Hepataprotective effects of ginsenoside Rg1 - A review

BACKGROUND AND ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng has been used as efficient tonic and for the treatment of various diseases including hepatic disorders. Ginseng saponins, also known as ginsenosides, are principal constituents and have been treated to be responsible for disparate ginseng health benefits. The current review mainly focuses on ginsenoside Rg1, a compound isolated from traditional Chinese herbal medicine Panax ginseng Meyer.

AIMS

To summary the hepataprotective effects and related mechanisms of ginsenoside Rg1, we conclude this review by combining the literature and our own researches.

METHODS

As evidenced, we organized the pharmacological function of ginsenoside Rg1 by searching the pubmed. It has been deeply studied and summarized in the field of neurobiology, however, in this paper we described the pharmacological function of Rg1 in liver related to antioxidative stress and anti-inflammation. R&D: Individual ginsenoside could be used since it shows a wide array of beneficial functions in the regulation and disorders of acute and chronic hepatotoxicity, hepatitis, hepatic fibrosis and cirrhosis in various pathways and different mechanisms. Of note, the antioxidant hepatic protection of ginsenoside Rg1 is mainly through the induction of Keap1-Nrf2-ARE signaling pathway.

CONCLUSION

The multi-target actions of Rg1 substantiates it as a promising drug candidate for the treatment of hepatic impairment in different factors induced liver diseases.

Pathophysiology, prevention, treatment, and outcomes of intestinal failure-associated liver disease

BACKGROUND

Intestinal failure-associated liver disease (IFALD) remains a serious problem in the treatment of infants with nutritional problems and short bowel syndrome.

METHODS

A review of the recent literature from 2010 to 2016, concentrating on articles related to the pathophysiology of IFALD and to outcomes of novel nutritional and pharmacological therapies for neonatal cholestasis in the post-surgical neonate.

RESULTS

The pathophysiology of IFALD relates to an increase sensitivity of the neonatal liver to cholestasis in the non-fed state; prolonged cholestasis almost inevitably results in liver damage which will progress from fibrosis to cirrhosis. Clinically discerned risk factors include premature birth, inflammation, sepsis, disruption of the enterohepatic circulation by creation of a proximal stoma, and the duration and type of parenteral nutritional support. Within the hepatocyte, the regulatory enzyme farsanoid receptor X (FXR) appears to play a pivotal role in the development of cholestasis. Recent studies have shown that its activity is suppressed by sepsis, and by plant phytosterols found in soy-based lipid preparations. This paradigm is reflected in the emerging consensus for the care of post-surgical neonates, which is based around a multi-disciplinary team approach. Using an algorithm-driven approach, an appropriate balance between caloric support and prevention of IFALD can be achieved.

CONCLUSIONS

Further prospective studies are required to further refine the optimal sequence of use of these therapies and the long-term effects on neurological development and hepatic function. However, with optimal care, the number of IF patients progressing to end-stage liver disease because of IFALD should be very low.

[Protective effect of quercetin against immunological liver injury through activating Nrf2/ARE signaling pathway]

Objective To observe the protective effect of quercetin against immunological liver injury induced by triptolide, and investigate the involvement of Nrf2/ARE signaling pathway in the protection. Methods Fifty C57BL/6J mice were randomly divided into five groups: control group, model group, (20, 50, 80) mg/kg quercetin pre-treatment groups. Each group included 10 mice. The mice were treated with different doses of quercetin once daily for consecutive 10 days. At the end of the experiment, triptolide (500 μg/kg) was given intragastrically to induce immunological liver injury in all groups except for the control group. Twenty-two hours later, the levels of serum ALT , AST were detected. The contents of GSH, SOD and MDA in liver tissue homogenates were measured through commercial kits. HE staining was performed to observe pathologic changes of the liver. The mRNA expressions of heme oxygenase-1 (HO-1), NQO1, glutamate-cysteine ligase catalytic subunit (GCLC) was tested by quantitative real-time PCR, and the protein expression of Nrf2 was detected by Western blotting. Results Compared with the model group, the serum activities of ALT and AST as well as MDA content remarkably decreased by the administration of quercetin (80 mg/kg), while GSH, SOD contents were elevated in liver tissues; pathologic changes of the liver was ameliorated evidently by quercetin; Nrf2 protein expression in the nucleus as well as mRNA expressions of HO-1, NQO1, GCLC increased. Moreover, the protective effect of 50 mg/kg quercetin was not as good as that of 80 mg/kg quercetin, and 20 mg/kg quercetin did little against the immunological liver injury. Conclusion High-dose quercetin can inhibit immunological liver injury induced by triptolide, and the mechanism may be associated with the activation of Nrf2/ARE signaling pathway.

The NF-κB inhibitor celastrol attenuates acute hepatic dysfunction induced by cecal ligation and puncture in rats

Acute hepatic dysfunction associating sepsis is mediated mainly by toll-like receptor-4 (TLR-4)/nuclear factor kappa-B (NF-κB) inflammatory pathway. This study explores potential hepatoprotective effect of the NF-κB inhibitor celastrol in cecal ligation and puncture (CLP) model in rats. Protective effect of celastrol (1mg/kg, i.p., 1h before CLP) was illustrated after 24h by preventing CLP-induced hepatic histopathological changes and elevation in serum hepatic biomarkers [alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB) and gamma aminotransferase (γ-GT)] without affecting mortality. Celastrol anti-inflammatory effect was illustrated by inhibiting increased serum and hepatic mRNA expression of interleukin-6 (IL-6) without affecting IL-10 elevation. Furthermore, celastrol inhibited CLP-induced elevations in hepatic mRNA expression of nuclear factor inhibitory protein kappa-B alpha (NFκBia), TLR-4, 5-lipoxygenase (5-LOX) and prevented NF-κB/p65 nuclear translocation and activation. In conclusion, celastrol prevented CLP-induced acute hepatic dysfunction through its anti-inflammatory effect by attenuating NF-κB activation, TLR-4 and 5-LOX expression with subsequent reduction in pro-inflammatory IL-6.

Predictors of Liver Toxicity Following Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma

PURPOSE

To identify risk factors associated with a decline in liver function after stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma.

METHODS AND MATERIALS

Data were analyzed from patients with hepatocellular carcinoma treated on clinical trials of 6-fraction SBRT. Liver toxicity was defined as an increase in Child-Pugh (CP) score ≥2 three months after SBRT. Clinical factors, SBRT details, and liver dose-volume histogram (DVH) parameters were tested for association with toxicity using logistic regression. CP class B patients were analyzed separately.

RESULTS

Among CP class A patients, 101 were evaluable, with a baseline score of A5 (72%) or A6 (28%). Fifty-three percent had portal vein thrombus. The median liver volume was 1286 cc (range, 766-3967 cc), and the median prescribed dose was 36 Gy (range, 27-54 Gy). Toxicity was seen in 26 patients (26%). Thrombus, baseline CP of A6, and lower platelet count were associated with toxicity on univariate analysis, as were several liver DVH-based parameters. Absolute and spared liver volumes were not significant. On multivariate analysis for CP class A patients, significant associations were found for baseline CP score of A6 (odds ratio [OR], 4.85), lower platelet count (OR, 0.90; median, 108 × 10⁹/L vs 150 × 10⁹/L), higher mean liver dose (OR, 1.33; median, 16.9 Gy vs 14.7 Gy), and higher dose to 800 cc of liver (OR, 1.11; median, 14.3 Gy vs 6.0 Gy). With 13 CP-B7 patients included or when dose to 800 cc of liver was replaced with other DVH parameters (eg, dose to 700 or 900 cc of liver) in the multivariate analysis, effective volume and portal vein thrombus were associated with an increased risk.

CONCLUSIONS

Baseline CP scores and higher liver doses (eg, mean dose, effective volume, doses to 700-900 cc) were strongly associated with liver function decline 3 months after SBRT. A lower baseline platelet count and portal vein thrombus were also associated with an increased risk.

