Cranberry flavonoids prevent toxic rat liver mitochondrial damage in vivo and scavenge free radicals in vitro

Anthocyanin-Rich Extract of Red Cabbage Attenuates Advanced Alcohol Hepatotoxicity in Rats in Association with Mitochondrial Activity Modulation

Aim

The liver is the main target for alcohol-induced injury. The aims of this work were to carry out further research into the mechanisms of liver damage induced by long-term administration of high-dose ethanol to rats and to evaluate the hepatoprotective potential of red cabbage (Brassica oleracea var. capitata f. rubra) anthocyanins (RCE).

Material/Methods

Male albino Wistar rats were divided into four groups. Group 1 was the control. Groups 2 through 4 received ethanol (4 g/kg body weight, 8 weeks). Group 3 received 11 mg RCE/kg and Group 4 received 22 mg RCE/kg. Dry lyophilised RCE was prepared from fresh red cabbage and analysed. We then evaluated the liver histology, mitochondrial respiration, and biochemical and immunological parameters in these groups of rats.

Results

The rat intoxication caused steatohepatitis characterised by macro- and microvesicular steatosis, ballooning and fatty liver dystrophies, lymphocytic infiltration, neutral lipid accumulation, and elevations of the serum activities of the liver injury marker enzymes. The treatment of alcohol-administered rats with RCE (mainly, cyanidin-3-diglucoside-5-glucoside, cyanidin-3-coumaroylrutinoside-5-hexoside, cyanidin-3-feruloylrutinoside-5-hexoside, delphinidin-3-feruloylrutinoside-hexoside) dose-dependently alleviated these pathological changes: The sizes of hepatocyte lipid vacuoles and the inflammatory signs were decreased, and the levels of the rat serum biochemical markers of liver injury, proinflammatory cytokines TNFα and IL-6, and the adipokine leptin (and not TGFβ) were significantly reversed. The RCE administration during intoxication completely recovered the changed liver mitochondria respiration rates and the ADP/O coefficient, as well as the phagocytic index and neutrophil metabolic activity in the blood. In experiments in vitro, RCE (13.6 μg/ml) modulated the respiratory parameters of isolated rat liver mitochondria, dissipated mitochondrial membrane potential, and inhibited the Ca2+-induced mitochondrial permeability transition.

Conclusion

The red cabbage anthocyanins could be useful for treatment of alcoholic liver injury due to their Ca2+-ionophoric/protonophoric activity, influence on Ca2+ homeostasis, and improving mitochondrial functions and inflammatory status.

Toxicity of Melastoma dodecandrum Lour. and its effects on lipopolysaccharide-induced inflammation and oxidative stress

Melastoma dodecandrum Lour. (MDL) is component used in traditional Chinese medicine that is widely distributed throughout southern China. MDL has been long utilized in clinical treatment for various conditions, such as inflammation. However, the toxicity and underlying anti-inflammatory mechanism of MDL remain to be elucidated. In the present study, Sprague-Dawley rats received intragastric administration of MDL for 2 months, and the toxicity of MDL was investigated. The rats were treated with lipopolysaccharide (LPS) for 8 h to determine the potential anti-inflammatory mechanism of MDL. The results demonstrated that MDL alone did not affect the expression levels of factors associated with inflammation (IL-1β, IL-6 and TNF-α) and oxidative stress [malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO)] in the rat serum and exerted no effects on rat liver and kidneys. By contrast, MDL attenuated LPS-induced inflammation and oxidative stress by regulating specific cytokines, such as IL-1β, IL-6, TNF-α, MDA, SOD and NO in the rat serum and alleviated LPS-induced liver and kidney damage. Additionally, compared with the LPS group, MDL inhibited CD4⁺ T cell differentiation into Th1 and Th17 cells and enhanced CD4⁺ T cell differentiation into Th2 and Treg cells. MDL also suppressed reactive oxygen species (ROS) production and mitochondrial apoptosis by modulating mitochondrial apoptosis-related proteins in spleen CD4⁺ T cells. In conclusion, the results of the present study demonstrated the non-toxic nature of MDL and revealed that it alleviated LPS-induced inflammation and oxidative stress by regulating differentiation and ROS production in CD4⁺ T cells.

Pathological Features of Mitochondrial Ultrastructure Predict Susceptibility to Post-TIPS Hepatic Encephalopathy

BACKGROUND

Post-TIPS hepatic encephalopathy (PSE) is a complex process involving numerous risk factors; the root cause is unclear, but an elevation of blood ammonia due to portosystemic shunt and metabolic disorders in hepatocytes has been proposed as an important risk factor.

AIMS

The aim of this study was to investigate the impact of pathological features of mitochondrial ultrastructure on PSE via transjugular liver biopsy at TIPS implantation.

METHODS

We evaluated the pathological damage of mitochondrial ultrastructure on recruited patients by the Flameng classification system. A score ≤2 (no or low damage) was defined as group A, and a score >2 (high damage level) was defined as group B; routine follow-up was required at 1 and 2 years; the incidence of PSE and multiple clinical data were recorded.

