039/c7md00569e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/14/2018] [Indexed: 12/25/2022]
Abstract
A series of indole derivatives was designed and synthesised to improve on activity and circumvent pharmacokinetic limitations experienced with the structurally related compound, ladostigil. The compounds consisted of a propargylamine moiety (a known MAO inhibitor and neuroprotector) at the N1 position and a ChE inhibiting diethyl-carbamate/urea moiety at the 5 or 6 position of the indole ring. In order to prevent or slow down the in vivo hydrolysis and deactivation associated with the carbamate function of ladostigil, a urea moeity was incorporated into selected compounds to obtain more metabolically stable structures. The majority of the synthesised compounds showed improved MAO-A inhibitory activity compared to ladostigil. The compounds possessing the propargylamine moiety showed good MAO-B inhibitory activity with 6 and 8 portraying IC50 values between 14-20 fold better than ladostigil. The ChE assay results indicated that the compounds have non-selective inhibitory activities on eeAChE and eqBuChE regardless of the type or position of substitution (IC50: 2-5 μM). MAO-A and MAO-B docking results showed that the propargylamine moiety was positioned in close proximity to the FAD cofactor suggesting that the good inhibitory activity may be attributed to the propargylamine moiety and irreversible inhibition as confirmed in the reversibility studies. Docking results also indicated that the compounds have interactions with important amino acids in the AChE and BuChE catalytic sites. Compound 6 was the most potent multifunctional agent showing better inhibitory activity than ladostigil in vitro on all enzymes tested (hMAO-A IC50 = 4.31 μM, hMAO-B IC50 = 2.62 μM, eeAChE IC50 = 3.70 μM, eqBuChE IC50 = 2.82 μM). Chemical stability tests confirmed the diethyl-urea containing compound 6 to be more stable than its diethyl-carbamate containing counterpart compound 8. Compound 6 also exerted significant neuroprotection (52.62% at 1 μM) against MPP+ insult to SH-SY5Y neural cells and has good in silico predicted ADMET properties. The favourable neuronal enzyme inhibitory activity, likely improved pharmacokinetic properties in vivo and the potent neuroprotective ability of compound 6 make it a promising compound for further development.
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Affiliation(s)
- Ireen Denya
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Sarel F Malan
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Adaze B Enogieru
- Department of Medical Biosciences , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa
| | - Sylvester I Omoruyi
- Department of Medical Biosciences , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa
| | - Okobi E Ekpo
- Department of Medical Biosciences , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa
| | - Erika Kapp
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Frank T Zindo
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
| | - Jacques Joubert
- Pharmaceutical Chemistry , School of Pharmacy , University of the Western Cape , Private Bag X17 , Bellville 7535 , South Africa . ; Tel: +27 21 959 2195
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Kapp E, Visser H, Sampson SL, Malan SF, Streicher EM, Foka GB, Warner DF, Omoruyi SI, Enogieru AB, Ekpo OE, Zindo FT, Joubert J. Versatility of 7-Substituted Coumarin Molecules as Antimycobacterial Agents, Neuronal Enzyme Inhibitors and Neuroprotective Agents. Molecules 2017; 22:molecules22101644. [PMID: 28973990 PMCID: PMC6151660 DOI: 10.3390/molecules22101644] [Citation(s) in RCA: 21] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 09/21/2017] [Accepted: 09/27/2017] [Indexed: 11/16/2022] Open
Abstract
A medium-throughput screen using Mycobacterium tuberculosis H37Rv was employed to screen an in-house library of structurally diverse compounds for antimycobacterial activity. In this initial screen, eleven 7-substituted coumarin derivatives with confirmed monoamine oxidase-B and cholinesterase inhibitory activities, demonstrated growth inhibition of more than 50% at 50 µM. This prompted further exploration of all the 7-substituted coumarins in our library. Four compounds showed promising MIC99 values of 8.31–29.70 µM and 44.15–57.17 µM on M. tuberculosis H37Rv in independent assays using GAST-Fe and 7H9+OADC media, respectively. These compounds were found to bind to albumin, which may explain the variations in MIC between the two assays. Preliminary data showed that they were able to maintain their activity in fluoroquinolone resistant mycobacteria. Structure-activity relationships indicated that structural modification on position 4 and/or 7 of the coumarin scaffold could direct the selectivity towards either the inhibition of neuronal enzymes or the antimycobacterial effect. Moderate cytotoxicities were observed for these compounds and slight selectivity towards mycobacteria was indicated. Further neuroprotective assays showed significant neuroprotection for selected compounds irrespective of their neuronal enzyme inhibitory properties. These coumarin molecules are thus interesting lead compounds that may provide insight into the design of new antimicrobacterial and neuroprotective agents.
