Browsing by Author "Farombi, E. O."

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Chemoprevention of aflatoxin B1-induced genotoxicity and hepatic oxidative damage in rats by kolaviron, a natural biflavonoid of garcinia kola seeds
(Lippincott Williams & Wilkins, 2005) Farombi, E. O.; Adepoju, B. F.; Ola-Davies, O. E.; Emerole, G. O.
The chemopreventive effects of kolaviron, a natural antioxidant biflavonoid from the seeds of Garcinia kola, on aflatoxin B1 (AFB1)-induced genotoxicity and hepatic oxidative damage was investigated in rats. Kolavironmadministered orally at a dose of 200 mg/kg once a day for the first 2 weeks and then 100 mg/kg twice a day for the last 4 weeks of AFB1 (2 mg/kg, single dose, intraperitoneal) treatment reduced the AFB1-increased activities of aspartate amino transferase (AST), alanine amino transferase (ALT) and gamma glutamyltransferase (c-GT) by 62%, 56% and 72% respectively. Malondialdehyde (MDA) formation and lipid hydroperoxide (LHP) accumulation were observed in the livers of AFB1-treated rats. Kolaviron significantly reduced the AFB1-induced MDA and LHP formation. Vitamins C and E were protective in reducing the increase in the activities of AST, ALT and c-GT as well as lipid peroxidation caused by AFB1 (P < 0.01). Administration of rats with kolaviron alone resulted in significant elevation in the activities of glutathione S-transferase, uridyl glucuronosyl transferase and NADH:quinone oxidoreductase by 2.45-, 1.62- and 1.38-folds respectively. In addition, kolaviron attenuated the AFB1-mediated decrease in the activities of these enzymes (P < 0.01). Pretreatment of rats with kolaviron, vitamins C and E alone did not exert genotoxicity assessed by the formation of micronucleated polychromatic erythrocytes (MNPCEs) (P> 0.05). Co-treatment of rats intraperitoneally with kolaviron (500 mg/kg) 30 min before and 30 min after AFB1 (1 mg/kg) administration inhibited the induction of MNPCEs by AFB1 (P < 0.001) after 72 h. While vitamin C was effective in reducing AFB1- induced MNPCEs formation, vitamin E did not elicit any antigenotoxic response. These results indicate kolaviron as effective chemopreventive agent against AFB1-induced genotoxicity and hepatic oxidative stress. Thus kolaviron may qualify for clinical trial in combating the menace of aflatoxicosis in endemic areas of aflatoxin contamination of foods.
Chemopreventives: untapped genii that compromise the science of the killer
(Ibadan University Press, 2016) Farombi, E. O.
Influence of Chloramphenicol and Amoxicillin on Rat Liver Microsomal Enzymes and Lipid Peroxidation
(2014-09) Adesanoye, O. A.; Ifezue, A. O. C.; Farombi, E. O.
Generation of reactive oxygen species beyond the antioxidant capacity of biological system has been reported to give rise to oxidative stress which through a series of events deregulates cellular functions, leading to oxidative damage and various pathological conditions. This study examined the effect of chloramphenicol and amoxicillin on liver microsomal enzymes Ca2+-ATPase and Glucose-6-Phosphatase (G-6-P) and lipid peroxidation in rats. Male Wistar strain rats weighing 120 – 195 g were divided into four groups. Group one, the control group, received physiological saline, group two received Amoxicillin at 10.71 mg/kg, group three received Chloramphenicol at 28.57 mg/kg, while group four was administered combination of chloramphenicol and amoxicillin. Drugs were administered for ten days and the animals sacrificed on the eleventh day. Detection of oxidation in liver microsomal fraction was carried out by assessment of lipid peroxidation and conjugated diene. Ca2+-ATPase and G-6-P activities and total protein content were also measured. Data were analysed by ANOVA and Student’s T-Test. Significant (p<0.05) decreases in G-6-P activity by 55.30%, 38.37%, 55.30% and Ca2+-ATPase activity by 38.99%, 30.16%, 26.88% were recorded with chloramphenicol, amoxicillin and chloramphenicol/amoxicillin treatments respectively when compared with the control group while total microsomal protein content was depleted by 70.50% 79.27%, 75.87% respectively. TBARS and Diene Conjugation were significantly (p<0.05) elevated in the treated groups. Findings from this study suggest that Chloramphenicol and Amoxicillin induced oxidative stress in rats and perturbed Ca2+ homeostasis presumably due to generation of free radicals.