Impact of Different Dietary Components on Gene Expression of Leptin and Adiponectin in Adipose Tissue of Obese Rats

Aim: This study was conducted to evaluate the impact of different dietary components on gene expression of leptin and adiponectin to understand how nutritional molecules affect gene response and some metabolic pathways in diet-induced obesity in rats.

Methodology: Obesity was induced in adult male Spargue-Dawley rats using high fat- high sucrose diet for 7.5 weeks. The animals were divided into 5 groups; 2 groups served as control groups and the other 3 groups treated with the high fiber and/or high antioxidant vitamins (A & E) diets. The study involved measurement of leptin and adiponectin gene expression in adipose tissue using PCR technique. In addition, measurement of energy intake, Lee index, serum adipokines (adipocytokines) and some oxidative stress markers.

Results: The results indicated that dietary induction of obesity resulted in significant (P<0.05) increase in body weight and Lee index compared with normal rats. Obesity caused significant (P<0.05) elevation in leptin mRNA level by 57.3% and reduction in adiponectin mRNA level by 35.1% in adipose tissue compared with normal group. However, treatment of obese rats with high fiber and antioxidant vitamins (A & E) diet caused significant (P<0.05) reduction in adipose tissue gene expression of leptin by 27.86% with increased adiponectin mRNA level by 41.84%. A significant (P<0.05) reduction was found in body weight and Lee index by 22.5% and 7.95% respectively compared with control obese rats. Also serum anti-inflammatory cytokines omentin and vaspin as well as antioxidants were increased, with reduction in pro-inflammatory cytokines as well as malondialdehyde and nitric oxide significantly (P<0.05) as compared with their levels in obese rats before treatment.

Conclusion: Dietary modification through reducing caloric intake and/or increasing antioxidant vitamins (A & E) may have some effect on the adipose tissue mRNA levels of leptin and adiponectin as well as adipocytokine serum levels related to obesity condition.