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Blueberry treatment attenuates D-galactose-induced oxidative stress and tissue damage in rat liver.

d‐galactose (GAL) causes aging‐related changes and oxidative stress in the organism. We investigated the effect of whole fresh blueberry (BB; Vaccinium corymbosum L.) treatment on oxidative stress in age‐related liver injury model.

Betaine treatment decreased oxidative stress, inflammation, and stellate cell activation in rats with alcoholic liver fibrosis

The aim of this study was to investigate the effect of betaine (BET) on alcoholic liver fibrosis in rats. Fibrosis was experimentally generated with ethanol plus carbon tetrachloride (ETH+CCl4) treatment. Rats were treated with ETH (5% v/v in drinking water) for 14 weeks. CCl4 was administered intraperitoneally (i.p.) 0.2mL/kg twice a week to rats in the last 6 weeks with/without commercial food containing BET (2% w/w). Serum hepatic damage markers, tumor necrosis factor-α, hepatic triglyceride (TG) and hydroxyproline (HYP) levels, and oxidative stress parameters were measured together with histopathologic observations. In addition, α-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions were assayed immunohistochemically to evaluate stellate cell (HSC) activation. mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were also determined. BET treatment diminished TG and HYP levels; prooxidant status and fibrotic changes; α-SMA, COL1A1 and TGF-β protein expressions; MMP-2, TIMP-1 and TIMP-2 mRNA expressions in the liver of fibrotic rats. In conclusion, these results indicate that the antifibrotic effect of BET may be related to its suppressive effects on oxidant and inflammatory processes together with HSC activation in alcoholic liver fibrosis.

High-fat diet plus carbon tetrachloride-induced liver fibrosis is alleviated by betaine treatment in rats.

Steatosis, the first lesion in non-alcoholic fatty liver disease (NAFLD), may progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Steatosis predisposes the liver to oxidative stress, inflammation, and cytokines. Betaine (BET) has antioxidant, antiinflammatory and hepatoprotective effects. However, the effects of BET on liver fibrosis development are unknown. Rats were treated with high-fat diet (60% of total calories from fat) for 14weeks. Carbon tetrachloride (0.2mL/kg; two times per week; i.p.) was administered to rats in the last 6weeks with/without commercial food containing BET (2%; w/w). Serum liver function tests and tumor necrosis factor-α, insulin resistance, hepatic triglyceride (TG) and hydroxyproline (HYP) levels and oxidative stress parameters were determined along with histopathologic observations. Alpha-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions and mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were evaluated. BET decreased TG and HYP levels, prooxidant status and fibrotic changes in the liver. α-SMA, COL1A1 and TGF-β1 protein expressions, MMP-2, TIMP-1, and TIMP-2 mRNA expressions diminished due to BET treatment. BET has an antifibrotic effect and this effect may be related to its antioxidant and antiinflammatory actions together with suppression on HSC activation.

Protective effects of carnosine alone and together with alpha-tocopherol on lipopolysaccharide (LPS) plus ethanol-induced liver injury

The aim of this study was to investigate the effect of carnosine (CAR) alone and together with vitamin E (Vit E) on alcoholic steatohepatitis (ASH) in rats. ASH was induced by ethanol (3 times; 5 g/kg; 12 h intervals, via gavage), followed by a single dose of lipopolysaccharide (LPS; 10 mg/kg; i.p.). CAR (250 mg/kg; i.p.) and Vit E (200 mg D-α-tocopherol/kg; via gavage) were administered 30 min before and 90 min after the LPS injection. CAR treatment lowered high serum transaminase activities together with hepatic histopathologic improvements in rats with ASH. Reactive oxygen species formation, malondialdehyde levels, myeloperoxidase activities and transforming growth factor β1 (TGF-β1) and collagen 1α1 (COL1A1) expressions were observed to decrease. These improvements were more remarkable in CAR plus Vit E-treated rats. Our results indicate that CAR may be effective in suppressing proinflammatory, prooxidant, and profibrotic factors in the liver of rats with ASH.

Carnosine decreased oxidation and glycation products in serum and liver of high-fat diet and low-dose streptozotocin-induced diabetic rats

High‐fat diet (HFD) and low‐dose streptozotocin (STZ)‐treated rats provide useful animal model for type II diabetes mellitus. Oxidative stress and advanced glycation end products (AGEs) play a role in the development of diabetic complications. Carnosine (CAR) has anti‐oxidant and anti‐glycating properties. We investigated the effects of CAR on oxidation and glycation products in HFD+STZ rats. Rats were fed with HFD (60% of total calories from fat) for 4 weeks, and then a single dose of STZ (40 mg/kg; i.p.) was applied. Rats with blood glucose levels above 200 mg/dl were fed with HFD until the end of the 12th week. CAR (250 mg/kg body weight; i.p.; five times a week) was administered to the rats for the last four weeks. CAR significantly decreased serum triglyceride (TG) (57.7%), cholesterol (35.6%) levels and hepatic marker enzyme activities of HFD+STZ rats. It significantly reduced serum reactive oxygen species (ROS) (23.7%), AGEs (13.4%) and advanced oxidized protein products (AOPP) (35.9%) and hepatic TG (59%), ROS (26%), malondialdehyde (MDA) (11.5%), protein carbonyl (PC) (19.2%) and AGE (20.2%) levels. Liver steatosis and hepatocyte ballooning were also significantly reduced. However, CAR treatment did not alter serum glucose and blood glycated haemoglobin and hepatic anti‐oxidant enzyme activities/mRNA expressions in HFD+STZ rats. Our results indicate that CAR decreased accumulation of oxidation and glycation products, such as MDA, AGE, AOPP and PC in the serum and liver and ameliorated hepatic dysfunction in HFD+STZ rats. This effect may be related to its anti‐oxidative, anti‐glycating, and anti‐lipogenic potential.

