digoxin and Hepatitis

Nonalcoholic steatohepatitis (NASH) is a progressive disorder with aberrant lipid accumulation and subsequent inflammatory and profibrotic response. Therapeutic efforts at lipid reduction via increasing cytoplasmic lipolysis unfortunately worsens hepatitis due to toxicity of liberated fatty acid. An alternative approach could be lipid reduction through autophagic disposal, i.e., lipophagy. We engineered a synthetic adaptor protein to induce lipophagy, combining a lipid droplet-targeting signal with optimized LC3-interacting domain. Activating hepatocyte lipophagy in vivo strongly mitigated both steatosis and hepatitis in a diet-induced mouse NASH model. Mechanistically, activated lipophagy promoted the excretion of lipid from hepatocytes, thereby suppressing harmful intracellular accumulation of nonesterified fatty acid. A high-content compound screen identified alpelisib and digoxin, clinically-approved compounds, as effective activators of lipophagy. Administration of alpelisib or digoxin in vivo strongly inhibited the transition to steatohepatitis. These data thus identify lipophagy as a promising therapeutic approach to prevent NASH progression.

Topics: Animals; Autophagy; Digoxin; Fatty Acids; Hepatitis; Hepatocytes; Lipid Metabolism; Lipids; Liver; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease

The cardiac glycoside digoxin was identified as a potent suppressor of pyruvate kinase isoform 2-hypoxia-inducible factor-α (PKM2-HIF-1α) pathway activation in liver injury mouse models via intraperitoneal injection. We have assessed the therapeutic effects of digoxin to reduce nonalcoholic steatohepatitis (NASH) by the clinically relevant oral route in mice and analyzed the cellular basis for this effect with differential involvement of liver cell subsets. C57BL/6J male mice were placed on a high-fat diet (HFD) for 10 wk and started concurrently with the gavage of digoxin (2.5, 0.5, 0.125 mg/kg twice a week) for 5 wk. Digoxin significantly reduced HFD-induced hepatic damage, steatosis, and liver inflammation across a wide dosage range. The lowest dose of digoxin (0.125 mg/kg) showed significant protective effects against liver injury and sterile inflammation. Consistently, digoxin attenuated HIF-1α sustained NLRP3 inflammasome activation in macrophages. We have reported for the first time that PKM2 is upregulated in hepatocytes with hepatic steatosis, and digoxin directly improved hepatocyte mitochondrial dysfunction and steatosis. Mechanistically, digoxin directly bound to PKM2 and inhibited PKM2 targeting HIF-1α transactivation without affecting PKM2 enzyme activation. Thus, oral digoxin showed potential to therapeutically inhibit liver injury in NASH through the regulation of PKM2-HIF-1α pathway activation with involvement of multiple cell types. Because of the large clinical experience with oral digoxin, this may have significant clinical applicability in human NASH.

Topics: Animals; Cell Line; Diet, High-Fat; Digoxin; Enzyme Inhibitors; Hepatitis; Hepatocytes; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Mice; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Pyruvate Kinase; Transcriptional Activation

Digoxin-like immunoreactive substance (DLIS) has been detected in several patient populations that were not receiving digoxin. We therefore studied the sensitivity of EMIT Convenience Pack Digoxin immunoassay to interference by DLIS in patients with liver failure. Serum digoxin was measured in cirrhotic patients with moderate to severe liver failure (Child-Pugh B or C grade), patients with mild liver disease (chronic hepatitis) and matched control patients without liver disease. Excluded were patients taking or who had ever received any cardiac glycoside in the past. Blood samples were obtained by venipuncture and assayed in duplicate. Twenty-two out of 30 cirrhotic patients (73%) showed false-positive results, vs. one of 6 patients (16.7%) with mild liver disease, and 1 of 10 (10%) controls. The serum DLIS level was negatively correlated with prothrombin activity (r = -0.55, p < 0.00011). Digoxin levels must be interpreted carefully in patients with moderate to severe liver failure.

Topics: Chronic Disease; Digoxin; Enzyme Multiplied Immunoassay Technique; False Positive Reactions; Female; Hepatitis; Humans; Liver Cirrhosis; Male; Middle Aged; Predictive Value of Tests; Prospective Studies

Topics: Acute Disease; Digoxin; Hepatitis; Humans

After i.v. application of 3h-digoxin or 3H-methyldigoxin to 5 healthy volunteers and 5 patients with acute hepatitis, respectively (0.75 mg daily for 3 days and 0.375 for the following 2 days) total radioactivity in urine and plasma were determined. Chloroform-soluble and -insoluble glycosides were separated and the chloroform-soluble fraction was determined by TLC. 3 days after methyldigoxin application plasma levels reached toxic values in the patient group (2.73 +/- 0.48 ng/ml), whereas in patients receiving digoxin a mean plasma level of 0.91 +/- 0.21 ng/ml was obtained. During the first 24 hours following administration of digoxin 44 +/- 12% of the dose were recovered in urine of control subjects and 48 +/- 13% in patients with acute hepatitis, after methyldigoxin 34 +/- 5% and 34 +/- 8%, respectively. Metabolism of digoxin in patients with acute hepatitis was unaltered, whereas a diminished demethylation rate of methyldigoxin could be observed. 16 patients with acute hepatitis and 7 healthy volunteers received unlabelled digoxin p.o. as maintenance dose. Plasma glycoside concentrations were studied by radioimmunoassay. The average glycoside plasma concentrations were 0.59 +/- 0.21 ng/ml and 0.63 +/- 0.24 ng/ml, respectively.

Topics: Animals; Cardiac Glycosides; Digoxin; Glomerular Filtration Rate; Hepatitis; Humans; Rats

Radioimmunologically determined digoxin and beta methyl digoxin values were the same in cardiopaths with and without clinical and instrumental changes referable to chronic cirrhosis or hepatitis. Lower values, however, were noted when gastroenteric disturbances were present. This was especially true of beta methyl digoxin in subjects with hyperkinetic-hyperchlorhydric syndromes due to depressed gastric pH, with a consequent inhibition of beta methyl digoxin absorption, presumably caused by lability of the molecule as a result of methylation of the terminal digitoxose group.

Topics: Aged; Blood Protein Disorders; Digoxin; Gastrointestinal Diseases; Heart Diseases; Hepatitis; Humans; Liver Cirrhosis; Middle Aged; Radioimmunoassay

Pharmocokinetics and metabolism of digoxin and beta-methyldigoxin have been studied in patients with acute hepatits after intravenous administration of both H-labeled glycosides. In contrast to digoxin, the rate of decline of radioactivity after administration of beta-methyldigoxin was significantly retarded in patients with acute hepatitis. The increase in plasma concentration after beta-methyldigoxin to patients with acute hepatitis is probably related to decreased demethylation.

Topics: Acute Disease; Adult; Aged; Chromatography, Thin Layer; Digoxin; Female; Hepatitis; Humans; Kinetics; Male; Methylation; Middle Aged