ABSTRACT
Silybum marianum (milk thistle) seeds and other parts of this medicinal plant have been used traditionally for centuries in the treatment of liver and several other diseases. Purified extracts made from the fruits of Silybum marianum (SM) chiefly contains silymarin and are available commercially. Silymarin is used as a dietary supplement and is one of the widely used alternative medicines. The present study was conducted to investigate the in- vitro antioxidant potential of SM seed extracts by DPPH method and to isolate the phytoconstituents present in ethyl acetate extract. Phytochemical investigation of the seeds of SM yielded eight aliphatic carbonyl hydrocarbons. The chemical structure of all the phytoconstituents were elucidated on the basis of spectral data analysis. Antioxidant activity of methanolic seed extract was found to be better than the ethyl acetate as well as standard ascorbic acid which could be due to high flavonoid content. Thus result of this study support use of silymarin as a dietary natural antioxidant supplement in drug and food industry to prevent free radical related diseases.