Glycine and uridine prevent D-galactosamine hepatotoxicity in the rat: role of Kupffer cells

Evaluation of Brown Micro-Algae Synergies With Low Dose γ-Radiation Against Chronic Hepatitis Induced by D-Galactosamine in Rats

Introduction

Hepatic inflammation is considered key driver of hepatic tissue impairment.We aimed to explore the interaction of Halamphora coffeaeformis (Amph.) with low dose ionizing γ radiation (γR) exposure against D-galactosamine (D-GaIN)-induced chronic hepatitis in Albino rats.

Methods

Chronic hepatitis was induced with single dose of D-GalN (400 mg/kg BW i.p.). Rats received 400 mg Amph/kg BW daily by gastric gavage concomitant with .25 Gy γ-R. Liver oxidative stress and inflammatory status were assessed. Gene expression levels of signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa B (NFKB) were estimated by q-PCR. D-Galactosamine injection significantly encouraged hepatic oxidative damage and inflammatory disturbance accompanied with improved intercellular adhesion molecule-1 level (ICAM-1).

Results

messenger RNA gene expression levels of STAT3 and NF-kB were expressively higher in D-GaIN-treated animals. Histopathological examination supported results. Interestingly, Amph treatment with γ-radiation (γ-R) subjection displayed significant improvement of oxidative and inflammatory status along with controlled signaling molecular factors which was supported by amended histological structure of induced liver hepatitis.

Conclusion

Results conclude the efficacious control of liver hepatitis progression by dual collaboration of Amph. with low dose γ-R via control of vital growth signaling factors linked with inflammation thru anti-inflammation, antioxidative and anti-proliferative activities.

Sulfamate-Tethered Aza-Wacker Cyclization Strategy for the Syntheses of 2-Amino-2-deoxyhexoses: Preparation of Orthogonally Protected d-Galactosamines

We present a new strategy for the assembly of protected d-galactosamine synthons. Our route uses a sulfamate-tethered aza-Wacker cyclization as a key step and commences from d-erythrono-1,4-lactone. This stands in contrast to most literature syntheses of 2-amino-2-deoxyhexose derivatives, as these generally employ glycals or hexoses as starting materials. This strategy may serve as a template for the assembly of many other 2-amino-2-deoxyhexoses with protection patterns difficult to access by conventional methods.

Investigation of Metabolome Underlying the Biological Mechanisms of Acute Heat Stressed Granulosa Cells

Heat stress affects granulosa cells and the ovarian follicular microenvironment, ultimately resulting in poor oocyte developmental competence. This study aims to investigate the metabo-lomics response of bovine granulosa cells (bGCs) to in vitro acute heat stress of 43 °C. Heat stress triggers oxidative stress-mediated apoptosis in cultured bGCs. Heat-stressed bGCs exhibited a time-dependent recovery of proliferation potential by 48 h. A total of 119 metabolites were identified through LC-MS/MS-based metabolomics of the spent culture media, out of which, 37 metabolites were determined as differentially involved in metabolic pathways related to bioenergetics support mechanisms and the physical adaptations of bGCs. Multiple analyses of metabolome data identified choline, citric acid, 3-hydroxy-3-methylglutaric acid, glutamine, and glycocyamine as being upregulated, while galactosamine, AICAR, ciliatine, 16-hydroxyhexadecanoic acid, lysine, succinic acid, uridine, xanthine, and uraconic acid were the important downregulated metabolites in acute heat stress. These differential metabolites were implicated in various important metabolic pathways directed towards bioenergetics support mechanisms including glycerophospholipid metabolism, the citrate cycle (TCA cycle), glyoxylate and dicarboxylate metabolism, and serine, threonine, and tyrosine metabolism. Our study presents important metabolites and metabolic pathways involved in the adaptation of bGCs to acute heat stress in vitro.

Adenovirus vector-attributed hepatotoxicity blocks clinical application in gene therapy

Adenoviruses (Ads), common self-limiting pathogens in humans and animals, usually cause conjunctivitis, mild upper respiratory tract infection or gastroenteritis in humans and hepatotoxicity syndrome in chickens and dogs, posing great threats to public health and livestock husbandry. Artificially modified Ads, which wipe out virulence-determining genes, are the most frequently used viral vectors in gene therapy, and some Ad vector (AdV)-related medicines and vaccines have been licensed and applied. Inherent liver tropism enables AdVs to specifically deliver drugs/genes to the liver; however, AdVs are closely associated with acute hepatotoxicity in immunocompromised individuals, and the side effects of AdVs, which stimulate a strong inflammatory reaction in the liver and cause acute hepatotoxicity, have largely limited clinical application. Therefore, this review systematically elucidates the intimate relationship between AdVs and hepatotoxicity in terms of virus and host and precisely illustrates the accumulated understanding in this field over the past decades. This review demonstrates the liver tropism of AdVs and molecular mechanism of AdV-induced hepatotoxicity and looks at the studies on AdV-mediated animal hepatotoxicity, which will undoubtedly deepen the understanding of AdV-caused liver injury and be of benefit in the further safe development of AdVs.

Investigations of adsorption behavior and anti-inflammatory activity of glycine functionalized Al12N12 and Al12ON11 fullerene-like cages

The adsorption behavior of the amino acid, glycine (Gly), via the carboxyl, hydroxyl, and amino groups onto the surfaces of Al₁₂N₁₂ and Al₁₆N₁₆ fullerene-like cages were computationally evaluated by the combination of density functional theory (DFT) and molecular docking studies. It was found that Gly can chemically bond with the Al₁₂N₁₂ and Al₁₆N₁₆ fullerene-like cages as its amino group being more favorable to interact with the aluminum atoms of the adsorbents compared to carboxyl and hydroxyl groups. Oxygen and carbon doping were reported to reduce steric hindrance for Glycine interaction at Al site of Al₁₂ON₁₁/Gly and Al₁₂CN₁₁/Gly complexes. Interaction was further enhanced by oxygen doping due to its greater electron withdrawing effect. Herein, the Al₁₂ON₁₁/Gly complex where two carbonyl groups of Gly are bonded to the aluminum atoms of the Al₁₂N₁₂ fullerene-like cage is the most stable interaction configuration showing ∆_adsH and ∆_adsG values of -81.74 kcal/mol and -66.21 kcal/mol, respectively. Computational studies also revealed the frequency shifts that occurred due to the interaction process. Molecular docking analysis revealed that the Al₁₂N₁₂/Gly (-11.7 kcal/mol) and the Al₁₂ON₁₁/Gly (-9.2 kcal/mol) complexes have a good binding affinity with protein tumor necrosis factor alpha (TNF-α). TNF-α was implicated as a key cytokine in various diseases, and it has been a validated therapeutic target for the treatment of rheumatoid arthritis. These results suggest that the Al₁₂N₁₂/Gly complex in comparison with the Al₁₆N₁₆/Gly, Al₁₂ON₁₁/Gly, and the Al₁₂CN₁₁/Gly complexes could be efficient inhibitors of TNF-α.

