Abstract
Free radicals are responsible in many disorders like cancer, Alzheimer's disease, cardiac reperfusion abnormalities and fibrosis. Oxidation of compounds and bacterial growth are responsible for food spoilage. So the present study evaluates in vitro antioxidant, antimicrobial and cytotoxic activities of methanolic extract of Rheum undulatum to explore it's use as food additives or preservatives. Twenty active compounds were identified using GC-MS and polyphenols were estimated. The nitric oxide radical, hydroxyl radical and superoxide anion radical were actively scavenged by R. undulatum extracts at a higher rate than by ascorbic acid. The DPPH free radical scavenging of R. undulatum extracts was high but slightly lower than ascorbic acid scavenging. Antimicrobial activity was observed against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Bacillus subtilis. Total polyphenolic content was estimated to be 60 mu g of gallic acid equivalents/mg of extract and FRAP value was found as 21.47 +/- 0.19 mu M/500 mu g. R. undulatum extract showed in vitro cytotoxic activity against mouse myoblast C2C12 cell line. Combined antioxidant, anti-bacterial and cytotoxic activity suggests potential use of R. undulatum extract in various applications as an additive or preservative in foods, as antibacterial agents and antioxidants.