ABSTRACT:
Diabetes mellitus is a group of metabolic disorders defined by elevated blood glucose levels because of insufficient insulin, inefficient insulin or both and serious complications can potentially occur in both type 1 and type 2 diabetics. Plants are known to inhibit polyol pathway and they can be a potential source of unique chemicals for drug development of inhibitors of aldose reductase (AR) and formation of advanced glycation end products (AGE). In this context, some folklore remedies for diabetes viz. roots of Hibiscus arnottianus L. (HA), seeds of Ziziphus jujuba Mill. (ZJ), seeds of Strychnos potatorum L. (SP) and roots of Erythrina variegata L were selected. The aqueous alcoholic extracts at 100 µg/ml exhibited 75.6 (HA), 83.63 (ZJ), 75.97 (SP) and 63.8 (EV) percentage of inhibitory activity on AR and 26.5 (HA), 79.3 (ZJ), 20.8 (SP) and 22.2 (EV) percentage of inhibitory activity on AGE. ZJ showed best inhibitory activity with an IC50 of 49.27 µg/ml and 60.63 µg/ml for AR and AGE, respectively. The fractions of ZJ at 50 µg/ml exhibited 49.85 (ZJ1), 54.95 (ZJ2), 56.1 (ZJ3) and 50.1 (ZJ4) percentage of inhibitory activity on AR and 30.4 (ZJ1), 76.8 (ZJ2), 54.6 (ZJ3) and 43.7 (ZJ4) percentage of inhibitory activity on AGE. Among all fractions, ZJ3 showed best inhibitory activity with an IC50 of 42.66 µg/ml and 31.72 µg/ml for AR and AGE, respectively. In the in vivo studies, galactitol levels in the lens were significantly reduced by ZJ3 (p<0.05) when compared to control. The efficacy of the fraction could be due to the presence of phenolic compounds and triterpenoids. The present work indicates the potential of folklore remedies for treating diabetic complications.