Effect of Carnosine on Renal Function, Oxidation and Glycation Products in the Kidneys of High-Fat Diet/Streptozotocin-Induced Diabetic Rats

High fat diet (HFD) and low dose of streptozotocin (STZ)-treated rats provide an animal model for type 2 Diabetes Mellitus (T2DM). Oxidative stress plays a role in the development of diabetic complications. Carnosine (CAR) has antioxidant and antiglycating properties. We investigated effects of CAR on renal function, oxidation and glycation products in HFD+STZ-rats. Rats were fed with HFD (60% of total calories from fat) for 4 weeks and then a single dose STZ (40 mg/kg; i.p.) was applied. Rats with blood glucose levels above 200 mg/dL were fed with HFD until the end of the 12th week. CAR (250 mg/kg body weight; i.p.; 5 times a week) was administered to rats for the last 4 weeks. Glycated hemoglobin (HbA1c), glucose, lipids, and andrenal function tests in serum as well as reactive oxygen species, malondialdehyde, protein carbonyl, advanced oxidation protein products, advanced glycation end products (AGEs), antioxidant power, and antioxidant enzyme activities and their mRNA expressions in kidneys were determined. CAR treatment did not alter glucose and HbA1c, but it decreased serum lipids, creatinine, and urea levels in HFD+STZ rats. Oxidation products of lipids and proteins and AGEs levels decreased, but antioxidant enzyme activities and their mRNA expressions remained unchanged due to CAR treatment. Our results indicate that CAR treatment alleviated renal function and decreased accumulation of oxidation and glycation products in kidneys in HFD+STZ-rats.

Carnosine and vitamin E – a promising pair in the combat against testicular oxidative stress in aged rats

Oxidative stress is considered to play a key role in ageing. Carnosine alone or together with vitamin E may prove to be helpful in dealing with problems of ageing through its antioxidant activity. Testis, by producing steroids and possessing a poor antioxidant system may become a strong target for the chronic oxidative stress generated during ageing. Therefore we investigated the in vivo effect of carnosine alone or together with vitamin E on testicular oxidative stress in aged rats. In this study, young (5 months) and aged (22 months) Wistar rats were used. Carnosine (250 mg kg−1; i.p.; 5 days per week) and vitamin E (200 mg kg−1; i.m.; twice per week) were given to aged rats for 2 months. Increased testicular lipid peroxidation and superoxide dismutase activity in aged rats were declined to the levels of young ones by both treatments. Decreased glutathione peroxidase and glutathione transferase activities returned to the level of youngs only by carnosine plus vitamin E treatment. Histopathological evaluation described by Johnsens score, also showed significant improvement with preserved spermatogenesis. Carnosine plus vitamin E treatment appears to stage a powerful performance by attenuating testicular oxidative stress and sparing the antioxidant system.

Carnosine prevents testicular oxidative stress and advanced glycation end product formation in D-galactose-induced aged rats

D‐Galactose is shown to mimic natural ageing in rodents by exacerbating oxidative stress and glycation. Steroid production and having a poor antioxidant system make testis vulnerable to galactose‐induced ageing. Antioxidation and antiglycating actions of carnosine may be intriguing for prevention of testicular ageing. In this study, male Wistar rats were applied D‐galactose (300 mg/kg; subcutaneously 5 days a week) and carnosine (250 mg/kg; intraperitoneally 5 days a week) along with D‐galactose for 2 months. D‐Galactose treatment increased testicular reactive oxygen species, thiobarbituric acid reactive substances, diene conjugates, protein carbonyls, advanced oxidation products of proteins and advanced glycation end products. Carnosine was capable of repelling oxidative stress and glycation produced by D‐galactose. Johnsens score, which describes histopathological evaluation, was also significantly improved with preserved spermatogenesis by carnosine. It appears that carnosine deters the testicular oxidative stress due to galactose‐induced ageing directly by its antioxidative and antiglycating properties.

Can Ultrasound Imaging Predict the Success of an Experimental Steatofibrosis Model

Abstract Our goal was to evaluate the role of ultrasound (US) imaging in an experimental 2-hit steatofibrosis rat model. Nineteen female Sprague-Dawley rats were divided into 2 groups: control group (n = 6) and high-fat diet carbontetrachloride (HFD-CCl4) group (n = 13) that was fed with HFD for 14 weeks. Ultrasound was performed to evaluate liver steatosis. The HFD-CCl4 group rats were divided further into 2 subgroups: HFD rats with liver steatosis [US (+) group; n = 6] and without steatosis [US (−) group; n = 7]. All rats in the subgroups were administered with CCl4. In both US (+) and US (−) subgroups, steatosis score, fibrosis score, triglyceride, and hydroxyproline contents were markedly higher compared with the control group. When compared with the US (−) group, triglyceride and hydroxyproline contents were significantly higher in the US (+) group, whereas steatosis and fibrosis scores were not different. Ultrasound imaging may be useful to assess the success of a 2-hit experimental steatofibrosis model.