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Olajide OA, Iwuanyanwu VU, Lepiarz-Raba I, Al-Hindawi AA, Aderogba MA, Sharp HL, Nash RJ. Garcinia kola and garcinoic acid suppress SARS-CoV-2 spike glycoprotein S1-induced hyper-inflammation in human PBMCs through inhibition of NF-κB activation. Phytother Res 2021; 35:6963-6973. [PMID: 34697842 PMCID: PMC8661957 DOI: 10.1002/ptr.7315] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/14/2021] [Accepted: 10/11/2021] [Indexed: 12/15/2022]
Abstract
Symptoms and complications associated with severe SARS-CoV-2 infection such as acute respiratory distress syndrome (ARDS) and organ damage have been linked to SARS-CoV-2 spike protein S1-induced increased production of pro-inflammatory cytokines by immune cells. In this study, the effects of an extract of Garcinia kola seeds and garcinoic acid were investigated in SARS-CoV-2 spike protein S1-stimulated human PBMCs. Results of ELISA experiments revealed that Garcinia kola extract (6.25, 12.5, and 25 μg/ml) and garcinoic acid (1.25, 2.5, and 5 μM) significantly reduced SARS-CoV-2 spike protein S1-induced secretion of TNFα, IL-6, IL-1β, and IL-8 in PBMCs. In-cell western assays showed that pre-treatment with Garcinia kola extract and garcinoic acid reduced expressions of both phospho-p65 and phospho-IκBα proteins, as well as NF-κB DNA binding capacity and NF-κB-driven luciferase expression following stimulation of PBMCs with spike protein S1. Furthermore, pre-treatment of PBMCs with Garcinia kola extract prior to stimulation with SARS-CoV-2 spike protein S1 resulted in reduced damage to adjacent A549 lung epithelial cells. These results suggest that the seed of Garcinia kola and garcinoic acid are natural products which may possess pharmacological/therapeutic benefits in reducing cytokine storm in severe SARS-CoV-2 and other coronavirus infections.
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Affiliation(s)
- Olumayokun A Olajide
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - Victoria U Iwuanyanwu
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - Izabela Lepiarz-Raba
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - Alaa A Al-Hindawi
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - Mutalib A Aderogba
- Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria
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Erhabor RC, Aderogba MA, Erhabor JO, Nkadimeng SM, McGaw LJ. In vitro bioactivity of the fractions and isolated compound from Combretum elaeagnoides leaf extract against selected foodborne pathogens. J Ethnopharmacol 2021; 273:113981. [PMID: 33647425 DOI: 10.1016/j.jep.2021.113981] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Combretum species are used traditionally for the treatment of diarrhoea, hookworm, fever, inflammation, pain and infectious diseases. Infections are commonly caused by the intake of food contaminated with foodborne pathogens. These are a significant concern in the food industry owing to their ability to form biofilms and cause food spoilage, despite the availability of modern food preservation techniques. Combretum elaeagnoides Klotzsch (Combretaceae) is used in southern African traditional medicine against infections and diarrhoea. AIM OF THE STUDY This study evaluated the antimicrobial ability of C. elaeagnoides leaf fractions and the isolated compound quercetin-3-O-rhamnoside against a panel of foodborne pathogens, and biofilms formed by them. The samples were also assessed for their antioxidant activity and cytotoxicity. MATERIALS AND METHODS Fractions prepared from the methanol extract of the leaves, and a bioactive compound (quercetin-3-O-rhamnoside) isolated from the ethyl acetate fraction were investigated for activity against nine reference and clinical strains of foodborne pathogens. The microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the fractions and compound. The inhibition of biofilm formation and the crystal violet staining assays were used to determine the antibiofilm efficacy. The DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay and the 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) electron reduction assay were used to determine the antioxidant potential of the fractions and compound. The cytotoxicity was assessed using the 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay against Vero African monkey kidney cells. RESULTS The fractions were active against all tested organisms, with MIC values ranging from 0.03 to 1.25 mg/mL. The best MBC was 0.63 mg/mL. All the fractions and the purified compound inhibited biofilm formation of Staphylococcus aureus and Salmonella Typhimurium, with percentage inhibition values greater than 50% at 1 mg/mL. The compound had very promising antibiofilm activity against Escherichia coli 1 (ATCC 25922) with percentage inhibition of >150%. The compound and fractions had good radical scavenging potential against the DPPH and ABTS radicals. Quercetin-3-O-rhamnoside and the fractions were relatively non-cytotoxic. CONCLUSION The ability of the fractions and compound to reduce and inhibit biofilm biomass and their promising antioxidant potential provide motivation to further investigate the use of plants to protect food products from contamination, as well as to treat infections characterized by bacterial biofilms.
