Protective Potential and Antidiabetic Activity of Bilberry Leaves in Zucker Rats

Objective: The protective potential of Bilberry Leaves Extract (BLE) was studied in the experiment on male diabetic obese Zucker rats (ZDF) rats (Crl:ZUC-Lepr(fa)) with liver metabolism disorders and hyperglycemia. Methods: Animals were fed with or without BLE (2 g/kg b.w.) orally via a gastric tube for 28 days. At the end of the experiment, biochemical and morphological indices were studied. Results: Daily intake of BLE in obese ZDF rats produced a marked and sustained decrease in body weight without an increase in food intake in comparison with untreated obese rats. By the end of the study, fasting blood glucose for rats receiving BLE was significantly lower than in control group (P<0.05). The serum levels of aspartate aminotransferase and alkaline phosphatase, biomarkers of liver damage, were significantly (P<0.05) lower in BLE group compared to the obese control animals. There were also reductions (P<0.05) in total cholesterol and high-density lipoproteins levels associated with BLE treatments. BLE administration to obese rats significantly reduced serum urea levels compared to the untreated obese rats. The results also showed a decrease in liver/body weight ratio which is undoubtedly a positive effect together with a general reduction in body weight in BLE treated animals. Conclusion: These data suggest that BLE inhibited the development of hyperglycemia, improved lipid metabolism, and influenced positively on some integral indices and a histological picture in the target organs of obese ZDF rats.