Antidepressant-lnduced Liver Injury

Objective:

To review principles of drug-induced liver injury (DILI), summarize characteristics of antidepressant-mediated liver Injury, and provide recommendations for monitoring and management.

Data Sources:

A search relating to antidepressant-induced liver injury was performed using MEDLINE (1966–March 2007). Search terms included antidepressant, cholestasis, hepatotoxicity, jaundice, liver injury, toxic hepatitis, and transaminases. Reference citations not Identified in the initial database search were also utilized.

Study Selection and Data Extraction:

All English-language case reports, letters, and review articles identified from the data sources were used. Case reports and letters relating to hepatotoxicity from antidepressant overdose were excluded.

Data Synthesis:

Antidepressant-induced liver injury described in published cases were of the idiopathic type and, by definition, cannot be predicted based on dose or specific risk factors. Paroxetine had the largest number of cases within the selective serotonin-reuptake inhibitor class. Nefazodone, a serotonin–norepinephrine reuptake inhibitor, appeared to have the most serious cases and is the only antidepressant agent that carries a Food and Drug Administration Black Box Warning regarding hepatotoxiciiy. The tricyclic antidepressants and monoamine oxidase Inhibitors are capable of producing hepatotoxicity, but fewer cases with these agents have been reported in the past 15 years, possibly due to a decline in their use. Causality has not been well established in all reports due to the concurrent use of other drugs and/or underlying liver disease.

Conclusions:

Most antidepressant agents have the potential to produce idiopathic liver injury. There is no way to prevent idiopathic DILI, but the severity of the reaction may be minimized with prompt recognition and early withdrawal of the agent. The clinician must be careful to provide ongoing therapy of the underlying depressive disorder and be aware of possible drug discontinuation syndromes should potential hepatotoxicity be suspected.

Statins are not a risk factor for liver damage associated with intravenous glucocorticoid pulse therapy for Graves' orbitopathy

OBJECTIVE

Acute liver damage (ALD) is associated with high-dose intravenous (iv) glucocorticoid (GC) (ivGC) pulse therapy in ~1 % of patients for Graves' orbitopathy (GO). It has been proposed that statins may increase the risk of ALD. Here we investigated the frequency of ALD according to the assumption of statins in a large retrospective cohort study.

METHODS

We studied 1076 consecutive patients with GO given ivGC. ALD was defined as an increase in alanine aminotransferase ≥300 U/l.

RESULTS

At the time of ivGC, 62 patients were taking statins and 1014 were not. The frequency of ALD has been reported to be 1.2 cases/100,000 statins users and 1300/100,000 in GO patients given ivGC. Thus, the expected frequency of ALD in patients given both statins and ivGC is 1560/100,000. Transferring these data to our series, one would have expected at least 0.96 cases of ALD (~one case), in the 62 patients given both ivGC and statins. However, no cases of ALD were observed in patients given statins, and the previously reported 14 cases of ALD in this series were seen in patients who were not taking statins.

CONCLUSIONS

The lack of observation of cases of ALD in patients given ivGC and statins is quite reassuring. Although caution should be applied to any patient candidate to ivGC treatment and this should be particularly accurate in patients given statins, our findings somehow justify the use of ivGC in patients under statins, although further studies in larger cohorts are needed to confirm our conclusions.

Evaluation of analgesic, anti-inflammatory, thrombolytic and hepatoprotective activities of roots of Premna esculenta (Roxb)

BACKGROUND

The objective of this study was to investigate the antinociceptive, anti-inflammatory, thrombolytic and hepatoprotective activities of root extracts of Premna esculenta (family: Verbenaceae).

METHODS

The analgesic activity was evaluated using the acetic-acid-induced writhing test in mice and radiant heat tail-flick method in rats. The anti-inflammatory activity was investigated by carrageenan-induced rat's paw edema, while the thrombolytic activity was evaluated by in vitro clot lysis model. The hepatoprotective activity was investigated against carbon-tetrachloride-induced liver damage in rats.

RESULTS

In acetic-acid-induced writhing test, chloroform and ethyl acetate fraction of ethanolic extract at a dose of 200 mg/kg showed a significant (p<0.001) reduction in the number of writhes with 85.96% and 61.98% of inhibition, respectively. In radiant heat tail-flick method, the ethanolic extract produced 88.49% (p<0.001) elongation of tail-flicking time at 90 min after oral administration at same dose level. In the carrageenan-induced edema test, the ethanolic extract at a dose of 200 mg/kg showed a significant inhibition of paw edema with 22.68% and 17.24% inhibition after the first and third hours of the study period, respectively. In clot lysis model, the ethanolic extract at 5 mg/mL induced a significant clot lysis activity (37.69%, p<0.001). Oral administration of ethanolic extract at the dose of 400 mg/kg/day for 7 days significantly (p<0.001) reduced the elevated levels of serum glutamic pyruvic transaminase, serum glutamyl oxaloacetate transaminase and alkaline phosphatase compared to the CCl4-treated control group.

CONCLUSIONS

The results of the study demonstrated the antinociceptive, anti-inflammatory, thrombolytic and hepatoprotective activities of roots of P. esculenta.

Cystathionine-Gamma-Lyase Gene Deletion Protects Mice against Inflammation and Liver Sieve Injury following Polymicrobial Sepsis

Background

Hydrogen sulfide (H₂S), produced by the activity of cystathionine-gamma-lyase (CSE), is a key mediator of inflammation in sepsis. The liver sinusoidal endothelial cells (LSECs) are important target and mediator of sepsis. The aim of this study was to investigate the role of CSE-derived H₂S on inflammation and LSECs fenestrae in caecal-ligation and puncture (CLP)-induced sepsis using CSE KO mice.

Methods

Sepsis was induced by CLP, and mice (C57BL/6J, male) were sacrificed after 8 hours. Liver, lung, and blood were collected and processed to measure CSE expression, H₂S synthesis, MPO activity, NF-κB p65, ERK1/2, and cytokines/chemokines levels. Diameter, frequency, porosity and gap area of the liver sieve were calculated from scanning electron micrographs of the LSECs.

Results

An increased CSE expression and H₂S synthesizing activity in the liver and lung of wild-type mice following CLP-induced sepsis. This was associated with an increased liver and lung MPO activity, and increased liver and lung and plasma levels of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and the chemokines MCP-1 and MIP-2α. Conversely, CSE KO mice had less liver and lung injury and reduced inflammation following CLP-induced sepsis as evidenced by decreased levels of H₂S synthesizing activity, MPO activity, and pro-inflammatory cytokines/chemokines production. Extracellular-regulated kinase (ERK1/2) and nuclear factor-κB p65 (NF-κB) became significantly activated after the CLP in WT mice but not in CSE KO mice. In addition, CLP-induced damage to the LSECs, as indicated by increased defenestration and gaps formation in the LSECs compared to WT sham control. CSE KO mice showed decreased defenestration and gaps formation following sepsis.

Conclusions

Mice with CSE (an H₂S synthesising enzyme) gene deletion are less susceptible to CLP-induced sepsis and associated inflammatory response through ERK1/2-NF-κB p65 pathway as evidenced by reduced inflammation, tissue damage, and LSECs defenestration and gaps formation.

