Tyrosol retards induction of fibrosis in rats

Liver fibrosis, which still does not have a standard treatment due to its complex pathogenesis, is an important cause of mortality and morbidity. In this study, it was aimed to examine the possible protective and antifibrotic effects of tyrosol on the liver through histopathologic, immunohistochemical, biochemical, and molecular methods in rats with chronic liver damage induced by thioacetamide (TAA). The study was carried out in four groups with eight rats in each group. Created groups are, respectively, control, TAA, tyrosol and TAA +tyrosol. Chronic liver damage was induced in the TAA and TAA +tyrosol groups by the addition of TAA (200 mg/L) to drinking water. Tyrosol (20 mg/kg/b.w./daily) was administered by oral gavage to tyrosol and TAA +tyrosol groups for 10 weeks. The results of this study demonstrate that the consumption of tyrosol alleviated the histopathologic changes such as inflammation, degeneration, and especially fibrosis induced by TAA in the liver. In addition, administration of tyrosol significantly attenuated alpha‐smooth muscle actin (α‐SMA) expression and apoptosis expression. Biochemically, it was determined that tyrosol increased glutathione (GSH) level, glutathione peroxidase (GSH.Px), and catalase (CAT) activities and showed antioxidant efficacy by reducing malondialdehyde (MDA) level. Moreover, it reduced inflammation and fibrosis by decreasing gene expression levels of tumor necrosis factor‐alpha (TNF‐α), interleukin‐6 (IL‐6), and transforming growth factor‐beta (TGF‐β1). Western blot analysis also revealed similar results in TGF‐β1 expression. As a result, tyrosol suppressed fibrogenesis thanks to its antioxidant, anti‐inflammatory, and anti‐apoptotic effects and showed an antifibrotic effect in the liver. Practical applications It is stated that tyrosol, a natural phenolic antioxidant found in olive oil, has neuroprotective, cardioprotective, anti‐inflammatory, and anticancer properties. In this study, tyrosol suppressed fibrogenesis thanks to its antioxidant, anti‐inflammatory, and anti‐apoptotic effects and showed an antifibrotic effect in the liver. Olive oil has an important place in the Mediterranean diet, which reduces the incidence of chronic diseases. It is thought that the anti‐fibrotic effect of tyrosol plays a role in this feature. As a result, it is thought that tyrosol can be used to prevent or slow down chronic liver diseases. It is stated that tyrosol, a natural phenolic antioxidant found in olive oil, has neuro