Protective role of rutin against combined exposure to lipopolysaccharide and D-galactosamine-induced dysfunctions in liver, kidney, and brain: Hematological, biochemical, and histological evidences

Protective efficacy of rutin over liver, kidney, and brain dysfunctions was evaluated in this investigation. Rutin (5, 10, and 20 mg/kg) was administered continuously for 6 days followed by single dose of D-galactosamine (300 mg/kg I.P.) and lipopolysaccharide (50 µg/kg I.P.) on the 6th day. Hematological, serological, biochemical, and histological aspects were considered for this study. One-way ANOVA (p ≤ .05) followed by Tukey's HSD post hoc test determined the statistical significance. Serum AST, ALT, ALP, urea, uric acid, and creatinine were increased significantly, whereas albumin and glucose were significantly decreased after combined exposure to LPS and D-GalN. Glutathione level and activity of SOD and catalase were decreased, whereas lipid peroxidation, triglycerides, and cholesterol were increased in tissue samples due to LPS- and D-GalN-induced toxicity. Prophylactic treatment of rutin maintained studied variables toward control claiming the protective role of rutin. PRACTICAL APPLICATION: Rutin is plenteous in a variety of commonly ingested foods such as onion, wine, grape, citrus fruits, tea, and buckwheat. Rutin supplement is recommended for the treatment of various diseases such as varicose veins, internal bleeding, or hemorrhoids. Rutin is better than well-known antithrombic agent, Juniferdin, or Bacitracin. In the present study, rutin showed protective effects against LPS- and D-GalN-induced multiorgan dysfunctions due to its anti-inflammatory and antioxidant properties. Therefore, rutin may be developed and practiced as a food supplement to cope with acute organ dysfunctions caused by inflammatory and oxidative damage.

Gallic Acid Protects from Acute Multiorgan Injury Induced by Lipopolysaccharide and D-galactosamine

BACKGROUND

Secondary metabolites of plants, the polyphenols, play a vital role in protection from many health problems in human beings. Structurally favored phytochemicals may be studied to protect multiorgan injury. At pharmacological doses, gallic acid is nontoxic to mammals and is generally absorbed in the intestine.

AIMS

In this present study, gallic acid was evaluated for its protective efficacy against Lipo Polysaccharide (LPS) and d-Galactosamine (D-GalN) induced multiorgan injury, i.e., liver, kidney and brain.

METHODS

Three different doses of gallic acid (5, 10 and 20 mg/kg p.o.) were administered to the experimental animals for 6 consecutive days, followed by exposure to LPS (50 μg/kg I.P.) and D-GalN (300 mg/kg I.P.) on the 6th day.

RESULTS

Exposure to LPS and D-GalN resulted in increased oxidative stress and proinflammatory cytokines. Altered hematology and serology due to LPS and D-GalN were restored towards control by gallic acid. Declined antioxidants such as reduced glutathione, superoxide dismutase and catalase due to injurious effects of LPS and D-GalN were rejuvenated by gallic acid.

DISCUSSION

Exposure to LPS and D-GalN severely increased lipid peroxidation, CYP2E1 activity and tissue lipids while lowered protein content. Gallic acid restored all these parameters towards control in dose dependent manner and 20 mg/kg dose provided the best protection. Histological study showed improved histoarchitecture of liver, kidney and brain that supported biochemical endpoints.

CONCLUSION

Gallic acid minimized oxidative stress and provided best protection at 20 mg/kg dose against LPS and D-GalN induced multi organ acute injury.

Recombinant Alkaline Phosphatase Prevents Acute on Chronic Liver Failure

The lipopolysaccharide (LPS)– toll-like receptor-4 (TLR4) pathway plays an important role in liver failure. Recombinant alkaline phosphatase (recAP) deactivates LPS. The aim of this study was to determine whether recAP prevents the progression of acute and acute-on-chronic liver failure (ACLF). Eight groups of rats were studied 4-weeks after sham surgery or bile duct ligation and were injected with saline or LPS to mimic ACLF. Acute liver failure was induced with Galactosamine-LPS and in both models animals were treated with recAP prior to LPS administration. In the ACLF model, the severity of liver dysfunction and brain edema was attenuated by recAP, associated with reduction in cytokines, chemokines, liver cell death, and brain water. The activity of LPS was reduced by recAP. The treatment was not effective in acute liver failure. Hepatic TLR4 expression was reduced by recAP in ACLF but not acute liver failure. Increased sensitivity to endotoxins in cirrhosis is associated with upregulation of hepatic TLR4, which explains susceptibility to development of ACLF whereas acute liver failure is likely due to direct hepatoxicity. RecAP prevents multiple organ injury by reducing receptor expression and is a potential novel treatment option for prevention of ACLF but not acute liver failure.

Assessment of animal experimental models of toxic liver injury in the context of their potential application as preclinical models for cell therapy

Preclinical animal models allow to study development and progression of several diseases, including liver disorders. These studies, for ethical reasons and medical limits, are impossible to carry out in human patients. At the same time, such experimental models constitute an important source of knowledge on pathomechanisms for drug- and virus-induced hepatotoxicity, both acute and chronic. Carbon tetrachloride, D-Galactosamine, and retrorsine are xenobiotics that can be used in immunocompetent animal models of hepatotoxicity, where chemical-intoxicated livers present histological features representative of human viruses-related infection. A prolonged derangement into liver architecture and functions commonly lead to cirrhosis, eventually resulting in hepatocellular carcinoma. In human, orthotopic liver transplantation commonly resolve most the problems related to cirrhosis. However, the shortage of donors does not allow all the patients in the waiting list to receive an organ on time. A promising alternative treatment for acute and chronic liver disease has been advised in liver cell transplantation, but the limited availability of hepatocytes for clinical approaches, in addition to the immunosuppressant regiment required to sustain cellular long-term engraftment have been encouraging the use of alternative cell sources. A recent effective source of stem cells have been recently identified in the human amnion membrane. Human amnion epithelial cells (hAEC) have been preclinically tested and proven sufficient to rescue immunocompetent rodents lethally intoxicated with drugs. The adoption of therapeutic procedures based on hAEC transplant in immunocompetent recipients affected by liver diseases, as well as patients with immune-related disorders, may constitute a successful new alternative therapy in regenerative medicine.