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Affiliation(s)
- Rosemary C Erhabor
- Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X01, Onderstepoort, 0110, South Africa.
| | - Mutalib A Aderogba
- Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X01, Onderstepoort, 0110, South Africa; Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
| | - Joseph O Erhabor
- Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X01, Onderstepoort, 0110, South Africa; Phytomedicine Unit, Department of Plant Biology and Biotechnology, University of Benin, PMB, 1154, Benin City, Nigeria.
| | - Sanah M Nkadimeng
- Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X01, Onderstepoort, 0110, South Africa.
| | - Lyndy J McGaw
- Phytomedicine Programme, Department of Paraclinical Sciences, University of Pretoria, Private Bag X01, Onderstepoort, 0110, South Africa.
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Ogunrinade FA, Guetchueng ST, Katola FO, Aderogba MA, Akande IS, Sarker SD, Olajide OA. Zanthoxylum zanthoxyloides inhibits lipopolysaccharide- and synthetic hemozoin-induced neuroinflammation in BV-2 microglia: roles of NF-κB transcription factor and NLRP3 inflammasome activation. J Pharm Pharmacol 2020; 73:118-134. [PMID: 33791805 DOI: 10.1093/jpp/rgaa019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The effects of a root extract of Zanthoxylum zanthoxyloides on neuroinflammation in BV-2 microglia stimulated with LPS and hemozoin were investigated. METHODS ELISA, enzyme immunoassay and Griess assay were used to evaluate levels of cytokines, PGE2 and NO in culture supernatants, respectively. Microglia-mediated neurotoxicity was evaluated using a BV-2 microglia-HT-22 neuron transwell co-culture. KEY FINDINGS Treatment with Z. zanthoxyloides caused reduced elevated levels of TNFα, IL-6, IL-1β, NO and PGE2, while increasing the levels of IL-10. In addition, there were reduced levels of iNOS and COX-2 proteins. This was accompanied by a prevention of microglia-mediated damage to HT-22 mouse hippocampal neurons. Z. zanthoxyloides reduced elevated levels of phospho-IκB and phospho-p65, while preventing degradation of IκB protein and DNA binding of p65. Further mechanistic studies revealed that Z. zanthoxyloides reduced the levels of pro-IL-1β and IL-1β in hemozoin-activated BV-2 microglia. This was accompanied by a reduction in caspase-1 activity and NLRP3 protein expression. Bioassay-guided fractionation resulted in the isolation of skimmianine as an anti-inflammatory compound in Z. zanthoxyloides. CONCLUSION This is the first report showing the inhibition of neuroinflammation in LPS- and hemozoin-activated BV-2 microglia by the root extract of Z. zanthoxyloides by targeting the activation of both NF-κB and NLRP3 inflammasome.
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Affiliation(s)
- Folashade A Ogunrinade
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - Stephanie T Guetchueng
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, UK
| | - Folashade O Katola
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
| | - Mutalib A Aderogba
- Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Idowu S Akande
- Department of Biochemistry, College of Medicine, University of Lagos, Nigeria
| | - Satyajit D Sarker
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, UK
| | - Olumayokun A Olajide
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, UK
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Ajayi OS, Aderogba MA, Obuotor EM, Majinda RRT. Acetylcholinesterase inhibitor from Anthocleista vogelii leaf extracts. J Ethnopharmacol 2019; 231:503-506. [PMID: 30415061 DOI: 10.1016/j.jep.2018.11.009] [Citation(s) in RCA: 15] [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] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/26/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Anthocleista vogelii (Planch) is used in folk medicine in conditions related to inflammation and oxidative stress. This suggests that some of its constituents could possess ability to reduce oxidative damage to cells and ameliorate inflammatory conditions which are two prominent features in the brain of a person suffering from Alzheimer's disease. AIM OF STUDY The leaf extracts were investigated for their bioactive constituents in our quest for novel compounds for the management of Alzheimer's disease. MATERIALS AND METHODS Anthocleista vogelii crude leaf extract obtained from 80% methanol was successively partitioned with n-hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. This gave four solvent fractions of the crude extract. These fractions and isolated compound were subjected to acetylcholinesterase (AChE) inhibitory activity test using the microplate assay method. The structure of the isolated compound was determined using spectroscopic methods (1D and 2D NMR, and MS). RESULTS The results of the acetylcholinesterase inhibitory assay revealed that n-BuOH and ethyl acetate fractions had the best activity with IC50 of 564.58 and 727.63 µg/mL respectively. Activity directed fractionation of each of these fractions led to the isolation of the same compound identified as a C-glucosylflavone; isovitexin-7-O-methyl ether (swertisin). This rare C-glucosylflavone co-exist as two rotamers and exhibited duplication of NMR signals. It is reported from this plant for the first time. Swertisin displayed better acetylcholinesterase inhibitory activity with IC50 of 32.09 µg/mL than physostigmine (eserine) with IC50 of 56.09 µg/mL used as a standard. CONCLUSIONS This study reports isolation and characterization of a rare C-glycosylflavone; isovitexin-7-O-methyl ether (swertisin). Isolated compound exhibited duplication of NMR signals and better acetylcholinesterase inhibitory activity than eserine used as a standard. The activity exhibited by this compound suggests that it could be useful in the management of Alzheimer's disease.
