Enhancement of Insulin Release from the Beta-cell Line INS-1 by an Ethanolic Extract of Bauhinia Variegata and Its Major Constituent Roseoside

Plants of the genus Bauhinia are used in several countries worldwide for the treatment of diabetes, and several related species have been shown to have hypoglycaemic effects in vivo in both normoglycaemic and alloxan- and streptozotocin-treated animal models. In this study, the insulin-secreting cell line INS-1 was used to examine the effects of the crude ethanolic extract of leaves of B. variegata L. var. Candida Voidt and its major metabolite (6 S,7 E,9 R)-9-hydroxymegastigma-4,7-dien-3-one-9- beta-glycopyraroside (roseoside) on insulinotropic activity. The crude extracts and the major metabolite were shown to increase insulin secretion in a dose-dependant manner.