Melatonin pretreatment enhances the therapeutic effects of exogenous mitochondria against hepatic ischemia-reperfusion injury in rats through suppression of mitochondrial permeability transition

We tested the hypothesis that melatonin (Mel) enhances exogenous mitochondria (Mito) treatment against rodent hepatic ischemia-reperfusion (IR) injury. In vitro study utilized three groups of hepatocytes (i.e. nontreatment, menadione, and menadione-melatonin treatment, 4.0 × 10(5) each), while in vivo study used adult male Sprague Dawley rats (n = 40) equally divided into sham-control (SC), IR (60-min left-lobe ischemia + 72-hr reperfusion), IR-Mel (melatonin at 30 min/6/8 hr after reperfusion), IR-Mito (mitochondria 15,000 μg/rat 30 min after reperfusion), and IR-Mel-Mito. Following menadione treatment in vitro, oxidative stress (NOX-1/NOX-2/oxidized protein), apoptotic (cleaved caspase-3/PARP), DNA damage (γ-H2AX/CD90/XRCC1), mitochondria damage (cytosolic cytochrome c) biomarkers, and mitochondrial permeability transition were found to be lower, whereas mitochondrial cytochrome c were found to be higher in hepatocytes with melatonin treatment compared to those without (all P < 0.001). In vivo study demonstrated highest liver injury score and serum AST in IR group, but lowest in SC group and higher in IR-Mito group than that in groups IR-Mel and IR-Mel-Mito, and higher in IR-Mel group than that in IR-Mel-Mito group after 72-hr reperfusion (all P < 0.003). Protein expressions of inflammatory (TNF-α/NF-κB/IL-1β/MMP-9), oxidative stress (NOX-1/NOX-2/oxidized protein), apoptotic (caspase-3/PARP/Bax), and mitochondria damage (cytosolic cytochrome c) biomarkers displayed an identical pattern, whereas mitochondria integrity marker (mitochondrial cytochrome c) showed an opposite pattern compared to that of liver injury score (all P < 0.001) among five groups. Microscopically, expressions of apoptotic nuclei, inflammatory (MPO(+) /CD68(+) /CD14(+) cells), and DNA damage (γ-H2AX(+) cells) biomarkers exhibited an identical pattern compared to that of liver injury score (all P < 0.001) among five groups. Melatonin-supported mitochondria treatment offered an additional benefit of alleviating hepatic IR injury.

Treatment With Human Wharton's Jelly-Derived Mesenchymal Stem Cells Attenuates Sepsis-Induced Kidney Injury, Liver Injury, and Endothelial Dysfunction

: The pathophysiology of sepsis involves complex cytokine and inflammatory mediator networks. Downregulation of endothelial nitric oxide synthase contributes to sepsis-induced endothelial dysfunction. Human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are known to reduce expression of proinflammatory cytokines and markers of apoptosis. We hypothesized that treatment with WJ-MSCs would protect renal, hepatic, and endothelial function in a cecal ligation and puncture (CLP) model of sepsis in rats. Rats were randomly divided into three groups: sham-operated rats; rats submitted to CLP and left untreated; and rats submitted to CLP and intraperitoneally injected, 6 hours later, with 1 × 10(6) WJ-MSCs. The glomerular filtration rate (GFR) was measured at 6 and 24 hours after CLP or sham surgery. All other studies were conducted at 24 hours after CLP or sham surgery. By 6 hours, GFR had decreased in the CLP rats. At 24 hours, Klotho renal expression significantly decreased. Treatment with WJ-MSCs improved the GFR; improved tubular function; decreased the CD68-positive cell count; decreased the fractional interstitial area; decreased expression of nuclear factor κB and of cytokines; increased expression of eNOS, vascular endothelial growth factor, and Klotho; attenuated renal apoptosis; ameliorated hepatic function; increased glycogen deposition in the liver; and improved survival. Sepsis-induced acute kidney injury is a state of Klotho deficiency, which WJ-MSCs can attenuate. Klotho protein expression was higher in WJ-MSCs than in human adipose-derived MSCs. Because WJ-MSCs preserve renal and hepatic function, they might play a protective role in sepsis.

SIGNIFICANCE

Sepsis is the leading cause of death in intensive care units. Although many different treatments for sepsis have been tested, sepsis-related mortality rates remain high. It was hypothesized in this study that treatment with human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) would protect renal, hepatic, and endothelial function in a model of sepsis in rats. Treatment with WJ-MSCs improved the glomerular filtration rate, improved tubular function, decreased expression of nuclear factor κB and of cytokines, increased expression of eNOS and of Klotho, attenuated renal apoptosis, and improved survival. Sepsis-induced acute kidney injury is a state of Klotho deficiency, which WJ-MSCs can attenuate.

Polyethylene glycols: An effective strategy for limiting liver ischemia reperfusion injury

Liver ischemia-reperfusion injury (IRI) is an inherent feature of liver surgery and liver transplantation in which damage to a hypoxic organ (ischemia) is exacerbated following the return of oxygen delivery (reperfusion). IRI is a major cause of primary non-function after transplantation and may lead to graft rejection, regardless of immunological considerations. The immediate response involves the disruption of cellular mitochondrial oxidative phosphorylation and the accumulation of metabolic intermediates during the ischemic period, and oxidative stress during blood flow restoration. Moreover, a complex cascade of inflammatory mediators is generated during reperfusion, contributing to the extension of the damage and finally to organ failure. A variety of pharmacological interventions (antioxidants, anti-cytokines, etc.) have been proposed to alleviate graft injury but their usefulness is limited by the local and specific action of the drugs and by their potential undesirable toxic effects. Polyethylene glycols (PEGs), which are non-toxic water-soluble compounds approved by the FDA, have been widely used as a vehicle or a base in food, cosmetics and pharmaceuticals, and also as adjuvants for ameliorating drug pharmacokinetics. Some PEGs are also currently used as additives in organ preservation solutions prior to transplantation in order to limit the damage associated with cold ischemia reperfusion. More recently, the administration of PEGs of different molecular weights by intravenous injection has emerged as a new therapeutic tool to protect liver grafts from IRI. In this review, we summarize the current knowledge concerning the use of PEGs as a useful target for limiting liver IRI.

Toward the Definition of the Mechanism of Action of Silymarin: Activities Related to Cellular Protection From Toxic Damage Induced by Chemotherapy

Silymarin, the active extract from milk thistle, has been extensively used in patients with liver disease of different etiology. Although silymarin is a complex of 7 flavonolignans and polyphenols, silibinin is usually regarded as the most active component. In vitro and in vivo studies indicate that silymarin and silibinin protect the liver from oxidative stress and sustained inflammatory processes, mainly driven by Reactive Oxygen Species (ROS) and secondary cytokines. Oxidative stress and inflammation are also involved in cellular damage of many other tissues and their role in the development and toxic reactions in patients receiving cancer therapies is established. The protective effects of silymarin and silibinin, demonstrated in various tissues, suggest a clinical application in cancer patients as an adjunct to established therapies, to prevent or reduce their toxicity. Here we discuss the possible mechanism of the protective action of silymarin and silibinin, focusing on cancer therapies as agents causing cellular damage.

Protective effect of N-acetylcysteine, caffeic acid and vitamin E on doxorubicin hepatotoxicity

The aim of this study was to compare the possible protective effects of N-acetylcysteine (NAC), caffeic acid (CAPE) and vitamin E (Vit-E) on doxorubicin-induced hepatotoxicity. Thirty-two male Wistar albino rats, weighing between 250 and 350 g were supplied and randomly divided into five groups. Animals in study groups were pretreated with a single dose of doxorubicin (Dox), which was administered intraperitoneally (i.p.). Control group (Group I) was treated with intraperitoneal saline injection. Group II did not received any antioxidant agent after the injection. Group III and Group IV were given CAPE and intraperitoneal vitamin E injection for eight days, respectively. Group V received NAC for eight days. The study was finished after 10 days. Tissue samples were collected from all animals and histopathological examination was performed. There was statistically significant difference between the experiment groups and controls by means of mononuclear cell infiltration and diameters of hepatic sinusoid, terminal hepatic venule (central vein) and portal area (portal canal). Changes related with hepatocellular damage were more prominent, whereas there was no significant difference between Dox and NAC given groups histopathologically. It was observed that structural changes were regressed after CAPE administration. However, this recovery was more prominent in vitamin E given group. These findings suggest that Dox induced liver damage could be efficiently reversed by vitamin E administration. It has been found that CAPE, but not NAC has protective effects on Dox-induced hepatocellular damage. Human & Experimental Toxicology (2007) 26, 519—525

Prevention of acute cadmium toxicity by Picroliv

The potential of Picroliv, a herbal extract against acute cadmium (Cd) intoxication, was evaluated in male rats. Biochemical and histopathological profile in rats pretreated with Picroliv (12 mg/kg, oral) followed by a single dose of Cd as cadmium chloride (CdCl2) (3 mg/kg, ip) revealed marked suppression of oxidative stress in liver and testes. The Cd-induced enhanced levels of lipid peroxidation, membrane fluidity and reduced levels of nonprotein sulphydryls and Na+K+ATPase were significantly restored to near normal by Picroliv pretreatment. In addition, the Cd-induced serum levels of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, gamma glutamyl transpeptidase and lactate dehydrogenase were restored to near basal levels. Hepatic and testicular histopathological damage was also minimized. The results strongly suggest definite hepatoand testicular protection by Picroliv. The antioxidant potential of the herbal extract in the major part, and not its chelating property, seems to be responsible for its ameliorative action.

miR-30b inhibits autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate

AIM: To explore the role and potential mechanism of miR-30b regulation of autophagy in hepatic ischemia-reperfusion injury (IRI).

METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco’s Modified Eagle’s Medium (DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30b on autophagy to promote hepatic IRI. The expression of miR-30b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nick-end labeling (TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene (Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.

RESULTS: miR-30b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30b could promote hepatic IRI. Furthermore, we found that miR-30b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.

CONCLUSION: miR-30b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.

Hepatoprotective effects of soluble rice protein in primary hepatocytes and in mice

BACKGROUND

The production of rice-derived by-products has increased owing to the growing use of processed rice products. The objective of this study was to isolate highly purified proteins from a rice by-product, rice syrup meal, and to examine their hepatoprotective effects in vitro and in vivo.

RESULTS

Soluble rice protein (SRP70) was obtained via enzymatic processing of rice syrup meal using Termamyl SC and Alcalase. Mass spectrometry analysis showed that SRP70 contained low-molecular-weight (<600 Da) peptides. SRP70 did not affect the viability of rat primary hepatocytes and ameliorated tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity. t-BHP-induced elevations in hepatocyte alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities were reduced by SRP70 in a dose-dependent manner. In addition, t-BHP exposure increased the level of malondialdehyde, a toxic reactive aldehyde, which was dose-dependently decreased by SRP70 treatment. These SRP70-induced decreases in biochemical parameters were also observed in vivo in mice. In particular, SRP70 increased the activities of liver antioxidant enzymes in t-BHP-treated mice, including catalase and glutathione peroxidase, as well as increasing the level of glutathione, an antioxidant peptide. SRP70-mediated activation of antioxidant enzymes was shown to be due to the up-regulation in their gene expressions, while nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase 4 (NOX4), a pro-oxidant enzyme, was down-regulated by SRP70. Hematoxylin and eosin staining also showed that SRP70 protected the liver from histopathological changes induced by t-BHP.

CONCLUSION

Taken together, these data showed that SRP70, which is derived from a rice-processing by-product, had hepatoprotective effects in vitro and in vivo.

Hepatic Warm Ischemia-Reperfusion-Induced Increase in Pulmonary Capillary Filtration Is Ameliorated by Administration of a Multidrug Resistance-Associated Protein 1 Inhibitor and Leukotriene D4 Antagonist (MK-571) Through Reducing Neutrophil Infiltration and Pulmonary Inflammation and Oxidative Stress in Rats

BACKGROUND

Hepatopulmonary syndrome (HPS) is the major complication subsequent to liver ischemia and reperfusion (I/R) injury after resection or transplantation of liver. Hallmarks of HPS include increases in pulmonary leukotrienes and neutrophil recruitment and infiltrating across capillaries. We aimed to investigate the protective efficacy of MK-571, a multidrug resistance-associated protein 1 inhibitor and leukotriene D4 agonist, against hepatic I/R injury-associated change in capillary filtration.

METHODS

Eighteen Sprague-Dawley male rats were evenly divided into a sham-operated group, a hepatic I/R group, and an MK-571-treated I/R group. MK-571 was administered intraperitoneally 15 min before hepatic ischemia and every 12 hours during reperfusion. Ischemia was conducted by occluding the hepatic artery and portal vein for 30 min, followed by removing the clamps and closing the incision. Forty-eight hours after hepatic ischemia, we assessed the pulmonary capillary filtration coefficient (Kfc) through the use of in vitro-isolated, perfused rat lung preparation. We also measured the lung wet-to-dry weight ratio (W/D) and protein concentration in broncho-alveolar lavage fluid (PCBAL). Lung inflammation and oxidative stress were evaluated by use of tissue tumor necrosis factor (TNF)-α and malondialdehyde levels and lavage differential macrophage and neutrophil cell count.

RESULTS

Hepatic I/R injury markedly increased Kfc, W/D, PCBAL, tissue TNF-α level, and differential neutrophil cell count (P < .05). MK-571 treatment reduced neutrophil infiltration and lung inflammation and improved pulmonary capillary filtration, collectively suggesting lung protection.

CONCLUSIONS

Treatment with MK-571 before and during hepatic ischemia and reperfusion protects lung against pulmonary capillary barrier function impairment through decreasing pulmonary lung inflammation and lavage neutrophils.

Odontella aurita-enriched diet prevents high fat diet-induced liver insulin resistance

The beneficial effect of polyunsaturated omega-3 fatty acid (w-3 FA) consumption regarding cardiovascular diseases, insulin resistance and inflammation has been widely reported. Fish oil is considered as the main source of commercialized w-3 FAs, and other alternative sources have been reported such as linseed or microalgae. However, despite numerous reports, the underlying mechanisms of action of w-3 FAs on insulin resistance are still not clearly established, especially those from microalgae. Here, we report that Odontella aurita, a microalga rich in w-3 FAs eicosapentaenoic acid, prevents high fat diet-induced insulin resistance and inflammation in the liver of Wistar rats. Indeed, a high fat diet (HFD) increased plasma insulin levels associated with the impairment of insulin receptor signaling and the up-regulation of toll-like receptor 4 (TLR4) expressions. Importantly, Odontella aurita-enriched HFD (HFOA) reduces body weight and plasma insulin levels and maintains normal insulin receptor expression and responsiveness. Furthermore, HFOA decreased TLR4 expression, JNK/p38 phosphorylation and pro-inflammatory factors. In conclusion, we demonstrate for the first time, to our knowledge, that diet supplementation with whole Ondontella aurita overcomes HFD-induced insulin resistance through the inhibition of TLR4/JNK/p38 MAP kinase signaling pathways.

Herbal Induced Hepatoprotection and Hepatotoxicity: A Critical Review

Traditional herbal drugs are wonderful remedies for the treatment of various devastating disorders. Recently, there has been a change in a universal fashion from synthetic to herbal medicine, which is like homecoming to nature. In the present situation, the dietary changes lead to liver disorders like non-alcoholic and alcoholic fatty liver disorders. India is one of the world’s twelve leading biodiversity centers with the presence of over 45,000 diverse plant species, out of this about 15,000-20,000 plants have good medicinal and therapeutic properties of which only about 7,000-7,500 are being used by traditional practitioners. Hepatic injury accounts for 3.5%-9.5% of all adverse drug reaction reports and up to 14.7% of fatal adverse reaction. Hepatic disorders/toxicity can occur by several mechanisms like Cytochrome P450 activation, lipid peroxidation, Induction of nitric acid synthase, mitochondrial dysfunction, activation of pro-inflammatory mediators and Bile acid-induced liver cell death. There are a number of drugs or therapies available for the treatment of hepatic disorders, but still there is a need for the novel drug discovery which can target multiple disease pathways. Traditional medicines have exhaustive ancient and scientific literature for curing a lot of life threatening disorders with less or no side effects. There are number of scientifically proved hepatoprotective herbal drugs like Andrographis paniculata, Ocimum sanctum, Solanum nigrum, Silybum marianum, Phyllanthus niruri etc. which are widely used for the treatment of liver disorders. However, there are various herbal plants and phytoconstituents, which are found to be hepatotoxic like Lanata camra Linn, Symphytum officinale, Azadirachta indica, Amantia phalloides etc. This review emphasizes on both sides of the coin like crucial aspects of phytoconstituents with reference to their hepatoprotective as well as hepatotoxic effects linked to use of herbal preparations.

