Apoptotic anticancer activity of a novel fatty alcohol ester isolated from cultured marine diatom, Phaeodactylum tricornutum

A novel fatty alcohol ester; nonyl 8-acetoxy-6-methyloctanoate (NAMO) was identified among the five isolated compounds from cultured marine diatom, Phaeodactylum tricornutum Bohlin. The anticancer effects of NAMO were examined through screening of three different cancer cell lines including a human promyelocytic leukemia (HL-60), a human lung carcinoma (A549) and a mouse melanoma (B16F10). A strong suppression of cancer cells growth was observed in HL-60 and its IC50 value was 65.15 μM compared to the other cancer cells in vitro. The apoptotic occurrence in HL-60 cells by NAMO was evidenced as the accumulation of DNA in sub-G1 phase and nuclear condensations dose-dependent manner. From the protein expression results it was revealed on the apoptotic pathway that NAMO switched on the apoptosis by activation of Bax and suppression of Bcl-xL through apoptotic inducing control of pro- and anti-apoptotic proteins, and by up-regulation of another inducers of apoptosis, caspase-3 and p53.