Chemoprevention of aflatoxin B1-induced genotoxicity and hepatic oxidative damage in rats by kolaviron, a natural biflavonoid of Garcinia kola seeds

Abstract

The chemopreventive effects of kolaviron, a natural antioxidant bioflavonoid from the seeds of Garcinia kola, on aflatoxin B1 (AFB1)-induced genotoxicity and hepatic oxidative damage was investigated in rats. Kolaviron administered 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 (gamma-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 gamma-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.

The microstructural effects of aqueous extract of Garcinia kola (Linn) on the hippocampus and cerebellum of malnourished mice

“…The mechanism of striatal cell death after systemic administration of 3-Nitropropionic acid is not well understood, although several factors may contribute to selective vulnerability of medium-sized spiny striatal neurons. Decortication, which removes putative gluatmatergic inputs to the caudate putamen, can protect against 3-Nitropropionic acid toxicity in the caudate putamen [4,[19][20] , and N-Methy-DAspartate receptors are up-regulated in both cortex and caudate putamen following 3-Nitropropionic acid injection [4,[21][22][23] . These are both lines of evidence for a secondary excitotoxic mechanism.…”

“…The mice in the treatment groups received 20 mg/kg body weight of 3-Nitropropioic acid intraperitoneally. The control group received an equivalent volume of distilled water intraperitoneally.…”

“…Animals in group A were fed malnourished diet ad libitum and given water liberally. Animals in group B were administered with 3-Nitropropionic acid (3-NP) (neurotoxin) only at 20 mg/kg body weight, group C were given only G. kola extracts, and group D were pretreated with G. kola extracts for seven days (200 mg/kg) prior to administration of neurotoxin (20 mg/kg body weight). After three days of neurotoxins administration in the relevant groups, the brains were excised and fixed in formal calcium for histological processing.…”

“…The tannin, saponin, oxalate, cyanogenic and cardiac glycosides of G. kola are 0.69 mg/100g, 15.70 mg/100g, 1.71 mg/100g, 59.56 mg/100g and 67.10 mg/100g of dry matter, respectively [20] . The essence of estimating the concentrations of these secondary plant metabolites is to establish advices on the quantity one can chew at a time.…”

Effect of dietary inclusions of bitter kola seed on geotactic behavior and oxidative stress markers in Drosophila melanogaster

“…It is often consumed among various cultures of Nigeria especially for its stimulatory effects (Atawodi et al., 1995). Although previous studies have reported various extracts and fractions of GK seed for their therapeutic uses in treating throat infections, bronchitis, cough, hepatitis, liver disorders (Farombi, Adepoju, Ola‐Davies, & Emerole, 2005), the fact that consumption of whole seeds especially for long time produce stimulant‐like effect could induce some toxicological effects which is worth investigating. This study therefore investigates the effects of GK seed on survival, locomotion, and oxidative stress markers in D. melanogaster .…”