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Affiliation(s)
- Erika Kapp
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Hanri Visser
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, Tygerberg 7505, South Africa.
| | - Samantha L Sampson
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, Tygerberg 7505, South Africa.
| | - Sarel F Malan
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Elizabeth M Streicher
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, Cape Town, Tygerberg 7505, South Africa.
| | - Germaine B Foka
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Digby F Warner
- Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit, Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Institute of Infectious Disease and Molecular Medicine and Department of Clinical Laboratory Sciences, University of Cape Town, Cape Town, Rondebosch 7700, South Africa.
| | - Sylvester I Omoruyi
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Adaze B Enogieru
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Okobi E Ekpo
- Department of Medical Biosciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Frank T Zindo
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
| | - Jacques Joubert
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, Bellville 7550, South Africa.
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Badmus JA, Ekpo OE, Rautenbach F, Marnewick JL, Hussein AA, Hiss DC. Isolation and antioxidant activity of flavonoids from Holarrhena floribunda (G.don) leaves. Acta Biochim Pol 2016; 63:353-8. [PMID: 27172363 DOI: 10.18388/abp.2015_1178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 08/17/2015] [Revised: 01/13/2016] [Accepted: 02/11/2016] [Indexed: 11/10/2022]
Abstract
Bioactive polyphenolics are ubiquitously present in plants and may play an important role in the prevention and management of certain human diseases. Three known flavonoids viz Kaemperol-3-O-rutinoside (1), quercetin-3-O-glucoside (2) and kaemperol-3-O-glucoside (3) and inseparable mixture (1:1) of quercetin-3-O-glucose/galactose (4) were isolated, and identified for the first time from Holarrhena floribunda. The antioxidant capacity using the ORAC, FRAP and TEAC assays and inhibition of lipid peroxidation were measured for isolated flavonoids. The result showed that compounds 2 and 4 showed significantly increased ORAC, TEAC, and FRAP activities with low pro-oxidant potential as well as improved lipid peroxidation inhibition levels when compared to compounds 1 and 3. The most active compounds were found to be flavonoids with a quercetin basic structure. These results imply that the isolated flavonoid glycosides are responsible for the antioxidant activity of the plant leaves and it forms the scientific basis for its traditional usage.