Role of macrophages in experimental liver injury and repair in mice

Liver macrophages make up the largest proportion of tissue macrophages in the host and consist of two dissimilar groups: Kupffer cells (KCs) and monocyte-derived macrophages (MoMø). As the liver is injured, KCs sense the injury and initiate inflammatory cascades mediated by the release of inflammatory cytokines and chemokines. Subsequently, inflammatory monocytes accumulate in the liver via chemokine-chemokine receptor interactions, resulting in massive inflammatory MoMø infiltration. When live r injury ceases, restorative macrophages, derived from recruited inflammatory monocytes (lymphocyte antigen 6 complex, locus C^hi monocytes), promote the resolution of hepatic damage and fibrosis. Consequently, a large number of studies have assessed the mechanisms by which liver macrophages exert their opposing functions at different time-points during liver injury. The present review primarily focuses on the diverse functions of macrophages in experimental liver injury, fibrosis and repair in mice and illustrates how macrophages may be targeted to treat liver disease.

Protective effect of lycopene against chemical and natural toxins: A review

People are exposed to a number of environmental, occupational, and therapeutic toxic agents which may be natural or man made. These hazardous substances may manifest as direct side effects on the function of organs or indirectly induced alteration of gene expression, cancer-associated metabolic pathways, and/or alter homeostasis. Lycopene, as a one of the most potent antioxidant, is found in fruits and vegetables. High-intake of lycopene has been shown to be effective in decreasing the risk of both natural toxins including mycotoxins, bacterial toxins, and chemical toxins including heavy metals, pesticides as well as herbicides. Recently, there is growing attention in understanding the mechanisms of the phytochemicals and carotenoids as antioxidative, antiapoptotic, radical scavenging, and chelating agents and their roles in the modulation of inflammatory pathways. This review summarizes available data from several recent studies about lycopene and its role against chemical and natural toxicants. © 2018 BioFactors, 45(1):5-23, 2019.

Anti‑apoptotic effects of human placental hydrolysate against hepatocyte toxicity in vivo and in vitro

Apoptosis and oxidative stress are essential for the pathogenesis of acute liver failure and fulminant hepatic failure. Human placental hydrolysate (hPH) has been reported to possess antioxidant and anti-inflammatory properties. In the present study, the protective effects of hPH against D-galactosamine (D-GalN)- and lipopolysaccharide (LPS)-induced hepatocyte apoptosis were investigated in vivo. In addition, the molecular mechanisms underlying the anti-apoptotic activities of hPH against D-GalN-induced cell death in vitro were examined. Male Sprague-Dawley rats were injected with D-GaIN/LPS with or without the administration of hPH. Rats were sacrificed 24 h after D-GaIN/LPS intraperitoneal injection, and the blood and liver samples were collected for future inflammation and hepatotoxicity analyses. Changes in cell viability, apoptosis protein expression, mitochondrial mass, mitochondrial membrane potential, reactive oxygen species generation, and the levels of proteins and mRNA associated with a protective mechanism were determined in HepG2 cells pretreated with hPH for 2 h prior to D-GalN exposure. The findings suggested that hPH treatment effectively protected against D-GalN/LPS-induced hepatocyte apoptosis by reducing the levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, interleukin-6, and tumor necrosis factor-α, and increasing the level of proliferating cell nuclear antigen. It was also found that hPH inhibited the apoptotic cell death induced by D-GalN. hPH activated the expression of antioxidant enzymes, including superoxide dismutase, glutathione peroxidase, and catalase, which were further upregulated by the Kelch-like ECH2-associated protein 1-p62-nuclear factor-erythroid 2-related factor 2 pathway, a component of oxidative stress defense mechanisms. Furthermore, hPH markedly reduced cytosolic and mitochondrial reactive oxygen species and rescued mitochondrial loss and dysfunction through the reduction of damage-regulated autophagy modulator, p53, and C/EBP homologous protein. Collectively, hPH exhibited a protective role in hepatocyte apoptosis by inhibiting oxidative stress and maintaining cell homeostasis. The underlying mechanisms may be associated with the inhibition of endoplasmic reticulum stress and minimization of the autophagy progress.

Toll-Like Receptor Ligand-Induced Liver Injury in D-Galactosamine-Sensitized Mice: Differences between TLR7/8 and TLR9 Ligands, Cytokine Patterns, and Cross-Tolerance Induction by TLR2 Ligand Pretreatment

Administration of Toll-like receptor ligands (TLRLs) is known to cause liver injury in D-galN-sensitized mice. In the present study, we aimed to complement preceding reports on the TLRL/D-galN system by analyzing comparisons among TLRLs, mouse strain dependence, effects on serum levels of cytokines, and effects of sequential administrations of different TLRLs. In a preliminary set of analyses, we first confirmed that liver failure can be induced by diverse TLRLs, including LTA and R848 in combination with D-galN. Analysis using TLR4-deficient mice excluded potential confounding effects of endogenous TLR4Ls that include those referred to as DAMPs in CpG DNA/D-galN hepatotoxicity. Subsequently, we showed that LTA pretreatment could prevent mortality in both CpG DNA/D-galN- and R848/D-galN-treated mice compared to without pretreatment. Incidentally, we observed that without the LTA pretreatment, CpG DNA/D-galN showed relatively higher liver-specific toxicity whereas R848/D-galN showed more symptoms of multiple organ failure. These findings suggest that, in D-galN-sensitized mice, different TLRLs not only show similarity in the ability to induce hepatic injury but also exhibit distinctive abilities in inducing systemic inflammation and multiple organ failure. These findings also suggest the potential usefulness of cross-tolerance induction using LTA in the prevention of organ failure in TLRL-mediated acute inflammation.

Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review

Glycine is most important and simple, nonessential amino acid in humans, animals, and many mammals. Generally, glycine is synthesized from choline, serine, hydroxyproline, and threonine through interorgan metabolism in which kidneys and liver are the primarily involved. Generally in common feeding conditions, glycine is not sufficiently synthesized in humans, animals, and birds. Glycine acts as precursor for several key metabolites of low molecular weight such as creatine, glutathione, haem, purines, and porphyrins. Glycine is very effective in improving the health and supports the growth and well-being of humans and animals. There are overwhelming reports supporting the role of supplementary glycine in prevention of many diseases and disorders including cancer. Dietary supplementation of proper dose of glycine is effectual in treating metabolic disorders in patients with cardiovascular diseases, several inflammatory diseases, obesity, cancers, and diabetes. Glycine also has the property to enhance the quality of sleep and neurological functions. In this review we will focus on the metabolism of glycine in humans and animals and the recent findings and advances about the beneficial effects and protection of glycine in different disease states.

In Vitro and In Vivo Experimental Hepatotoxic Models in Liver Research: Applications to the Assessment of Potential Hepatoprotective Drugs

This mini-review highlights our and others’ experience about in vitro and in vivo models that are being used to follow up events of liver injuries under various hepatotoxic agents and potential hepatoprotective drugs. Due to limitations of the outcomes in each model, we focus primarily on two models. First, a developed perfusion method for isolated immobilized hepatocytes that improves the process of oxygenation and helps in end-product removal is of considerable value in improving cell maintenance. This cellular model is presented as a short-term research-scale laboratory bioreactor with various physiological, biochemical, molecular, toxicological and pharmacological applications. Second, the in vivo model of D-galactosamine and lipopolysaccharide (D-GalN/LPS) combination-induced liver damage is described with some details. Recently, we have revealed that resveratrol and other natural polyphenols attenuate D-GalN/LPS-induced hepatitis. Moreover, we reported that D-GalN/LPS down-regulates sirtuin 1 in rat liver. Therefore, we discuss here the role of sirtuin 1 modulation in hepatoprotection. A successful development of pharmacotherapy for liver diseases depends on the suitability of in vitro and in vivo hepatic injury systems. Several models are available to screen the hepatotoxic or hepatoprotective activity of any substance. It is important to combine different methods for confirmation of the findings.

The role of glycine in regulated cell death

The cytoprotective effects of glycine against cell death have been recognized for over 28 years. They are expressed in multiple cell types and injury settings that lead to necrosis, but are still not widely appreciated or considered in the conceptualization of cell death pathways. In this paper, we review the available data on the expression of this phenomenon, its relationship to major pathophysiologic pathways that lead to cell death and immunomodulatory effects, the hypothesis that it involves suppression by glycine of the development of a hydrophilic death channel of molecular dimensions in the plasma membrane, and evidence for its impact on disease processes in vivo.

Experimental models of hepatotoxicity related to acute liver failure

Acute liver failure can be the consequence of various etiologies, with most cases arising from drug-induced hepatotoxicity in Western countries. Despite advances in this field, the management of acute liver failure continues to be one of the most challenging problems in clinical medicine. The availability of adequate experimental models is of crucial importance to provide a better understanding of this condition and to allow identification of novel drug targets, testing the efficacy of new therapeutic interventions and acting as models for assessing mechanisms of toxicity. Experimental models of hepatotoxicity related to acute liver failure rely on surgical procedures, chemical exposure or viral infection. Each of these models has a number of strengths and weaknesses. This paper specifically reviews commonly used chemical in vivo and in vitro models of hepatotoxicity associated with acute liver failure.

The effect of D-galactosamine on lean and steatotic rat hepatocytes in primary culture

The aim of our work was to compare the effect of D-galactosamine (GalN) on primary cultures of lean and steatotic rat hepatocytes isolated from intact and fatty liver, respectively. GalN caused more severe injury to steatotic hepatocytes than to lean cells as documented by lactate dehydrogenase leakage. Necrotic mode of cell death strongly prevails over apoptosis since we did not observe any significant increase in activities of caspase 3, 8 and 9 in any group of hepatocytes treated with GalN. Reactive oxygen species (ROS) formation and lipid peroxidation were elevated in a dose-dependent manner by GalN and were significantly more pronounced in fatty hepatocytes. A decrease in the percentage of hepatocytes with energized mitochondria was observed from 30 mM and 10 mM GalN in lean and steatotic hepatocytes, respectively. Our results undoubtedly indicate that steatotic hepatocytes exert higher sensitivity to the toxic effect of GalN. This sensitivity may be caused by more intensive GalN-induced ROS production and lipid peroxidation and by higher susceptibility of mitochondria to loss of mitochondrial membrane potential in steatotic hepatocytes. In our experimental arrangement, apoptosis does not seem to participate considerably on hepatotoxic action of GalN in either group of hepatocytes.

Oestrogen sulfotransferase ablation sensitizes mice to sepsis

Sepsis is the host's deleterious systemic inflammatory response to microbial infections. Here we report an essential role for the oestrogen sulfotransferase (EST or SULT1E1), a conjugating enzyme that sulfonates and deactivates estrogens, in sepsis response. Both the caecal ligation and puncture (CLP) and lipopolysaccharide models of sepsis induce the expression of EST and compromise the activity of oestrogen, an anti-inflammatory hormone. Surprisingly, EST ablation sensitizes mice to sepsis-induced death. Mechanistically, EST ablation attenuates sepsis-induced inflammatory responses due to compromised oestrogen deactivation, leading to increased sepsis lethality. In contrast, transgenic overexpression of EST promotes oestrogen deactivation and sensitizes mice to CLP-induced inflammatory response. The induction of EST by sepsis is NF-κB dependent and EST is a NF-κB-target gene. The reciprocal regulation of inflammation and EST may represent a yet-to-be-explored mechanism of endocrine regulation of inflammation, which has an impact on the clinical outcome of sepsis.

Protective effect of wild ginseng cambial meristematic cells on d-galactosamine-induced hepatotoxicity in rats

Background

Panax ginseng has a wide range of biological activities including anti-inflammatory, antioxidant, and immunomodulatory functions. Wild ginseng cambial meristematic cells (CMCs) were obtained from P. ginseng cambium. This study examined the protective mechanism of wild ginseng CMCs against d-galactosamine (GalN)-induced liver injury. GalN, a well-known hepatotoxicant, causes severe hepatocellular inflammatory damage and clinical features similar to those of human viral hepatitis in experimental animals.

