ABSTRACT

The aim of this present study was to investigate the in vitro antidiabetic effect of plumbagin isolated from plumbago zeylanica on pancreatic lipase, alpha amylase, alpha glucosidase and its mode of inhibition on these enzymes and its effect on protein glycation. The compound dissolved in % 1 dimethylsulfoxide (DMSO) for pancreatic lipase, alpha glucosidase and alpha amylase assays and absolute dimethysulfoxide for protein glycation was examined at concentrations of 50, 25, 12.5, 6.25, 3.125 and l .56µg/ml. The antidiabetic effect was found to be concentration dependent. The compound showed a significant percentage inhibition on alpha amylase and alpha glucosidase at concentration of 50µg/ml with 75.95 and 79.85% respectively when compared with the standard drug acarbose with percentage inhibition of 78.52% while pancreatic lipase was weakly inhibited by the compound having percentage inhibition of 33.51 % at hightest concentration of 50µg/ml when compared to orlistat at concentration of 50µg/ml with percentage inhibition of 57.48%. Also, the compound moderatly inhibited protein glycation with percentage of 69 and 66% compared to aminoguanidine which showed a percentage inhibition of 82% when induced with glucose and fructose respectively. In addition, plumbagin was shown to be a competitive, uncompetitive and mixed inhibitor of alpha amylase, alpha glucosidase and pancreatic lipase respectively. From the results obtained plumbagin can be used as a therapeutic agent with fewer side effects however, further studies are needed to determine the in vivo effect of plumbagin and its level of toxicity.