Fas Receptor Activation by Endogenous Opioids Is A New Mechanism for Cardiomyopathy in Cirrhotic Rats

Synergetic Effect of Lupeol and Naringin Against Bile Duct Ligation Induced Cardiac Injury in Rats via Modulating Nitrite Level (eNos) and NF-kB /p65 Expression

Cardiac dysfunction such as cirrhotic cardiomyopathy is more common in liver cirrhosis related disorders including primary biliary cholangitis or biliary cirrhosis and primary sclerosing cholangitis. Bile duct ligation (BDL) is an effective model of biliary cholestasis, producing oxidative damage and fibrosis. This research was designed to evaluate the effect of Lupeol and Naringin and its combination on bile duct ligation induced cardiac injury in rats. For pharmacological evaluation, rats were randomly divided into seven groups; intrahepatic cholestasis induced by ligation of the bile duct might lead to cirrhotic cardiomyopathy. The results were analyzed by physical, biochemical and histological examination. The Lupeol (100 mg/kg, p.o.), Naringin (100 mg/kg, p.o.) and its combination (100 mg/kg each) treated group significantly improved physical infarct size, biochemical (Nitrite, SOD, CAT, and GSH) and histological (heart tissue- mitochondrial function/integrity and fibrosis) alterations occurs due to BDL-ligation. This study was concluded that oral administration of Lupeol, Naringin, and its combination has a curative potential against BDL-induced cardiac injury in rats by reducing oxidative stress and inflammatory reactions, resulting in reduced heart necrosis/myocardial infarction and increased myocardial activity. It also inhibits cardiac damage in the rat heart, these effects may be linked to the NO level (eNOS) is increased and the inactivation of the NF-kB-p65 expression pathways.This study also provides new insights into the development of lupeol and Naringin combination that can be used as supportive therapy for cardiovascular diseases.

1-Methyl tryptophan, an indoleamine 2,3-dioxygenase inhibitor, attenuates cardiac and hepatic dysfunction in rats with biliary cirrhosis

Kynurenine Pathway (KP) is the dominant metabolic route of tryptophan which is catalyzed by indoleamine-2,3-dioxygenase (IDO). This pathway is upregulated in liver disease where the level of KP metabolites correlates with the severity of disease. Cirrhosis is associated with cardiac dysfunction, which manifests itself during severe physiological challenges such as liver transplantation. Cardiac dysfunction in cirrhosis is linked to systemic inflammation and impaired cardiac beta-adrenergic signaling pathways. The KP pathway is involved in modulation of cardiac signaling and is upregulated by systemic inflammation. Therefore, this study aimed to evaluate the effect of IDO inhibition on development of cardiac dysfunction in an experimental model of cirrhosis. Cirrhosis was induced by bile duct ligation (BDL). Experimental groups were given either 1-methyl tryptophan (1-MT, 1, 3, 9 mg/kg), or saline. 28 days after BDL, cardiac chronotropic response to epinephrine was assessed ex vivo. HPLC was employed to measure hepatic and cardiac levels of tryptophan, kynurenine and kynurenic acid. Cirrhosis in rats was associated with impaired cardiac chronotropic responsiveness to adrenergic stimulation. 1-MT dose-dependently improved cirrhosis-induced chronotropic dysfunction as well as elevated serum levels of CRP and IL-6 in BDL rats. Hepatic and cardiac kynurenine/tryptophan ratio were elevated in cirrhotic rats and were reduced following 1-MT administration. Chronic administration of 1-MT could also reduce hepatic inflammation, fibrosis and ductular proliferation. 1-MT attenuates cardiac dysfunction in rats with biliary cirrhosis. This protective effect is not limited to the cardiac function as liver histopathologic changes were also improved following chronic 1-MT administration.

Preconditioning and anti-apoptotic effects of Metformin and Cyclosporine-A in an isolated bile duct-ligated rat heart

Despite all previous studies relating to the mechanism of cirrhotic cardiomyopathy (CCM), the role of cirrhosis on Ischemic Preconditioning (IPC) has not yet been explored. The present study strives to assess the cardioprotective role of IPC in bile duct ligated (BDL) rats as well as the cardioprotective role of Cyclosporin-A (CsA) and Metformin (Met) in CCM. Cirrhosis was induced by bile duct ligation (BDL). Rats' hearts were isolated and attached to a Langendorff Apparatus. The pharmacological preconditioning with Met and CsA was done before the main ischemia. Myocardial infarct size, hemodynamic and electrophysiological parameters, biochemical markers, and apoptotic indices were determined at the end of the experiment. Infarct size, apoptotic indices, arrhythmia score, and incidence of VF decreased significantly in the IPC group in comparison with the I/R group. These significant decreases were abolished in the IPC (BDL) group. Met significantly decreased the infarct size and apoptotic indices compared with I/R (BDL) and normal groups, while CsA led to similar decreases except in the level of caspase-3 and -8. Met and CsA decreased and increased the arrhythmia score and incidence of VF in the BDL groups, respectively. Functional recovery indices decreased in the I/R (BDL) and IPC (BDL) groups. Met improved these parameters. Therefore, the current study depicted that the cardioprotective effect of Met and CsA on BDL rats is mediated through the balance between pAMPK and apoptosis in the mitochondria.