Original article Phytochemical analysis and antioxidants activity of Silybum marianum (L.) Gaertn.

Abstract

The present study was an attempt to evaluate the phytochemical constituents and antioxidants potential of the methanol extract of leaves of Silybum marianum (L.) Gaertn., a known hepatoprotectant. For the evaluation of antioxidant activities of silymarin, assayed of total antioxidant activity, total reducing power (FRAP), 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH), superoxide anion radical scavenging, hydrogen peroxide scavenging and ferrous ions (Fe 2+ ) chelating activity. The phytochemicals of silymarin were determined qualitatively and quantitatively by using standard methods. Qualitative analysis revealed that S. marianum is rich in phytochemicals, viz., alkaloids, terpenoids, steroids, phenols, flavonoids and glycosides. Quantification of flavonoids (223 mg/g) and phenols (312 mg/g) were also evaluated. The DPPH and chelating activity of silymarin were significantly high, i.e., 95% and 85%, respectively at 21 µg/ml concentration, whereas FRAP and phosphomolybdenum reduction assay showed maximum activity, i.e., 0.88 and 0.089, respectively at 21 µg/ml concentration. Free radicals scavengers like hydrogen peroxide and superoxide anions showed maximum inhibition percentage, i.e., 83% and 96%, respectively at 21 µg/ ml concentration. The research study concludes that the leaves of S. marianum showed the highest antioxidant activities at 21 µg/ml. It could be used in low concentrations in herbal medicine, pharmacological and food industry effectively.