Protective Effects of Celastrol on Diabetic Liver Injury via TLR4/MyD88/NF-κB Signaling Pathway in Type 2 Diabetic Rats

Immune and inflammatory pathways play a central role in the pathogenesis of diabetic liver injury. Celastrol is a potent immunosuppressive and anti-inflammatory agent. So far, there is no evidence regarding the mechanism of innate immune alterations of celastrol on diabetic liver injury in type 2 diabetic animal models. The present study was aimed at investigating protective effects of celastrol on the liver injury in diabetic rats and at elucidating the possible involved mechanisms. We analyzed the liver histopathological and biochemical changes and the expressions of TLR4 mediated signaling pathway. Compared to the normal control group, diabetic rats were found to have obvious steatohepatitis and proinflammatory cytokine activities were significantly upregulated. Celastrol-treated diabetic rats show reduced hepatic inflammation and macrophages infiltration. The expressions of TLR4, MyD88, NF-κB, and downstream inflammatory factors IL-1β and TNFα in the hepatic tissue of treated rats were downregulated in a dose-dependent manner. We firstly found that celastrol treatment could delay the progression of diabetic liver disease in type 2 diabetic rats via inhibition of TLR4/MyD88/NF-κB signaling cascade pathways and its downstream inflammatory effectors.

[Coffee as hepatoprotective factor]

The mind about the coffee did change upon the recent studies and metaanalysis of the last years. Consensual protective effect of coffee on the progression of chronic liver diseases (NASH, viral hepatitis, liver cirrhosis, hepatocelullar carcinoma) was detected in experimental, clinical and large population studies together with decrease of mortality. Antioxidant, antifibrotic, insulinsensitizing and anticarcinogenic effect of coffee were detected. Modulation of genetic expression of key enzymes of fatty acid synthesis, modulation of mRNA included in autophagia, reduction of stress of endoplasmatic reticulum together with decrease of proinflammatory cytokines and decrease of fibrogenesis are main mechanisms. Chlorogenic acids, diterpens (cafestol, kahweol), caffein, polyfenols and melanoidins are key protective components of coffee. Inverse dose-dependent correlation of coffee consumption with liver diseases was found in clinical and population studies. Coffee is non-pharmacological tool of primary and secondary prevention of chronic liver diseases. Review of published data together with supposed mechanisms of hepatoprotection are given.Key words: coffee - hepatoprotective effect - metaanalysis.

New drug delivery system for liver sinusoidal endothelial cells for ischemia-reperfusion injury

AIM: To investigate the cytoprotective effects in hepatic ischemia-reperfusion injury, we developed a new formulation of hyaluronic acid (HA) and sphingosine 1-phophate.

METHODS: We divided Sprague-Dawley rats into 4 groups: control, HA, sphingosine 1-phosphate (S1P), and HA-S1P. After the administration of each agent, we subjected the rat livers to total ischemia followed by reperfusion. After reperfusion, we performed the following investigations: alanine aminotransferase (ALT), histological findings, TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining, and transmission electron microscopy (TEM). We also investigated the expression of proteins associated with apoptosis, hepatoprotection, and S1P accumulation.

RESULTS: S1P accumulated in the HA-S1P group livers more than S1P group livers. Serum ALT levels, TUNEL-positive hepatocytes, and expression of cleaved caspase-3 expression, were significantly decreased in the HA-S1P group. TEM revealed that the liver sinusoidal endothelial cell (LSEC) lining was preserved in the HA-S1P group. Moreover, the HA-S1P group showed a greater increase in the HO-1 protein levels compared to the S1P group.

CONCLUSION: Our results suggest that HA-S1P exhibits cytoprotective effects in the liver through the inhibition of LSEC apoptosis. HA-S1P is an effective agent for hepatic ischemia/reperfusion injury.

Pharmacological Studies of Artichoke Leaf Extract and Their Health Benefits

Artichoke (Cynara scolymus) leaf extract was one of the few herbal remedies which the clinical and experimental trials have complemented each other. Both experimental and clinical effects have been verified through extensive biomedical herbal remedy research. Specifically, antioxidant, choleretic, hepatoprotective, bile-enhancing and lipid-lowering effects have been demonstrated, which corresponded with its historical use. Ongoing research seems to indicate that artichoke indeed have medicinal qualities. Most significant appears to be its beneficial effect on the liver. In animal studies, liquid extracts of the roots and leaves of artichoke have demonstrated an ability to protect the liver, with possibly even to help liver cells regenerate. Although research is not yet conclusive, scientists were optimistic that its long-standing use in humans for digestive and bowel problems was indeed justified. It may also play a role in lowering cholesterol and thus help to prevent heart disease. Boiled wild artichoke reduced postprandial glycemic and insulinemic responses in normal subjects but has no effect on metabolic syndrome patients. This article intended to review the wide ranging pharmacological effects of artichoke leaf extract.

NADPH oxidase 4 regulates homocysteine metabolism and protects against acetaminophen-induced liver damage in mice

Glutathione is the major intracellular redox buffer in the liver and is critical for hepatic detoxification of xenobiotics and other environmental toxins. Hepatic glutathione is also a major systemic store for other organs and thus impacts on pathologies such as Alzheimer's disease, Sickle Cell Anaemia and chronic diseases associated with aging. Glutathione levels are determined in part by the availability of cysteine, generated from homocysteine through the transsulfuration pathway. The partitioning of homocysteine between remethylation and transsulfuration pathways is known to be subject to redox-dependent regulation, but the underlying mechanisms are not known. An association between plasma Hcy and a single nucleotide polymorphism within the NADPH oxidase 4 locus led us to investigate the involvement of this reactive oxygen species- generating enzyme in homocysteine metabolism. Here we demonstrate that NADPH oxidase 4 ablation in mice results in increased flux of homocysteine through the betaine-dependent remethylation pathway to methionine, catalysed by betaine-homocysteine-methyltransferase within the liver. As a consequence NADPH oxidase 4-null mice display significantly lowered plasma homocysteine and the flux of homocysteine through the transsulfuration pathway is reduced, resulting in lower hepatic cysteine and glutathione levels. Mice deficient in NADPH oxidase 4 had markedly increased susceptibility to acetaminophen-induced hepatic injury which could be corrected by administration of N-acetyl cysteine. We thus conclude that under physiological conditions, NADPH oxidase 4-derived reactive oxygen species is a regulator of the partitioning of the metabolic flux of homocysteine, which impacts upon hepatic cysteine and glutathione levels and thereby upon defence against environmental toxins.

Retinoic acid receptor α promotes autophagy to alleviate liver ischemia and reperfusion injury

AIM: To study the role of autophagy and the relationship between retinoic acid receptor α (RARα) and autophagy in liver ischemia and reperfusion (IR) injury.

METHODS: All-trans retinoic acid (ATRA) was administered to mice for two weeks before operation. Reverse transcription-polymerase chain reaction and Western blot were used to detect the expression levels of related factors. To demonstrate the role of RARα, LE540, a RARα inhibitor, was used to treat hepatocytes injured by H₂O₂in vitro.

RESULTS: ATRA pretreatment noticeably diminished levels of serum alanine aminotransferase and aspartate aminotransferase as well as the degree of histopathological changes. Apoptosis was also inhibited, whereas autophagy was promoted. In vitro, RARα was inhibited by LE540, which resulted in decreased autophagy and increased apoptosis. Similarly, the expression of Foxo3a and p-Akt was downregulated, but Foxo1 expression was upregulated.

