Abstract: To investigate the effect of Cordyceps fermentation mycelium (CM) on oxidative stress in insulin resistant (IR) rats.IR rats were respectively treated with low,medium and high dose of CM (1.65 g/kg feed,3.30 g/kg feed and 6.60 g/kg feed).The oral glucose tolerance test was used to observe the hypoglycemic effect of different doses of CM,and the changes of blood lipid and oxidative stress were observed.The mRNA expressions of Nrf2,HO-1 and NQO1 in muscle and liver were assayed by RT-PCR,Western blot was used to detect the expressions of protein.It was found that CM can significantly improve fasting blood glucose,blood lipid and oxidative stress level in IR rats,and increase the mRNA expression of Nrf2,HO-1 and NQO1in muscle and liver,and increase the expression of Nrf2 and NQO1 protein in liver,which is dose dependent.The results suggested that CM can alleviate oxidative stress in IR rats.

Key words: Cordyceps fermentation mycelium, dexamethasone, insulin resistance, oxidative stress