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Affiliation(s)
- O S Ajayi
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria; Department of Chemistry, University of Botswana, Gaborone, Botswana
| | - M A Aderogba
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
| | - E M Obuotor
- Department of Biochemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - R R T Majinda
- Department of Chemistry, University of Botswana, Gaborone, Botswana
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Velagapudi R, Ajileye OO, Okorji U, Jain P, Aderogba MA, Olajide OA. Agathisflavone isolated from Anacardium occidentale suppresses SIRT1-mediated neuroinflammation in BV2 microglia and neurotoxicity in APPSwe-transfected SH-SY5Y cells. Phytother Res 2018; 32:1957-1966. [PMID: 29786910 DOI: 10.1002/ptr.6122] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 04/24/2018] [Accepted: 04/27/2018] [Indexed: 01/01/2023]
Abstract
Agathisflavone is a bioactive compound in Anacardium occidentale. In this study, we investigated inhibition neuroinflammation in BV2 microglia by agathisflavone. Neuroprotective activity of the compound was investigated in differentiated SH-SY5Y cells. Experiments in lipopolysaccharide (LPS)-activated BV2 microglia showed that pretreatment with agathisflavone (5-20 μM) produced significant reduction in the release of tumour necrosis factor-α, interleukin-6, interleukin-1β, NO, and PGE2 from the cells. Immunoblotting experiments also revealed that agathisflavone reduced levels of iNOS and COX-2 protein. Further studies revealed that agathisflavone reduced neuroinflammation by targeting critical steps in NF-κB signalling in BV2 microglia. Treatment of SH-SY5Y cells with conditioned medium from LPS-activated BV2 microglia produced a significant reduction in neuronal viability. However, conditioned medium from BV2 cells that were stimulated with LPS in the presence of agathisflavone did not induce neurotoxicity. Agathisflavone also produced neuroprotection in APPSwe plasmid-transfected SH-SY5Y neurons. The compound further attenuated LPS-induced and APPSwe plasmid-induced reduction in SIRT1 in BV2 microglia and SH-SY5Y, respectively. In the presence of EX527, agathisflavone lost its anti-inflammatory and neuroprotective activities. Our results suggest that agathisflavone inhibits neuroinflammation in BV2 microglia by targeting NF-κB signalling pathway. The compound also reduces neurotoxicity through mechanisms that are possibly linked to SIRT1 in the microglia and neurons.
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Affiliation(s)
- Ravikanth Velagapudi
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, UK
| | - Olusiji O Ajileye
- Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Uchechukwu Okorji
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, UK
| | - Priya Jain
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, UK
| | - Mutalib A Aderogba
- Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Olumayokun A Olajide
- Department of Pharmacy, School of Applied Sciences, University of Huddersfield, Huddersfield, HD1 3DH, UK
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Madikizela B, Aderogba MA, Finnie JF, Van Staden J. Isolation and characterization of antimicrobial compounds from Terminalia phanerophlebia Engl. & Diels leaf extracts. J Ethnopharmacol 2014; 156:228-234. [PMID: 25218320 DOI: 10.1016/j.jep.2014.09.003] [Citation(s) in RCA: 11] [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] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/26/2014] [Accepted: 09/02/2014] [Indexed: 06/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The emergence of drug resistant-tuberculosis and other pathogenic diseases over the past decades, constitutes a serious threat to human health worldwide. According to a 2012 report by the World Health Organization (WHO), South Africa, China, India and Russia are the countries with the highest prevalence of Multi-Drug Resistant tuberculosis (MDR-tuberculosis) as they represented 60% of the total. Several reports have documented antimycobacterial properties of Terminalia species but only a few species from this genus have been explored for their antimycobacterial constituents. The crude extracts of Terminalia phanerophlebia showed good antimicrobial activities in our previous study against two Mycobacterium as well as two other bacterial strains responsible for opportunistic infections related to respiratory ailments. This paper studies the isolation of compounds responsible for such activities and to isolate compounds responsible for antimicrobial activities from the crude extracts of Terminalia phanerophlebia leaves. MATERIALS AND METHODS Terminalia phanerophlebia crude extracts obtained from 80% methanol was successively extracted with hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. The fractions obtained and isolated compounds were tested for their antibacterial activities against Mycobacterium aurum, Mycobacterium tuberculosis, Staphylococcus aureus and Klebsiella pneumoniae. Bioguided fractionation of the EtOAc fraction afforded two bioactive compounds. Structure elucidation was carried out using NMR (1D and 2D) spectroscopic methods. RESULTS EtOAc fraction exhibited highest antimicrobial activities and its fractionation afforded methyl