Total ginsenosides of Chinese ginseng induces cell cycle arrest and apoptosis in colorectal carcinoma HT-29 cells

Colorectal carcinoma (CRC) is the most frequent malignant disease of the gastrointestinal tract and it has a poor prognosis. The current treatment options for CRC are far from optimal; they have limited efficacy and toxic effects. Chinese ginseng (the dried root of Panax ginseng) is a medicinal herb, of which ginsenosides are the most effective anticancer component. The aim of the present study was to evaluate the anti-CRC effect of total ginsenosides of Chinese ginseng (TGCG), by analyzing the cellular and molecular pathways. This was done via MTT assay, morphological observation (DAPI staining), flow cytometry for cell cycle and apoptosis analyses, reverse transcription-quantitative polymerase chain reaction and western blot analysis. The results revealed that TGCG inhibited cell proliferation and induced cell cycle arrest and cell apoptosis in HT-29 cells in a dose-dependent manner. The mRNA expression of CDK2, CDK4, CDK6, BAX, CDKN2B, CASP8, CASP3, TP53, TOP1, MYC, MDM2, and CCND1 and the protein expression of cyclin-dependent kinase (Cdk) 2, Cdk4, Cyclin D1, Bax, p21^WAF1, p27^Kip1, c-Myc, p15^INK4b, and p53 were revealed to be modulated by TGCG in HT-29 cells, and are all factors associated with DNA damage, cell proliferation, cell cycle and apoptosis. In conclusion, TGCG induced cell cycle arrest at the G₀/G₁ and G₂/M phases and induced apoptosis in HT-29 cells through the c-Myc- and p53-mediated signaling pathways, possibly in response to DNA damage. Therefore, TGCG may be regarded a promising candidate for development as an anticancer agent for the treatment of CRC.