Saikokeishito Extract Exerts a Therapeutic Effect on α-Naphthylisothiocyanate-Induced Liver Injury in Rats through Attenuation of Enhanced Neutrophil Infiltration and Oxidative Stress in the Liver Tissue

We examined whether Saikokeishito extract (TJ-10), a traditional Japanese herbal medicine, exerts a therapeutic effect on α-naphthylisothiocyanate (ANIT)-induced liver injury in rats through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. In rats treated once with ANIT (75 mg/kg, i.p.), liver injury with cholestasis occurred 24 h after treatment and progressed at 48 h. When ANIT-treated rats orally received TJ-10 (0.26, 1.3 or 2.6 g/kg) at 24 h after the treatment, progressive liver injury with cholestasis was significantly attenuated at 48 h after the treatment at the dose of 1.3 or 2.6 g/kg. At 24 h after ANIT treatment, increases in hepatic lipid peroxide and reduced glutathione contents and myeloperoxidase activity occurred with decreases in hepatic superoxide dismutase and glutathione reductase activities. At 48 h after ANIT treatment, these changes except for reduced glutathione were enhanced with decreases in catalase, Se-glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. TJ-10 (1.3 or 2.6 g/kg) post-administered to ANIT-treated rats attenuated these changes found at 48 h after the treatment significantly. These results indicate that TJ-10 exerts a therapeutic effect on ANIT-induced liver injury in rats possibly through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue.