Pinocembrin suppresses proliferation and enhances apoptosis in lung cancer cells in vitro by restraining autophagy.

Lung cancer is one of the leading causes of human death, and the 5-year survival rate for lung cancer patients remains a relative low level. Pinocembrin (Pino) was reported to play an important role in the inhibition of cancer development, so this study was designed to explore the role of pino in lung cancer. A549 cells were treated with different concentration of Pino (25, 50, 100, 150 and 200 µM) for 24, 48 and 72, respectively to detect cell viability by Cell counting kit-8 (CCK-8) assay. Then, the proliferation, apoptosis and autophagy of A549 cells under pino exposure were detected using colony formation, TUNEL and immunofluorescence staining, respectively. Western blot was used to analyze proliferation-, apoptosis-, and autophagy-related proteins. To measure the effects of pino on cell autophagy, the above-mentioned functional assays were conducted again in A549 cells treated with pino and 20 µM autophagy activator rapamycin (RAPA). Declined trends in cell viability, proliferation, and autophagy were found in A549 cells treated with increasing doses of pino, by contrast with those without any treatment. Additionally, the apoptosis of A549 cells was enhanced upon pino exposure, accompanied by elevated caspase3 activity. However, RAPA reversed the anti-proliferative, anti-autophagic and pro-apoptotic properties of pino in A549 cells. In conclusion, this paper is the first to verify that pino suppresses the proliferation and enhances the apoptosis of lung cancer cells by restraining autophagy, indicating that pino has potential therapeutic effects on the treatment of lung cancer.