CONCLUSION: This research provides evidence that ATRA can protect the liver from IR injury by promoting autophagy, which is dependent on Foxo3/p-Akt/Foxo1 signaling.

The Role of Oxidative Stress and Antioxidants in Liver Diseases

A complex antioxidant system has been developed in mammals to relieve oxidative stress. However, excessive reactive species derived from oxygen and nitrogen may still lead to oxidative damage to tissue and organs. Oxidative stress has been considered as a conjoint pathological mechanism, and it contributes to initiation and progression of liver injury. A lot of risk factors, including alcohol, drugs, environmental pollutants and irradiation, may induce oxidative stress in liver, which in turn results in severe liver diseases, such as alcoholic liver disease and non-alcoholic steatohepatitis. Application of antioxidants signifies a rational curative strategy to prevent and cure liver diseases involving oxidative stress. Although conclusions drawn from clinical studies remain uncertain, animal studies have revealed the promising in vivo therapeutic effect of antioxidants on liver diseases. Natural antioxidants contained in edible or medicinal plants often possess strong antioxidant and free radical scavenging abilities as well as anti-inflammatory action, which are also supposed to be the basis of other bioactivities and health benefits. In this review, PubMed was extensively searched for literature research. The keywords for searching oxidative stress were free radicals, reactive oxygen, nitrogen species, anti-oxidative therapy, Chinese medicines, natural products, antioxidants and liver diseases. The literature, including ours, with studies on oxidative stress and anti-oxidative therapy in liver diseases were the focus. Various factors that cause oxidative stress in liver and effects of antioxidants in the prevention and treatment of liver diseases were summarized, questioned, and discussed.

Shinzami Korean purple-fleshed sweet potato extract prevents ischaemia-reperfusion-induced liver damage in rats

BACKGROUND

This study was designed to investigate the hepatoprotective effect of an extract from Shinzami, a variety of purple sweet potato, in rats injured by hepatic ischaemia-reperfusion (I/R).

RESULTS

Pretreatment with Shinzami extract decreased the aspirate aminotransferase and alanine aminotransferase serum levels in our hepatic I/R rat model. The glutathione level and superoxide dismutase activity level were significantly higher in the rats pretreated with the Shinzami extract compared with the hepatic I/R rats, and the glutathione peroxidase activity level was higher in pretreated rats. The total anthocyanins extracted from Shinzami, however, only increased the superoxide dismutase activity level in the hepatic I/R rats. Rats pretreated with the Shinzami extract or anthocyanins demonstrated attenuated hepatic pathological changes, such as hepatic distortion, haemorrhage, necrosis and inflammatory cell infiltration compared with the hepatic I/R control rats.

CONCLUSION

Shinzami extract and anthocyanins have a hepatoprotective effect on the liver damage induced by hepatic I/R by improving antioxidant status. Furthermore, the Shinzami extract may have a more potent effect on the antioxidant status compared with the Shinzami anthocyanins alone.

In Vitro Bioaccessibility, Human Gut Microbiota Metabolites and Hepatoprotective Potential of Chebulic Ellagitannins: A Case of Padma Hepaten® Formulation

Chebulic ellagitannins (ChET) are plant-derived polyphenols containing chebulic acid subunits, possessing a wide spectrum of biological activities that might contribute to health benefits in humans. The herbal formulation Padma Hepaten containing ChETs as the main phenolics, is used as a hepatoprotective remedy. In the present study, an in vitro dynamic model simulating gastrointestinal digestion, including dialysability, was applied to estimate the bioaccessibility of the main phenolics of Padma Hepaten. Results indicated that phenolic release was mainly achieved during the gastric phase (recovery 59.38%-97.04%), with a slight further release during intestinal digestion. Dialysis experiments showed that dialysable phenolics were 64.11% and 22.93%-26.05% of their native concentrations, respectively, for gallic acid/simple gallate esters and ellagitanins/ellagic acid, in contrast to 20.67% and 28.37%-55.35% for the same groups in the non-dialyzed part of the intestinal media. Investigation of human gut microbiota metabolites of Padma Hepaten and pure ChETs (chebulinic, chebulagic acids) established the formation of bioactive urolithins (A, B, C, D, M5). The fact of urolithin formation during microbial transformation from ChETs and ChET-containing plant material was revealed for the first time. Evaluation of the protective effect of ChETs colonic metabolites and urolithins on tert-butyl hydroperoxide (t-BHP)-induced oxidative injury in cultured rat primary hepatocytes demonstrated their significant reversion of the t-BHP-induced cell cytotoxicity, malonic dialdehyde production and lactate dehydrogenase leakage. The most potent compound was urolithin C with close values of hepatoprotection to gallic acid. The data obtained indicate that in the case of Padma Hepaten, we speculate that urolithins have the potential to play a role in the hepatic prevention against oxidative damage.

Cromoglycate, not ketotifen, ameliorated the injured effect of warm ischemia/reperfusion in rat liver: role of mast cell degranulation, oxidative stress, proinflammatory cytokine, and inducible nitric oxide synthase

Hepatic ischemia/reperfusion (ISCH/REP) is a major clinical problem that is considered to be the most common cause of postoperative liver failure. Recently, mast cells have been proposed to play an important role in the pathophysiology of ISCH/REP in many organs. In contrast, the role played by mast cells during ISCH/REP-induced liver damage has remained an issue of debate. This study aimed to investigate the protective role of mast cells in order to search for an effective therapeutic agent that could protect against fatal ISCH/REP-induced liver damage. A model of warm ISCH/REP was induced in the liver of rats. Four groups of rats were used in this study: Group I: SHAM (normal saline, intravenously [iv]); Group II: ISCH/REP; Group III: sodium cromoglycate + ISCH/REP (CROM + ISCH/REP), and Group IV: ketotifen (KET) + ISCH/REP (KET + ISCH/REP). Liver damage was assessed both histopathologically and biochemically. Mast cell degranulation was assessed histochemically. Lipid peroxidation (malondialdehyde [MDA]) as well as the levels of glutathione (GSH), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), the formation of nitric oxide (NO), and the expression of inducible NO synthase (iNOS) were determined. The results of this study revealed increased mast cell degranulation in the liver during the acute phase of ISCH/REP. Moreover, CROM, but not KET, decreased the activity of alanine aminotransferase, aspartate aminotransferase, and lactic dehydrogenase and maintained normal liver tissue histology. Both CROM and KET protected against mast cell degranulation in the liver. In addition, both CROM and KET decreased IL-6 and TNF-α. However, CROM, but not KET, decreased MDA formation and increased GSH. Furthermore, KET, but not CROM, increased both NO formation and iNOS expression. In conclusion, this study clearly demonstrated mast cell degranulation in warm ISCH/REP in the liver of rats. More importantly, CROM, but not KET, ameliorated the effect of ISCH/REP-induced injury in rat liver. CROM may protect the liver through mast cell stabilization, inhibition of TNF-α, IL-6, MDA, and iNOS and increased GSH. KET may maintain ISCH/REP-induced liver injury through the NO/iNOS pathway.

Evaluation of the protective effect of Zhi-Zi-da-Huang decoction on acute liver injury with cholestasis induced by α-naphthylisothiocyanate in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-Zi-Da-Huang decoction (ZZDHD), a classic traditional Chinese medicine (TCM) formula composed of four herbal medicines, has been widely used to treat various hepatobiliary disorders for a long time in China. However, the pharmacological effect of ZZDHD on liver injury with cholestasis is unrevealed.

AIM OF THE STUDY

To investigate the hepatoprotective effect of ZZDHD against α-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis in rats.

