Studies On Antitumor Activities Of Pufas From Nitzschial. Laevis

Polyunsaturated fatty acids (PUFAs) purified from Nitzschia.Laevis were main biologically active substances,which can effect the Proliferation of cancer cell lines. And the Mechanism was Preliminary studied here, provided a theoretical basis for the antitumor activity study of PUFAs from Nitzschia LaevisArachidonic acid (AA) is a kind of ω-6PUFAs,and Eicosapentaenoic acid (EPA) is a kind of ω-3PUFAs. They were used on cancer cell lines and EPA induces apoptosis in tumor cells, and the best effect dose of EPA is75μg/mL. EPA did not significantly effect on human normal liver L-02cells. HepG-2cells showed typical of apoptosis by HE, AO/EB staining. EPA caused a concentration-dependent apoptotic cell death.The present study was undertaken to determine the molecular mechanism by which EPA induces apoptosis in HepG-2cells. EPA caused ROS generation and EPA-induced cell death was prevented by antioxidants, suggesting involvement of ROS generation in EPA-induced cell death. EPA induced an activation of ERK and JNK, which was blocked by antioxidants N-acetylcysteine (NAC). Cells were prevented by the JNK inhibitor and ERK inhibitor. EPA triggered the mitochondrial apoptotic pathway indicated by reduced Bcl-2expression, the decrease of mitochondrial membrane potential and cytochrome C release. The NAC, JNK and ERK inhibitor blocked the cells apoptosis induced by EPA. These results suggest that the EPA induces cell death through the phosphorylation of JNK and ERK dependent of ROS. And activation of JNK adjusted mitochondrial apoptotic pathway significantly.