Antioxidant Activity of Flavolignans from Silybum marianum (L).Gaertn. Fruits

The flavolignans silybin (1) and 2,3-dehydrosilybin (2) were isolated from fruits of milk thistle [Silybum marianum (L). Gaertn.] cultivated in the Samara region (Russian Federation). 2,3-dehydrosilybin (2) for the first time in Russian Federation is described for the given plant. Silybin and 2,3-dehydrosilybin and also the fluid extract of Silybum marianum fruits, have expressed antioxidant activity, decreasing the level of the lipid peroxidation caused FeSO4 in the homogenate of a rat liver. The antioxidant activity of 2,3-dehydrosilybin is reported for the first time and on 14,0% above those of silybin. The discovery of the antioxidant activity for 2,3-dehydrosilybin allows in a new fashion to discuss the contribution of flavolignans in biological activity of hepatoprotective remedies on the basis of Silybum marianum drugs.of flavolignans in biological activity of hepatoprotective remedies on the basis of Silybum marianum drugs.