Montelukast prevents mice against carbon tetrachloride- and methionine-choline deficient diet-induced liver fibrosis: Reducing hepatic stellate cell activation and inflammation

Montelukast is an antagonist of cysteinyl leukotriene receptor 1 (CysLTR1) that protects against inflammation and oxidative stress. However, the function of montelukast in liver fibrosis remains unknown. In this study, we examined whether the pharmacological inhibition of CysLTR1 could protect mice against hepatic fibrosis.Carbon tetrachloride (CCl4) and methionine-choline deficient (MCD) diet models were used in this study. The expression of CysLTR1 in liver were detected by RT-qPCR and Western blot analysis. Liver hydroxyproline levels, fibrotic genes expression, serum biochemical indexes and inflammatory factors were used to evaluate the effect of montelukast on liver fibrosis, injury, and inflammation. In vitro, we used the RT-qPCR and Western blot analysis to assess CysLTR1 in mouse primary hepatic stellate cell (HSC) and human LX-2 cell line. The role of montelukast on HSC activation and the underlying mechaisms were determined using RT-qPCR analysis, Western blot and immunostaining assays.Chronic stimulation from CCl4 and MCD diet upregulated the mRNA and protein levels of CysLTR1 in the liver. Pharmacological inhibition of CysLTR1 by montelukast ameliorated liver inflammation and fibrosis in both models. Mechanistically, montelukast suppressed HSC activation by targeting the TGFβ/Smad pathway in vitro. The hepatoprotective effect of montelukast was also associated with reduced liver injury and inflammation.Montelukast suppressed CCl4- and MCD-induced chronic hepatic inflammation and liver fibrosis. CysLTR1 might be a therapeutic target for treating liver fibrosis.