Antioxidant and Cytotoxic Attributes of Paris polyphylla Smith from Sikkim Himalaya

Introduction: Paris polyphylla Smith is a high value medicinal plant available in Sikkim Himalaya which is well known in local traditional medicine system. Scientific study to ascertain its claimed biological activity is lacking. The objective of this work was to determine the antioxidant and anticancer activity of Paris polyphylla rhizomes. Methods: Phytochemical analysis were carried out by standard methods. Antioxidant activity of the methanolic extract was carried out by DPPH, ABTS, OH-radical and Fe²⁺chelating activity assays. Cytotoxicity of the extract was determined by MTT assay on three cancer cell lines: HeLa, HepG2 and PC3. Results: Of the P. polyphylla from two altitudinal zones, P. polyphylla from Tholung (PPT), the one from the higher altitude showed higher total phenolic contents in methanolic extracts of rhizomes as compraed to that from the lower altitude i.e., P. polyphylla from Uttaray (PPU). PPT also showed a higher content of total falvonoid and total flavonols. Both types of plant were excellent scavenger of DPPH and ABTS radical and Fe²⁺ chelator. A trend of a relatively greater antioxidant activity of PPT was established through these assay methods. In MTT assay, both the extract showed significant dose-dependent inhibition of HeLa cell growth after 72 hrs of treatment, while the extract had a moderately positive effect on the inhibition of PC3 and HepG2 cells growth. Conclusion: The study suggested a strong antioxidant activity and appreciable cytotoxic activity of P. polyphylla from Sikkim Himalaya. Of the two varieties, PPT was more pronounced in both type of activities.