Kolaviron modulates cellular redox status and impairment of membrane protein activities induced by potassium bromate (KBrO(3)) in rats.

In this study, we examined the modulatory effects of kolaviron, a biflavonoid from Garcinia kola seeds on the antioxidant defense mechanisms, cellular redox status and oxidative stress in the kidney and liver of rats pretreated with potassium bromate (KBrO(3)) intragastrically as a single dose of 300 mg kg(-1)weight for 4 weeks. Treatment of rats with KBrO(3)resulted in an insignificant difference (P> 0.05) in body weight compared to controls. However, a significant increase in kidney/body weight ratio (P< 0.001) was observed in rats treated with KBrO(3)while liver/body weight ratio was not affected. KBrO(3)depressed the activities of superoxide dismutase, glutathione peroxidase and catalase (P< 0.001) in the kidney but not in the liver. Kolaviron (200 mg kg(-1)body weight) administered three times a week for 4 weeks inhibited the decrease mediated by KBrO(3)of these enzymes in the kidney by 29, 88 and 45%, respectively. Similarly, kolaviron reduced the KBrO(3)-induced decrease in the activities of gamma -glutamyltransferase and microsomal Ca(2+)ATPase by 73 and 63% in the kidney. In addition, the extract elicited a 27 and 25% decrease in the KBrO(3)-induced increase in malondialdehyde and lipid hydroperoxide formation in the kidney. Kolaviron also attenuated the KBrO(3)-decreased activities of glucose 6-phosphatase, 5 prime prime or minute nucleotidase and alkaline phosphatase (membrane enzymes) by 72, 57 and 25% respectively. The results of the present investigation indicate the antioxidative effect of kolaviron, a natural antioxidant, on drug-induced kidney toxicity. Kolaviron may therefore intervene in the cellular redox status and depression of membrane protein activities caused by KBrO(3)and other environmental carcinogens in the kidney. Copyright 2002 Academic Press.