ABSTRACT
The present study was aimed to investigate the alpha-amylase inhibition and antioxidant activities of methanolic extract of Amaranthus caudatus Linn [MeAc]. Methanolic extract of Amaranthus caudatus was screened for alpha-amylase inhibition activity by CNPG3 method [2-chloro-p-nitrophenyl-alpha-D-maltotrioside] and antioxidant activity was evaluated by 1,1-diphenyl-2-picryl-hydrazile [DPPH] free radical scavenging, superoxide dismutase [SOD] scavenging, hydroxyl free radical scavenging, nitric oxide [NO] radical scavenging, and 2.2'-azinobis-3-ethylbenzothiazole-6-sulfonic acid [ABTS] radical scavenging assays. MeAc was also screened for non enzymatic hemoglycosylation. The methanolic extract of Amaranthus caudatus showed potent alpha-amylase inhibition activity [IC50 19.233 micro g/ml]. MeAc showed significant antioxidant activity in all the in vitro antioxidant models. Furthermore, the MeAc was found to be extremely effective in scavenging ABTS radical activity [IC50 48.75 +/- 1.1 micro g/ ml] when compared to DPPH [IC50 77.5 +/- 0.4 micro g/ml], SOD [IC50 62.5 +/- 2.1 micro g/ml], hydroxyl [IC50 88.50 +/- 1.8 micro g/ml] and NO [IC50 67.5 +/- 2.2 micro g/ml] scavenging activity. The methanolic extract of A. caudatus showed potent alpha-amylase inhibition and antioxidant activities