Isolation and Identification of Lactobacillus plantarum HFY05 from Natural Fermented Yak Yogurt and Its Effect on Alcoholic Liver Injury in Mice

Abstract

Yak yogurt is a type of naturally fermented dairy product prepared by herdsmen in the Qinghai-Tibet Plateau, which is rich in microorganisms. In this study, a strain of Lactobacillus plantarum was isolated and identified from yak yogurt in Hongyuan, Sichuan Province and named Lactobacillus plantarum HFY05 (LP-HFY05). LP-HFY05 was compared with a common commercial strain of Lactobacillus delbrueckii subsp. bulgaricus (LDSB). LP-HFY05 showed better anti-artificial gastric acid and bile salt effects than LDSB in in vitro experiments, indicating its potential as a probiotic. In animal experiments, long-term alcohol gavage induced alcoholic liver injury. LP-HFY05 effectively reduced the liver index of mice with liver injury, downregulated the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglyceride, total cholesterol, blood urea nitrogen, nitric oxide, and MDA and upregulated the levels of albumin, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase in the serum of liver-injured mice. LP-HFY05 also reduced the levels of interleukin (IL)-6, IL-12, tumor necrosis factor-alpha, and interferon-gamma in the serum of liver-injured mice. The pathological observations showed that LP-HFY05 reduced the damage to liver cells caused by alcohol. Quantitative polymerase chain reaction and Western blot assays further showed that LP-HFY05 upregulated neuronal nitric oxide synthase, endothelial nitric oxide synthase, manganese-SOD, cuprozinc-SOD, CAT, and inhibitor of κB-α mRNA and protein expression and downregulated the expression of nuclear factor-κB-p65 and inducible nitric oxide synthase in the livers of liver-injured mice. A fecal analysis revealed that LP-HFY05 regulated the microbial content in the intestinal tract of mice with liver injury, increased the content of beneficial bacteria, including Bacteroides, Bifidobacterium, and Lactobacillus and reduced the content of harmful bacteria, including Firmicutes, Actinobacteria, Proteobacteria, and Enterobacteriaceae, thus, regulating intestinal microorganisms to protect against liver injury. The effect of LP-HFY05 on liver-injured mice was better than that of LDSB, and the effect was similar to that of silymarin. LP-HFY05 is a high-quality microbial strain with a liver protective effect on experimental mice with alcoholic liver injury.

Taxonomic Characterization, and Secondary Metabolite Analysis of Streptomyces triticiradicis sp. nov.: A Novel Actinomycete with Antifungal Activity

“…After that, the total DNA was extracted according to the lysozyme-sodium dodecyl sulfate-phenol/chloroform method [30]. The primers and procedure for PCR amplification were carried out as described by Yi et al [31]. The PCR product was purified and cloned into the vector pMD19-T (Takara, Shiga, Japan) and sequenced using an Applied Biosystems DNA sequencer (model 3730XL, Applied Biosystems Inc., Foster City, CA, USA).…”

Effects of Lactobacillus fermentum CQPC04 on Lipid Reduction in C57BL/6J Mice

“…In order to preserve the strains, 0.5 mL of twice-activated bacteria-containing medium and 0.5 mL of 40% sterile glycerol were mixed well in a 2-mL centrifuge tube. The tube was sealed with a sealing film, labeled, and put aside for later use (Yi et al, 2019).…”

“…Three drops of decolorizing solution were applied, and the bacterial sample was decolorized for 30−60 s. The circle was washed with water, dried, stained with safranine staining solution for 30 s, rinsed with purified water, and dried with absorbent paper. The sample was completely dried prior to microscopic examination (Yi et al, 2019).…”

“…After the membrane was transferred, the PVDF membrane was sealed with 1 × TBST solution containing 5% skim milk for 1 h. The sealed PVDF membrane (Thermo Fisher Scientific, Waltham, MA, United States) was then washed with 1 × TBST. The primary antibody was incubated at 25 • C for 2 h. After washing the PVDF membrane five times with 1 × TBST, the secondary antibody (Thermo Fisher Scientific, Waltham, MA, United States) was incubated at 25 • C for 1 h. Finally, the PVDF membrane was sprayed with Supersignal West Pico PLUS and placed in the imaging system for observation (Tanon 5200, Shanghai Tanon Technology Co., Ltd., Shanghai, China) (Yi et al, 2019).…”

Prophylactic Effect of Lactobacillus plantarum YS4 on Oxazolone‐Induced Colitis in BALB/c Mice

“…Ulcerative colitis is a type of inflammatory bowel disease that can potentially lead to cancer. The age of onset of colitis is typically 20–50 years old, and it can seriously threaten the quality of life of patients [ 1 ]. The immunopathogenesis and immunosuppressive treatment of colitis are currently the research topics of significant interest.…”