Tounong Powder () extracts induce G1 cell cycle arrest and apoptosis in LoVo cells.

Abstract

To further explore the anti-cancer effect of Tounong Powder () extracts (TNSEs) on human colon cancer LoVo cells and examine the possible molecular mechanisms. The contents of TNSEs were determined by liquid chromatograph-mass spectrometer (LC-MS) analysis after extraction with water and methanol. Variations of cell morphological features were observed using fluorescence microscopy. Cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle distribution and apoptosis were analyzed using flow cytometry at different TNSE doses (0, 62.5, 125, or 250 μg/mL). Protein expressions of phosphatidylinositol 3-kinase (PI3K), phosphate protein kinase B (p-AKT), phosphate mammalian target of rapamycin (p-mTOR), p-p70s6k1, cleaved caspase-9 and -3 were detected using Western blot analysis. TNSEs induced cell growth inhibition in a concentration- and time-dependent manner. Flow cytometric analysis showed apoptotic cells and cell cycle arrest at the G phase after TNSEs treatment compared with controls. Furthermore, TNSEs significantly down-regulated the proteins PI3K, p-AKT, p-mTOR, and p-p70s6k1, and up-regulated the proteins cleaved caspase-9 and -3 dosedependently, as determined by Western blot. TNSEs reduced LoVo cell proliferation, and caused apoptosis and cell-cycle arrest in LoVo cells. This effect might be associated with regulation of the PI3K/AKT signaling pathway.