ANTIOXIDANT AND ANTIDIABETIC PROPERTIES OF TAMARINDUS INDICA LEAF ETHANOLIC EXTRACT FROM MALAYSIA

Sridevi Chigurupati1, Eric Wong Kwang Yiik2, Shantini Vijayabalan2, Kesavanarayanan Krishnan Selvarajan3, Ahmad Alhowail4, Sitansu Sekhar Nanda5 and Suprava Das6

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 ?g/ml and 1.62±0.66 ?g/ml, respectively; and employing ?-amylase and ?-glucosidase inhibition assays, TIME in vitro antidiabetic ability was 2.24±0.07 ?g/ml and 2.26±0.07 ?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.