Antioxidant Activities of Iranian Corn Silk

Traditionally corn silk (CS) has been used as diuretic, antilithiasic, uricosuric, and antiseptic. It is used for the treatment of edema as well as for cystitis, gout, kidney stones, nephritis, and prostatitis. In the present study, the antioxidant properties of ethanol-water extract from CS were estimated by different methods. Also phenol and flavonoid content of the extract were measured by Folin Ciocalteu and AlCl3 assays. CS extract contained a significant amount of phenol and flavonoids. The percentage of DPPH radical scavenged by CS extract was 92.6 at a concentration of 1.6 mg ml. IC50 of the extract and the standard compounds butylated hydroxytoluene (BHA) and quercetin was 0.59, 0.053, and 0.025 mg ml, respectively. Iron chelating activity of the extract was less than the standard compounds. CS extract showed nitric oxide-scavenging effect less than the reference agent (quercetin). The extract showed a high reducing ability. According to ferric thiocyanate (FTC) method, the extract showed more than 88% inhibition of linoleic acid peroxidation. It might be concluded that some of the properties of CS in traditional medicine is due to its antioxidant ability.