Protective effect of post-ischemic treatment with trans-resveratrol on cytokine production and neutrophil recruitment by rat liver

Effects of beer, wine, and baijiu consumption on non-alcoholic fatty liver disease: Potential implications of the flavor compounds in the alcoholic beverages

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease and its global incidence is estimated to be 24%. Beer, wine, and Chinese baijiu have been consumed worldwide including by the NAFLD population. A better understanding of the effects of these alcoholic beverages on NAFLD would potentially improve management of patients with NAFLD and reduce the risks for progression to fibrosis, cirrhosis, and hepatocellular carcinoma. There is evidence suggesting some positive effects, such as the antioxidative effects of bioactive flavor compounds in beer, wine, and baijiu. These effects could potentially counteract the oxidative stress caused by the metabolism of ethanol contained in the beverages. In the current review, the aim is to evaluate and discuss the current human-based and laboratory-based study evidence of effects on hepatic lipid metabolism and NAFLD from ingested ethanol, the polyphenols in beer and wine, and the bioactive flavor compounds in baijiu, and their potential mechanism. It is concluded that for the potential beneficial effects of wine and beer on NAFLD, inconsistence and contrasting data exist suggesting the need for further studies. There is insufficient baijiu specific human-based study for the effects on NAFLD. Although laboratory-based studies on baijiu showed the antioxidative effects of the bioactive flavor compounds on the liver, it remains elusive whether the antioxidative effect from the relatively low abundance of the bioactivate compounds could outweigh the oxidative stress and toxic effects from the ethanol component of the beverages.

Resveratrol promotes liver cell survival in mice liver-induced ischemia-reperfusion through unfolded protein response: a possible approach in liver transplantation

Background

Ischemia-reperfusion (I/R) of the liver is a multifactorial condition that happens during transplantation and surgery. The deleterious effects of I/R result from the acute production of reactive oxygen species (ROS), which can trigger immediate tissue damage and induce a series of destructive cellular responses, including apoptosis organ failure and inflammation. The production of ROS in the I/R process can damage the antioxidant system and cause liver damage. Resveratrol has been shown to have antioxidant properties in several investigations. Here, we address the therapeutic effect of resveratrol on I/R-induced liver injury by focusing on unfolded protein response (UPR) signaling pathway.

Methods

Five minutes before reperfusion, resveratrol was injected into the tail vein of mice. They were ischemic for 1 h and then re-perfused for 3 h before being slaughtered (I/R). The activity of liver enzymes and the expression levels of genes involved in the unfolded protein response pathway were used to measure the hepatic damage.

Results

Our results revealed that the low dose of resveratrol (0.02 and 0.2 mg/kg) post-ischemic treatment significantly reduced the ALT and AST levels. In addition, compared with the control group, the expression of UPR pathway genes GRP78, PERK, IRE1α, CHOP, and XBP1 was significantly reduced in the resveratrol group. In the mice that received lower doses of resveratrol (0.02 and 0.2 mg/kg), the histopathological changes induced by I/R were significantly improved; however, the highest dose (2 mg/kg) of resveratrol could not significantly protect and solve the I/R damage.

Conclusion

The findings of this study suggest that hepatic ischemia occurs after liver transplantation and that receiving low-dose resveratrol treatment before reperfusion may promote graft survival through inhibition of UPR arms, especially PERK and IRE1α.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40360-022-00611-4.

Better neuroprotective profile of caffeic acid phenyl ester over resveratrol in non-traumatic ischemia-reperfusion injury of the spinal cord

BACKGROUND

Spinal cord ischemia has serious sequelae. The aim of this study is to investigate the effects of resveratrol and caffeic acid phenyl ester (CAPE), a propolis derivative, on spinal cord injury induced by ischemia-reperfusion (IR).

METHODS

In our research, 30 male Wistar albino rats, 200-250 gr, were used. Before the experiment, during a week of the process, the rats were fed with these two agents, and the experimental group rats were exposed to spinal cord IR injury. At the end of the experiment, spinal cord samples were taken from the sacrificed rats. Bax, p53, nNOS, and Beclin-1 immunoreactivity moreover TUNEL (+) cells were evaluated with immunohistochemically in the IR-induced damaged rats.

