Protective effects of probiotics on acute alcohol-induced liver injury in mice through alcohol metabolizing enzymes activation and hepatic TNF-α response reduction

Purpose: The role of tumor necrosis factor-alpha (TNF alpha) and toll-like receptor 4 (TLR 4) in the pathogenesis of alcoholic liver disease (ALD) has been widely entrenched. We investigated the profitable effects of Bifidobacterium bifidum YRT3115 and Bifidobacterium animalis subsp. lactis KV9 on tumor necrosis factor-alpha (TNF alpha) expression and injury response to acute alcohol gavage in mice. Methods: Ninety-six C57BL/6 mice were classified into 4 groups: control, intragastric administration of white spirit, intragastric administration of white spirit + YRT3115 and intragastric administration of white spirit + KV9. The mice were treated daily with probiotics and white spirit until 15 days. The body weight, food intake, liver weight and liver index of mice were measured. Duration of alcohol-induced loss of righting reflex (LORR) was also evaluated. The concentration of ethanol (EtOH) and acetaldehyde (AcH) in mice blood were performed by a head-space GC. The activity of aspartate transaminase (AST) and alanine transaminase (ALT) in mice serum, activity of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in mice liver were performed by commercial kits. The liver mRNA levels of TNF-alpha, CYP2E1 and TLR 4 were evaluated by RT-PCR. The protein level of TNF-alpha was evaluated by Western-blot. Results: After intragastric administration white spirit, B. animalis subsp. lactis KV9 reduced duration of LORR, recovery of loss of righting reflex (RORR) and was significantly reduced the concentration of EtOH in blood of mice, by 15.69% at 30 min, 15.01% at 60 min and 45.01% at 120 min (p < 0.05) and reduced the concentration of AcH, by 45.75% at 30 min, 59.66% at 60 min (p < 0.05). Meanwhile, B. animalis subsp. lactis KV9 significantly increased nearly56.69% activity of ADH and nearly 68.02% activity of ALDH in liver (p < 0.05) and reduced 22.12% activity of AST and 27.53% activity of ALT in mice serum (p < 0.05). In addition, alcohol induced TNF-alpha, CYP2E1 and TLR 4 expression were reduced by B. animalis subsp. lactis KV9 in mice liver. Conclusion: This paper demonstrated that B. animalis subsp. lactis KV9 supplementation reduced markedly hepatic inflammation, liver injury and improve alcohol metabolism, but B. bifidum YRT3115 was not. These results suggested firmly that treatment with B. animalis subsp. lactis KV9 could potential ameliorate liver from the injury of alcohol.