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Affiliation(s)
- Jelili A Badmus
- Department of Medical Biosciences, University of the Western Cape, New Life Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
| | - Okobi E Ekpo
- Department of Medical Biosciences, University of the Western Cape, New Life Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
| | - Fanie Rautenbach
- Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town South Africa
| | - Jeanine L Marnewick
- Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town South Africa
| | - Ahmed A Hussein
- Department of Chemistry, University of the Western Cape, Chemical Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
| | - Donavon C Hiss
- Department of Medical Biosciences, University of the Western Cape, New Life Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
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Ajibade AJ, Adenowo TK, Caxton-Martins EA, Ekpo OE. Effect of quinine administration on Purkinje cells in the cerebellar cortex of adult Wistar rats. West Afr J Med 2008; 27:37-40. [PMID: 18689302] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE The effect of quinine commonly used for the treatment of Chloroquine resistant malaria and cerebral malaria on the population and transverse diameters of Purkinje cells in the cerebellar cortex was investigated. METHODS Twenty-seven adult male wistar rats weighing between 150 g and 190 g were separated into three groups, each containing nine rats. The rats in group I were injected intramuscularly with equivalent volume of physiological saline, while group II rats were injected intramuscularly with an initial 20 mg/kg body weight dose of quinine followed by a 10 mg/kg body weight dose given 8 hourly for 7 days. The group III rats received the same treatment as group II, but were subjected to a withdrawal period of one week. The cerebellum of each rat was removed and fixed in 10% formol saline for routine histological procedures. RESULTS The Purkinje cell population reduced significantly (P < 0.05) from the mean value of 363 +/- 5.2 cells/mm2 in group I to a mean value of 239 +/- 9.5 cells/mm2 in group II and 220 +/- 6.6 cells/mm2 in group III rats. The transverse diameters of the Purkinje cells also reduced significantly (p < 0.05) from the mean value of 1.20 +/- 0.02 microm in the group I to a mean value of 1.09 +/- 0.1 microm in group II and 0.75 +/- 0.03 microm in group III. CONCLUSION The observed decrease in population and diameters of Purkinje cells in the treatment groups may impair cerebellar functions since they are the principal neurons of the cerebellum.
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Affiliation(s)
- A J Ajibade
- Department of Anatomy, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
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Pretorius E, Ekpo OE, Smit E. Comparative ultrastructural analyses of platelets and fibrin networks using the murine model of asthma. ACTA ACUST UNITED AC 2007; 59:105-14. [PMID: 17600694 DOI: 10.1016/j.etp.2007.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Accepted: 02/13/2007] [Indexed: 11/19/2022]
Abstract
The murine Balb/c asthma model has been used successfully for a number of in vivo immunological applications and for testing novel therapeutics, and it is a reliable, clinically relevant facsimile of the human disease. Here we investigate whether this model can be used to study other components of the human body, e.g. ultrastructure. In particular, we investigate the effect of the phytomedicine Euphorbia hirta (used to treat asthma), on the ultrastructure of fibrin as well as platelets, cellular structures that both play an important role in the coagulation process. Hydrocortisone is used as positive control. Ultrastructure of the fibrin networks and platelets of control mice were compared to mice that were asthmatic, treated with two concentrations of hydrocortisone and one concentration of the plant material. Results indicate control mice possess major, thick fibers and minor thin fibers as well as tight round platelet aggregates with typical pseudopodia formation. Minor fibers of asthmatic mice have a netlike appearance covering the major fibers, while the platelets seem to form loosely connected, granular aggregates. Both concentrations of hydrocortisone make the fibrin more fragile and that platelet morphology changes form a tight platelet aggregate to a more granular aggregate not closely fused to each other. We conclude that E. hirta does not impact on the fragility of the fibrin and that it prevents the minor fibers to form the dense netlike layer over the major fibers, as is seen in untreated asthmatic mice. This ultrastructural morphology might give us better insight into asthma and the possible new treatment regimes.
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Affiliation(s)
- E Pretorius
- Department of Anatomy, School of Health Sciences, Faculty of Health Sciences, University of Pretoria, BMW Building, P.O. Box 2034, Pretoria 0001, South Africa.