Methods

Hepatotoxicity was induced in rats using GalN (700 mg/kg, i.p.). Wild ginseng CMCs was administered orally once a day for 2 wks, and then 2 h prior to and 6 h after GalN injection.

Results

Wild ginseng CMCs attenuated the increase in serum aminotransferase activity that occurs 24 h after GalN injection. Wild ginseng CMCs also attenuated the GalN-induced increase in serum tumor necrosis factor-α, interleukin-6 level, and hepatic cyclooxygenase-2 protein and mRNA expression. Wild ginseng CMCs augmented the increase in serum interleukin -10 and hepatic heme oxygenase-1 protein and mRNA expression that was induced by GalN, inhibited the increase in the nuclear level of nuclear factor-kappa B, and enhanced the increase in NF-E2-related factor 2.

Conclusion

Our findings suggest that wild ginseng CMCs protects liver against GalN-induced inflammation by suppressing proinflammatory mediators and enhancing production of anti-inflammatory mediators.

Protective effects of lupeol against D-galactosamine and lipopolysaccharide-induced fulminant hepatic failure in mice

This study examined the hepatoprotective effects of lupeol (1, a major active triterpenoid isolated from Adenophora triphylla var. japonica) against d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced fulminant hepatic failure. Mice were orally administered 1 (25, 50, and 100 mg/kg; dissolved in olive oil) 1 h before GalN (800 mg/kg)/LPS (40 μg/kg) treatment. Treatment with GalN/LPS resulted in increased levels of serum alanine aminotransferase, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, as well as increased mortality, all of which were attenuated by treatment with 1. In addition, levels of toll-like receptor (TLR)4, myeloid differentiation primary response gene 88, TIR-domain-containing adapter-inducing interferon-β (TRIF), IL-1 receptor-associated kinase (IRAK)-1, and TNF receptor associated factor 6 protein expression were increased by GalN/LPS. These increases, except TRIF, were attenuated by 1. Interestingly, 1 augmented GalN/LPS-mediated increases in the protein expression of IRAK-M, a negative regulator of TLR signaling. Following GalN/LPS treatment, nuclear translocation of nuclear factor-κB and the levels of TNF-α and IL-6 mRNA expression increased, which were attenuated by 1. Together, the present findings suggest that lupeol (1) ameliorates GalN/LPS-induced liver injury, which may be due to inhibition of IRAK-mediated TLR inflammatory signaling.

Hepatotoxic constituents and toxicological mechanism of Xanthium strumarium L. fruits

ETHNOPHARMACOLOGICAL RELEVANCE

In the recent years, the international community has attached increasing importance to possible toxicity associated with Traditional Chinese Medicine (TCM). And hepatotoxicity is one of the major concerns, a fundamental pathological process induced by toxicant. This paper is in an attempt to identify the hepatotoxic components in Xanthium strumarium L. fruits (XSF) and interpret the toxicological mechanism induced by XSF.

MATERIALS AND METHODS

XSF extract was prepared and seven characteristic components were isolated and identified in XSF water extracts. We evaluated their hepatotoxicity effect on cell proliferation and lactate dehydrogenase (LDH) activity in L-02 and BRL liver cell line. An integrated metabonomics study using high-resolution (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy combined with multivariate statistical analysis was undertake to elucidate the hepatotoxicity mechanism induced in rats by XSF. The urine and serum metabolites were measured after treatment of rats with XSF (7.5, 15.0 and 30.0 g/kg/day) for 5 days.

RESULTS

The results showed that atractyloside, carboxyatractyloside, 4'-desulphate-atractyloside and XSF induced significant cytotoxic effects in both L-02 and BRL liver cell lines, indicating that atractyloside, carboxyatractyloside, and 4'-desulphate-atractyloside were the toxic components of XSF. When rats were treated with XSF at 30.0 g/kg the hepatotoxicity was reflected in the changes observed in serum biochemical profiles and by the histopathological examination of the liver. The levels of VLDL/LDL, 3-HB, lactate, acetate, acetone and glutamate in serum were increased in this group, while d-glucose, choline and valine were decreased. The elevation in the levels of succinate, citrate, 2-oxo-glutamate, glycine, 3-HB, acetate, lactate, hippurate, dimethylglycine, methylamine, dimethylamine, phenylalanine and tryptophan was observed in urine, in contrast a reduction in the intensities of taurine, d-glucose, N-acetyl-glucoprotein and trimethylamine-N-oxide (TMAO) was observed.

CONCLUSIONS

The results demonstrate that the major hepatotoxicity constituents are atractyloside, carboxyatractyloside and 4'-desulphate-atractyloside, and the hepatotoxicity of XSF involves mitochondrial inability, fatty acid metabolism, and some amino acids metabolism. This integrated (1)H NMR -based metabolic profiling approach has been able to capture and probe the metabolic alterations associated with the onset and progression of hepatotoxicity induced by XSF, and permits a comprehensive understanding of systemic toxicity for phytochemicals and other types of xenobiotic agents.

Identification of a hepatoprotective peptide in wheat gluten hydrolysate against D-galactosamine-induced acute hepatitis in rats

A hepatoprotective peptide, pyroglutamyl leucine (pyroGlu-Leu), was identified in wheat gluten hydrolysate through an in vivo activity-guided fractionation approach based on D-galactosamine-induced acute hepatitis in rats and fractionation of peptides with large-scale preparative ampholine-free isoelectric focusing. The active acidic fraction predominantly consisted of pyroglutamyl peptides and free pyroglutamic acid. Pyroglutamyl peptides were derivatized with phenyl isothiocyanate after removal of a pyroglutamyl residue by pyroglutamate aminopeptidase. The derivatives were purified by reversed-phase HPLC and subjected to sequence analysis. The active fraction contained pyroGlu-Ile, pyroGlu-Leu, pyroGlu-Gln, pyroGlu-Gln-Gln, and free pyroGlu. Ingestion of pyroGlu-Leu at 20 mg/kg body weight significantly decreased serum aspartate and alanine aminotransferases to approximately 30% and 20% of those values of the vehicle group, respectively, which were near the normal levels. Thirty minutes after ingestion of pyroGlu-Leu at 20 mg/kg, the concentration of pyroGlu-Leu in portal blood plasma increased to approximately 2 μM.

