Prediction of Antidiabetic Compounds in Curcuma longa – In vitro and In silico Investigations

Abstract

Mitigation of postprandial blood glucose and inhibition of carbohydrate-digesting enzymes is an indispensable measure  for the treatment or management of type II diabetes mellitus. Medicinal plants due to their diverse bioactive  compounds have been reported umpteen times in the management and treatment of diabetes. Hence, the research  exploits both in vitro and in silico methodologies to investigate the antidiabetic capacity of Curcuma longa aqueous  extract. Its phytochemical components were deduced and quantified in conjunction with its antioxidant potential and  inhibitory potential against alpha-amylase and alpha-glucosidase (enzymes indispensable to carbohydrate metabolism)  through in vitro assay. GC-MS revealed bioactive compounds from Aqueous Curcuma longa extract were subjected to  ADMET profile, Lipinski rule, and Molecular docking studies. Curcuma longa aqueous extract had enormous phenol, flavonoid, and tannin. The extract scavenged DPPH and NO in addition to its inhibitory capacity against alpha-amylase  and alpha-glucosidase with IC₅₀ values of 93.34ug/ml and 45.23ug/ml respectively. Consensus molecular docking  studies revealed stigmasterol and 2-[4-(1-Ethyl-3- methyl-1H-pyrazol- 4-yl)-4-oxobut-2-enamido]benzoic acid as top-rank  hits against alphaglucosidase. They also proclaimed promising ADMET and bioactive properties in comparison to the  standard, acarbose. Consequently, they could be prospective compounds that contribute highly to alpha-glucosidase  inhibition as observed in the enzyme assay result. The inhibitory potential of Curcuma longa might be due to the strong  binding affinity of its bioactive compounds to alphaglucosidase. Therefore, this research establishes Curcuma longa as a  functional food for the management of type-2 diabetes while the bioactive compounds especially stigmasterol and  2-[4- (1-Ethyl-3-methyl-1H-pyrazol- 4-yl)-4-oxobut-2-enamido]benzoic acid could be a nutraceutical for the management  of type 2 diabetes.