Effect of flavonoid-rich extract of Tamarix articulata Vahl. on glucose and lipid metabolism in normal and diabetic rats.

OBJECTIVE: The present study was carried out in order to evaluate the antidiabetic and antihyperlipidemic potential of flavonoid-rich extract of Tamarix articulata (FRETA) in both normal and streptozotocin (STZ)-induced diabetic rats.

MATERIAL AND METHODS: Normal and diabetic rats were treated with the FRETA for 7 days. At the end of treatment, a range of parameters were tested including blood lipid profile, histopathological changes in both liver and pancreas and oral glucose tolerance test (OGTT).

RESULTS: The blood glucose levels were lowered in both normal and diabetic rats treated with FRETA. Single oral administration of FRETA reduced blood glucose levels significantly in both normal and diabetic rats six hours after administration (P<0.001; P<0.0001 respectively). Furthermore, blood glucose levels were decreased significantly (P<0.0001) in diabetic rats after 7 days of treatment. According to the oral glucose tolerance test, the FRETA (5 mg/kg) was shown to prevent significantly the increase on blood glucose levels in diabetic treated rats. In addition, FRETA (5 mg/kg) showed a strong hypolipidemic effect both in normal and STZ rats after 7 days of once daily oral treatment. FRETA induced a significant decrease of plasma triglyceride and total cholesterol concentrations both in normal and diabetic rats. In contrast, plasma HDL-c levels were increased significantly (P<0.0001) both in normal and diabetic rats. In addition, FRETA showed a remarkable in vitro antioxidant activity and revealed inhibitory concentration of 50% of free radicals (IC50) of 31.92 μg/ml.

CONCLUSION: In diabetic rats flavonoids from Tamarix articulata showed antidiabetic and hypolipidemic activities.