Cytotoxic and Antiproliferative Activity of Polyisoprenoids in Seventeen Mangroves Species Against WiDr Colon Cancer Cells

Background: Secondary metabolites from the group of isoprenoid compounds are widely distributed in mangrove plants. Polyisoprenoids (dolichol and polyprenol) are known to have benefits as anticancer agents. The present study was conducted to determine the cytotoxic potential of polyisoprenoids in leaves from seventeen selected mangrove species against colon cancer (WiDr) cells. Methods: Cytotoxic activity was evaluated by MTT assay in vitro using WiDr human colon cancer cells and 3T3 fibroblasts from Swiss albino mouse embryo tissue as controls. Mechanisms of action were approached by assessing apoptosis and the cell cycle using flow cytometry and fluorescence microscopy with annexin V-FITC, as well as expression of Bcl-2 and cyclin D1 by immunocytochemistry. Results: Polyisoprenoids from N. fruticans leaves demonstrated the highest anticancer activity, with an IC50 of 180.2 μg/mL, as compared to 397.7 μg/mL against 3T3 normal cells. Significant decrease in the expression of Bcl-2 and cyclin D1 was also noted, facilitating apoptosis and arrest of the cell cycle in the G0-G1 phase in WiDr cells. The present study showed for the first time that polyisoprenoids from N. fruticans exhibit concrete anticancer activity in vitro, decreasing cell proliferation and inducing apoptosis in colon cancer cells. Conclusions: Polyisoprenoids isolated from N. fruticans leaves may have promise as a source of anticancer agents.