Therapeutic Efficacy of Some Commercially Sold Antidiabetic Herbal Teas in Streptozotocin-Induced Diabetes in Wistar Rats

The hypoglycaemic efficacy and the effect on haematology of some commercially available antidiabetic herbal teas were evaluated in Streptozotocin-induced diabetes in Wistar rats. Twenty-five (25) male Wistar rats were divided into 5 groups of five rats each. Diabetes was induced in 20 rats by a single intraperitoneal injection of Streptozotocin (STZ) at 50 mg/kg body weight. Group 1 received only distilled water. Group 2 was an untreated control, and Group 3 was treated with Metformin (METF) at 500 mg/kg body weight. Groups 4 and 5 were Tea A and Tea B at 200 mg/kg body weight, respectively, for 14 days. The Fasting blood glucose and body weights of rats were taken at day 0, 1, 3, 7, and 14, blood sample for haematology was taken after 14 days of treatment. The result shows a (P<0.05) increases in fasting blood glucose in STZ-treated rats. The groups treated with metformin and the antidiabetic teas A and B for 14 days in STZ-diabetic rats showed significantly reduced fasting blood glucose levels (P < 0.05). The haemogram after the treatment period revealed a significant (P<0.05) reduction in PCV, RBC, and Hb of non-treated and Tea A-treated diabetic rats, as well as a decrease in WBC of Tea A-treated group, compared to the METF-treated and normal control. Therefore, the two herbal anti-diabetic teas tested exerted an anti-diabetic effect by promoting hypoglycaemic action. Still, tea A showed a tendency to fail to ameliorate the haematological effects of Streptozotocin in Streptozotocin-induced diabetic rats.