[Effect of lipoic acid on gene expression related to oxidative stress, lipid and glucose metabolism of mice fed with high fat diet].

OBJECTIVE

To explore the effect of lipoic acid (LA) on oxidative stress, lipid and glucose metabolism of mice fed with high fat diet (HFD).

METHODS

C57BL/6 mice were randomly assigned to three groups (n=8). The control group were administrated with an ordinary diet. The two experimental groups were fed with a high fat diet, high fat plus 0.1% LA. Fasting plasma glucose, insulin, lipid level and certain antioxidant indexes were examined after 6 wk. The gene expression profiles in liver were examined by the GeneChip microarray system.

RESULTS

Hyperlipidemia and glycometabolism disorders, accompanied by a depressed antioxidant defense system, were observed in HFD-fed mice. These changes were partially, restored in the LA-treated group. There were correlations between MDA and the ratio of HDL-CITC (r = -0.47, P < 0.05), homeostasis model assessment (HOMA) index (r = 0.74, P < 0.05). DNA microarray analysis of liver showed that LA ingestion up-regulated the expression of genes related to free-radical scavenger enzymes, oxidation and glycometabolism.

CONCLUSION

LA could improve insulin resistance and hyperlipidemia associated with HFD feeding in mice. The mechanism may involve preventing oxidative stress by scavenging reactive oxygen species (ROS) directly and increasing those of free-radical scavenger enzymes genes expression indirectly.