Isolation and Characterization of a Flavonoid and a Neolignan from Silybum marianum: In-vitro Cytotoxic Evaluation

Silybum marianum, a remarkable medicinal plant displays multifarious medicinal properties including anticancer, hepatoprotective, antioxidant, immunomodulatory, anti-inflammatory, neuroprotective, antibacterial and cosmeceutical properties. The promising antiproliferative potential of S. marianum demands further exploitation of bioactive compounds responsible for its medicinal properties. In the current study, Silybin B and (+/-)-trans-dehydrodiferulate dimethyl ester were isolated from S. marianum and characterized by NMR and FTIR spectroscopy. The antiproliferative activity of isolated compounds was investigated by sulforhodamine B assay against HeLa, HepG2 and BHK21 cell lines. Flow cytometery, DAPI, reactive oxygen species accumulation and comet assays were performed to validate the cytotoxic effect of potent compounds. Silybin B was more potent anticancer agent with an IC50 value of 23.85 +/- 5.98 mu g/mL and 21.07 +/- 4.16 mu g/mL against HeLa and HepG2 cell lines, respectively. The findings of all assays confirmed its apoptotic, cytotoxic and genotoxic effects on HeLa cells.