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15
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Avwioro OG, Onwuka SK, Moody JO, Agbedahunsi JM, Oduola T, Ekpo OE, Oladele AA. Curcuma longa extract as a histological dye for collagen fibres and red blood cells. J Anat 2007; 210:600-3. [PMID: 17451535 PMCID: PMC2375739 DOI: 10.1111/j.1469-7580.2007.00721.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [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] [Accepted: 01/29/2007] [Indexed: 11/29/2022] Open
Abstract
Crude ethanolic extract and column chromatographic fractions of the Allepey cultivar of Curcuma longa Roxb, commonly called turmeric (tumeric) in commerce, were used as a stain for tissue sections. Staining was carried out under basic, acidic and neutral media conditions. Inorganic and organic dissolution solvents were used. The stain was used as a counterstain after alum and iron haematoxylins. C. longa stained collagen fibres, cytoplasm, red blood cells and muscle cells yellow. It also stained in a fashion similar to eosin, except for its intense yellow colour. Preliminary phytochemical evaluation of the active column fraction revealed that it contained flavonoids, free anthraquinone and deoxy sugar. A cheap, natural dye can thus be obtained from C. longa.
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Affiliation(s)
- O G Avwioro
- Department of Histopathology, School of Medical Laboratory Science, Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria.
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16
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Pretorius E, Humphries P, Ekpo OE, Smit E, van der Merwe CF. Comparative Ultrastructural Analyses of Mouse, Rabbit, and Human Platelets and Fibrin Networks. Microsc Res Tech 2007; 70:823-7. [PMID: 17576129 DOI: 10.1002/jemt.20482] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [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: 11/10/2022]
Abstract
Platelets and fibrin play an important role in the coagulation process, where they are involved in the maintenance of hemostasis. Fibrin dysfunction is associated with the development of vascular complications, while proneness to the formation of tight and rigid fibrin networks is independently associated with thrombotic disease. Here we investigate the ultrastructure of human, rabbit, and mouse platelets and fibrin networks, using the scanning electron microscope. Human and rabbit fibrin and platelets, with regards to morphology as well as size of major and minor fibers compare well with each other. However, mouse fibers are much thinner and form a flimsy branching network. Platelet aggregate morphology of all three species compare well with each other. We conclude that rabbit platelet and fibrin networks could be used successfully when studying the effect of pharmaceutical products in preclinical trials, when looking at the effects of these products on morphology and ultrastructure.
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Affiliation(s)
- E Pretorius
- Department of Anatomy, School of Health Sciences, Faculty of Health Sciences, University of Pretoria, South Africa.
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17
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Imosemi IO, Malomo AO, Oladejo OW, Osuagwu FC, Ekpo OE, Akang EEU, Shokunbi MT. Gross morphological studies on the effect of cyanide on the developing cerebellum of wistar rat (rattus novegicus). Afr J Med Med Sci 2005; 34:59-63. [PMID: 15971556] [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: 05/03/2023]
Abstract
The teratogenic effect of maternal cyanide consumption on the gross morphology of the post-natal phase of the developing rat cerebellum was studied. Twenty pregnant female rats weighing between 170 g and 190 g were separated into control and experimental groups. The control animals were fed a standard diet of mice cubes, while the experimental animals were fed 500 ppm potassium cyanide, mixed with the standard diet. The diets were fed to the animals and their litters in separate cages and water provided ad libitum during gestation and to the offspring after birth. After birth, the offspring (five per group) of days 1, 9, 14, 21, 28 and 50 were weighed, killed by cervical dislocation and the gross parameters studied. In the experimental animals, no significant differences were observed in the studied parameters between the control and experimental animals on day 1. A significant reduction in body weight was observed on day 14 (P < 0.05). The brain weight was significantly reduced on day 9 (P < 0.05). Similarly, the cerebellar weight was significantly reduced on days 14,21 and 28 (P < 0.05). The maximum vermal length was significantly reduced on day 50 (P < 0.05), and the maximum side-to-side dimension of the cerebellum was also reduced on day 28 (P < 0.05). There was no reduction in the thickness (anteroposterior dimension) of the cerebellum in the experimental group (P > 0.05). From the result, it is inferred that maternal consumption of 500 ppm cyanide causes reduction in the cerebellar weight, vermal length and side-to-side dimension of the developing cerebellum in postnatal life in rats.
