Antioxidant and antipyretic properties of methanolic extract of Amaranthus spinosus leaves

Objective: Methanolic extract of Amaranthus spinosus (A. spinosus) leaves was screened for antioxidant and antipyretic activities. Methods: Antioxidant activity was measured by 1,1-diphenyl-2-picryl-hydrazile (DPPH) free radical scavenging, superoxide anion radical scavenging, hydroxyl free radical scavenging, nitric oxide radical scavenging, 2,2'-azinobis-3-ethylbenzothiazole-6 sulfonic acid (ABTS) radical scavenging assays and total phenolic content was also determined. Antipyretic activity of methanolic extract of A. spinosus was measured by yeast induced pyrexia method at concentration of 200 and 400 mg/kg using paracetamol as standard drug. Results: Methanolic extract of A. spinosus showed potent antioxidant activity. The IC50 value was (87.50 +/- 3.52) mu g/mL, (98.80 +/- 1.40) mu g/mL, (106.25 +/- 0.20) mu g/mL, (88.70 +/- 0.62) mu g/mL and (147.50 +/- 2.61) mu g/mL for DPPH, superoxide, hydroxyl, nitric oxide and ABTS radical scavenging activities. Methanolic extract of A. spinosus showed significant (P<0.01) antipyretic activity.