Evaluation of antioxidant activity and its association with plant development in Silybum marianum L.

Silybum (S.) marianum L is medicinally important plant species from Asteraceae family. S. marianum have multiple industrial applications and its annual demand varies from 18 to 20 tons/annum. It is renowned for production of important antioxidants which are used for the regeneration of damaged hepatic cells. In this study we have evaluated antioxidant activity and its relation with plant development. Seeds were germinated under controlled conditions and DPPH-scavenging activity (DSA) was evaluated from 10 to 100 days in these seed derived plants. However, maximum DSA in leaves (60%) and intact plants (65.43%) was observed in 80 days old plants. The effect of different radiation doses (gamma; 5-20 kGy) on DSA (%) was also investigated. The treated (20 kGy) seeds germinated in soil and on MS-medium showed 45.43% and 59.26% DSA, respectively. However, untreated seed-derived plants showed 44.53% DSA. Silymarin was extracted from seeds and maximum activity (80.75%) was observed in higher concentrations (250 mu g/ml ethanol). This study suggested that not only the seeds but the whole plants of S. marianum can be used for the protection of liver from toxins and infections. (C) 2013 Elsevier B.V. All rights reserved.