EFFECT OF VITAMIN-C SUPPLEMENTATION ON HEPATIC CYTOCHROME-P450 MIXED-FUNCTION OXIDASE ACTIVITY IN STREPTOZOTOCIN-DIABETIC RATS

The effect of vitamin C supplementation on hepatic cytochrome P450 exp ression was investigated in streptozotocin (STZ) diabetic male Wistar Albino rats. STZ-treated rats displayed the usual characteristics of d iabetes including; hyperphagia, polydipsia, decreased body weight gain and also the increased expression and activity of hepatic CYP1A, 2B, 2E and 4A proteins. Vitamin C administration in drinking water (2% w/v ) was associated with significant decreases in the levels of hyperglyc aemia (P < 0.05), glycosylated haemoglobin (P < 0.05), hyperlipidaemia (P < 0.001), and hyperketonaemia (P < 0.001) associated with STZ-diab etes. Vitamin C-treatment selectively reduced the activity and express ion of CYP2E proteins (P < 0.001). These effects on CYP2E expression m ay be mediated by the reduced levels of circulating ketone bodies, how ever, a direct effect on CYP2E expression in diabetes cannot be discou nted.