Free Radical Scavenging Activity of Sida cordifolia Linn. Extracts Measured by Hydrogen Peroxide, DPPH, ABTS and Ferric Reducing Antioxidant Methods

Abstract

Antioxidants inhibit free radical reactions in our body and prevent cellular damage. Plant based polyphenols and flavonidic substances have been known as good antioxidants. Sida cordifolia Linn. exhibits many therapeutic pharmacological properties such as wound healing, anti-microbial, anti-inflammatory and hepato-protective due to presence of many polyphenols and flavonoids in its roots and seeds. Antioxidant capacities of aqueous and alcoholic (ethanol) extracts of Sida cordifolia roots were evaluated using in vitro standard procedures by assessing their free radical scavenging capacities. Total phenol content was assessed as 18.70 and 23.26 GAE/mg while the total flavonoid content was found to be 15.03 and 6.62 QE/mg for alcoholic and aqueous extract respectively. IC50 (µg/ml) of alcoholic extract, aqueous extract and ascorbic acid was found to be 36.189 ±0.993, 31.297 ±2.791 and 15.503 ±1.356 respectively in hydrogen peroxide radical scavenging, 1.520 ±0.075, 1.027 ±0.012 and 0.879 ±0.273 in DPPH radical scavenging assay, and 232 ±15.163, 179 ±53.894 and 6.627 ±0.061 during FRAP essay. Similarly, during ABTS radical scavenging assay, IC50 (µg/ml) was assessed as 332.960 ±2.177, 162.155 ±9.736 and 6.779 ±0.167 for alcoholic, aqueous extract and Trolox respectively. While both extracts showed significant free radical scavenging activity, the aqueous extract exhibits higher activity than alcoholic extract.