Bifidobacterium Infantis And Combination Of Bifidobacterium Infantis And EGCG:in Vitro Stress Effects On Colorectal Cancer Cells

In the process of tumor development,inducing apoptosis of tumor cells is a highly anticipated cancer control strategy.In the rapidly developing modern society,unhealthy lifestyles and rapidly-changed dietary structures have led to a rapid rise in the number of people suffering from colorectal cancer,which seriously affects the life quality of people.It is of great practical significance to reduce the risk of colorectal cancer through diet intake of bioactive ingredients.Probiotics play an important role in maintaining intestinal health.Bifidobacterium infantis is one kind of common intestinal probiotic with anti-inflammatory and anticancer properties.As the main catechin in tea,epigallocatechin-3-gallate(EGCG)has also been proven to have bioactive effects such as anti-inflammatory,anti-oxidation,and regulating intestinal flora.Based on the in vitro intestinal epithelial model containing Caco-2 cell monolayers with electrospun polylactic acid nanofiber membrane as the scaffolds,this paper systematically evaluated the in vitro stress effects of B.infantis and EGCG on the colorectal cancer cells and their synergistic effects of B.infantis and EGCG.The detailed works are as follows:(1)Caco-2 cells were cultured in vitro to form dense cell monolayers.The supernate and cells of B.infantis in planktonic and biofilm phenotype were added to co-culture with Caco-2cells for 24 h under the normal state or the inflammatory state(caused by E.coli)of Caco-2cells.The results showed that B.infantis and its supernatant inhibited the activity of Caco-2cells,and the inhibition ratios of Caco-2 cells by the bacteria groups were significantly higher than that of the supernatant groups.Cells of B.infantis significantly destroyed the compactness of Caco-2 cells monolayer,and promoted the apoptosis of Caco-2 cells.Under the inflammatory state of Caco-2 cells(caused by E.coli),B.infantis made the apoptosis rate,especially the late apoptosis rate,of Caco-2 cells higher than under the normal state of Caco-2cells.B.infantis and its supernatant decreased the TEER values of Caco-2 cells monolayers significantly.(2)Under the normal state and the inflammatory state(caused by E.coli)of Caco-2 cells,supernatants and cells of B.infantis in both planktonic and biofilm phenotypes combined with EGCG had synergistic stress effects on Caco-2 cells.The results showed that the combination of B.infantis and EGCG inhibited the activity of Caco-2 cells to a certain extent,further enhanced the damage to the barrier function,and further promoted the apoptosis of Caco-2cells.In conclusion,B.infantis significantly destroyed the compactness of the monolayer barrier of colon cancer Caco-2 cells,inhibited the activity of Caco-2 cells,and promoted cell apoptosis of Caco-2 cells.The combination of B.infantis and EGCG further enhanced the damage to the barrier function of Caco-2 cell monolayers and further promoted the apoptosis of Caco-2 cells.When Caco-2 cells were in an inflammatory state,the synergetic stress effects of B.infantis and EGCG on Caco-2 cells were more effective.