RESULTS

A total of 78 cases in group A and 42 in group B completed the study. The incidence of PSE after 1 and 2 years in group B (35.7% and 45.2%, respectively) was significantly higher than that in group A (16.7% and 24.4%, respectively); the 1- and 2-year OR (95% CI) were 2.778 (1.166-6.615) and 2.565 (1.155-5.696), respectively, for groups A and B. Importantly, group B had worse incidence of PSE than group A [P=0.014, hazard ratio (95%CI): 2.172 (1.190-4.678)].

CONCLUSION

Aggressive damage to mitochondrial ultrastructure in liver shunt predicts susceptibility to PSE. The registration number is NCT02540382.

Natural Dietary Pigments: Potential Mediators against Hepatic Damage Induced by Over-The-Counter Non-Steroidal Anti-Inflammatory and Analgesic Drugs

Over-the-counter (OTC) analgesics are among the most widely prescribed and purchased drugs around the world. Most analgesics, including non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen, are metabolized in the liver. The hepatocytes are responsible for drug metabolism and detoxification. Cytochrome P450 enzymes are phase I enzymes expressed mainly in hepatocytes and they account for ≈75% of the metabolism of clinically used drugs and other xenobiotics. These metabolic reactions eliminate potentially toxic compounds but, paradoxically, also result in the generation of toxic or carcinogenic metabolites. Cumulative or overdoses of OTC analgesic drugs can induce acute liver failure (ALF) either directly or indirectly after their biotransformation. ALF is the result of massive death of hepatocytes induced by oxidative stress. There is an increased interest in the use of natural dietary products as nutritional supplements and/or medications to prevent or cure many diseases. The therapeutic activity of natural products may be associated with their antioxidant capacity, although additional mechanisms may also play a role (e.g., anti-inflammatory actions). Dietary antioxidants such as flavonoids, betalains and carotenoids play a preventive role against OTC analgesics-induced ALF. In this review, we will summarize the pathobiology of OTC analgesic-induced ALF and the use of natural pigments in its prevention and therapy.

Effects of glucosyl-hesperidin and physical training on body weight, plasma lipids, oxidative status and vascular reactivity of rats fed with high-fat diet

OBJECTIVE

The aim of the study was to evaluate the effects of supplementation with glucosyl hesperidin (GH), with or without physical training, on body weight, fat depot, glucose and plasma lipids, oxidative status and vascular function of rats fed with high-fat diet (HFD).

METHODS

After weaning, male Wistar rats were fed with an HFD plus fructose for 12 weeks and started receiving oral antioxidant supplementation and/or physical training after the fourth week of diet for eight further weeks. Body weight, epididymal and retroperitoneal fat, plasma glucose and lipids, oxidative status and mesenteric artery reactivity were evaluated.

RESULTS

Rats fed with HFD presented higher body weight gain and fat accumulation compared to control rats, while GH supplementation did not influence these parameters. Physical training reduced the body weight gain and fat accumulation and modulated the oxidative status by increasing superoxide dismutase activity and total antioxidant capacity and reducing lipid peroxidation. GH alone decreased lipid peroxidation. However, when given to exercised rats, it impaired the response elicited by physical training. HFD caused endothelial dysfunction, and neither GH nor physical exercise prevented it. Potency of sodium nitroprusside was increased in exercised animals but not in GH-supplemented rats.

CONCLUSION

Physical exercise partially decreased the body fat accumulation, decreased plasma levels of glucose and lipids and improved general oxidative status and endothelium-independent relaxation in mesenteric arteries of rats fed with HFD. GH exhibited benefits only in the oxidative status. However, GH given in association with physical exercise did not cause further changes in addition to those promoted by physical exercise. On the contrary, in exercised animals, GH prevented those changes elicited by physical training in plasma glucose and lipids, oxidative status and endothelium-independent relaxation.

Cytoprotective Mechanisms Mediated by Polyphenols from Chilean Native Berries against Free Radical-Induced Damage on AGS Cells

The prevalence of cytoprotective mechanisms induced by polyphenols such as activation of intracellular antioxidant responses (ICM) and direct free radical scavenging was investigated in native Chilean species of strawberries, raspberries, and currants. Human gastric epithelial cells were co- and preincubated with polyphenolic-enriched extracts (PEEs) from Chilean raspberries (Rubus geoides), strawberries (Fragaria chiloensis ssp. chiloensis f. chiloensis), and currants (Ribes magellanicum) and challenged with peroxyl and hydroxyl radicals. Cellular protection was determined in terms of cell viability, glyoxalase I and glutathione s-transferases activities, and carboxymethyl lysine (CML) and malondialdehyde levels. Our results indicate that cytoprotection induced by ICM was the prevalent mechanism for Rubus geoides and F. chiloensis. This agreed with increased levels of glyoxalase I and glutathione S-transferase activities in cells preincubated with PEEs. ORAC index indicated that F. chiloensis was the most efficient peroxyl radical scavenger. Moreover, ICM mediated by F. chiloensis was effective in protecting cells from CML accumulation in contrast to the protective effects induced by free radical scavenging. Our results indicate that although both polyphenol-mediated mechanisms can exert protective effects, ICM was the most prevalent in AGS cells. These results suggest a potential use of these native berries as functional food.