Indonesian Pasuruan propolis extract does not exert anti-proliferation and pro-apoptotic effect on human colon carcinoma cell line HT-29

Purpose: To evaluate the anti-cancer activity of Indonesian Pasuruan propolis extract (PPE) against HT-29 human colon carcinoma cell line. Methods: HT-29 cells were cultured and treated in different concentrations of PPE (50, 100, 200, 400 μg/mL) for 24 h. The cells were evaluated by several indicators such as cell proliferation and apoptosis as well as the expression of protein Ki67, p53, cyclin D1, and Bcl-xL. Results: Administration of PPE inhibited cell proliferation of HT-29 in concentration-dependent manner but the effect was not significant (p = 0.842); the results were similar with regard to the expression of Ki67 in HT-29 cells (p = 0.953). Administration of 400 μg/mL PPE insignificantly decreased cyclin D1 expression (p = 0.149). The concentration of PPE at 50, 100, and 200 μg/mL induced cell apoptosis of HT-29 cells initially, but the level of apoptosis subsequently decreased (p = 0.416). Furthermore, the expressions of p53 and Bcl-xL decreased following treatment with PPE at 50, 100 and 200 μg/mL but increased for the PPE 400 μg/mL group (p = 0.000). Conclusion: PPE reduced the expressions of p53, Ki67, cyclin D1, and Bcl-xL insignificantly as it it generally failed inhibit cell proliferation and promote cell apoptosis of HT-29 cells.