The Association Between Fennel Extract, Serum Lipid Profile, and Leptin Receptor Expression

INTRODUCTION: Obesity is among the most severe challenges of our era, with significant health consequences and a high economic burden for health systems. Therefore, many countries have developed political agendas to cope with this ever-rising challenge. Along with chemical medications developed to manage obesity, researchers have focused on some natural ingredients and herbal extracts that are effective in reducing weight. The current study investigated the association between Foeniculum vulgar (fennel) extracts and body weight, lipid profile, and leptin. METHODS: In total, 35 adult male BALB/c mice were investigated in sham, fennel 50 mg/kg, fennel 100 mg/kg, and fennel 200 mg/kg (n=7) groups. The mice were administered fennel extracts for fourteen days while weighted at the intervention’s beginning and end. Then, their weight, lipid profile, serum leptin, and expression of leptin protein in the hypothalamus were measured. RESULTS: After providing the intervention, leptin receptor protein expression was increased in all groups, while serum leptin didn’t change significantly. Moreover, a significant decrease was observed in the cholesterol dose of 100 mg/kg/day, triglycerides in 100 and 200 mg/kg/day, and LDL in 50 and 100 mg/kg/day. Serum HDL was increased significantly in a dose of 100 mg/kg/day. CONCLUSION: Fennel extract can decrease the lipid profile by changing the expression of the leptin receptor. HIGHLIGHTS: Obesity contributes to many health problems and dyslipidemia. Leptin is known for its hunger-blocking can regulate food intake and affects the levels of lipid. circulation. Fennel is a plant with strong antioxidant activities [18] that can influence (increase) satiety and (reduce) food intake. Fennel contains phytosterols that are known to reduce cholesterol solubilization that in turn decreases its absorption. Fennel extract can improve the lipid profile by influencing the leptin receptor expression. PLAIN LANGUAGE SUMMARY: Obesity is one of the most serious challenges of our era, with significant health consequences. Researchers have focused on some natural ingredients and herbal extracts. The current study aimed to investigate the association between Foeniculum vulgar (fennel) extracts and body weight, lipid profile, and leptin. After treatment of fennel, leptin receptor protein expression was increased in all groups, while serum leptin didn’t change significantly. A significant decrease was observed in the cholesterol, triglycerides and LDL in some doses of fennel. Serum HDL was increased significantly in a dose of 100 mg/kg/day. So fennel extract can decrease the lipid profile by changing the expression of the leptin receptor.