[Purpose]
The objective of this study is to investigate the protective effect of lactic acid bacteria (LAB) against ethanol-induced liver injury.
[Methods]
1.Cultivation of LAB and Cell Culture
The 9 strains of LAB isolated from grains were cultured in De Man-Rogosa-Sharpe (MRS) agar at 30℃. HepG2 cells and Caco-2 cells were cultured in Dulbecco's modified eagle's medium (DMEM; Gibco) with 10% fetal bovine serum (FBS; Gibco) and 1% penicillin-streptomycin (PS; Cytiva) at 37℃ in a 5% CO2 incubator.
2.Aldehyde dehydrogenase (ALDH) activity
ALDH activity was determined using aldehyde dehydrogenase activity colorimetric assay kit.
3.mRNA Extraction and Quantitative Real Time-Polymerase Chain Reaction
Under ethanol induced HepG2 cells, mRNA expression related to lipid metabolism was examined.
4.Probiotic Properties
To confirm the probiotics properties, Gastrointestinal Tract (GIT) Stability and Adhesion test was assayed.
[Results]
1.Three strains - W. paramesenteroides H23(3.14 fold of control) ,P. pentosaceus H11(1.73 fold of control) ,P. pentosaceus K22(2.36 fold of control) showed higher activity than L. chungangensis(1.60 fold of control).
2. Expression levels of SREBP1c, ACC, and SCD1, which are lipogenesis-related factors, were increased by about 3.5-fold after treatment of HepG2 cells with ethanol when compared with control. However, LAB displayed a marked inhibition rate that ranged from 1.5 to 2.5-fold.
3.The properties of W. paramesenteroides H23, P. pentosaceus H11, P. pentosaceus K22 as probiotics were assessed in artificial GIT and adhesin ability. In stimulated GIT, all strains had a survival rate of >95%. Additionally, all strains could adhere to Caco-2 cells, with an adhesion rate ranging from 88.6 to 96.4%.
