Echinocystic acid induces the apoptosis, and inhibits the migration and invasion of non-small cell lung cancer cells.

An increasing amount of evidence has demonstrated the anticancer activity of triterpenes extracted from traditional medicines. Echinocystic acid (EA), a natural triterpene isolated from Eclipta prostrata (L.) L., has previously been shown to exhibit anticancer activity in HepG2 and HL-60 cells. The aim of the present study was to investigate the anticancer activity of EA in non-small cell lung cancer (NSCLC) cells. For this purpose, the viability and proliferation of A549 cells were determined using a Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine staining. The migratory and invasive ability of the A549 cells were measured using wound healing and Transwell assays. Hoechst staining was also performed to detect the apoptosis of A549 cells. The proliferation of A549 cells and the distributions of different growth phases were determined using a flow cytometer. Western blot analysis was used to detect the expression levels of cyclin D, partitioning defective 3 homolog (Par3), PI3K, Akt, mTOR, Bax, Bcl-2 and caspase-3. EA inhibited the proliferation, and the migratory and invasive abilities of cultured lung carcinoma cells (A549 cells), and induced cell cycle arrest in the G1 phase of the cell cycle. Treatment with EA upregulated Par3 expression and inhibited the PI3K/Akt/mTOR pathway in vitro. In addition, EA treatment inhibited tumor growth, suppressed proliferation and induced the apoptosis of tumor cells in NSCLC tumor xenografts in mice. On the whole, these results suggest that EA may represent a potential therapeutic agent for NSCLC.