title: Effects of Aronia melanocarpa Fruit Juice on Isolated Rat Hepatocytes.
abstract: BACKGROUND
  Aronia melanocarpa (Michx.) Elliot fruits are very rich in polyphenols - procyanidins, flavonoids, and phenolic acids.
  
  
  OBJECTIVE
  On rat hepatocytes, isolated by two-stepped collagenase perfusion, we investigated the effect of A. melanocarpa fruit juice (AMFJ) in two models of liver toxicity caused by (i) metabolic bioactivation of carbon tetrachloride (CCl4), and (ii) tert-butyl hydroperoxide (t-BuOOH)-induced oxidative stress.
  
  
  METHODS
  Isolated rat hepatocytes are a suitable model for hepatotoxicity studies. We determined the main parameters of the functional and metabolic status of rat hepatocytes: Cell viability (measured by trypan blue exclusion) and the levels of lactate dehydrogenase (LDH), reduced glutathione (GSH), and malondialdehyde (MDA). These parameters were used to investigate the protective effects of AMFJ in the two toxicity models. The effects of AMFJ were compared with those of silymarin. The cells were treated either with AMFJ or silymarin at increasing concentrations of 5 μg/ml, 10 μg/ml, 30 μg/ml, 50 μg/ml, and 100 μg/ml which were used for measuring of IC50.
  
  
  RESULTS
  In both toxicity models - CCl4 and t-BuOOH, AMFJ showed statistically significant cytoprotective and antioxidant activities. AMFJ prevented the loss of cell viability and GSH depletion, decreased LDH leakage and MDA production. The effects of AMFJ at the concentrations of 5, 10, 30, and 50 μg/ml were similar to those of the same concentrations of silymarin, while the effect of the highest AMFJ concentration of 100 μg/ml was higher than that of the same silymarin concentration. The effects were concentration-dependent and more prominent in the t-BuOOH model, compared to those in the CCl4 model.
  
  
  CONCLUSIONS
  The cytoprotective and antioxidant effects of AMFJ established in this study might be due to its polyphenolic ingredients, which could influence the cytochrome P450-mediated metabolism of the experimental hepatotoxic substances (CCl4 and t-BuOOH) and could act as free radical scavengers. The stronger effects of the highest AMFJ concentration in comparison with that of silymarin were possibly due to the combined presence of different polyphenols in the juice.
  
  
  CONCLUSIONS
  On rat hepatocytes, isolated by two-stepped collagenase perfusion, we investigated the effect of Aronia melanocarpa fruit juice (AMFJ) in two models of liver toxicity caused by i) metabolic bioactivation of carbon tetrachloride (CCl4), and ii) tert-butyl hydroperoxide (t-BuOOH)-induced oxidative stress. In both toxicity models - CCl4 and t-BuOOH, AMFJ showed statistically significant cytoprotective and antioxidant activities. AMFJ prevented the loss of cell viability and GSH depletion, decreased LDH leakage and MDA production. The effects of AMFJ at the concentrations of 5, 10, 30, and 50 μg/ml were similar to those of the same concentrations of silymarin, while the effect of the highest AMFJ concentration of 100 μg/ml was higher than that of the same silymarin concentration. The effects were concentration-dependent and were more prominent in the t-BuOOH model, compared to those in the CCl4 model.
authors.affiliation: Department of Pharmacology, Pharmacotherapy and Toxicology, Faculty of Pharmacy, Laboratory of Drug Metabolism and Drug Toxicity, Medical University of Sofia, Sofia, Bulgaria.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kondeva-Burdina
authors.affiliation: Department of Preclinical and Clinical Pharmacology, Medical University, Varna, Bulgaria.
authors.forename: Stefka
authors.initials: S
authors.lastname: Valcheva-Kuzmanova
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria.
authors.forename: Tsvetelina
authors.initials: T
authors.lastname: Markova
authors.affiliation: Department of Pharmacology, Pharmacotherapy and Toxicology, Faculty of Pharmacy, Laboratory of Drug Metabolism and Drug Toxicity, Medical University of Sofia, Sofia, Bulgaria.
authors.forename: Mitka
authors.initials: M
authors.lastname: Mitcheva
authors.affiliation: Department of Preclinical and Clinical Pharmacology, Medical University, Varna, Bulgaria.
authors.forename: Anna
authors.initials: A
authors.lastname: Belcheva
keywords: Aronia melanocarpa fruit juice; carbon tetrachloride; cytoprotection; isolated hepatocytes; tert-butyl hydroperoxide