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Affiliation(s)
- I O Imosemi
- Department of Anatomy, College of Medicine, University of Ibadan.
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18
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Osuagwu FC, Oladejo OW, Imosemi IO, Adewoyin BA, Adewoyin OO, Aiku A, Ekpo OE, Oluwadara OO, Ozegbe PC, Akang EEU. Wound healing activities of methanolic extracts Ocimum gratissimum leaf in Wistar rats - a preliminary study. Afr J Med Med Sci 2004; 33:23-6. [PMID: 15490789] [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: 05/01/2023]
Abstract
The wound healing effect of leaf extracts of Ocimum gratissimum was investigated in adult male Wistar rats. Two groups of adult male Wistar rats, average body weight 170g, had a 2cm by 2cm square wound inflicted on the dorsolateral aspect of their trunk with Paniculus Carnosus removed. Experimental group had their wound dressed with methanolic leaf extracts of Ocimum gratissimum while control group had their wounds dressed with normal saline dressing. All animals had wound dressing done every five days; wound dimension measured and, wound morphometry assessed. Wound biopsy was done by random selection in each group on day 10 and the day of complete re-epithelisation. Routine paraffin wax processing was done, slides stained with haematoxylene and eosin for histological assessment of fibroblast count, neovascularisation and granulation tissue profile. The result revealed significant wound contraction (P<0.05) on day 10 in the experimental group (mean 73.40 +/- 3.30)cm2 compared with the control group (mean 53.50 +/- 4.32)cm2. Histology of the healed scar showed non-significant (P>0.05) decrease in the mean fibroblast count forthe experimental group (83.80 +/- 5.70) relative to fibroblast count of 90.20 +/- 17.90 in the control group. The mean blood vessel count was also non-significantly lowered (P>0.05) in the experimental group (9.20 +/- 1.20) relative to the control group (13.40 +/- 2.40). Granulation tissue histology on day 10 showed denser inflammatory infiltrate as reflected by increased cellularity in the control group relative to that of the experimental group which though appeared adequate was not as dense as the control group. Thus we suggest that the methanolic extracts of O. gratissimum could be a potential wound healing agent due to its ability to enhance wound contraction.
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Affiliation(s)
- F C Osuagwu
- Department of Anatomy, University of Ibadan, Ibadan, Nigeria.
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Oladejo OW, Imosemi IO, Osuagwu FC, Oyedele OO, Oluwadara OO, Ekpo OE, Aiku A, Adewoyin O, Akang EEU. A comparative study of the wound healing properties of honey and Ageratum conyzoides. Afr J Med Med Sci 2003; 32:193-6. [PMID: 15032468] [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: 04/29/2023]
Abstract
The present study investigates the wound healing properties of methanolic extracts of Ageratum conyzoides leaves compared with those of honey. Thirty Wistar rats were randomized into 3 groups of 10 animals each. They were fed with standard rat cubes and Tap water weighed and acclimatized to laboratory conditions for one week. Under anesthesia, each animal had the skin of its dorsolateral flank shaved after which an area of the skin was excised. On achieving haemostasis, the wounds were packed with gauze soaked in the appropriate dressing for each group. Measurement of wound size, and wound biopsies were taken on the 10th day post-wound creation. Together with healed wound samples, these were processed for histology. Fibroblast and blood vessel densities per unit area of wound were determined for the healed wound samples. Histologically, the day 10 Ageratum sections showed fewer inflammatory cells compared with similar honey and Control sections. Also, healed scar sections of wounds dressed with the herb extract showed more fibrosis. Honey and Ageratum caused significant greater wound contraction than controls (p = 0.001 and 0.005 respectively). Healed wounds from the Ageratum group had significantly fewer fibroblasts than honey and controls (p = 0.012 and 0.036 respectively).
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Affiliation(s)
- O W Oladejo
- Department of Anatomy, College of Medicine, University of Ibadan, Nigeria
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