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 expression was investigated in streptozotocin (STZ) diabetic male Wistar Albino rats. STZ-treated rats displayed the usual characteristics of diabetes 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 hyperglycaemia (P < 0.05), glycosylated haemoglobin (P < 0.05), hyperlipidaemia (P < 0.001), and hyperketonaemia (P < 0.001) associated with STZ-diabetes. Vitamin C-treatment selectively reduced the activity and expression of CYP2E proteins (P < 0.001). These effects on CYP2E expression may be mediated by the reduced levels of circulating ketone bodies, however, a direct effect on CYP2E expression in diabetes cannot be discounted.
Clarke
J
J
School of Biomedical Sciences, University of Ulster, Londonderry, Northern Ireland, UK.
Snelling
J
J
Ioannides
C
C
Flatt
P R
PR
Barnett
C R
CR
D000818:Animals; D001205:Ascorbic Acid / Q000097:blood / Q000494:pharmacology*; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000008:administration & dosage
D013311:Streptozocin; D003577:Cytochrome P-450 Enzyme System; D001205:Ascorbic Acid