| Colon cancer is serious harm to human health nowdays. Large amounts of data show that the main cause of the tumor is the diet that consists of a large amounts of high fat and high-energy food. It is reported that taking probiotics can effectively inhibit the proliferation of cancer.In this paper, the antiproliferative effects of the EPS, S layer protein and heat-treated bacterial cells of 8 Lactobacillus plantarum was studied by using MTS and flow cytometer analysis; the antioxidant activities of the EPS and surface protein of Lactobacillus strain with antiproliferative activity was studied throuth scavenging effect on DPPH free radical, hydroxyl free radical and superoxide anion; acid and bile salt resistance of Lactobacillus was done. The results were as follows:1. There is difference between 8 strains of EPS production capacity ability of Lactobacillus studied. 3rd highest strains of EPS production capacity, its concentrations can reach 6.36 mg/mL, the 14 th is lowest strains, the concentration is 3.95 mg/mL; there is difference between 8 strains of S-layer protein production capacity ability too. Strain of 3rd highest protein concentrations, its concentrations could reach to 49.25 mg/m L, the lowest strains is 9th, its concentrations reach to 2.06 mg/m L.2. The EPS, S layer protein and heat-treated bacterial cells produced by Lactobacillu may inhibit colon cancer cell proliferation of HT-29 in varying degrees, Significant differences between the strains(p<0.05). At the concentrations of 250 μg/mL, 3rd and 31 st strains significantly higher other strains(p<0.05), the inhibitory rate could reach to 14.28% of 3rd strains; At the concentrations of 500 μg/mL, the inhibitory rate is 30.76% of 3th strains of S-layer proteins inhibit colon cancer cell proliferation of HT-29, as compared to LGG(p<0.05), LGG could reach to 10.3%; At the concentrations of 108 cfu/m L of heat-treated bacteria cells of 13 th and 31 st, significantly higher other strains(p<0.05), 13 th strains inhibition rate could reach to 14.11%; Flow cytometry analysis, it can induce apoptosis in colon cancer cells, at concentration of 500 μg/ m L surface protein of 3rd strains, the apoptosis rate is 84.86%, it can induce apoptosis in colon cancer cells at concentration of 500 μg/ m L of EPS of 3rd strains, The apoptosis could reach to 75.78 %.3. The scavenging ·DPPH effect of the 13 th strains was significantly higher than other strains and LGG(p<0.05) When the concentration of EPS reach to 500 μg/m L, the scavenging DPPH radical rate is 30.82% of the 3rd strains; the S-layer proteins of the 3rd strains could scavenge ·DPPH too, the scavenging DPPH radical rate is 8.54%, obvious stronger than other strains(p<0.05); in the test of scavenging O2-· ability, when the concentration of 500 μg/m L of EPS from 13 th strains, scavenging O2-· rate was 59.44%, it was significantly higher than other strains(p<0.05); the S-layer proteins from 3rd strains scavenging O2- radical rate is 13.34%, significant higher than other strains(p<0.05); In the test of scavenging OH· ability, at the concentration of 500 μg/mL, the scavenging effect of EPS from 3rd strains is 39.2%, significantly higher than other strains and LGG(p<0.05), the scavenging OH·rate is 13.01% of S-layer proteins from 3rd strains, significantly higher than other strains and LGG(p<0.05).4. There is fewer living bacteria survive of 3rd strain after culture 18 h in the pH 3.0. and the bacteriahad not survived at pH 2.0. Culture with 0.4% of the Bile Salt 18 h, there is survival bacteria living. strain 3 similar with LGG in acid and bile salt.It can be drawn from these results through the experiments: We found that the S-layer proteins and extracellular polysaccharidesthe from Lactobacillus plantarum 3, could inhibit the proliferation of HT-29 cell.And it also has the function of scavenging active oxygen; In conclusion, the strains 3 have a good ability of acid-tolerance and bile-salt-resistant, it is a potential probiotic strain that has the beneficial function. |
PDF Full Text Request