Dual therapy with zinc acetate and rifaximin prevents from ethanol-induced liver fibrosis by maintaining intestinal barrier integrity

Abstract

BACKGROUND Hepatic overload of gut-derived lipopolysaccharide dictates the progression of alcoholic liver disease (ALD) by inducing oxidative stress and activating Kupffer cells and hepatic stellate cells through toll-like receptor 4 signaling. Therefore, targeting the maintenance of intestinal barrier integrity has attracted attention for the treatment of ALD. Zinc acetate and rifaximin, which is a nonabsorbable antibiotic, had been clinically used for patients with cirrhosis, particularly those with hepatic encephalopathy, and had been known to improve intestinal barrier dysfunction. However, only few studies focused on their efficacies in preventing the ALD-related fibrosis development. AIM To investigate the effects of a combined zinc acetate with rifaximin on liver fibrosis in a mouse ALD model. METHODS To induce ALD-related liver fibrosis, female C57BL/6J mice were fed a 2.5% (v/v) ethanol-containing Lieber-DeCarli liquid diet and received intraperitoneal carbon tetrachloride (CCl 4 ) injection twice weekly (1 mL/kg) for 8 wk. Zinc acetate (100 mg/L) and/or rifaximin (100 mg/L) were orally administered during experimental period. Hepatic steatosis, inflammation and fibrosis as well as intestinal barrier function were evaluated by histological and molecular analyses. Moreover, the direct effects of both agents on Caco-2 barrier function were assessed by in vitro assays. RESULTS In the ethanol plus CCl 4 -treated mice, combination of zinc acetate and rifaximin attenuated oxidative lipid peroxidation with downregulation of Nox2 and Nox4 . This combination significantly inhibited the Kupffer cells expansion and the proinflammatory response with blunted hepatic exposure of lipopolysaccharide and the toll-like receptor 4/nuclear factor kB pathway. Consequently, liver fibrosis and hepatic stellate cells activation were efficiently suppressed with downregulation of Mmp-2, -9, -13, and Timp1 . Both agents improved the atrophic changes and permeability in the ileum, with restoration of tight junction proteins (TJPs) by decreasing the expressions of tumor necrosis factor α and myosin light chain kinase. In the in vitro assay, both agents directly reinforced ethanol or lipopolysaccharide-stimulated paracellular permeability and upregulated TJPs in Caco-2 cells. CONCLUSION Dual therapy with zinc acetate and rifaximin may serve as a strategy to prevent ALD-related fibrosis by maintaining intestinal barrier integrity.

Identification of biomarkers co-associated with M1 macrophages, ferroptosis and cuproptosis in alcoholic hepatitis by bioinformatics and experimental verification

“…analyzed miRNA expression in alcoholics to further characterize the genetic influence of alcoholism and the influence of alcohol consumption on predicted target mRNA expression, which involved THBS2 ( 49 ). In mice treated with ethanol and CCl 4 , down-regulation of TIMP1 effectively inhibited hepatic fibrosis and activation of hepatic stellate cell ( 50 ). Clinical studies have found that alcohol consumption in adolescents leads to elevated serum TIMP1 concentrations ( 51 ).…”

RNA-seq Analysis Reveals Potential Synergic Effects of Acetate and Cold Exposure on Interscapular Brown Adipose Tissue in Mice

“…[37], insulin secretion [38], and adipokine secretion, etc. Indeed, as the important metabolites of anaerobic bacteria in gut, the acetate was also implied as a key regulator of intestinal homeostasis [39], intestinal barrier integrity [40], intestinal inflammation [41], etc. All these impacts could profoundly affect the body's metabolism and thus influence the function of brown adipose tissue.…”

Experimental In Vivo Toxicity Models for Alcohol Toxicity

“…For example, successful results have been achieved with the use of hepatotoxins or viral proteins such as CCl 4 , a high-fat diet, acetaminophen, iron, or diethylnitrosamine (DEN). 51 In Fujimoto et al’s 51 study, female C57BL/6J mice were fed with an LDE diet with 2.5% (v/v) of total calories being ethanol for 8 weeks. One mL/kg of CCl 4 administered intraperitoneally twice a week.…”