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

To investigate the antitumour efficacy of luteolin on gastric cancer (GC) and study the mechanism underpinning the action. 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. 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. 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.