Efficacy of luteolin on the human gastric cancer cell line MKN45 and underlying mechanism.

OBJECTIVE: To investigate the antitumour efficacy of luteolin on gastric cancer (GC) and study the mechanism underpinning the action. METHODS: Effects of luteolin on cell growth inhibition, apoptosis, and cell cycle arrest in MKN45 cells were investigated using the cell counting kit-8 assay. Changes in the mitochondrial membrane potential after luteolin treatment were assessed using 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanineiodi-de (JC-1) staining. To investigate whether apoptotic effect by luteolin is related to the phosphoinositide 3-kinase/v-akt murine thymoma viral oncogene (PI3K/Akt) pathway, cells were additionally treated with LY294002, a PI3K/Akt pathway inhibitor. Moreover, the expressions of apoptosis-related proteins, namely B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein (Bax), Akt, p-Akt, caspase-3, and cytochrome C, were detected after luteolin treatment. RESULTS: The study revealed that in MKN45 cells, luteolin could inhibit the cell proliferation in a time- and dose-dependent manner; block the cell cycle in the S-phase; induce apoptosis; reduce the mitochondrial membrane potential; increase the expression of Bax, caspase-3, and cytochrome C; and decrease the expression of Bcl-2 and p-Akt. Luteolin might be involved in the PI3K/Akt signalling pathway, indicating that this pathway could be a therapeutic target for GC treatment. CONCLUSION: Luteolin could inhibit the proliferation of GC cells and block the cell cycle in the S-phase. The mechanism of inducing apoptosis in these cells was related to the PI3K/Akt signalling pathway.