Evaluation of the antioxidant activity of Sida cordifolia

Sida cordifolia Linn. (Malvaceac) is commonly known as bala and widely used in Ayurveda. The comparative antioxidant potential of ethanol extracts of Sida cordifolia leaf, stem, root, and whole plant was studied. Anti-lipid peroxidation, free-radical scavenging, reducing power, nitric oxide scavenging, superoxide scavenging antioxidant assay, and further estimation of total phenolic content and HPTLC studies were carried out. Various antioxidant activities were compared with standard antioxidants such as BHA, alpha-tocopherol, and ascorbic acid. Ethanol extracts were found to be a good scavenger of DPPH radical in the order roots > stem > leaves > whole plant with values 76.62%, 63.87%, 58% and 29% at a dose of 1 mg, respectively. All extracts of Sida cordifolia (SC) have effective reducing power and free-radical scavenging activity. Only the root extract exhibited superoxide-scavenging activity and inhibited lipid peroxidation in rat liver homogenate. All these antioxidant properties were concentration dependent. In addition, total phenolics content of all the extracts of S. cordifolia were determined as gallic acid equivalents. The highest antioxidant activity was observed in the root extract. The results obtained in the current study indicate that S. cordifolia is a potential source of natural antioxidants.