Abstract
Tamarindus indica (T. indica; Family Leguminosae) is widely used in various traditional medicine and food preparations. Antioxidant and antidiabetic activities of T. indica leaf extracts from Malaysian macerated (TIME) and Soxhlet (TISE) were investigated. In TIME and TISE, total phenolic (TP) content was 1.80 mg gallic acid equivalent (GAE)/g and 1.01 mg GAE/g respectively, and total flavonoid (TF) content 1.44 mg rutin equivalent (RUE)/g and 1.04 mg RUE/g respectively. TIME was selected for further studies due to its higher TP and TF contents. Using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical scavenging assays, TIME radical scavenging capacity was 1.42 +/- 0.3 mu g/ml and 1.62 +/- 0.66 mu g/ml, respectively; and employing alpha-amylase and alpha-glucosidase inhibition assays, TIME in vitro antidiabetic ability was 2.24 +/- 0.07 mu g/ml and 2.26 +/- 0.07 mu g/ml. Acute oral toxicity study in rat revealed TIME was safe up to 2,000 mg/kg body weight (BW), and treatment with 200 mg/kg BW TIME significantly lowered elevated blood glucose levels to those of glucose-loaded normoglycemic and streptozotocin-induced diabetic rats. The results suggest TIME from Malaysia has therapeutic potential as a natural product antioxidant and antidiabetic.