In continuation of our search for bioactive natural products that can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation, 50 extracts/fractions from 21 families of medicinal plants from West and Central Africa were evaluated for inhibitory activity against tyrosinase (E:C:1.14.18.1), the rate-limiting enzyme in melanin synthesis. Four extracts including the methanol extract of Garcinia kola seeds at 100 microg/ml displayed >60% inhibition of tyrosinase activity. Preparative high-speed counter-current chromatography with solvent system composed of n-hexane-ethyl acetate-methanol-water (3:5:3:5) successfully separated the most active extract from G. kola seed. By stepwise increase of the flow-rate of the mobile phase, five major biflavanones including GB-I-glucoside (1) GB-1a (2), GB-1 (3), GB-2 (4), kolaflavonone (5) were successfully isolated in 6 h. Compound (4) was the most potent (IC(50) 582 microM) and compared favorably with a reference tyrosinase inhibitor (kojic acid, IC(50) 130 microM).
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http://dx.doi.org/10.1016/j.chroma.2007.02.085 | DOI Listing |
In Silico Pharmacol
November 2024
Department of Chemistry, University of Ibadan, Ibadan, Oyo State Nigeria.
Unlabelled: Estrogen hormone dependence accounts for a major cause in the incidence of women breast cancer. ER- is the major ER subtype in the mammary epithelium and plays a critical role in breast cancer progression. Tamoxifen (1-[4-(2-dimethylaminoethoxy)-phenyl]-1,2- diphenylbut-1(Z)-ene) is a nonsteroidal antiestrogen prodrug which formed pharmacologically active metabolite, 4-hydroxytamoxifen, largely used for endocrine therapy in pre and postmenopausal women with ER-positive breast cancer.
View Article and Find Full Text PDFHeliyon
November 2024
University of Douala, Advanced Teachers Training School for Technical Education, Laboratory of Forest Resources and Wood Valorization, PO Box 1872, Douala, Cameroon.
The value chain analyses of a product can provide vital information for improving the production, value addition, market organization and boost the contribution of the product to the income of the stakeholders involved. Hence, this study was carried out on the value chain in Belabo, Cameroon. Twenty-three focus group discussions were held, and semi-structured surveys were administered to 135 stakeholders engaged in the value chain in the Belabo municipality.
View Article and Find Full Text PDFBiol Trace Elem Res
October 2024
Gastrointestinal Secretion and Inflammation Research Unit, Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Nigeria.
Hexavalent chromium [Cr(VI)] is of public health significance due to its toxicity and carcinogenic effects. Kolaviron, a bio-flavonoid fraction from Garcinia kola seed, has been reported to possess gastroprotective and antioxidative properties. We hypothesize that Kolaviron-fortified diet will attenuate chromium (VI)-induced gut dysfunction and oxidative damage in Drosophila melanogaster.
View Article and Find Full Text PDFBrain Commun
August 2024
Brain Research Africa Initiative (BRAIN), Yaoundé, Cameroon.
J Med Food
October 2024
Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University Zaria, Zaria, Nigeria.
is a medicinal food commonly consumed in Sub-Sahara Africa, for which Kolaviron (KV) is the active portion. As a follow-up to our earlier chemopreventive studies, we investigated the chemotherapeutic effects of KV on experimentally induced mammary carcinogenesis in female Wistar rats. Mammary carcinogenesis was induced using 80 mg/kg of 7,12-dimethylbenzanthracene (DMBA) administered by oral gavage.
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