RESULTS

It has been clearly determined that the TUNEL (+) apoptotic cell number and immunopositive cells of nNOS, Beclin-1, p53, Bax were raised in the IR group. However, these increments partially were restored in the resveratrol and CAPE-fed rats with IR-induced injury.

CONCLUSION

In light of our data, resveratrol, and CAPE could be beneficial in spinal cord IR injury. Although both agents provide beneficial effects, it can be said that CAPE is partially more effective in spinal cord injury caused by IR.

Therapeutic Applications of Resveratrol in Hepatic Encephalopathy through Its Regulation of the Microbiota, Brain Edema, and Inflammation

Hepatic encephalopathy is a common complication in patients with liver cirrhosis and portosystemic shunting. Patients with hepatic encephalopathy present a variety of clinical features, including neuropsychiatric manifestations, cognitive dysfunction, impaired gut barrier function, hyperammonemia, and chronic neuroinflammation. These pathogeneses have been linked to various factors, including ammonia-induced oxidative stress, neuronal cell death, alterations in the gut microbiome, astrocyte swelling, and blood-brain barrier disruptions. Many researchers have focused on identifying novel therapeutics and prebiotics in the hope of improving the treatment of these conditions. Resveratrol is a natural polyphenic compound and is known to exert several pharmacological effects, including antioxidant, anti-inflammatory, and neuroprotective activities. Recent studies suggest that resveratrol contributes to improving the neuropathogenic effects of liver failure. Here, we review the current evidence describing resveratrol's effects in neuropathogenesis and its impact on the gut-liver axis relating to hepatic encephalopathy. We highlight the hypothesis that resveratrol exerts diverse effects in hepatic encephalopathy and suggest that these effects are likely mediated by changes to the gut microbiota, brain edema, and neuroinflammation.

The Role of Resveratrol in Liver Disease: A Comprehensive Review from In Vitro to Clinical Trials

Many studies have shown that resveratrol has a lot of therapeutic effects on liver disorders. Its administration can significantly increase the survival rate after liver transplantation, reduce fat deposition and ischemia-induced necrosis and apoptosis in Wistar rats. Resveratrol can provide Liver protection against chemical, cholestatic, and alcohol-mediated damage. It can improve glucose metabolism and lipid profile, reduce liver fibrosis, and steatosis. Additionally, it is capable of altering the fatty acid composition of the liver cells. Resveratrol may be a potential treatment option for the management of non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory, antioxidant, and calorie-restricting effects. There are also studies that have evaluated the effect of resveratrol on lipid and liver enzyme profiles among patients with metabolic syndrome (MetS) and related disorders. Based on the extent of liver disease worldwide and the need to find new treatment possibilities, this review critically examines current in vitro and in vivo preclinical studies and human clinical studies related to liver protection.

Differentiation of human dental pulp stem cells into neuronal by resveratrol

Dental pulp stem cells (DPSCs) have been proposed as a promising source of stem cells in nerve regeneration due to their close embryonic origin and ease of harvest. Resveratrol (RSV) is a natural polyphenolic and possesses many biological functions such as anti-inflammatory activity and protection against atherosclerosis and neuroprotective activities. There is increasing evidence showing that RSV plays a pivotal role in neuron protection and neuronal differentiation. In this study, we isolated DPSCs from impacted third molars and investigated whether RSV induces neuronal differentiation of DPSCs. To avoid loss of DPSCs multipotency, all the experiments were conducted on cells at early passages. RT-PCR results showed that RSV-treated DPSCs (RSV-DPSCs) significantly increased the expression of the neuroprogenitor marker Nestin. When RSV-DPSCs were differentiated with neuronal induction media (RSV-dDPSCs), they showed a cell morphology similar to neurons. The expression of neuronal-specific marker genes Nestin, Musashi, and NF-M in RSV-dDPSCs was significantly increased. Immunocytochemical staining and Western blot analysis showed that the expression of neuronal marker proteins, Nestin, and NF-M, was significantly increased in RSV-dDPSCs. Therefore, we have shown that RSV treatment, along with the use of neuronal induction media, effectively promotes neuronal cell differentiation of DPSCs.

Role of food-derived antioxidant agents against acetaminophen-induced hepatotoxicity

Context Acetaminophen (APAP), also known as paracetamol and N-acetyl p-aminophenol, is one of the most frequently used drugs for analgesic and antipyretic purposes on a worldwide basis. It is safe and effective at recommended doses but has the potential for causing hepatotoxicity and acute liver failure (ALF) with overdose. To solve this problem, different strategies have been developed, including the use of compounds isolated from food, which have been studied to characterize their efficacy as natural dietary antioxidants. Objective The objective of this study is to show the beneficial effects of a variety of natural compounds and their use against acetaminophen-induced hepatotoxicity. Methods PubMed database was reviewed to compile data about natural compounds with hepatoprotective effects against APAP toxicity. Results and conclusion As a result, the health-promoting properties of 13 different food-derived compounds with protective effect against APAP-induced hepatotoxicity were described as well as the mechanisms involved in hepatoprotection.

The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival

The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer's (LR) solution for liver perfusion and preservation in vitro or combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic gene Bcl-2 and decreasing the expression of the proapoptosis genes of Caspase-3 and Bax, and further protects hepatocytes from apoptotic death and improves liver function.

Resveratrol and liver: A systematic review

Background:

Recent studies demonstrated that resveratrol has many therapeutic effects on liver disorders. Resveratrol significantly increased survival after liver transplantation, decreased fat deposition, necrosis, and apoptosis which induced by ischemia in Wistar rats. It provided liver protection against chemical, cholestatic, and alcohol injury. Resveratrol can improve glucose metabolism and lipid profile and decrease liver fibrosis and steatosis. Furthermore, it was able to alter hepatic cell fatty acid composition. According to extension of liver disease around the world and necessity of finding new threat, this review critically examines the current preclinical in vitro and in vivo studies on the preventive and therapeutic effects of resveratrol in liver disorders.

Materials and Methods:

A search in PubMed, Google Scholar, and Scopus was undertaken to identify relevant literature using search terms, including “liver,” “hepatic,” and “Resveratrol.” Both in vivo and in vitro studies were included. No time limiting considered for this search.

Results:

A total of 76 articles were eligible for this review. In these articles, resveratrol shows antioxidative properties in different models of hepatitis resulting in reducing of hepatic fibrosis.

Conclusion:

Resveratrol could reduce hepatic steatosis through modulating the insulin resistance and lipid profile in animals. These high quality preclinical studies propose the potential therapeutic implication of resveratrol in liver disorders especially those with hepatic steatosis. Resveratrol can play a pivotal role in prevention and treatment of liver disorders by reducing hepatic fibrosis.

The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival

The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer's (LR) solution for liver perfusion and preservation in vitro or combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic gene Bcl-2 and decreasing the expression of the proapoptosis genes of Caspase-3 and Bax, and further protects hepatocytes from apoptotic death and improves liver function.

Critical review of resveratrol in xenobiotic-induced hepatotoxicity

Use of natural products is increasingly popular. In fact, many patients with liver diseases self-medicate with herbal supplements. Resveratrol (RSV), in particular, is a common natural product that can reduce injury in experimental models of liver disease. Xenobiotic hepatotoxicity is a particularly important area-of-need for therapeutics. Drug-induced liver injury, for example, is the most common cause of acute liver failure (ALF) and ALF-induced deaths in many countries. Importantly, RSV protects against hepatotoxicity in animal models in vivo caused by several drugs and chemicals and may be an effective intervention. Although many mechanisms have been proposed to explain the protection, not all are consistent with other data. Furthermore, RSV suffers from other issues, including limited bioavailability due to extensive hepatic metabolism. The purpose of this article is to summarize recent findings on the protective effects of RSV in xenobiotic-induced liver injury and other forms of liver injury and to provide a critical review of the underlying mechanisms. New mechanisms that are more consistent with data emerging from the toxicology field are suggested. Efforts to move RSV into clinical use are also considered. Overall, RSV is a promising candidate for therapeutic use, but additional studies are needed to better understand its effects.

