Pomolic acid and its glucopyranose ester promote apoptosis through autophagy in HT-29 colon cancer cells

BACKGROUND: Colon cancer remains a leading cause of death globally. Pomolic acid (PA) can be separated from the ethyl acetate fraction of achyrocline satureioides. AIM: To determine the effects of PA and its glucopyranose ester, pomolic acid-28-O-β-D-glucopyranosyl ester (PAO), on colon cancer HT-29 cells. METHODS: 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay was used to measure cell viability. Apoptosis was detected via hoechst 33342 staining. PI single staining was identified by flow cytometry to determine the cycle and scratch assay was used to observe the migration of HT-29 cells. The levels of mRNA and proteins were evaluated by q polymerase chain reaction and western blotting, respectively. RESULTS: PA and PAO considerably inhibited the growth of the HT-29 cell line in a time and dose-dependent manner. After the administration of PA and PAO for 24 and 48 h, cell apoptosis was significantly promoted and HT-29 cells were arrested in the G(0)/G(1) stage. The Bax/Bcl2 ratio was also increased, which activated cysteinyl aspartate specific proteinase 3, leading to apoptosis; it also increased the expression of light chain 3 II/I and Beclin1, which activated autophagy and caused cell death. This in turn increased the expression of p62 to promote cell apoptosis, inhibiting the levels of signal transducer and activator of transcription 3 (STAT3) and p-STAT3, suppressing the level of Bcl2, and promoting cell. CONCLUSION: Both PA and PAO provide novel therapeutic strategies for treating colorectal cancer.