Objective To investigate the inhibitory effect and mechanism of pennogenin 3-O-β-chacotrioside (P3C), an active ingredient from Paris polyphylla, on the proliferation of Burkitt’s lymphoma (BL) cells, as well as the combined effect of P3C and the chemotherapeutic drug etoposide (VP-16) on BL cell proliferation. Methods The inhibitory effects of different concentrations of P3C alone or in combination with VP-16 on Raji and CA46 cells proliferation were assessed using CCK-8 assay. Flow cytometry was employed to analyze cell cycle distribution and apoptosis. Western blotting was used to detect the expressions of proteins related to cell cycle, apoptosis and autophagy. qRT-PCR was used to detect the expressions of autophagy-related genes. Using an immunodeficient mouse xenograft model, after P3C intervention, the effect of P3C on tumor growth in vivo was monitored via live imaging. Western blotting was performed to detect the expressions of Ki67 and apoptosis-related proteins cystein-asparate protease-3 (Caspase-3) and poly ADP-ribose polymerase (PARP) in tumor tissues. Results P3C inhibited the viability of Raji and CA46 cells in a dose-dependent manner, with half inhibitory concentration (IC₅₀) values of 1.12, 0.97 μmol/L, respectively, and induced G₀/G₁ phase cell cycle arrest. P3C significantly increased the proportion of apoptotic cells and elevated the expressions of apoptosis-related proteins such as Caspase-3, Caspase-9 and PARP, increased the expressions of autophagy-related genes and proteins such as microtubule-associated protein light chain 3 (LC3), autophagy-related gene 5 (ATG5) and ATG7, decreased the expression of p62, increased the phosphorylation level of p38, while decreased the phosphorylation level of extracellular regulated protein kinases (ERK), all of which were statistically significant compared with control group (P < 0.05, 0.01, 0.001). P3C and etoposide had a good synergistic effect, with a collaboration index (CI) < 1. Compared with the monotherapy group, the drug combination group had a stronger killing effect on Raji and CA46 cells, and further promoted p38 and reduced ERK phosphorylation levels (P < 0.05, 0.01, 0.001). In the in vivo experiments, compared with model group, P3C significantly inhibited tumor growth (P < 0.05, 0.01, 0.001), significantly reduced Ki67 protein expression in tumor tissue (P < 0.001), and significantly increases Caspase-3 and PARP protein expressions (P < 0.05), which was consistent with the results of cell experiments. Conclusion P3C could effectively inhibit the proliferation of Burkitt’s lymphoma cells, induce apoptosis, autophagy, and cell cycle G₀/G₁ arrest, as well as their growth and proliferation in vivo. At the same time, it could enhance the killing effect of chemotherapy drug etoposide on Burkitt’s lymphoma cells, and may achieve anti-tumor effects by regulating p38/ERK signaling pathway.

Paris polyphylla Sm.  /  pennogenin 3-O-β-chacotrioside  /  Burkitt lymphoma  /  apoptosis  /  autophagy  /  MAPK signaling pathway