Apoptosis in HepG2 cells induced by Pteris semipinnata extract 5F involves p53 activation and VEGF inhibition

Objective: To observe the effect of Pteris semipinnata extract, ent-11α-hydroxy-15-oxokaur-16-en-19-oic-acid (5F), on human hepatoma HepG2 cells about the proliferation and to investigate the role of p53, VEGF, and Caspase-3 in 5F-induced HepG2 cell apoptosis. Methods: MTT Assay was used to determine the effect of 5F on proliferation of HepG2 cells, and cytoplasmic mono- and oligonucleosomes of HepG2 cells treated with 5F was assessed with Cell Death Detection ELISA Kit for determining whether 5F can induce apoptosis. Apoptotic nuclear morphology was assessed using Hoechst/PI assay. The effect on the expression levels of p53 and VEGF protein in HepG2 cells was detected by Western blotting analysis , and Caspase-3 activity was measured by a Caspase-3 Colorimetric Assay Kit. Results: The cytotoxicity of 5F on HepG2 cells was elevated with 5F concentration increasing. Cytoplasmic mono- and oligonucleosomes were induced by 5F in HepG2 cells, and the induction was in a concentration-dependent manner. After treatment with 5F, the apoptotic change such as chromatin condensation was confirmed by Hoechst/ PI staining. The level of p53 in nucleus was significantly elevated in HepG2 cells after 5F treatment, but the level of VEGF in cytosol was decreased. Moreover, the activity of Caspase-3 increased in a concentration-dependent manner. Conclusion: 5F mediated apoptosis involves p53 and Caspase-3 activation, VEGF down regulation in HepG2 cells. 5F might have a therapeutic value against human cancer cell lines and especially on hepatocellular carcinoma (HCC) cells.