Yoshito Tanaka1, Masaki Kaibori1, Hirokazu Miki1, Richi Nakatake1, Katsuji Tokuhara1, Mikio Nishizawa2, Tadayoshi Okumura3, A-Hon Kwon1. 1. Department of Surgery, Kansai Medical University, Hirakata, Osaka, Japan. 2. Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan. 3. Department of Surgery, Kansai Medical University, Hirakata, Osaka, Japan; Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan. Electronic address: okumura@hirakata.kmu.ac.jp.
Abstract
BACKGROUND: Recent evidence indicates that alpha-lipoic acid (α-LA) has a variety of liver-protective effects through the suppression of inflammatory mediators including tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS). However, there are few reports that α-LA markedly enhanced the survival rate in animal models of liver injury with more than 90% death. The aim of this study was to investigate the beneficial effects of α-LA in a rat model of acute liver injury and to clarify the mechanisms of α-LA action. METHODS: Rats were treated with d-galactosamine and lipopolysaccharide (GalN and LPS) to induce acute liver injury. α-LA (100 mg/kg) was administered intraperitoneally 1 h before GalN and LPS injection. Inflammatory mediators including TNF-α and iNOS were analyzed. RESULTS: A single injection of α-LA improved the survival rate by more than 80%. α-LA prevented serum transaminase increases, histopathologic changes, and apoptosis in the liver. In the serum, α-LA decreased TNF-α production and increased interleukin (IL)-10 production. In the liver, α-LA reduced TNF-α and IL-6 messenger RNA (mRNA) but enhanced IL-10 mRNA. α-LA decreased the expression of iNOS mRNA and its antisense transcript, leading to the reduction of iNOS protein expression and resulting in the inhibition of nitric oxide production. An electrophoretic mobility shift assay revealed that α-LA reduced the activation of nuclear factor-kappa B induced by GalN and LPS. CONCLUSIONS: α-LA inhibited the induction of inflammatory mediators, such as TNF-α and iNOS, in part through the inhibition of nuclear factor-kappa B activation and enhanced the induction of IL-10. α-LA may have therapeutic potential for use in the prevention of acute liver injury.
BACKGROUND: Recent evidence indicates that alpha-lipoic acid (α-LA) has a variety of liver-protective effects through the suppression of inflammatory mediators including tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS). However, there are few reports that α-LA markedly enhanced the survival rate in animal models of liver injury with more than 90% death. The aim of this study was to investigate the beneficial effects of α-LA in a rat model of acute liver injury and to clarify the mechanisms of α-LA action. METHODS:Rats were treated with d-galactosamine and lipopolysaccharide (GalN and LPS) to induce acute liver injury. α-LA (100 mg/kg) was administered intraperitoneally 1 h before GalN and LPS injection. Inflammatory mediators including TNF-α and iNOS were analyzed. RESULTS: A single injection of α-LA improved the survival rate by more than 80%. α-LA prevented serum transaminase increases, histopathologic changes, and apoptosis in the liver. In the serum, α-LA decreased TNF-α production and increased interleukin (IL)-10 production. In the liver, α-LA reduced TNF-α and IL-6 messenger RNA (mRNA) but enhanced IL-10 mRNA. α-LA decreased the expression of iNOS mRNA and its antisense transcript, leading to the reduction of iNOS protein expression and resulting in the inhibition of nitric oxide production. An electrophoretic mobility shift assay revealed that α-LA reduced the activation of nuclear factor-kappa B induced by GalN and LPS. CONCLUSIONS: α-LA inhibited the induction of inflammatory mediators, such as TNF-α and iNOS, in part through the inhibition of nuclear factor-kappa B activation and enhanced the induction of IL-10. α-LA may have therapeutic potential for use in the prevention of acute liver injury.
Authors: Eman M El-Mancy; Dalia Mahmoud Abdelmonem Elsherbini; Rasha Hamed Al-Serwi; Mohamed El-Sherbiny; Gehan Ahmed Shaker; Abdel-Moneim Hafez Abdel-Moneim; Eman T Enan; Nehal M Elsherbiny Journal: Toxics Date: 2022-08-02