Organ-Protective Effects of Red Wine Extract, Resveratrol, in Oxidative Stress-Mediated Reperfusion Injury

Resveratrol, a polyphenol extracted from red wine, possesses potential antioxidative and anti-inflammatory effects, including the reduction of free radicals and proinflammatory mediators overproduction, the alteration of the expression of adhesion molecules, and the inhibition of neutrophil function. A growing body of evidence indicates that resveratrol plays an important role in reducing organ damage following ischemia- and hemorrhage-induced reperfusion injury. Such protective phenomenon is reported to be implicated in decreasing the formation and reaction of reactive oxygen species and pro-nflammatory cytokines, as well as the mediation of a variety of intracellular signaling pathways, including the nitric oxide synthase, nicotinamide adenine dinucleotide phosphate oxidase, deacetylase sirtuin 1, mitogen-activated protein kinase, peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, hemeoxygenase-1, and estrogen receptor-related pathways. Reperfusion injury is a complex pathophysiological process that involves multiple factors and pathways. The resveratrol is an effective reactive oxygen species scavenger that exhibits an antioxidative property. In this review, the organ-protective effects of resveratrol in oxidative stress-related reperfusion injury will be discussed.

Resveratrol Decreases TXNIP mRNA and Protein Nuclear Expressions With an Arterial Function Improvement in Old Mice

Aging leads to a high prevalence of glucose intolerance and cardiovascular diseases, with oxidative stress playing a potential role. Resveratrol has shown promising effects on glucose tolerance and tends to improve endothelial function in elderly patients. Thioredoxin-interacting protein (TXNIP) was recently proposed as a potential link connecting glucose metabolism to oxidative stress. Here, we investigated the resveratrol-induced improvement of arterial aging phenotype in old mice and the expression of aortic TXNIP. Using an in vivo model of old mice with or without 3-month resveratrol treatment, we investigated the effects of resveratrol on age-related impairments from a cardiovascular Doppler analysis, to a molecular level, by studying inflammation and oxidative stress factors. We found a dual effect of resveratrol, with a decrease of age-related glucose intolerance and oxidative stress imbalance leading to reduced matrix remodeling that forestalls arterial aging phenotype in terms of intima-media thickness and arterial distensibility. These results provide the first evidence that aortic TXNIP mRNA and protein nuclear expressions are increased in the arterial aging and decreased by resveratrol treatment. In conclusion, we demonstrated that resveratrol helped to restore several aging impaired processes in old mice, with a decrease of aortic TXNIP mRNA and protein nuclear expressions.

Resveratrol prevents protein nitration and release of endonucleases from mitochondria during acetaminophen hepatotoxicity

Overdose of acetaminophen (APAP) is a common cause of acute liver injury and liver failure. The mechanism involves formation of a reactive metabolite, protein binding, oxidative stress and activation of c-Jun N-terminal kinase (JNK), mitochondrial dysfunction, and nuclear DNA fragmentation caused by endonucleases released from damaged mitochondria. Previous work has shown that the natural product resveratrol (RSV) can protect against APAP hepatotoxicity in mice through prevention of lipid peroxidation and anti-inflammatory effects. However, these earlier studies did not take into consideration several fundamental aspects of the pathophysiology. To address this, we treated C57Bl/6 mice with 300 mg/kg APAP followed by 50 mg/kg RSV 1.5 h later. Our results confirmed that RSV reduced liver injury after APAP overdose in mice. Importantly, RSV did not inhibit reactive metabolite formation and protein bindings, nor did it reduce activation of JNK. However, RSV decreased protein nitration after APAP treatment, possibly through direct scavenging of peroxynitrite. Interestingly, RSV also inhibited release of apoptosis-inducing factor and endonuclease G from mitochondria independent of Bax pore formation and prevented the downstream nuclear DNA fragmentation. Our data show that RSV protects against APAP hepatotoxicity both through antioxidant effects and by preventing mitochondrial release of endonucleases and nuclear DNA damage.

Resveratrol effectively attenuates α-naphthyl-isothiocyanate-induced acute cholestasis and liver injury through choleretic and anti-inflammatory mechanisms

AIM

α-Naphthylisothiocyanate (ANIT) is a well-characterized cholestatic agent for rats. The aim of this study was to examine whether resveratrol could attenuate ANIT-induced acute cholestasis and liver injury in rats.

METHODS

SD rats were treated with resveratrol (15 or 30 mg/kg, ip) or a positive control drug ursodeoxycholic acid (100 mg/kg, po) for 5 consecutive days followed by a single dose of ANIT (60 mg/kg, po). Bile flow, and serum biochemical markers and bile constituents were measured 48 h after ANIT administration. Hepatic levels of oxidative repair enzymes (glutathione peroxidase, catalase and MnSOD), myeloperoxidase activity, TNF-α, IL-6 and ATP content, as well as the expression of liver transporter genes and proteins were assayed.

RESULTS

ANIT exposure resulted in serious cholestasis and liver injury, as shown by marked neutrophil infiltration in liver, dramatically increased serum levels of ALT, AST, GGT, ALP, TBA, TBIL, IBIL and DBIL, and significantly decreased bile excretion and biliary output of GSH and HCO3(-). ANIT significantly increased TNF-α and IL-6 release and myeloperoxidase activity, decreased mitochondrial biogenesis in liver, but had little effect on hepatic oxidative repair enzymes and ATP content. Furthermore, ANIT significantly decreased the expression of Mrp2, FXR and Cyp7a1, markedly increased Mrp3 expression in liver. Pretreatment with resveratrol attenuated ANIT-induced acute cholestasis and liver injury, and other pathological changes. Pretreatment with ursodeoxycholic acid was less effective.

CONCLUSION

Resveratrol effectively attenuates ANIT-induced acute cholestasis and liver injury in rats, possibly through suppression of neutrophil infiltration, as well as upregulation of expression of hepatic transporters and enzymes, thus decreasing accumulation of bile acids.

Protective effects of resveratrol on hepatotoxicity induced by isoniazid and rifampicin via SIRT1 modulation

Acute liver injury was induced in male BALB/c mice by coadministering isoniazid and rifampicin. In this work, the effects of resveratrol (1) were investigated in the hepatotoxicity caused by isoniazid-rifampicin in mice. Compound 1 was administered 30 min prior to isoniazid-rifampicin. Serum biochemical tests, liver histopathological examination, oxidative stress, myeloperoxidase activity, cytokine production (TNF-α, IL-12p70, and IL-10), and mRNA expression of SIRT1-7 and PPAR-γ/PGC1-α were evaluated. The administration of 1 significantly decreased aspartate transaminase and alanine aminotransferase levels, myeloperoxidase activity, and cytokine levels. Furthermore, 1 reverted the decrease of catalase and glutathione activities and ameliorated the histopathological alterations associated with antituberculosis drugs. Modulation of SIRT1 and PPAR-γ/PGC1-α expression is likely involved in the protective effects of 1. The results presented herein show that 1 was able to largely prevent the hepatotoxicity induced by isoniazid and rifampicin in mice, mainly by modulating SIRT1 mRNA expression.

Dual effects of resveratrol on arterial damage induced by insulin resistance in aged mice

Aging leads to increased insulin resistance and arterial dysfunction, with oxidative stress playing an important role. This study explored the metabolic and arterial effects of a chronic treatment with resveratrol, an antioxidant polyphenol compound that has been shown to restore insulin sensitivity and decrease oxidative stress, in old mice with or without a high-protein diet renutrition care. High-protein diet tended to increase insulin resistance and atheromatous risk. Resveratrol improved insulin sensitivity in old mice fed standard diet by decreasing homeostasis model of assessment-insulin resistance and resistin levels. However, resveratrol did not improve insulin resistance status in old mice receiving the high-protein diet. In contrast, resveratrol exhibited deleterious effects by increasing inflammation state and superoxide production and diminishing aortic distensibility. In conclusion, we demonstrate that resveratrol has beneficial or deleterious effects on insulin sensitivity and arterial function, depending on nutritional status in our models.

Review of recent data on the metabolism, biological effects, and toxicity of resveratrol in humans

Several recently published clinical trials have extended our knowledge on the use of resveratrol (RVT) to treat several human pathological and metabolic disorders. Herein, we present insights into the metabolism, biological effects, and toxicity of RVT in humans. Recent data show that RVT exhibits antioxidant and anti-inflammatory activities. It can also improve glucose and lipid metabolism, it acts on cardiovascular parameters, and can modify some pathways involved in carcinogenesis. However, these effects are mostly tiny and the results are sometimes controversial as they depend on the protocols (i.e. dose, form of administration, patients' characteristics, adjuvant therapy, etc.). Toxicological data confirm that RVT is well tolerated. Any adverse effects (mainly concerning the abdomen), at doses of ≥0.5 g/day for long periods, remain moderate and reversible. Nevertheless, the efficacy and safety of RVT need to be further investigated.

Resveratrol protects spinal cord dorsal column from hypoxic injury by activating Nrf-2

Damage from oxidative stress plays a critical role in spinal cord injury. Nuclear factor erythroid 2-related factor (Nrf-2) signaling pathway can be activated by cellular oxidative stress. Resveratrol, a plant-derived polyphenolic compound found in red wine, has antioxidant properties. In the present study, we have examined the neuroprotective effect of resveratrol and the role of Nrf-2 in spinal cord hypoxic injury. The spinal cord was removed from adult male Wistar rats from T2-T10 and the dorsal column was used to induce hypoxic injury in vitro with and without treatment with resveratrol (50μM). Significant changes were found in the compound action potential (CAP) of spinal cord dorsal column, and hematoxyline and eosin (H&E) staining showed that resveratrol significantly improved neuronal injury. The biochemical assays showed significant changes in lipid peroxidase (LPO), reduced glutathione (GSH), superoxide dismutase (SOD), protein carbonyl (PC), mitochondrial ATP content, and mitochondrial Ca(++). Furthermore, using immunohistochemistry and Western blot, we found that after resveratrol treatment during hypoxic injury there was a significant activation of NrF-2 and down regulation of the glial fibrillary acidic protein (GFAP) content. The results show that resveratrol treatment has neuroprotective effects on CAP, Ca(++) loading, and biochemical parameters after hypoxic injury. The neuroprotective effect is likely to be exerted by increased activation of transcription factor Nrf-2 by resveratrol along with its direct antioxidant effect to ameliorate the oxidative damage and preserve mitochondrial function.

Improving the function of liver grafts exposed to warm ischemia by the Leuven drug protocol: exploring the molecular basis by microarray

Livers exposed to warm ischemia (WI) before transplantation are at risk for primary nonfunction (PNF), graft dysfunction, and ischemic biliary strictures, all associated with ischemia/reperfusion injury (IRI). Our multifactorial approach, Leuven drug protocol (LDP), has been shown to reduce these effects and increase recipient survival in WI/IRI-damaged porcine liver transplantation. The aim was the identification of the molecular mechanisms responsible for the hepatoprotective effects of the LDP. Porcine livers were exposed to 45 minutes of WI, cold-stored for 4 hours, transplanted, and either modulated (LDP group; n = 3) or not modulated (control group; n = 4). In the LDP group, the donor livers were flushed with streptokinase and epoprostenol before cold perfusion; the recipients received intravenous glycine, a-1-acid-glycoprotein, FR167653 (a mitogen-activated protein kinase inhibitor), a-tocopherol, glutathione, and apotransferrin. Liver samples were taken before WI and 1 hour after reperfusion. Gene expression was determined with microarrays and molecular pathways and key regulatory genes were identified. The number of genes changed between baseline and 1 hour after reperfusion was 686 in the LDP group and 325 in the control group. The extra genes in the LDP group belonged predominantly to pathways related to cytokine activity, apoptosis, and cell proliferation. We identified 7 genes that were suppressed in the LDP group. These genes could be linked in part to the administered drugs. New potential drug targets were identified on the basis of genes induced in the control group but unaffected in the LDP group and interactions predicted by the literature. In conclusion, the LDP primarily resulted in the suppression of inflammation-regulating genes in IRI. Furthermore, the microarray technique helped us to identify additional gene targets.

Injury of the hepatic barrier and intestinal barrier in patients with small-for-size graft syndrome after partial liver transplantation: mechanisms and protective measures

The intestinal barrier can resist the invasion of pathogens and prevent harmful substances from going into blood circulation to maintain the stability of internal environment, while the hepatic barrier is a vital structure that can protect liver function and prevent endotoxin and virus from entering the liver to damage hepatocytes. Both the two barrier structures are most vulnerable to damage after partial liver transplantation due to the occurrence of postoperative 'small-for-size graft syndrome'. The pathogenesis of 'small-for-size graft syndrome' is associated with postoperative portal hypertension and hyperperfusion. How to effectively control the occurrence of 'small-for-size graft syndrome' and to protect the intestinal barrier and hepatic barrier postoperatively are key to the maintenance of intestinal and hepatic functions. The primary aim of this paper is to review the mechanisms underlying the development of injury of the hepatic barrier and intestinal barrier in patients with small-for-size graft syndrome after partial liver transplantation and to propose the corresponding protective measures.

