Effects Of Lactic Acid Bacteria On Reducing Patulin Toxicity

Patuin(PAT), a toxin secondary metabolite produced by Penicillium, Aspergillus and other fungi genus, widely exists in food and fodder. Excessive consumption of PAT can cause oxidative stress response, gastrointestinal disorders, kidney disease and other symptoms, which could cause serious harm to human health. In recent years, the removal of mycotoxin by lactic acid bacteria has provided a new way for the removing of PAT. Lactic acid bacteria is of low cost, has no danger to food nutrition, and has potential prebiotic effect, thus the study of its scavenging effects on the PAT and its potential protective effect against PAT toxicity in vivo are of profound significance for food safety and human health.In this paper, 48 lactic acid bacteria strains were uesed for measuring the removing capability of PAT, a bacteria strain, removing more than 90% PAT within 24 h was obtained as the most efficiently one. By morphology characteristics and 16 S r DNA gene sequence analysis, the strain was identified as Lactobacillus plantarum, and named L. plantarum LB-11. L. plantarum LB-11 had good tolerance to PAT, and were able to grow normally in MRS medium at a concentration of 1000 μg/L, 5000 μg/L and 10000 μg/L.Then main mechanism of PAT-removing-capability of L. plantarum LB-11 was explored, the PAT removal efficiency of viable cells and inactivated cells, as well as different cell components including cell pellets, cell walls and cell extracts were compared. It was found that, the removing PAT efficiency of inactivated cells, cell walls and cell extracts were significantly lower than intact living cell pellets, which showed that the PAT-removng-capability of L. plantarum LB-11 mainly depends on the intact living cells. Meanwhile, after detoxification of PAT by living bacteria, there appeared a new peak in the HPLC chromatogram. By the use of LC-MS, the peak was presumably corresponding to E-ascladiol based on the retention time and fragments, which, indicated that the mechanism of PAT removal was mainly biodegradation. Micronucleus assay was used to verify the detoxification efficacy of L. plantarum LB-11. The results showed that PAT solution treated by L. plantarum LB-11 could significantly reduced micronuclei formation in He GP2 cells which indicted the new substance was not as poisonous as PAT, and achieve the purpose of reducing the toxicity of PAT.Finally, the effects of L. plantarum LB-11 on the mice with PAT gavage were studied, mice were gaveged with PAT solution(2.56 mg/kg bw/day) to establish a PAT intoxication animal model. In L. plantarum LB-11 intervention group, mice were firstly gaveged with PAT(2.56 mg/kg bw/day), then gaveged with L. plantarum LB-11(1×1010 CFU/m L, 0.2 m L) within 2 hours. The test took 28 days, at the end of the experimet, blood samples were taken by eyeball extirpation, liver, kidney and intestine tissues were stored for detection of biochemical indicators, histopathological changes and intestinal iniestinal microflora count to investigate the effect of LB-11 on PAT infection model. The results showed a significant increase of serum alanine aminotransferase(ALT), aspartate aminotransferase(AST) and lactate dehydrogenase(LDH) levels in the serum of mice gaveged with PAT. PAT also caused the malondialdehyde(MDA) content in the liver and kidney to increase,while superoxide dismutase(SOD), glutathione peroxidase(GSH-PX) and glutathione(GSH) content in the liver and kidney of PAT attacked mice were reduced,which indicated that PAT exposed in mice would lead to oxidative damage in liver and kidney. The balance of intestinal mieroflora was broken with numbers of Lactobacillus and Bacillus bifidus decreased, while Enteric bacilli were increased. On histopathological examination, intestine tissues from PAT-treated mice showed structure disorder with villus and mucosal glands falling off. Gaveged with L. plantarum LB-11 could effectively alleviate the injury induced by PAT, making the biochemical indicators of kidney and liver and gut microbial composition return to normal. Intestinal tissues also became normal structure.In summary, L. plantarum LB-11 could effectively eliminate the negative effects of PAT on liver, kidney and intestine, improve the intestinal micro ecological environment balance.