Diabetes mellitus (DM) consists of a group of syndromes characterized by hyperglycemia. Prevalence of both type 1 and type 2 DM is increasing worldwide, the prevalence of type 2 is rising much more rapidly because of increasing obesity and reduced activity levels as countries become more industrialized. Operculina turpethum, a medicinal plant widely used in the traditional Ayurveda and Siddha systems of medicine for the treatment of diabetes mellitus. The antidiabetic potential of the methanolic extract of O. turpethum stem (MEOTS) and methanolic extract of O. turpethum root (MEOTR) was evaluated in the Streptozotocin (STZ) - induced type 2 diabetic models. The dose 100 mg/kg of MEOTS and MEOTR were administered to normal, glucose loaded and experimental diabetic rats for 21 days. The signi?cantly (p< 0.05) reduction in fasting blood glucose levels were observed in the normal rats at 3 h as well as in the treated diabetic animals at 21 days, thereby justifying the use of the plant in the indigenous system of medicine.DOI: http://dx.doi.org/10.3329/icpj.v1i9.11618 International Current Pharmaceutical Journal 2012, 1(9): 272-278

The aim of this study was to evaluate the free-radical scavenging capacity and antioxidant activity of methanolic extracts of Operculina turpethum leaves (MEOTL), stem (MEOTS), and roots (MEOTR) in vitro methods. The antioxidant activity was evaluated by reducing power, 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) photometric assay, nitric oxide free radical scavenging, iron chelation, hydrogen peroxide (H 2 O 2) scavenging activities. The total phenolic content was determined by the Folin-Ciocalteu method. The percent reduction and IC 50 values were calculated using standard methods. The MEOTS and MEOTR exhibited scavenging activity lower than gallic acid at similar concentrations in Folin-Ciocalteu method. The IC 50 values of the ascorbic acid, MEOTL, MEOTS, and MEOTR were found to be 46.67 ± 1.67, 50.01 ± 2.13, 72.63 ± 2.76 and 85.0 ± 3.55 µg, respectively in DPPH assay. The IC 50 values of the ascorbic acid, MEOTL, MEOTS, and MEOTR were found to be 14.32 ± 1.45, 18.15 ± 2.23, 20.80 ± 1.88 and 23.71 ± 2.67 µg, respectively in reducing power method. Among all extracts, MEOTS has higher antioxidant activity. Further investigations are needed to identify the lead molecule and to elucidate the structure and exact mechanism of action for their antioxidant activity.