Effects of Normal Diet with or without Naringin Supplement Following Ethanol Diet on Changes in Lipid Profiles and Antioxidant Enzyme Activities in Rats

This study was performed to investigate the effect of normal diet with or without naringin supplement on the lipid and antioxidant metabolism in ethanol-treated rats for a short tenn. Male Sprague-Dawley rats were divided into three groups (n=10), which were assigned to one of three dietary categories : $E_8$ : ethanol diet for 8 wks, $E_4N_4$ : ethanol diet for the first 4 wks and normal diet for the last 4 wks, $E_4Nna_4$ : ethanol diet for the first 4 wks and normal diet with naringin supplement for the last 4 wks. Plasma total cholesterol concentrations were significantly higher in ethanol fed rats for 8 weeks. The HDL-C/total-C ratios of the $E_4N_4$ and the $E_4Nna_4$ groups were significantly higher than that of the $E_8$ group, while the atherogenic index was lower in the $E_4N_4$ and the $E_4Nna_4$ groups than in the $E_8$ group. The $E_4N_4$ and $E_4Nna_4$ diets significantly lowered both the hepatic cholesterol and triglyceride levels compared to the $E_8$ group. Accumulation of hepatic lipid droplets was observed to be the highest in the $E_8$ group. In the current study, the naringin supplement to normal diet significantly lowered both the hepatic HMG-CoA reductase and ACAT activities in ethanol pre-treated rats for 4 weeks. Antioxidant enzyme activities were also upregulated when ethanol feeding was ceased. Naringin supplement given for 4 weeks after ethanol cessation resulted in a significant decrease in the plasma cholesterol and hepatic lipids and plasma TBARS as well as the hepatic HMG-CoA reductase and ACAT activities compared to the rats given ethanol diet for the entire 8 weeks. Replacement of normal diet following a short tenn ethanol feeding was effective for the recovery of ethanol-induced fatty liver and for normalizing plasma and hepatic lipid profiles and antioxidant enzyme activities, regardless of an additional phytochemical supplement, naringin. The effect of naringin could seemingly be more evident if its supplementation period had been extended longer than 4 weeks after ethanol cessation.