Metabonomic analysis of liver tissue from BALB/c mice with D-galactosamine/lipopolysaccharide-induced acute hepatic failure

Background

Compared with biofluids, target tissues and organs more directly reflect the pathophysiological state of a disease process. In this study, a D-galactosamine (GalN) / lipopolysaccharide (LPS)-induced mouse model was constructed to investigate metabonomics of liver tissue and directly characterize metabolic changes in acute liver failure (ALF).

Methods

After pretreatment of liver tissue, gas chromatography coupled to time-of-flight mass spectrometry (GC/TOFMS) was used to separate and identify the liver metabolites. Partial least squares – discriminant analysis models were constructed to separate the ALF and control groups and to find those compounds whose liver levels differed significantly between the two groups.

Results

Distinct clustering was observed between the ALF and control mice. Fifty-eight endogenous metabolites were identified. Compared with the control mice, many metabolites, including sugars, amino acids, fatty acids, and organic acids, underwent significant changes in the ALF group, some of which differed from changes observed in plasma. Significant reduction of some important intermediate metabolites indicates that production of ketone bodies, the tricarboxylic acid and urea cycles, gluconeogenesis, glycolysis and pentose phosphate pathways are inhibited after GalN/LPS administration.

Conclusions

GC/TOFMS can be a powerful technique to perform metabonomic studies of liver tissue. GalN/LPS treatment can severely disturb substance metabolism in the liver, with different effects on metabolites compared with those observed in the plasma.

Ex vivo magnetic resonance imaging of transplanted hepatocytes in a rat model of acute liver failure

Hepatocyte transplantation is being evaluated as an alternative to liver transplantation. However, the fate of hepatocytes after transplantation is not well defined. The aims of the study were to improve hepatocyte labeling in vitro using superparamagnetic iron oxide nanoparticles (SPIOs) and to perform in vivo experiments on tracking labeled cells by magnetic resonance imaging (MRI). Human and rat hepatocytes were labeled in vitro for 16 h with clinically approved SPIOs (12.5 µg Fe/ml) and protamine sulfate (3 µg/ml) as a transfection agent. Increased cellular iron uptake was obtained, and cell viability and function were shown not to be affected by labeling. Labeled cells (2,000/µl) could be detected on T2-weighted images in vitro using a 7T MR scanner. In a rat model of acute liver failure (ALF), female recipients received intrasplenic transplantation of 2 × 10(7) male rat hepatocytes 28-30 h after intraperitoneal injection of d-galactosamine (1.2 g/kg). There were four groups (n = 4 each): vehicle injection, injection of freshly isolated cells labeled with CM-DiI, injection of cultured cells labeled with CM-DiI, and injection of cultured cells labeled with both SPIOs and CM-DiI. Ex vivo T2*-weighted gradient-echo images at 7T MRI were acquired at day 7 post-ALF induction. Six days after transplantation, SPIOs were detected in the rat liver as a decrease in the MRI signal intensity in the surviving animals. Histologically, most of the SPIOs were located in Kupffer cells, indicating clearance of labeled hepatocytes. Furthermore, labeled cells could not be detected in the liver by the fluorescent dye or by PCR for the Y-chromosome (Sry-2 gene). In conclusion, optimum conditions to label human hepatocytes with SPIOs were established and did not affect cell viability or metabolic function and were sufficient for in vitro MRI detection. However, the clearance of hepatocytes after transplantation limits the value of MRI for assessing long-term hepatocyte engraftment.

Modulation of spontaneous and lipopolysaccharide-induced nitric oxide production and apoptosis by d-galactosamine in rat hepatocyte culture: the significance of combinations of different methods

ABSTRACT Apoptotic markers and signals produced by xenobiotics as hepatotoxic D-galactosamine (D-GalN) and lipopolysaccharide (LPS) are extensively investigated in vivo. The contribution of various cells and factors as nitric oxide (NO) in mediating hepatocyte apoptosis in a rat model of systemic endotoxemia was reported. Therefore, the aim of the present work was to study the in vitro effect of D-GalN on nonstimulated or LPS-treated rat hepatocytes in culture and the potential involvement of NO in this process. Our results showed that the spontaneous and LPS-induced NO production was completely blocked by D-GalN during 0 to 24 hours. However, D-GalN slightly enhanced NO production during 24 to 48 hours. D-GalN was more potent to induce hepatocyte apoptosis and necrosis during 24 to 48 than 0 to 24 hours as evidenced morphologically (Annexin V/propidium iodide staining) and biochemically (caspase-3-like activity, alanine-aminotransferase leakage, MTT test). Interestingly, D-GalN treatment suppressed mitochondrial cytochrome C release throughout the study. LPS addition to D-GalN considerably aggravated apoptotic/necrotic markers only during 0 to 24 hours. Surprisingly, a share of apoptotic cells was distinctly lower after LPS + GalN treatment than after LPS alone during 0 to 24 hours, while 24- to 48-hour incubation produced massive apoptotic/necrotic hepatocytes. It may be concluded that there is a significant modulation of NO production by D-GalN. Because the role of NO is only partly decisive in the apoptotic/necrotic events, and considering the fraction of the cells completing apoptosis while others that turn toward necrosis (aponecrosis), caution should be exercised in apoptosis data interpretation and combinations of different test methods should be applied.

Innate immune cells in liver inflammation

Innate immune system is the first line of defence against invading pathogens that is critical for the overall survival of the host. Human liver is characterised by a dual blood supply, with 80% of blood entering through the portal vein carrying nutrients and bacterial endotoxin from the gastrointestinal tract. The liver is thus constantly exposed to antigenic loads. Therefore, pathogenic microorganism must be efficiently eliminated whilst harmless antigens derived from the gastrointestinal tract need to be tolerized in the liver. In order to achieve this, the liver innate immune system is equipped with multiple cellular components; monocytes, macrophages, granulocytes, natural killer cells, and dendritic cells which coordinate to exert tolerogenic environment at the same time detect, respond, and eliminate invading pathogens, infected or transformed self to mount immunity. This paper will discuss the innate immune cells that take part in human liver inflammation, and their roles in both resolution of inflammation and tissue repair.