Mangafodipir protects against hepatic ischemia-reperfusion injury in mice

Introduction and Aim

Mangafodipir is a contrast agent used in magnetic resonance imaging that concentrates in the liver and displays pleiotropic antioxidant properties. Since reactive oxygen species are involved in ischemia-reperfusion damages, we hypothesized that the use of mangafodipir could prevent liver lesions in a mouse model of hepatic ischemia reperfusion injury. Mangafodipir (MnDPDP) was compared to ischemic preconditioning and intermittent inflow occlusion for the prevention of hepatic ischemia-reperfusion injury in the mouse.

Methods

Mice were subjected to 70% hepatic ischemia (continuous ischemia) for 90 min. Thirty minutes before the ischemic period, either mangafodipir (10 mg/kg) or saline was injected intraperitoneally. Those experimental groups were compared with one group of mice preconditioned by 10 minutes' ischemia followed by 15 minutes' reperfusion, and one group with intermittent inflow occlusion. Hepatic ischemia-reperfusion injury was evaluated by measurement of serum levels of aspartate aminotransferase (ASAT) activity, histologic analysis of the livers, and determination of hepatocyte apoptosis (cytochrome c release, caspase 3 activity). The effect of mangafodipir on the survival rate of mice was studied in a model of total hepatic ischemia.

Results

Mangafodipir prevented experimental hepatic ischemia-reperfusion injuries in the mouse as indicated by a reduction in serum ASAT activity (P<0.01), in liver tissue damages, in markers of apoptosis (P<0.01), and by higher rates of survival in treated than in untreated animals (P<0.001). The level of protection by mangafodipir was similar to that observed following intermittent inflow occlusion and higher than after ischemic preconditioning.

Conclusions

Mangafodipir is a potential new preventive treatment for hepatic ischemia-reperfusion injury.

Resveratrol improves neuron protection and functional recovery in rat model of spinal cord injury

Researches on the pathology of spinal cord injury (SCI) have been recently focused on oxidative radicals stress and inflammation associated neuronal apoptosis. Resveratrol, a natural phenolic compound, has been extensively studied and shown a wide variety of health beneficial effects, including prevention of cardiovascular diseases and cancer and neuroprotective activities. However, the study of its potential role in neuroprotection and underlying mechanism in SCI model has been limited. In this study, we investigated the effect of resveratrol on neurologic functions and histopathologic changes after SCI and the mechanism underlying its neuroprotective effects. First, neuronal function after SCI was evaluated with Basso Beattle Bresnahan locomotor rating scale (BBB) and the result showed that injured animals treated with resveratrol showed a significant increase in BBB scores. Further, histopathological alternations were evaluated with HE and Nissl staining, showing a restored neural morphology and an increase of the number of neurons after resveratrol administration. To explore the underlying mechanism, anti-oxidation effect of resveratrol was assessed by measuring superoxide dismutase (SOD) activity and malondialdehyde (MDA) level after SCI. Resveratrol treatment reversed the decrease of SOD activity and increase of MDA level caused by SCI, suggesting its anti-oxidation role in response to the injury. In addition, resveratrol treatment suppressed immunoreactivity and expression of inflammatory cytokines including IL-1β, IL-10, TNF-α, and myeloperoxidase (MPO) after SCI, suggesting an anti-inflammation effect of resveratrol. Finally, resveratrol treatment inhibited injury-induced apoptosis as assessed by electrical microscopy and TUNEL staining and affected the expression level of apoptosis-related gene Bax, Bcl-2 and caspase-3, which indicated its anti-apoptosis role after SCI. Our data suggest that resveratrol significantly promotes the recovery of rat dorsal neuronal function after SCI, and this effect is related to its characteristics of anti-oxidation, anti-inflammation and anti-apoptosis.