gallate (methyl-3,4,5-trihydroxybenzoate) (1) and a phenylpropanoid glucoside, 1,6-di-O-coumaroyl glucopyranoside (2) These compounds are reported from Terminalia phanerophlebia for the first time. Both compounds showed good antimicrobial activity against all bacterial strains tested with minimum inhibitory concentration (MIC) values ranging from 63 to 250 µg/mL. Inhibition of Mycobacterium tuberculosis by 1,6-di-O-coumaroyl glucopyranoside (2) at a MIC value of 63 µg/mL was noteworthy, as this bacterial strain is reported to be the leading cause of tuberculosis worldwide. CONCLUSIONS Good antimicrobial activities exhibited by the compounds isolated from Terminalia phanerophlebia authenticate the traditional use of this plant in treating tuberculosis and its related symptoms. Compound (2), 1,6-di-O-coumaroyl glucopyranoside could serve as a lead compound for tuberculosis drug discovery.
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Affiliation(s)
- B Madikizela
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, Private Bag X01,Pietermaritzburg, South Africa
| | - M A Aderogba
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, Private Bag X01,Pietermaritzburg, South Africa
| | - J F Finnie
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, Private Bag X01,Pietermaritzburg, South Africa
| | - J Van Staden
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Scottsville 3209, Private Bag X01,Pietermaritzburg, South Africa.
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Madikizela B, Aderogba MA, Van Staden J. Isolation and characterization of antimicrobial constituents of Searsia chirindensis L. (Anacardiaceae) leaf extracts. J Ethnopharmacol 2013; 150:609-613. [PMID: 24060408 DOI: 10.1016/j.jep.2013.09.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/30/2013] [Accepted: 09/06/2013] [Indexed: 06/02/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Searsia chirindensis is used in South African traditional medicine for management of bacterial infections such as diarrhoea. Aim of the study was to examine the phytochemical composition from the leaves of Searsia chirindensis that is responsible for the ethnomedicinal use of this plant. MATERIALS AND METHODS The crude extract (80% methanol) was extracted sequentially with dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol. The extracts and isolated compounds were tested for their antibacterial activity against Gram-negative (Campylobacter jejuni, Escherichia coli and Shigella flexneri) and Gram-positive (Staphylococcus aureus) bacterial strains using the microdilution method. Bioguided fractionation of EtOAc fraction afforded five phenolic compounds. Structural elucidation was carried out using NMR (1D and 2D) spectroscopic analyses. RESULTS Of the three fractions obtained from the crude extract, EtOAc was the most active and its fractionation afforded methyl gallate (1), and four flavonol glycosides: myricetin-3-O-arabinopyranoside (2), myricetrin-3-O-rhamnoside (3), kaempferol-3-O-rhamnoside (4) and quercetin-3-O-arabinofuranoside (5). These compounds are reported from Searsia chirindensis for the first time. All the compounds showed good antibacterial activity against all bacterial strains tested. Their minimum inhibitory concentrations ranged from 30 to 250 µg/mL. CONCLUSIONS Antibacterial activity demonstrated by the extracts and isolated compounds provides credence to the ethnomedicinal use of Searsia chirindensis against diarrhoea.
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Affiliation(s)
- Balungile Madikizela
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
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Rengasamy KRR, Aderogba MA, Amoo SO, Stirk WA, Van Staden J. Potential antiradical and alpha-glucosidase inhibitors from Ecklonia maxima (Osbeck) Papenfuss. Food Chem 2013; 141:1412-5. [PMID: 23790932 DOI: 10.1016/j.foodchem.2013.04.019] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [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: 11/09/2012] [Revised: 04/03/2013] [Accepted: 04/06/2013] [Indexed: 12/19/2022]
Abstract
Alpha-glucosidase inhibitors play a potential role in the treatment of type 2 diabetes by delaying glucose absorption in the small intestine. Ecklonia maxima, a brown alga which grows abundantly on the west coast of South Africa, is used to produce alginate, animal feed, nutritional supplements and fertilizer. The crude aqueous methanol extract, four solvent fractions and three phlorotannins: 1,3,5-trihydroxybenezene (phloroglucinol) (1), dibenzo [1,4] dioxine-2,4,7,9-tetraol (2) and hexahydroxyphenoxydibenzo [1,4] dioxine (eckol) (3) isolated from E. maxima were evaluated for antiradical and alpha-glucosidase inhibitory activities. All the phlorotannins tested had strong antioxidant activities on DPPH free radicals with EC50 values ranging from 0.008 to 0.128μM. Compounds 2 and 3 demonstrated stronger antioxidant activity and an alpha-glucosidase inhibitory property than positive controls. These results suggest that E. maxima could be a natural source of potent antioxidants and alpha-glucosidase inhibitors. This study could facilitate effective utilization of E. maxima as an oral antidiabetic drug or functional food ingredient with a promising role in the formulation of medicines and nutrition supplements.
