Studies on the antioxidant activity of Costus igneus leaf extract

Plan: The antioxidant activity studies of the extract of Costus igneus leaves Preface: Costus igneus commonly known as fiery costus or Spiral flag is a species of herbaceous plant. It is claimed to help build up insulin in the human body and is sometimes referred to as insulin plant. Insulin plant Costus igneus (Fam: Zingiberaceae) is a tropical evergreen shrub with large, smooth, dark green leaves. The Costus igneus is valued mainly for its tonic, stimulant, and antiseptic properties. It is said to be aphrodisiac and to be able to prevent the hair from turning grey. Its root is anodyne, antibacterial, antispasmodic, aphrodisiac, carminative, stimulant, stomachic, tonic and vermifuge. Methodology: In the present study the antioxidant activity of the leaf extract was studied using four methods viz. DPPH assay, reducing power assay, superoxide radical scavenging assay, and Folin-ciocalteu assay. Outcome: The studies have proved that extract possesses antioxidant activity. In reducing power assay, the plant extract showed 75.43 % increase in reducing power compared to Ascorbic acid which showed 91.94%, at a concentration of 16µg/ml. In DPPH assay, plant extract produced 71.85% DPPH scavenging activity, compared to Ascorbic acid which produced 84.47% at a concentration of 160µg/ml. In superoxide scavenging activity, the plant extract produced 68.19% radical scavenging activity compared to the standard which showed 79.78% at a concentration of 800µg/ml. The IC50 was found to be177 and 367 µg/ ml of the standard and plant extract respectively.