Cytotoxic and antioxidative activities of Plantago lagopus L. and characterization of its bioactive compounds.

Bioactivity guided isolation and characterization of phytoconstituents from the aerial parts of Plantago lagopus L. were performed to give a new insight into the usage of Plantago species in traditional medicine. The extract showed strong radical scavenging effects against DPPH, nitric oxide (NO) and superoxide (SO) radicals comparable to that of known antioxidants 3-t-butyl-4-hydroxyanisole, ascorbic acid (vitamin C), and quercetin in addition to its cytotoxic activities against HEP-2 (human larynx epidermoid carcinoma) and RD (human rhabdomyosarcoma) cell lines based on MTT assay for growth inhibition. The gallic acid equivalent total phenolic content of the plant was found to be 79.94 mg/g dry extract. Phenylethanoid glycosides, verbascoside and calceorioside A were isolated from the most active fraction and both compounds showed strong radical scavenging activity against tested radicals and cytotoxicity against HEP-2, RD and MCF-7 (human breast adenocarcinoma) cell lines. In addition apoptotic cell death was observed in histological analysis. Taken together, these findings suggest that verbascoside and calceorioside A may be used in cancer prevention.