Insulin-mimetic effect of (-) epicatechin on osmotic fragility of human erythrocytes.

(-) Epicatechin, a benzopyran extracted from the bark of Pterocarpus marsupium, is reported to have insulin like activity. The present work is undertaken to study the effect of insulin on erythrocyte osmotic fragility (OF) and then to evaluate the insulin-like role of (-) epicatechin on human erythrocytes. Insulin exerts a protective effect on erythrocyte OF and shows a dose response which is similar to other typical insulin effects i.e. a maximum at 0.1 nM and a lower effect at higher and lower concentration. (-) Epicatechin (1 mM) also shows protective effect, similar to insulin, on the OF. Ouabain (1 mM) has completely abolished the insulin effect on OF, and failed to have any effect on the action of (-) epicatechin, showing that (-) epicatechin and insulin act by a different mechanism of action while eliciting their protective effects on red cell OF.