Anticancer Effects of Camellia nitidissima Chi Polysaccharide on Hepatocellular Carcinoma Cells via Apoptosis

Hepatocellular carcinoma (HCC) becomes the fifth most common tumor in the world. Accumulating evidences have shown that Camellia nitidissima Chi (CNC) has significant antitumor effects and plays key roles in cancer treatment. However, there are few studies on the anticancer active ingredients of CNC, the underlying mechanisms remain poorly understood. This study was aimed to investigate whether polysaccharides from CNC (CNP) had anticancer effects on HCC cells and its potential mechanism. MHCC-97H and SMMC-7721 cells were incubated with different doses of CNP (10, 25, 50, and 100 μg/ml) for desired timing points. To detect the inhibitory effect on HCCs, we examined whether CNP induced the apoptosis of MHCC-97H and SMMC-7721 by cell viability assay, Annexin V FITC/PI and Hoechst 33258 staining, wound healing assay and intracellular reactive oxygen species measurement. Moreover, western blot confirmation was performed for the associated protein targets. CNP significantly inhibited the proliferation and migration of MHCC-97H and SMMC-7721 cells, the inhibitory concentrations (IC50) of CNP at 48 hours in MHCC-97H and SMMC-7721 were 76.639 and 176.225 μg/ml, respectively. CNP promoted cell apoptosis, especially at the early stage of apoptosis, induced chromatin condensation, and increased the reactive oxygen species levels in MHCC-97H and SMMC-7721. Moreover, CNP caused upregulation of Bax and caspase-3, as well as downregulation of epidermal growth factor receptor (EGFR) expression. These observations above suggest CNP could be a great potential for HCC treatment with anticancer ability, providing an essential basis for the molecular mechanism of CNC treating cancer.