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Affiliation(s)
- Kannan R R Rengasamy
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
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Kannan RR, Aderogba MA, Ndhlala AR, Stirk WA, Van Staden J. Acetylcholinesterase inhibitory activity of phlorotannins isolated from the brown alga, Ecklonia maxima (Osbeck) Papenfuss. Food Res Int 2013. [DOI: 10.1016/j.foodres.2012.11.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Pendota SC, Aderogba MA, Ndhlala AR, Van Staden J. Antimicrobial and acetylcholinesterase inhibitory activities of Buddleja salviifolia (L.) Lam. leaf extracts and isolated compounds. J Ethnopharmacol 2013; 148:515-520. [PMID: 23665162 DOI: 10.1016/j.jep.2013.04.047] [Citation(s) in RCA: 28] [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: 02/13/2013] [Revised: 04/17/2013] [Accepted: 04/21/2013] [Indexed: 06/02/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Buddleja salviifolia leaves are used for the treatment of eye infections and neurodegenerative conditions by various tribes in South Africa. AIM OF STUDY This study was designed to isolate the phenolic constituents from the leaf extracts of Buddleja salviifolia and evaluate their antimicrobial and acetylcholinesterase (AChE) activities. MATERIAL AND METHODS Three phenolic compounds were isolated from the ethyl acetate fraction of a 20% aqueous methanol leaf extract of Buddleja salviifolia using Sephadex LH-20 and silica gel columns. Structure elucidation of the isolated compounds was carried out using spectroscopic techniques: mass spectrometry (ESI-TOF-MS) and NMR (1D and 2D). The extracts and isolated compounds were evaluated for antimicrobial and acetylcholinesterase activities using the microdilution technique. The bacteria used for the antimicrobial assays were Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli and Klebsiella pneumoniae. RESULTS The isolated compounds were characterized as: 4'-hydroxyphenyl ethyl vanillate (1) a new natural product, acteoside (2) and quercetin (3). The crude extract, fractions and the isolated compounds from the leaves of the plant exhibited a broad spectrum of antibacterial activity. The EtOAc fraction exhibited good activity against Bacillus subtilis and Staphylococcus aureus with MIC values ranging from 780.0 to 390.0 µg/mL. Isolated compound 2 exhibited good activity against Staphylococcus aureus with an MIC value of 62.5 µg/mL. The hexane and DCM fractions of leaves showed the best activity against Candida albicans with MIC and MFC values of 390.0 µg/mL. In the AChE inhibitory test, among the tested extracts, the hexane fraction was the most potent with an IC50 value of 107.4 µg/mL, whereas for the isolated compounds, it was compound (3) (quercetin) with an IC50 value of 66.8 µg/mL. CONCLUSIONS Activities demonstrated by the extracts and isolated compounds support the ethnopharmacological use of Buddleja salviifolia against eye infections and neurodegenerative diseases.
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Affiliation(s)
- S C Pendota
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
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Aderogba MA, Ndhlala AR, Van Staden J. Acetylcholinesterase Inhibitors from Croton sylvaticus Ethyl Acetate Leaf Extract and their Mutagenic Effects. Nat Prod Commun 2013. [DOI: 10.1177/1934578x1300800628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Croton sylvaticus is a medicinal plant widely employed in the management of inflammatory conditions, infections and oxidative stress related diseases such as insomnia, abdominal and internal inflammations. The activities demonstrated by the plant extracts support that its constituents possess the ability to reduce oxidative damage to body cells. Repeated column fractionation of the ethyl acetate fraction of a 20% aqueous methanol leaf extract using acetylcholinesterase (AChE) activity directed on Sephadex LH-20 afforded three compounds identified by mass spectrometry, and 1D and 2D NMR spectroscopy as: 2′-(3″,4″-dihydroxyphenyl)-ethyl-4-hydroxybenzoate (1), 3, 3′, 4′, 5, 7-pentahydroxyflavone (quercetin) (2), and 3, 4′, 5, 7-tetrahydroxyflavone (kaempferol) (3). These compounds are reported from the leaf extracts of C. sylvaticus for the first time and compound 1 is a new natural product. The microplate technique was used to determine the inhibitory effects of the plant extracts (crude and solvent fractions) and isolated compounds against AChE. The IC50 values of the compounds ranged from 60.7 to 415.0 μg/mL, with compound 2 having the best inhibitory activity; the IC50 values of the plant crude extract and solvent fractions ranged from 235.0 to 4695.0 μg/mL. The ethyl acetate fraction had the best inhibitory activity (IC50=235.0 μg/mL). The three compounds showed no mutagenic effects against Salmonella typhimurium tester strains TA98 and TA100. The activity demonstrated by these compounds suggests that they could be effective in the management of neurodegenerative disorders.
