The Effect of Aqueous Extract of Quercus Infectoria on Insulin Resistance and Free Fatty Acids in Insulin-Resistant Rats Induced by a High-Fructose Diet

Insulin resistance is a pathological condition in which cells fail to respond normally to insulin. The most important cause of insulin resistance is abdominal obesity. Increased abdominal fat increases the amount of free fatty acids and decreases adiponectin, which directly affects insulin signaling. Due to the role of Quercus infectoria in lowering blood sugar, we investigated the mechanism of action and the effect of its aqueous extract on insulin resistance in insulin-resistant Rats.

The animals were fed fructose-rich or normal food for six weeks. At the end of six weeks, the animals were divided into 4 groups including receiving plant extracts, pioglitazone, control, and normal food, and then treated for 2 weeks. At the end of the treatment period serum Glucose, triglyceride, and cholesterol levels were measured by autoanalyzer; Insulin and adiponectin levels were measured by ELISA; plasma free fatty acids were measured by gas chromatography, and HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) index was calculated by the formula. A one-way ANOVA test was used for statistical analysis.

In the Quercus infectoria group, the concentrations of glucose (129.3±6.8 mg/dl), triglyceride (79.8±5.1mg/dl), insulin (31.2±6.32pmol/L) and HOMA-IR (1.6±0.32) significantly decreased compared to the control group with glucose (187.5± 15.9 mg/dl), Triglyceride (217.6±18.5 mg/dl), Insulin (137.6±34.2 pmol/L) and HOMA-IR (9.7±2.13) decreased. The concentration of total free fatty acids and adiponectin did not change.

This study showed the beneficial effects of aqueous extracts of Quercus infectoria on reducing insulin resistance in insulin-resistant rats.