FENNEL-BASED DIETARY INTERVENTION MODULATES OBESITY-RELATED BIOMARKERS IN EXPERIMENTAL RATS

Abstract

Obesity is a complex metabolic disorder associated with multiple physiological disturbances, including dyslipidemia, hyperglycemia, and organ dysfunction. The present study aimed to evaluate the effects of dietary supplementation with Foeniculum vulgare on obesity-related metabolic and histopathological biomarkers in a high-fat diet–induced rat model. Thirty male Sprague-Dawley rats were randomly assigned into five groups: a normal control group, an obese control group, and three obese groups supplemented with fennel powder at levels of 3%, 5%, and 7% for 28 days. Obesity was induced using a high-fat diet prior to the intervention. Proximate chemical composition and phenolic profile of fennel were analyzed using standard methods and HPLC-DAD, respectively. Biological evaluation included measurements of feed intake, body weight gain, and feed efficiency ratio. Biochemical assessments covered serum lipid profile, liver and kidney function markers, and glucose levels, in addition to histopathological examination of cardiac tissue. The results demonstrated that fennel is rich in carbohydrates, dietary fiber, and bioactive phenolic compounds, with gallic acid identified as the predominant constituent. Dietary supplementation with fennel significantly modulated metabolic parameters in obese rats. The 5% fennel group showed the most pronounced improvement in lipid profile, including reductions in LDL-c and VLDL-c and an improved LDL/HDL ratio. Liver enzymes (AST and ALT) and renal markers (urea and uric acid) were also significantly reduced at this level. Meanwhile, the 7% fennel group exhibited the greatest reduction in body weight gain and the most notable improvement in cardiac tissue structure. Serum glucose levels decreased progressively with increasing fennel concentration, indicating a dose-dependent hypoglycemic effect. In conclusion, dietary supplementation with Foeniculum vulgare exerts beneficial effects on obesity-induced metabolic and histological alterations through multi-target mechanisms. These findings suggest that fennel may serve as a promising functional food component for the management of obesity and its associated complications.