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Affiliation(s)
- Mutalib A. Aderogba
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Ashwell R. Ndhlala
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
| | - Johannes Van Staden
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa
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Ndhlala AR, Aderogba MA, Ncube B, Van Staden J. Anti-oxidative and cholinesterase inhibitory effects of leaf extracts and their isolated compounds from two closely related Croton species. Molecules 2013; 18:1916-32. [PMID: 23377133 PMCID: PMC6270636 DOI: 10.3390/molecules18021916] [Citation(s) in RCA: 30] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/07/2013] [Accepted: 01/15/2013] [Indexed: 11/16/2022] Open
Abstract
A comparative evaluation of the antioxidant and acetylcholinesterase inhibitory activity of the leaf extracts of Croton gratissimus and Croton zambesicus (subgratissimus) and compounds isolated from the extracts was carried out to determine their potential and suitability or otherwise as a substitute for each other in the management of oxidative and neurodegenerative conditions. Different antioxidant assays (DPPH, FRAP, β-carotene-linoleic and the lipid peroxidation models) and the microplate assay for acetylcholinesterase (AChE) inhibition were carried out separately to study the activities of the crude leaf extracts and four solvent fractions from each of the two Croton species. Bioassay guided fractionation was used to target antioxidant constituents of the crude extracts and ethyl acetate fractions of 20% aqueous methanol extract of C. gratissimus on silica gel and Sephadex LH-20 columns resulted in the isolation of kaempferol-3-O-β-6’’(p-coumaroyl) glucopyranoside (tiliroside, 2), apigenin-6-C-glucoside (isovitexin, 3) and kampferol (4). The extract of C. zambesicus yielded quercetin-3-O-β-6’’(p-coumaroyl) glucopyranoside-3’-methyl ether (helichrysoside-3’-methyl ether, 1), kaempferol-3-O-β-6’’(p-coumaroyl) glucopyranoside (tiliroside, 2) and apigenin-6-C-glucoside (isovitexin, 3). Three of the isolated compounds and their different combinations were also included in the bioassays. In all the assays performed, the antioxidant capacity and AChE inhibitory effects of C. zambesicus extracts were weaker than those of C. gratissimus. This suggests that C. gratissimus may not be substituted by C. zambesicus, despite the similarity in some of their constituents. Generally, the combinations made from the isolated compounds showed better activities in most of the assays compared to the individual isolated compounds. This suggests mechanisms such as synergism and/or additive effects to be taking place. This study established low, moderate and high antioxidant activities as well as AChE inhibitory effects by the crude extracts, fractions, compounds and compound combinations. This means some of the extracts, isolated compounds and compound combinations could be useful in the management of neurodegenerative conditions and serve as sources of natural neurodegenerative agents.
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Affiliation(s)
- Ashwell R. Ndhlala
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa; E-Mails: (A.R.N.); (M.A.A.); (B.N.)
| | - Mutalib A. Aderogba
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa; E-Mails: (A.R.N.); (M.A.A.); (B.N.)
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife 220005, Nigeria
| | - Bhekumthetho Ncube
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa; E-Mails: (A.R.N.); (M.A.A.); (B.N.)
