The Protective Effect of Kefir and Vitamin C on Azoxymethane Induced Toxicity and Induction of Metallothionein in Mice

The present study was conducted to investigate whether vitamin C or kefir (a milk-based fermentation  product) protected Swiss albino mice from azoxymethane (AOM) toxicity. We also investigated the effect  of AOM administration on the induction of metallothionein (MT) expression in mice tissues. 40 12-weekold  male/female (20:20) Swiss albino mice with a mean weight of 31.4 g were allocated into four groups.  Animals in the first group were the control group. Animals in the other three groups were treated with  AOM (5mg/kg body weight) subcutaneously twice weekly for a total of 7 weeks. Animals in the second  group were treated only with AOM. Those in the third group were allowed access to kefir (50% wt/vol) ad  libitum. Those in the fourth group received vitamin C subcutaneously (500 mg/kg) per day for 7 weeks. Six  weeks after the final AOM treatment, all animals were sacrificed and necropsied. AOM administration  caused severe liver lesions including enlarged hepatocytes (megalocytes) and many contained enlarged  nuclei. Vitamin C and kefir administration clearly reduced the severity of AOM induced liver lesions.  Induction of MT expression was observed in the liver and kidneys, particularly in the centrilobular zones  and renal cortex, mainly in the distal renal tubules, collecting tubules, Henle's loop, and medulla, respectively.  In conclusion, vitamin C and kefir supplementation were found to be able to reduce the severity of  hepatotoxic lesions.,