Lignan enriched fraction (LRF) of Phyllanthus amarus promotes apoptotic cell death in human cervical cancer cells in vitro.

Phyllanthus amarus is widely grown in this sub-continent and used traditionally to treat many common ailments. In the present study, lignan rich fraction of P. amarus extract was used on cervical cancer cell lines (HeLa, SiHa and C33A) to study it's mechanism of cell death induction. As the cells were treated with IC50 doses of LRF, characteristic apoptotic features were observed. Increased sub G0 population were observed both in Hela and C33 cells, while G1/S arrest was observed in SiHa cells than their untreated counterparts. Increased production of ROS and change in MMP were also detected in the treated cells. Presence of γH2AX, was observed by immunofluorescence. Reduced expression of HPV (16/18) as well as ET-1, an autocrine growth substance, were observed in the treated cells. Immunoblotting as well as ICFC studies showed enhanced expressions of BAX, Caspase 3 and PARP (cleaved) in the treated cells. A major lignan, phyllanthin was isolated from the chloroform fraction and showed strong irreversible affinities for viral E6 and MDM2 in in silico analysis. The study conclusively indicates that LRF has the potential to induce apoptotic cell death in cervical cancer cells by activation of p53 and p21 against DNA damage.