| | - Johannes Van Staden
- Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa; E-Mails: (A.R.N.); (M.A.A.); (B.N.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +27-33-260-5130; Fax: +27-33-260-5897
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Olajide OA, Aderogba MA, Fiebich BL. Mechanisms of anti-inflammatory property of Anacardium occidentale stem bark: inhibition of NF-κB and MAPK signalling in the microglia. J Ethnopharmacol 2013; 145:42-49. [PMID: 23142196 DOI: 10.1016/j.jep.2012.10.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 10/16/2012] [Accepted: 10/17/2012] [Indexed: 06/01/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Anacardium occidentale is used in traditional African medicine for the treatment of arthritis, fever, aches, pains, and inflammation of the extremities. AIM OF THE STUDY In this study, we investigated the molecular mechanisms responsible for anti-inflammatory effects of a stem bark extract of A. occidentale (ANE) in LPS-stimulated microglia. MATERIALS AND METHODS Nitric oxide (NO), prostaglandin E(2) and cytokine (TNFα and IL-6) production were evaluated in supernatants from LPS-stimulated BV-2 cells. Cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and microsomal prostaglandin E2 synthase (mPGES-1) protein expressions in rat primary microglia were measured using western blot. The effects of ANE on NF-κB activation and nuclear translocation were evaluated in the luciferase reporter gene assay and ELISA, while ability of ANE to influence IκB phosphorylation was determined using ELISA specific for phospho-IκB. The involvement of MAPK phosphorylation in the anti-inflammatory actions of ANE was evaluated using specific ELISA for phospho-p38, phospho-p42/44 and phospho-JNK. The MTT assay was used to determine the effect of ANE on BV-2 microglia viability. RESULTS ANE (25-100 μg/ml) produced significant (p<0.05) reduction in the production of NO, PGE(2), TNFα and IL-6 in BV-2 microglia stimulated with LPS for 24h. Pre-treatment with ANE caused a significant (p<0.05) inhibition of COX-2, iNOS and mPGES-1 protein expressions in the rat primary microglia. Further experiments showed that ANE inhibited COX-2 and iNOS protein expression via IκB-mediated nuclear translocation and transactivation of NF-κB. Our studies also revealed that ANE produced significant (p<0.05) and dose-dependent inhibition of p38, p42/44 and JNK MAPK phosphorylation in LPS-activated BV-2 microglia. CONCLUSIONS We conclude that ANE has an anti-inflammatory property related to inhibition of inflammation-associated cytokine production as well as iNOS and COX-2 gene expression by blocking NF-κB and MAPK pathways in the microglia. It is also suggested that mPGES-1 inhibition contributes to the effect of ANE on PGE(2) production in the microglia.
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Affiliation(s)
- Olumayokun A Olajide
- Division of Pharmacy and Pharmaceutical Science, School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom.
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Aderogba MA, McGaw LJ, Bezabih M, Abegaz BM. Isolation and characterisation of novel antioxidant constituents of Croton zambesicus leaf extract. Nat Prod Res 2011; 25:1224-33. [PMID: 21762034 DOI: 10.1080/14786419.2010.532499] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A 1,1-diphenyl-2-picrylhydrazyl (DPPH)-activity-directed fractionation was used to target antioxidant constituents of the ethyl acetate fraction obtained from a 20% aqueous methanol crude extract of Croton zambesicus leaf. Repeated column chromatography of the fraction on silica gel and Sephadex LH-20 led to the isolation of a new natural product, identified as quercetin-3-O-β-6″(p-coumaroyl) glucopyranoside-3'-methyl ether, helichrysoside-3'-methyl ether (1), along with kaempferol-3-O-β-6″(p-coumaroyl) glucopyranoside, tiliroside (2) and apigenin-6-C-glucoside, isovitexin (3) as the antioxidant constituents. The structures of the isolated compounds were elucidated using spectroscopic techniques, namely NMR (1D and 2D) and mass spectrometry. Compounds 1 and 2 are reported from this species for the first time. In the qualitative antioxidant assay, the three isolated compounds instantly bleached the DPPH (0.2% MeOH) purple colour indicating antioxidant activity. In the quantitative antioxidant assay, all the isolated compounds demonstrated weak antioxidant activity compared to quercetin and rutin used as positive control antioxidant agents. The compounds displayed little to no cytotoxicity against Vero cells in an in vitro assay. The presence of these antioxidant compounds in the leaf extract of C. zambesicus could provide a rationale for the ethnomedicinal use of the plant in the management of oxidative-stress-related diseases in folk medicine.
