Simultaneous determination of Paris saponins I, II, VI, and VII in Paridis Rhizoma by UPLC-ELSD method Effect of Paridis Rhizoma total saponins on apoptosis of human gastric cancer cell MKN-45 and Fas/FasL signaling pathway Simultaneous determination of Paris saponins I, II, VI, and VII in Paridis Rhizoma by UPLC-ELSD method