Abstract
Currently there is a great deal of interest in the study of natural compounds with free radical scavenging activity because of their potential role in maintaining human health and preventing diseases. In this paper, we report the antioxidant and cytoprotective properties of 4-(2-hydroxypropan-2-yl)-1-methylcyclohexane-1,2-diol (HPMCD) isolated from the aqueous extract of Decalepis hamiltonii roots. Our results show that HPMCD is a potent scavenger of superoxide (O-2(center dot-)), hydroxyl (center dot OH), nitric oxide (center dot NO), and lipid peroxide (LOO center dot) physiologically relevant free radicals with IC50 values in nmolar (56-582) range. HPMCD also exhibited concentration dependent secondary antioxidant activities like reducing power, metal chelating activity, and inhibition of protein carbonylation. Further, HPMCD at nmolar concentration prevented CuSO4-induced human LDL oxidation. Apart from the in vitro free radical scavenging activity HPMCD demonstrated cytoprotective activity in primary hepatocytes and ehrlich ascites tumor (EAT) cells against oxidative stress inducing xenobiotics. The mechanism of cytoprotective action involved maintaining the intracellular glutathione (GSH), scavenging of reactive oxygen species (ROS), and inhibition of lipid peroxidation (LPO). Based on the results it is suggested that HPMCD is a novel bioactive molecule with health implications in both prevention and amelioration of diseases involving oxidative stress as well as in the general well being. (c) 2012 Elsevier Ltd. All rights reserved.