Antioxidant and antimicrobial activity of seed extracts of Silybum marianum L. from Uttarakhand, India

In recent years, considerable attention has been laid on medicinal plants with antioxidant and antimicrobial activity. Silybum marianum L. has been used for centuries in traditional medicine. The aim of this study was to evaluate antibacterial activities of ethanolic (ET), methanolic (ME), petroleum ether (PE); acetone (AC) seed extracts of S. marianum with total phenolic and flavonoids contents, and DPPH radical scavenging activities. Petroleum ether and ethanolic extracts were having high total phenolic and flavonoids contents, DPPH radical scavenging activities and antimicrobial activity. The results of the study indicated that seed extracts have antimicrobial effect on Gram positive bacteria, Bacillus cereus, Bacillus licheniformis and Staphylococcus aureus, and the ethanolic extract has shown highest antibacterial activity. MIC was lowest for petroleum ether and ethanolic seed extract whereas aqueous and acetone extracts have shown highest MIC. The findings of study indicated that seed-extracts S. marianum has high antioxidant activity and efficacy against pathogenic microorganism and it will be further utilized for active molecules isolation and adoption of crude extract formulations.