Polysaccharide fromPatrinia heterophyllaBunge Inhibits HeLa Cell Proliferation Through Induction of Apoptosis and Cell Cycle Arrest

Abstract

Background: Traditional Chinese medicine was used to provide the novel basis for pharmaceutical drug discovery. In recent years, polysaccharides isolated from traditional Chinese medicinal herbs were widely studied to find an additional treatment for cancer therapy. Patrinia heterophylla Bunge usually functions as a folklore medicine against leucorrhea, metrorrhagia, and metrostaxis. The bioactive compounds of Patrinia heterophylla Bunge, such as “polysaccharide,” were found to possess potent anticancer activity. Methods: The present study investigated whether polysaccharide of Patrinia heterophylla Bunge (PHB-P) inhibits the growth of human cervical cancer HeLa cells by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Detection of apoptosis was performed by DNA fragmentation and TdT-mediated dUTP nick-end labeling (TUNEL) staining assays. Meanwhile, the distribution of the cell cycle was analyzed by flow cytometry. An immunohistochemical (IHC) assay was performed on the protein expression productions of apoptosis-associated p53, Bcl-2, and Bax genes in HeLa cells. Results: Treatment of HeLa cells with PHB-P resulted in a growth inhibition effect, and the IC50 value was 52 μg/mL. Compared with the control group, HeLa cells generated apoptosis and accumulated in the G0/G1 phase with treatment of PHB-P (50 μg/mL). Furthermore, down-regulation of the Bcl-2 gene and up-regulation of the p53 and Bax genes were observed in the PHB-P (50 μg/mL)-treated HeLa cells. Conclusion: Our data suggested that PHB-P might act as an inhibitor of HeLa cell proliferation in vitro and might be a potential, natural apoptosis-inducing anticancer agent.