Melatonin is an indolamine, mainly secreted by the pineal gland into the blood of mammalian species. The potential for protective effects of melatonin on carbon tetrachloride (CCl(4))-induced acute liver injury in rats was investigated in this work. CCl(4) exerts its toxic effects by generation of free radicals; it was intragastrically administered to male Wistar rats (4 g kg(-1) body weight) at 20 h before the animals were decapitated. Melatonin (15 mg kg(-1) body weight) was administered intraperitoneally three times: 30 min before and at 2 and 4 h after CCl(4) injection. Rats injected with CCl(4) alone showed significant lipid and hydropic dystrophy of the liver, massive necrosis of hepatocytes, marked increases in free and conjugated bilirubin levels, elevation of hepatic enzymes (alanine aminotransferase and aspartate aminotransferase) in plasma, as well as NO accumulation in liver and in blood. Melatonin administered at a pharmacological dose diminished the toxic effects of CCl(4). Thus it decreased both the structural and functional injury of hepatocytes and clearly exerted hepatoprotective effects. Melatonin administration also reduced CCl(4)-induced NO generation. These findings suggest that the effect of melatonin on CCl(4)-induced acute liver injury depends on the antioxidant action of melatonin.

The protective effect of red cabbage extract (RCE) was evaluated in rats with streptozotocin-induced diabetes, assessing a probable role of this extract in the prevention of erythrocyte impairments associated with a high risk of vascular complications in diabetes. RCE was analyzed by ultrahigh performance liquid chromatography and mass spectrometry, and 11 anthocyanins, 3 hydroxybenzoic acids and 9 hydroxycinnamic acids were identified. Type 1 diabetes was induced by streptozotocin (60 mg kg) in Wistar male rats (n = 8 per group). After 7 days of acclimatization, streptozotocin-treated rats were given RCE (800 mg kg) or vehicle by intragastric administration for 4 weeks. The RCE treatment lowered blood glucose, and glycated and fetal hemoglobin concentrations and improved glucose tolerance as well as considerably raised serum insulin, proinsulin and C-peptide levels in streptozotocin-treated rats. Simultaneously, RCE improved pancreatic islet morphology, increasing the amount of pancreatic β-cells in diabetic animals. The RCE administration prevented anemia in rats with streptozotocin-induced diabetes, enhanced erythrocyte resistance to acid hemolysis, and normalized reticulocyte production as well as sialic acid content in erythrocyte membranes. The enhanced lectin-induced erythrocyte aggregation in diabetic rats was significantly lowered after the RCE treatment. RCE demonstrated a significant antioxidant effect, decreasing MDA and protein carbonyl contents and increasing catalase and glutathione peroxidase activities in erythrocytes. These results indicate that RCE can be considered as a promising candidate for use as a drug or a food supplement to alleviate diabetes and its vascular complications.

Background and aims Alcoholic steatohepatitis (ASH)-the inflammation of fatty liver-is caused by chronic alcohol consumption and represents one of the leading chronic liver diseases in Western Countries. ASH can lead to organ dysfunction or progress to hepatocellular carcinoma (HCC). Long-term alcohol abstinence reduces this probability and is the prerequisite for liver transplantation-the only effective therapy option at present. Elevated enzymatic activity of cytochrome P450 2E1 (CYP2E1) is known to be critically responsible for the development of ASH due to excessively high levels of reactive oxygen species (ROS) during metabolization of ethanol. Up to now, no rational drug discovery process was successfully initiated to target CYP2E1 for the treatment of ASH. Methods In this study, we applied a rational drug design concept to develop drug candidates (NCE) including preclinical studies. Results A new class of drug candidates was generated successfully. Two of the most promising small compounds named 12-Imidazolyl-1-dodecanol (abbr.: I-ol) and 1-Imidazolyldodecane (abbr.: I-an) were selected at the end of this process of drug discovery and developability. These new ω-imidazolyl-alkyl derivatives act as strong chimeric CYP2E1 inhibitors at a

Background/objectives: Effects of norursodeoxycholic acid (norUDCA) and ursodeoxycholic acid (UDCA) on liver fibrosis progression and liver fibrosis reversal in thioacetamide (TAA)-treated rats were studied. Methods: Advanced liver fibrosis was induced by TAA treatment (200 mg/kg, i.p.) for 12 weeks. In the second experiment resolution of liver fibrosis was assessed after 8 weeks of TAA withdrawal. During 8 last weeks of each trial, fibrotic rats were daily administered with UDCA (80 mg/kg) and norUDCA (equimolar to 80 mg/kg of UDCA) by oral gavage. Liver fibrosis was assessed by Sirius red staining, liver hydroxyproline and serum fibrosis markers determination. Results: The TAA treatment resulted in advanced fibrosis and increase in liver hydroxyproline content and serum fibrosis markers. These signs of fibrosis were less pronounced in rats after TAA withdrawal. Treatment with of norUDCA significantly decreased the total and relative liver hydroxyproline contents in rats with fibrosis reversal, whereas UDCA did not change these parameters. Both compounds decreased serum TGFb and type IV collagen contents, whereas other serum markers did not differ from the placebo group. In the fibrosis progression model the square of connective tissue was decreased by norUDCA. Serum type IV collagen and procollagen III-NT contents in these experiments were lowered by both UDCA and norUDCA, whereas rest of serum fibrosis markers were diminished only by norUDCA. Conclusions: Both norUDCA and UDCA showed therapeutic and prophylactic antifibrotic effect in rats with TAA-induced liver fibrosis. For most of tested parameters norUDCA was more effective than UDCA, especially in the experiment with liver fibrosis regression. ( J CLIN EXP HEPATOL 2014;4:293-301)

Betulin, a pentacyclic triterpene, possesses antioxidant, anti-inflammatory and hepatoprotective properties. The aim of this study was to evaluate the impact of liver mitochondria in hepatoprotection of betulin using a rat model of alcoholic steatohepatitis induced by ethanol administration (4 g/kg, intragastric) for 8 weeks. The treatment with betulin (50 and 100 mg/kg b.w., intragastric) during this period attenuated the histological signs of steatohepatitis and lowered the serum and liver triglyceride contents, as well as the serum activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Betulin (100 mg/kg) decreased the liver/body weight ratio and inhibited the increase in the serum levels of TNFα, IL-1β, TGFβ, and hyaluronic acid, demonstrating hepatoprotective, anti-inflammatory, and antifibrotic potential. Betulin also inhibited the formation of superoxide anions in mitochondria and the end-products of lipid peroxidation in liver tissue, the amount of which was significantly increased in ethanol-treated rats. The disturbances in mitochondrial respiration, uncoupling of oxidative phosphorylation and decreasing of mitochondrial complex I, II, and IV activities in rats with steatohepatitis, were reverted by betulin administration. The increased susceptibility of mitochondria to Ca2+-induced permeability transition pore formation in the hepatitis group was improved in rats treated with betulin. In conclusion, betulin, having antioxidant properties, exerts a beneficial effect in the rat model of alcoholic steatohepatitis via prevention of liver mitochondria dysfunction, which may be attributed to the inhibition of mitochondrial permeability transition.