Effects Of Lipoic Acid And N-Acetylcysteine On Antioxidant Capability And Lipid Metabolism In Rats Fed A High-Fat Diet

In present study aimed at determination the effects of Lipoic acid (LA) and N-acetylcysteine (NAC) on blood lipid and antioxidant metabolism of rats fed high-fat diet. Forty male SD rats were divided into 5 groups: control group, high-fat group, LA group (0.1%), NAC group (0.1%) and LA (0.1%) + NAC (0.1%) group. After 4 weeks,T-AOC, GSH and MDA levels, the activity of SOD in serum and tissues were measured respectively; TG, TC, HDL-C,LDL-C levels, the activities of LPL and HL in serum and AI were also determined respectively. In addition, the oxidative damage of mitochondria DNA and the expression of mRNA of HL and HPL in heart and liver were detected by single-cell gel electrophoresis and RT-PCR respectively. The results were shown as follows:1. The high-fat diet decreased the total antioxidative capacity, superoxide dismutase and glutathione level significantly; provoked organism oxidative stress and oxidative damage of mitochondria DNA in liver and lipid peroxidation (P<0.05). LA and NAC could improve the antioxidative capability, prevent lipid peroxidation, reduce the level of malonaldehyde and preserve oxidative damage of mitochondria DNA in liver (P<0.05).2. The high-fat diet disturbed blood lipid metabolism which resulted in hyperlipidemia in rats. LA and NAC could reduce the contents of TG, TC, LDL-C in serum, decrease atherosclerotic index (AI), increase the content of HDL-C in serum significantly (P<0.05).3. The high-fat diet reduced the activities of lipoprotein lipase (LPL) and hepatic lipase (HL) and the mRNA expression levels of LPL and HL in liver and heart tissues (P<0.05). LA and NAC could increase the mRNA express levels of LPL and HL, improve the activities of LPL and HL significantly (P<0.05), this maybe one of the important molecule mechanism of blood lipid adjusting and atherosclerotic preventing by LA and NAC.4. Hypolipemic and antioxidation properties of LA are better than those of NAC, but the difference is not significant (P>0.05). LA and NAC don't display synergistic action.