Increased Anticancer Activity of Organic Kimchi with Starters Demonstrated in HT-29 Cancer Cells

This study aims to investigate the effects of kimchi made with organic ingredients and lactic acid bacteria (LAB) as starters (Leuconostoc mesenteroides + Lactiplantibacillus plantarum) on HT-29 human colon carcinoma cells. Four types of kimchi (standard kimchi (SK), commercial kimchi (CK), anticancer kimchi (AK), and organic anticancer kimchi (OAK)) were evaluated. The results show that, among the different types of kimchi studied, OAK presents high DPPH free-radical scavenging activity and total phenol and flavonoid contents, and the MTT assay shows that the growth inhibition rate against HT-29 cancer cells is the highest. In addition, the quantitative reverse transcription polymerase chain reaction (RT-qPCR) results show that, compared to SK and CK, AK and OAK can effectively down-regulate the mRNA expression of anti-apoptotic gene Bcl-2 and up-regulate the mRNA expression of the cell cycle arrest genes p21 and p53; pro-apoptotic genes Bim, Bak, and Bad; and genes for caspases 3 9. Subsequently, a Western blot test confirmed that the expression of Bcl-2 decreased and the expressions of p53, Bax, and caspases 3 and 9 increased in OAK. The abovementioned results indicate that the anticancer kimchi prepared with organic ingredients and starters of lactic acid bacteria effectively present the best antioxidant activity and inhibit the proliferation of HT-29 cancer cells by promoting apoptosis and cell cycle arrest.