Suppressive effect of modified arabinoxylan from rice bran (MGN-3) on D-galactosamine-induced IL-18 expression and hepatitis in rats

We investigated in this study the effect of modified arabinoxylan from rice bran (MGN-3) and its fractions on D-galactosamine (D-GalN)-induced IL-18 expression and hepatitis in rats. Male Wistar rats were pretreated with MGN-3 or fractions of the MGN-3 hydrolysate, or with saline 1 h before administering D-GalN (400 mg/kg B.W.). The serum transaminase activities, IL-18 mRNA expression level in the liver and IL-18 concentration in the serum were determined 24 h after injecting D-GalN. Both the oral and intraperitoneal administration of MGN-3 (20 mg/kg B.W.) alleviated D-GalN-induced hepatic injury under these experimental conditions. The low-molecular-weight fraction (LMW) of MGN-3 showed the strongest protective effect on D-GalN-induced liver injury, its main sugar component being glucose. Moreover, the D-GalN-induced IL-18 expression was significantly reduced by treating with MGN-3 and LMW. The results suggest that MGN-3 and LMW could provide significant protection against D-GalN liver injury, and that IL-18 might be involved in their protective influence.

Combined proteomic and metabolomic profiling of serum reveals association of the complement system with obesity and identifies novel markers of body fat mass changes

Obesity is associated with multiple adverse health effects and a high risk of developing metabolic and cardiovascular diseases. Therefore, there is a great need to identify circulating parameters that link changes in body fat mass with obesity. This study combines proteomic and metabolomic approaches to identify circulating molecules that discriminate healthy lean from healthy obese individuals in an exploratory study design. To correct for variations in physical activity, study participants performed a one hour exercise bout to exhaustion. Subsequently, circulating factors differing between lean and obese individuals, independent of physical activity, were identified. The DIGE approach yielded 126 differentially abundant spots representing 39 unique proteins. Differential abundance of proteins was confirmed by ELISA for antithrombin-III, clusterin, complement C3 and complement C3b, pigment epithelium-derived factor (PEDF), retinol binding protein 4 (RBP4), serum amyloid P (SAP), and vitamin-D binding protein (VDBP). Targeted serum metabolomics of 163 metabolites identified 12 metabolites significantly related to obesity. Among those, glycine (GLY), glutamine (GLN), and glycero-phosphatidylcholine 42:0 (PCaa 42:0) serum concentrations were higher, whereas PCaa 32:0, PCaa 32:1, and PCaa 40:5 were decreased in obese compared to lean individuals. The integrated bioinformatic evaluation of proteome and metabolome data yielded an improved group separation score of 2.65 in contrast to 2.02 and 2.16 for the single-type use of proteomic or metabolomics data, respectively. The identified circulating parameters were further investigated in an extended set of 30 volunteers and in the context of two intervention studies. Those included 14 obese patients who had undergone sleeve gastrectomy and 12 patients on a hypocaloric diet. For determining the long-term adaptation process the samples were taken six months after the treatment. In multivariate regression analyses, SAP, CLU, RBP4, PEDF, GLN, and C18:2 showed the strongest correlation to changes in body fat mass. The combined serum proteomic and metabolomic profiling reveals a link between the complement system and obesity and identifies both novel (C3b, CLU, VDBP, and all metabolites) and confirms previously discovered markers (PEDF, RBP4, C3, ATIII, and SAP) of body fat mass changes.

Differential Oxidative Stress Responses to D-Galactosamine-Lipopolysaccharide Hepatotoxicity Based on Real Time PCR Analysis of Selected Oxidant/Antioxidant and Apoptotic Gene Expressions in Rat

Oxidative stress and apoptosis are proposed mechanisms of cellular injury in studies of xenobiotic hepatotoxicity. This study is focused on addressing the mutual relationship and early signals of these mechanisms in the D-galactosamine and lipopolysaccharide (D-GalN/LPS) hepatotoxicity model, with the help of standard liver function and biochemistry tests, histology, and measurement of gene expression by RT-PCR. Intraperitoneal injection of 400 mg/kg D-GalN and 50 μg/kg LPS was able to induce hepatotoxicity in rats, as evidenced by significant increases in liver enzymes (ALT, AST) and raised bilirubin levels in plasma. Heme oxygenase-1 and nitric oxide synthase-2 gene expressions were significantly increased, along with levels of their products, bilirubin and nitrite. The gene expression of glutathione peroxidase 1 remained unchanged, whereas a decrease in superoxide dismutase 1 gene expression was noted. Furthermore, the significant increase in the gene expression of apoptotic genes Bid, Bax and caspase-3 indicate early activation of apoptotic pathways, which was confirmed by histological evaluation. In contrast, the measured caspase-3 activity remained unchanged. Overall, the results have revealed differential oxidative stress and apoptotic responses, which deserves further investigations in this hepatotoxicity model.

Chemical shift calibration of 1H MAS NMR liver tissue spectra exemplified using a study of glycine protection of galactosamine toxicity

High-resolution (1)H magic angle spinning (MAS) NMR spectroscopy is a useful tool for analysing intact tissues as a component of metabonomic studies. The effect of referencing MAS NMR spectra to the chemical shifts of glucose or to that or trimethylsilylpropionic acid on the resultant multivariate statistical models have been investigated. It is shown that referencing to known chemical shifts of either alpha-glucose or beta-glucose in (1)H MAS NMR-based metabolic data of intact liver tissues is preferred. This has been exemplified in studies of galactosamine toxicity in the rat where co-administration of glycine ameliorates the toxic response. This approach leads to better aligned sets of spectra and reduces the inter-sample variability in multivariate statistical models. If glucose is not present in the tissue under study, then a number of alternative internal reference chemical shifts are presented. Finally, the chemical shift difference between that of the anomeric H1 proton of alpha-glucose and residual water is confirmed as a suitable internal temperature calibration method.