MATERIALS AND METHODS

The rats were intragastrically (i.g.) given ZZDHD at doses of 1, 2 and 4 g/kg (crude drug/body weight) once a day for seven days and treated with ANIT (75 mg/kg via i.g.) to cause liver injury at 12h after the fifth administration. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GTP), total bilirubin (TBIL), direct bilirubin (DBIL) and total bile acid (TBA), as well as bile flow were measured at 48 h after ANIT treatment to evaluate the protective effect of ZZDHD. Moreover, the possible protective mechanisms were elucidated by assays of liver enzyme activities and component contents including malondialdehyde (MDA), myeloperoxidase (MPO), lipid peroxide (LPO), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). The biochemical observations were supplemented by histopathological examination. Ultra fast liquid chromatography-mass spectrometry (UFLC-MS) was used for the phytochemical analysis of ZZDHD.

RESULTS

The high dose (4 g/kg) and middle dose (2g/kg) of ZZDHD exhibited significant and dose-dependent protective effect on ANIT-induced liver injury with cholestasis by reversing the changes in bile flow, the serum and hepatic enzymes, and histopathology of the liver tissue. Meanwhile, it was found that the low dose (1g/kg) of ZZDHD did not improve the biochemical indexes except serum TBIL, DBIL and TBA, which showed little protective effect. Phytochemical analysis revealed the presence of sixteen compounds in ZZDHD.

CONCLUSIONS

This study indicates that ZZDHD exerted a hepatoprotective effect on ANIT-induced liver injury with cholestasis in rats, and the mechanism of this activity is possibly related to its antioxidant properties.

The effect of melatonin on the liver of rats exposed to microwave radiation

OBJECTIVES

We aimed to clarify if melatonin treatment (2 mg/kg i.p.) may favorably impact the liver tissue in rats exposed to microwave radiation. The experiment was performed on 84 six-weeks-old Wistar male rats exposed for 4h a day, for 20, 40 and 60 days, respectively, to microwaves (900 MHz, 100-300 microT, 54-160 V/m). Rats were divided in to four groups: I (control) - rats treated with saline, II (Mel) - rats treated with melatonin, III (MWs) - microwave exposed rats, IV (MWs + Mel) - MWs exposed rats treated with melatonin. We evaluated oxidative stress parameters (malondialdehyde and carbonyl group content), catalase, xanthine oxidase, deoxyribonuclease I and II activity.

BACKGROUND

Oxidative stress is the key mechanism of the microwave induced tissue injury. Melatonin, a lipophilic indoleamine primarily synthesized and released from the pineal gland is a powerful antioxidant.

RESULTS

Exposure to microwaves caused an increase in malondialdehyde after 40 (p < 0.01), protein carbonyl content after 20 (p < 0.05), catalase (p < 0.05) and xantine oxidase activity (p < 0.05) after 40 days. Increase in deoxyribonuclease I activity was observed after 60 days (p < 0.05), while deoxyribonuclease II activity was unaffected. Melatonin treatment led to malondialdehyde decrease after 40 days (p< 0.05), but surprisingly had no effect on other analyzed parameters.

CONCLUSION

Melatonin exerts certain antioxidant effects in the liver of rats exposed to microwaves, by diminishing the intensity of lipid peroxidation(Fig. 6, Ref. 32).

Mesenchymal stem cell-conditioned medium prevents radiation-induced liver injury by inhibiting inflammation and protecting sinusoidal endothelial cells

Current management of radiation-induced liver injury is limited. Sinusoidal endothelial cell (SEC) apoptosis and inflammation are considered to be initiating events in hepatic damage. We hypothesized that mesenchymal stem cells (MSCs) possess anti-apoptotic and anti-inflammatory actions during hepatic irradiation, acting via paracrine mechanisms. This study aims to examine whether MSC-derived bioactive components are protective against radiation-induced liver injury in rats. MSC-conditioned medium (MSC-CM) was generated from rat bone marrow-derived MSCs. The effect of MSC-CM on the viability of irradiated SECs was examined by flow cytometric analysis. Activation of the Akt and ERK pathways was analyzed by western blot. MSC-CM was also delivered to Sprague-Dawley rats immediately before receiving liver irradiation, followed by testing for pathological features, changes in serum hyaluronic acid, ALT, and inflammatory cytokine levels, and liver cell apoptosis. MSC-CM enhanced the viability of irradiated SECs in vitro and induced Akt and ERK phosphorylation in these cells. Infusion of MSC-CM immediately before liver irradiation provided a significant anti-apoptotic effect on SECs and improved the histopathological features of injury in the irradiated liver. MSC-CM also reduced the secretion and expression of inflammatory cytokines and increased the expression of anti-inflammatory cytokines. MSC-derived bioactive components could be a novel therapeutic approach for treating radiation-induced liver injury.

Grape seed proanthocyanidin protects liver against ischemia/reperfusion injury by attenuating endoplasmic reticulum stress

AIM: To explore the effect of grape seed proanthocyanidin (GSP) in liver ischemia/reperfusion (IR) injury and alleviation of endoplasmic reticulum stress.

METHODS: Male Sprague-Dawley rats (220-250 g) were divided into three groups, namely, sham, IR, and GSP groups (n = 8 each). A liver IR (70%) model was established and reperfused for 6 h. Prior to reperfusion, the GSP group was administered with GSP (100 mg/kg) for 15 d, and liver histology was then investigated. Serum aminotransferase and inflammatory mediators coupled with superoxide dismutase and methane dicarboxylic aldehyde were detected. Western blot was conducted to analyze the expression of glucose-regulated protein 78, CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb. Apoptotic cells were detected by TUNEL staining.

RESULTS: The serum aminotransferase, apoptotic cells, and Suzuki scores decreased in the GSP group compared with the IR group (Ps < 0.05). The methane dicarboxylic aldehyde level was decreased in the GSP group, but the superoxide dismutase level was reversed (Ps < 0.05). Similarly, GSP downregulated the proinflammatory factors and upregulated the levels of anti-inflammatory factors (Ps < 0.05). Western blot data showed that GSP increased glucose-regulated protein 78 expression and suppressed expression of CCAAT/enhancer-binding protein homologous protein, activating transcription factor-4, inositol-requiring enzyme-1, procaspase-12, and nuclear factor-κb compared with the IR group.

CONCLUSION: GSP possesses antioxidative, anti-inflammatory, and antiapoptotic effects by relieving endoplasmic reticulum stress through regulation of related signaling pathways to protect the liver against IR injury.

Hepatoprotective properties of extensively studied medicinal plant active constituents: possible common mechanisms

CONTEXT

We focused on certain plant active constituents considered to be the most promising/studied for liver disease and that were critically investigated from the basic science point of view and, to some extent, the clinical one. Due to insufficient pharmacological data, most of the herbal formulations containing these molecules cannot be recommended for the treatment of liver disease.

OBJECTIVE

To present the most promising compounds tested experimentally and/or clinically and describe in brief popular models in experimental testing of potential hepatoprotective compounds.

METHODS

A literature search using Web of Science (WOS), PubMed, and Google search was performed.

RESULTS

Focusing on a few herbal hepatoprotective active constituents is useful to health professionals working in the field of therapeutics to develop evidence-based hepatoprotective agents by conducting research on pure chemical structures or on molecular modifications using computational chemistry. This review demonstrates that multi-pathways in the liver pathobiology can be interrupted at one or more levels by natural hepatoprotective studied, such as interference with the oxidative stress at multiple levels to reduce reactive oxygen/nitrogen species, resulting in ameliorating hepatotoxicity.

CONCLUSION

Hepatoprotective constituents of herbal medications are poorly absorbed after oral administration; methods that can improve their bioavailability are being developed. It is recommended that controlled prospective double-blind multicenter studies on isolated active plant constituents, or on related newly designed molecules after structural modifications, should be performed. This effort will lead to expanding the existing, limited drugs for the vast majority of liver diseases.