Resveratrol and liver disease: from bench to bedside and community

Liver diseases incorporate several maladies, which can range from benign histological changes to serious life-threatening conditions. These may include inborn metabolic disease, primary and metastatic cancers, alcoholic cirrhosis, viral hepatitis and drug-induced hepatotoxicity. Liver disease remains a major cause of morbidity and mortality with significant economic and social costs. Several novel approaches are currently being studied which may provide a better therapeutic outcome. The use of naturally occurring phytochemicals, some of them obtained from dietary sources, in the amelioration of illness have recently gained considerable popularity. These agents, having anti-oxidant and anti-inflammatory properties, provide a safe and effective means of ameliorating chronic disease. Resveratrol, a grape polyphenol, has shown considerable promise as a therapeutic agent in the treatment of the aforementioned liver ailments. Several studies have highlighted the hepatoprotective properties of resveratrol. Resveratrol has been shown to prevent hepatic damage because of free radicals and inflammatory cytokines, induce anti-oxidant enzymes and elevate glutathione content. Resveratrol has also been shown to modulate varied signal transduction pathways implicated in liver diseases. This review critically examines the current preclinical in vitro and in vivo studies on the preventive and therapeutic effects of resveratrol in liver diseases. The review highlights the pharmacological mechanisms involved in mediating the aforementioned effects. Toxicity, pharmacokinetics and clinical bioavailability of resveratrol are also reviewed in this article. The challenges involved, future directions and novel approaches such as site-specific drug delivery in the use of resveratrol for the prevention and treatment of liver disease are also discussed.

trans-Resveratrol downregulates Txnip overexpression occurring during liver ischemia-reperfusion

Txnip (thioredoxin-interacting protein) is a protein with multifunctional roles in cellular responses and stress-related diseases. Txnip is involved in intracellular redox regulation and has been recently described as a possible link between redox state and metabolism. trans-Resveratrol (T-res) is a natural phytoalexin with antiproliferative, antiapoptotic and antioxidative effects. However, to date there have been no reports of the implication of Txnip in a model of liver acute stress such as ischemia-reperfusion (I/R) and no work has looked for a T-res effect on Txnip. Here we studied the effects of a post-ischemic treatment of T-res on the liver thioredoxin (Trx)/Txnip system and investigated whether the T-res effects were dependent on *NO production. In this work, liver I/R induced hepatic Txnip expression and T-res inhibited I/R Txnip expression. This decrease in Txnip expression by T-res was associated with an increase in liver Trx redox activity and a decrease in hepatic I/R-induced Trx-1 expression with no effect on Trx-2, on plasma Trx redox activity or on liver and plasma Trx reductase activity, independently of *NO production. In conclusion, these results show that in our model, not only did T-res protect Trx redox activity by diminishing the Txnip protein expression; it also reduced secretion of Trx1. This is the first report of a major implication of the Trx1/Txnip system in hepatic I/R injuries. It also affirms the importance of the antioxidant effect of T-res on the Trx1/Txnip system.

Protection against severe intestinal ischemia/reperfusion injury in rats by intravenous resveratrol

BACKGROUND

Repetitive enteral or intraperitoneal administration of resveratrol at high doses has recently been found to protect the small intestine against acute ischemia/reperfusion (I/R) injury. In the present work, the protective potential of solvent-free continuous intravenous infusions of small amounts of resveratrol was studied in a model of severe intestinal I/R injury.

MATERIALS AND METHODS

Mesenteric ischemia was induced in male Wistar rats (six animals/group) by superior mesenteric artery occlusion (SMAO, 90 min) and reperfusion (120 min) by reopening of the microvascular clamp. Resveratrol (0.056 or 0.28 mg/kg) was continuously perfused into the jugular vein (0.014 or 0.07 mg/kg × h) starting 30 min before SMAO; an SMAO control group and sham groups (no SMAO) receiving either 0.9% NaCl solution or resveratrol (0.28 mg/kg) were included. During the experimental procedure, isotonic saline was given at a systolic blood pressure below 90 mmHg, and several parameters including those of biomonitoring and blood gas analysis were measured. Small intestine injury was assessed macroscopically, from released plasma enzyme activities, from the tissue contents of thiobarbituric acid-reactive substances and hemoglobin, from the tissue myeloperoxidase activity, and histopathologically.

RESULTS

Resveratrol at only 0.056 mg/kg significantly decreased the macroscopic damage score, the tissue myeloperoxidase activity, the hemoglobin content, the histopathologic score, and the plasma glutamate-pyruvate transaminase activity, but it did not improve the systemic and metabolic parameters. Instead, during reperfusion, significantly higher volumes of saline were administered to animals receiving the polyphenol, although resveratrol did not significantly affect any parameters in sham-operated animals.

CONCLUSIONS

Low doses of intravenously administered resveratrol considerably protected the rat small intestine against severe I/R injury, despite some adverse effects on blood pressure under these conditions.