ABSTRACT
ObjectiveTo study the effects of Toddalia asiatica alcohol extract on autophagy and apoptosis of non-small cell lung cancer A549 cells， and to explore its possible mechanism. MethodA549 cells were cultured in vitro. Cell counting kit-8 （CCK-8） was used to detect the proliferation of A549 cells， and cell survival rate was calculated to screen the drug concentration. The apoptosis in each dose group and that after the use of 3-methyladenine （3-MA）， an autophagy inhibitor， were detected by flow cytometry combined with Annexin V-FITC/PI double staining. Western blot was used to detect the expression levels of apoptosis-related proteins such as B cell lymphocytoma-2（Bcl-2）， Bcl-2-associated X protein（Bax）， microtubule-associated protein 1 light chain 3 （LC3）， cleaved cysteinyl aspartate-specific protease-3 （cleaved Caspase-3）， activated poly （Adenosine diphosphate） ribonucleotide polymerase （cleaved PARP1）， PARP1， activated death activator （t-Bid）， Bid， and ubiquitin-binding protein p62 in each group and those after the use of 3-MA. ResultCompared with the conditions in the control group， the cell survival rate in 0.25 g·L-1 group （P<0.05）， and 0.5， 1， 2， 4 g·L-1 groups （P<0.01） was decreased after 24 h intervention. Additionally， the cell survival rate was reduced in a concentration-dependent manner at 48 h and it was less than 10% at 4 g·L-1 （P<0.01）. Compared with the conditions in the control group， the total apoptosis rate in 0.5 g·L-1 group was increased （P<0.05）， and the apoptosis rate in 1 and 2 g·L-1 groups was also increased （P<0.01）. Compared with the 2 g·L-1 group and 3-MA group， the 3-MA combined with T. asiatica alcohol extract had significantly decreased apoptosis rate （P<0.01）. Compared with the conditions in the control group， elevated expression of pro-apoptotic proteins cleaved PARP1， Bax and t-Bid in 1 and 2 g·L-1 groups （P<0.05， P<0.01）， and reduced expression of Bid in the 2 g·L-1 group （P<0.01） were found. Compared with the conditions in the control group， the expression of anti-apoptotic protein Bcl-2 （P<0.05， P<0.01） and the level of p62 （P<0.01） were down-regulated in 0.5， 1， 2 g·L-1 groups， while the level of LC3 Ⅱ protein was up-regulated （P<0.01）， with certain concentration dependence. ConclusionT. asiatica alcohol extract could significantly inhibit the proliferation of A549 cells， which might be related to promoting autophagy and inducing apoptosis.