Astaxanthin Pretreatment Attenuates Hepatic Ischemia Reperfusion-Induced Apoptosis and Autophagy via the ROS/MAPK Pathway in Mice

Background: Hepatic ischemia reperfusion (IR) is an important issue in complex liver resection and liver transplantation. The aim of the present study was to determine the protective effect of astaxanthin (ASX), an antioxidant, on hepatic IR injury via the reactive oxygen species/mitogen-activated protein kinase (ROS/MAPK) pathway. Methods: Mice were randomized into a sham, IR, ASX or IR + ASX group. The mice received ASX at different doses (30 mg/kg or 60 mg/kg) for 14 days. Serum and tissue samples at 2 h, 8 h and 24 h after abdominal surgery were collected to assess alanine aminotransferase (ALT), aspartate aminotransferase (AST), inflammation factors, ROS, and key proteins in the MAPK family. Results: ASX reduced the release of ROS and cytokines leading to inhibition of apoptosis and autophagy via down-regulation of the activated phosphorylation of related proteins in the MAPK family, such as P38 MAPK, JNK and ERK in this model of hepatic IR injury. Conclusion: Apoptosis and autophagy caused by hepatic IR injury were inhibited by ASX following a reduction in the release of ROS and inflammatory cytokines, and the relationship between the two may be associated with the inactivation of the MAPK family.

Hepatoprotective effects of remote perconditioning during renal ischemia

BACKGROUND

Novel treatment strategies are required to reduce the development of hepatic injury during surgical procedure in which renal ischemia/reperfusion (IR) is inevitable. Remote perconditioning (rPeC) has been proved to reduce the extent of kidney damages induced by renal IR injury. The aim of this study was to determine the protective effect of rPeC against hepatic injury caused by renal ischemia.

METHODS

Male rats were subjected to the right nephrectomy and randomized as: sham, no additional intervention; IR, 45 min of left renal pedicle occlusion; rPeC, four cycles of 5-min limb IR administered at the beginning of renal ischemia. After 24-h of reperfusion, the plasma and tissue samples were taken.

RESULTS

A significant improvement in hepatic functional injury and oxidative damages were observed in the rPeC group compared to the IR group. However, histological evaluation and plasma levels of TNF-α revealed no significant difference among groups.

CONCLUSIONS

It is concluded that rPeC exerted protective effects on renal IR-induced hepatic injury as a remote organ. The protection may be a consequence of the reduction in oxidative stress in the liver. This simple approach may be a promising strategy against IR-induced remote organ damages in the clinical practice (Fig. 4, Ref. 23).

The protective effects of dexmedetomidine on hepatic ischemia reperfusion injury

OBJECTIVE

The aim of this study was to evaluate the effect of dexmedetomidine (100 µg/kg-ip) on liver ischemia and reperfusion (I/R) in rats.

METHODS

Twenty-four Wistar Albino rats were separated into three groups as control (C), ischemia-reperfusion injury (I/R) and dexmedetomidine group (I/R-D). Ischemia was induced with portal clampage for 45 minutes and reperfusion period was 45 minutes after declampage. Group I/R-D was received dexmedetomidine 100 µg/kg i.p. 30 min before portal clampage. Thiobarbutiric Acid-Reactive Substances (TBARS), glutathioneS-transferase (GST), superoxide dismutase (SOD), Catalase (CAT), and Paraoxonase 1 (PON-1) were investigated in blood samples. Also HSP60 and p53-positive hepatocytes were counted under ImageJ image analysis program.

RESULTS

All parameters, except GST levels, were significant between the groups (p < 0.05). Although HSP60 expression was significantly increased between I/R, I/R-D and C groups there were no significant differences between I/R-D and C (p = 0.443). On the other hand, p53 expression was also significantly increased between I/R, I/R-D and C groups At the same time, there were no significant differences between I/R-D and C groups (p = 0.354).

CONCLUSION

All the results suggest that dexmedetomidine has beneficial effects on liver ischemia/reperfusion stress (Tab. 1, Fig. 2, Ref. 49).

α-tocopherol supplementation prevents lead acetate and hypoxia-induced hepatic dysfunction

OBJECTIVE

Lead (Pb) is a long-known poison of environment and industrial origin. Its prolonged exposure affects cellular material and alters cellular genetics and produces oxidative damages. In this study, we investigated the exposure of chronic sustained hypoxia or lead acetate alone or in combination with or without supplementation of α-tocopherol on hepatic oxidative and nitrosative stress in rats.

MATERIALS AND METHODS

The rats weighing 165 ± 5 g were exposed to chronic sustained hypoxia (10% oxygen) or lead acetate (25 mg/kg of body weight, intraperitoneally) alone or in combination with or without supplementation of α-tocopherol (10 mg/100 g b.wt, intramuscularly). The body weight of all the rats was recorded on the day 1 of the treatment and the day of sacrifice. Serum lipid profile was estimated by using a biochemical analyzer. Oxidant and enzymatic antioxidants status was evaluated by using spectrophotometer. Serum levels of hypoxia inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) were measured by using ELISA technique. Histopathological assessments of hepatic tissue were also done.

RESULTS

Exposure of both lead and hypoxia showed decreased body weight, altered serum lipid profile, oxidant and enzymatic antioxidants status, serum HIF-1α and VEGF concentrations. Simultaneous α-tocopherol supplementation showed beneficial effects to all these alterations. Histopathological observations also showed hepatic degenerative changes after lead or hypoxia exposure either alone or in combination, but remarkable improvement has been noticed after α-tocopherol supplementation.

CONCLUSION

Supplementation of α-tocopherol is beneficial to counter both lead acetate and hypoxia induced hepatic cytotoxicities possibly by reducing oxidative and nitrosative stress.

Hepatoprotective effects of selenium during diabetes in rats

The present study investigated the hepatoprotective role of selenium during alloxan-induced diabetes in rats. Male Wistar rats were divided into four groups, namely, normal control, selenium treated, diabetic, and selenium-treated diabetic. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose rate of 150 mg/kg body weight. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 ppm in drinking water, ad libitum for two time durations of 2 and 4 weeks. The effects of different treatments were studied on various parameters in rat liver, which included serum glucose levels, serum insulin levels, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid peroxidation (LPO), glutathione reduced (GSH), oxidized glutathione (GSSG), total glutathione (TG), superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase, metallothionein (MT), and histoarchitecture. A significant increase in the serum glucose levels, LPO levels, and in enzyme activities of ALP, ALT, and AST was observed in diabetic rats which, however, got decreased significantly upon supplementation with selenium. On the contrary, decreased enzyme activities of GSSG, SOD, and CAT and depressed levels of GSH as well as serum insulin levels were observed in diabetic rats which got improved following selenium supplementation. Interestingly, MT levels were increased both in diabetic and selenium-treated diabetic rats. Further, marked alterations in histoarchitecture were seen in diabetic rats with the prominent features being congestion in sinusoids, lipid accumulation, and centrilobular hepatocyte degeneration. However, selenium treatment to diabetic rats showed overall improvement in the hepatic histoarchitecture.

Protective Effect of Thalidomide on Liver Injury in Rats with Acute Pancreatitis via Inhibition of Oxidative Stress

This study was designed to investigate the preventive effect of thalidomide on acute pancreatitis-associated liver injury in the rat and analyze its relationship with oxidative stress. The acute pancreatitis of rats was induced by the retrograde injection of 5% sodium taurocholate into the biliopancreatic duct. Thalidomide (100 mg/kg) was given daily via the intragastric route for 8 days before this injection. The levels of oxidative stress parameters including superoxide dismutase (SOD), glutathione peroxidase (GSHpx), and malondialdehyde (MDA) in the liver were detected by biochemical assay. Nuclear factor-κB p65 (NF-κBp65), tumor necrosis factor α (TNF-α), and intercellular adhesion molecule-1 (ICAM-1) protein and mRNA levels in the liver were detected using western blots and reverse transcriptase polymerase chain reaction, respectively. Compared with the untreated model group, liver histopathology, SOD, GSHpx, MDA levels, NF-κBp65, TNF-α, ICAM-1 protein, and mRNA levels in the liver of rats given thalidomide were improved significantly. Results demonstrate that thalidomide may exert its effects on oxidative stress to attenuate the progression of acute pancreatitis-associated liver injury in rats.