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Affiliation(s)
- M A Aderogba
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
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Shai LJ, McGaw LJ, Aderogba MA, Mdee LK, Eloff JN. Four pentacyclic triterpenoids with antifungal and antibacterial activity from Curtisia dentata (Burm.f) C.A. Sm. leaves. J Ethnopharmacol 2008; 119:238-244. [PMID: 18662765 DOI: 10.1016/j.jep.2008.06.036] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 06/23/2008] [Accepted: 06/27/2008] [Indexed: 05/26/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Curtisia dentata is used in southern Africa to treat various diseases of bacterial and fungal origin in humans and animals to such a degree that the species is vulnerable and declining [Dold, A.R., Cocks, M.L., 2001. Traditional veterinary medicine in the Alice district of the Eastern Cape Province, South Africa. South African Journal of Science 97, 375-379]. Preliminary studies indicated good activity against Candida albicans. AIM OF THE STUDY The phytochemistry and antimicrobial activity of this plant species has not been extensively investigated, and a closer examination of the compounds responsible for antimicrobial activity was warranted. MATERIALS AND METHODS Broth microdilution assay and bioautography were used to evaluate antibacterial and antifungal activity in Curtisia dentata leaf extracts and fractions. Bioassay-directed fractionation using column chromatography yielded four compounds characterised by spectroscopic methods. RESULTS Lupeol (1), betulinic acid (2), ursolic acid (3) and 2alpha-hydroxyursolic acid (4) were isolated from Curtisia dentata leaves. Betulinic acid, ursolic acid and 2alpha-hydroxyursolic acid appreciably inhibited fungal growth with MIC values ranging from 8 to 63mug/mL. CONCLUSIONS The isolation of four antibacterial and antifungal triterpenoids is reported for the first time from Curtisia dentata. This study provides information on the antimicrobial compounds of this species, as well as a preliminary rationale for the use in traditional South African medicine.
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Affiliation(s)
- L J Shai
- Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110 Pretoria, South Africa
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Abstract
The antioxidant activity of the crude extract and solvent fractions obtained from the leaves of Bauhinia galpinii was evaluated in terms of capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The crude extract and the more polar solvent fractions (ethyl acetate and butanol) showed considerable antioxidant activity. The antioxidant potential of the extracts, expressed as EC50, ranged between 28.85 +/- 1.28 microg mL(-1)and 118.16 +/- 6.41 microg mL(-1). L-Ascorbic acid was used as a standard (EC50 = 19.79 +/- 0.14 microM). Bioassay guided fractionation of the two active solvent fractions led to the isolation of three flavonoid glycosides, identified as: quercetin-3-O-galactopyranoside (1), myricetin-3-O-galactopyranoside (2), and 2''-O-rhamnosylvitexin (3). These compounds are reported for the first time from this species. The structures of the compounds were determined on the basis of spectral studies (1H NMR, 13C NMR and MS). Their antioxidant potential was evaluated using a DPPH spectrophotometric assay. Compound 2 had higher and 3 had lower antioxidant activity than L-ascorbic acid. No cytotoxic effects were displayed by compounds 1 and 3, but compound 2 was cytotoxic to Vero cells (LC50 = 74.68 microg mL(-1)) and bovine dermis cells (LC50 = 30.69 microg mL(-1)).
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Affiliation(s)
- M A Aderogba
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
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Bizimenyera ES, Aderogba MA, Eloff JN, Swan GE. Potential of neuroprotective antioxidant-based therapeutics from Peltophorum africanum Sond. (Fabaceae). Afr J Tradit Complement Altern Med 2006; 4:99-106. [PMID: 20162078 DOI: 10.4314/ajtcam.v4i1.31199] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There is ample scientific and empirical evidence supporting the use of plant-derived antioxidants for the control of neurodegenerative disorders. Antioxidants may have neuroprotective (preventing apoptosis) and neuroregenerative roles, by reducing or reversing cellular damage and by slowing progression of neuronal cell loss. Although demand for phytotherapeutic agents is growing, there is need for their scientific validation before plant-derived extracts gain wider acceptance and use. We have evaluated antioxidant potential of Peltophorum africanum (weeping wattle), a plant widespread in the tropics and traditionally used, inter alia, for the relief of acute and chronic pain, anxiety and depression. The dried leaves, bark and root of P. africanum were extracted with acetone. Thin layer chromatograms were sprayed with 0.2% 2,2-diphenyl-1-picryl hydrazyl (DPPH) in methanol for screening for antioxidants. Quantification of antioxidant activity was assessed against 6-hydroxy-2, 5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) and L-ascorbic acid (both standard antioxidants), using two free radicals, 2,2'-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and DPPH, respectively. Results of our study show that the bark and root extracts had higher antioxidant activity than L-ascorbic acid and Trolox, a synthetic vitamin-E analogue. The respective TEAC (Trolox Equivalent Antioxidant Capacity) values for the bark and root extracts, and Trolox were 1.08, 1.28 and 1.0. EC(50) values for L-ascorbic acid (5.04 microg/mL) was more active than the leaf 6.54 (microg/mL), but much less active than the bark (4.37 microg/mL) and root (3.82 microg/mL) extracts. Continued work on P. africanum, and other plants rich in antioxidants, may avail neuroscientists with potent neuroprotective antioxidant therapeutics.
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Affiliation(s)
- E S Bizimenyera
- Programme for Phytomedicine, Department of Paraclinical Sciences, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa.
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