Valuable effects of lactobacillus and citicoline on steatohepatitis: role of Nrf2/HO-1 and gut microbiota

Abstract

Non-alcoholic steatohepatitis (NASH) is a more dangerous form of chronic non-alcoholic fatty liver disease (NAFLD). In the current investigation, the influence of citicoline on high-fat diet (HFD)-induced NASH was examined, both alone and in combination with Lactobacillus (probiotic). NASH was induced by feeding HFD (10% sugar, 10% lard stearin, 2% cholesterol, and 0.5% cholic acid) to rats for 13 weeks and received single i.p. injection of streptozotocin (STZ, 30 mg/kg) after 4 weeks. Citicoline was given at two dose levels (250 mg and 500 mg, i.p.) at the beginning of the sixth week, and in combination with an oral suspension of Lactobacillus every day for eight weeks until the study's conclusion. HFD/STZ induced steatohepatitis as shown by histopathological changes, elevated serum liver enzymes, serum hyperlipidemia and hepatic fat accumulation. Moreover, HFD convinced oxidative stress by increased lipid peroxidation marker (MDA) and decreased antioxidant enzymes (GSH and TAC). Upregulation of TLR4/NF-kB and the downstream inflammatory cascade (TNF-α, and IL-6) as well as Pentaraxin, fetuin-B and apoptotic markers (caspase-3 and Bax) were observed. NASH rats also had massive increase in Bacteroides spp., Fusobacterium spp., E. coli, Clostridium spp., Providencia spp., Prevotella interrmedia, and P. gingivalis while remarkable drop in Bifidobacteria spp. and Lactobacillus spp. Co-treatment with citicoline alone and with Lactobacillus improve histopathological NASH outcomes and reversed all of these molecular pathological alterations linked to NASH via upregulating the expression of Nrf2/HO-1 and downregulating TLR4/NF-kB signaling pathways. These results suggest that citicoline and lactobacillus may represent new hepatoprotective strategies against NASH progression.