Resveratrol attenuates lipopolysaccharide-induced hepatitis in D-galactosamine sensitized rats: role of nitric oxide synthase 2 and heme oxygenase-1

The goal of study was directed to investigate the effects of resveratrol (RES) pretreatment on the enhancing action of D-galactosamine (D-GalN; 800 mg/kg) on lipopolysaccharide (LPS; 0.5 microg/kg) inducing liver failure in rats. Liver function was assessed by determination of plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), alpha-glutathione S-transferase (alpha GST) and bilirubin (BILI). Plasma NO(2)(-) was assessed by NO(2)(-)/NO(3)(-) colorimetric kit. The estimation of nonenzymatic and enzymatic antioxidants (glutathione and catalase) was performed in plasma and liver homogenate. Lipid peroxidation was evaluated by the thiobarbituric acid reacting substances (TBARS) and the conjugated dienes (CD). Morphological examinations using light and electron microscopy were performed. Observations related to pharmacological increases of inducible nitric oxide synthase (NOS-2)/nitric oxide (NO) and inducible heme oxygenase (HO-1) in fulminant hepatic failure and modulation by resveratrol were followed up by real-time reverse transcription PCR (RT-PCR) in liver tissue. In the present study we found that among the mechanisms responsible for the hepatoprotective effect of resveratrol in the LPS/D-GalN liver toxicity model are reduction in NO, downregulation of NOS-2, modification of oxidative stress parameters and modulation of HO-1 which led to overall improvement in hepatotoxic markers and morphology after the hepatic insult.

Glycine and glycine receptor signalling in non-neuronal cells

Glycine is an inhibitory neurotransmitter acting mainly in the caudal part of the central nervous system. Besides this neurotransmitter function, glycine has cytoprotective and modulatory effects in different non-neuronal cell types. Modulatory effects were mainly described in immune cells, endothelial cells and macroglial cells, where glycine modulates proliferation, differentiation, migration and cytokine production. Activation of glycine receptors (GlyRs) causes membrane potential changes that in turn modulate calcium flux and downstream effects in these cells. Cytoprotective effects were mainly described in renal cells, hepatocytes and endothelial cells, where glycine protects cells from ischemic cell death. In these cell types, glycine has been suggested to stabilize porous defects that develop in the plasma membranes of ischemic cells, leading to leakage of macromolecules and subsequent cell death. Although there is some evidence linking these effects to the activation of GlyRs, they seem to operate in an entirely different mode from classical neuronal subtypes.

Hormonal regulation of pro-inflammatory and lipid peroxidation processes in liver of old ovariectomized female rats

There is now a large body of evidence suggesting that the decline in ovarian function with menopause is associated with spontaneous increases in pro-inflammatory cytokines. On the other hand, oxidative stress has been implicated in the pathogenesis of several alterations due to menopause, and can arise through the increased production of lipid peroxides (LPO) and/or a deficiency of antioxidant defense. The aim of the present study was to investigate the effect of aging and ovariectomy on various physiological parameters related to inflammation and oxidative stress in livers obtained from old female rats and the influence of chronic exogenous administration of estrogens, phytoestrogens and growth hormone on these. Thirty-six female Wistar rats of 22 months of age were used in the present study. Twelve of them remained intact, and the other 24 had been ovariectomized at 12 months of age. Intact animals were divided into two groups and treated for 10 weeks with GH or saline, and ovariectomized animals were divided into four groups and treated for the same time with GH, estrogens, phytoestrogens or saline. A group of 2 month old intact female rats was used as young control. Protein expression of iNOS, HO-1, IL-6, TNFalpha, and IL-1beta were determined by Western blot analysis. The levels of NO( x ), LPO, TNFalpha, IL-1beta, IL-6 and IL-10 were determined in different fractions of the liver. Levels of LPO in the liver homogenates as well as iNOS protein expression and NO( x ) levels were increased in old rats as compared to young animals; this effect was more evident in ovariectomized animals. Pro-inflammatory cytokines TNF-alpha, IL-1beta and IL-6 were significantly increased and anti-inflammatory IL-10 decreased during ageing and after ovariectomy. Aging also significantly increased expression of HO-1 protein and ovariectomized rats showed an additional increase. Hormonal administration to the ovariectomized groups decreased NO( x ), LPO levels and pro-inflammatory cytokines as compared with untreated rats. Significant rise in IL-10 and reductions in the iNOS, IL-6, TNFalpha and IL-1beta proteins expression were also found. Oxidative stress and inflammation induced during aging in the liver are more marked in castrated than in intact old females. Administration of the different hormonal replacement therapies was able to inhibit the induction of pro-inflammatory cytokines and iNOS, decreased the levels of oxidative stress markers and had therapeutic potential in the prevention of liver injury.

Liquiritigenin, a flavonoid aglycone from licorice, has a choleretic effect and the ability to induce hepatic transporters and phase-II enzymes

Liquiritigenin (LQ), an active component of licorice, has an inhibitory effect on LPS-induced inhibitory nitric oxide synthase expression. This study investigated the effects of LQ on choleresis, the expression of hepatic transporters and phase-II enzymes, and fulminant hepatitis. The choleretic effect and the pharmacokinetics of LQ and its glucuronides were monitored in rats. After intravenous administration of LQ, the total area under the plasma concentration-time curve of glucuronyl metabolites was greater than that of LQ in plasma, which accompanied elevations in bile flow rate and biliary excretion of bile acid, glutathione, and bilirubin. The expressions of hepatocellular transporters and phase-II enzymes were assessed by immunoblots, real-time PCR, and immunohistochemistry. In the livers of rats treated with LQ, the protein and mRNA levels of multidrug resistance protein 2 and bile salt export pump were increased in the liver, which was verified by their increased localizations in canalicular membrane. In addition, LQ treatment enhanced the expression levels of major hepatic phase-II enzymes. Consistent with these results, LQ treatments attenuated galactosamine/LPS-induced hepatitis in rats, as supported by decreases in the plasma alanine aminotransferase, liver necrosis, and plasma TNF-alpha. These results demonstrate that LQ has a choleretic effect and the ability to induce transporters and phase-II enzymes in the liver, which may be associated with a hepatoprotective effect against galactosamine/LPS. Our findings may provide insight into understanding the action of LQ and its therapeutic use for liver disease.

L-Gln and L-Ser suppress the D-galactosamine-induced IL-18 expression and hepatitis

D-Galactosamine (GalN) induces acute hepatitis in experimental animals and this hepatitis has been shown to be suppressed by preceding ingestion of amino acids such as Gly, L-Ser, and L-Gln. However, little is known about the mechanism of its action. The present study shows for the first time that IL-18 reduction is involved in the suppressive actions of L-Gln and L-Ser on GalN-induced hepatitis. Elevation of IL-18 mRNA expression in liver and its concentration in serum in GalN-treated rats were found to be suppressed by preceding ingestion of 10% L-Gln- or 10% L-Ser diets, and resulted in the attenuation of the increase in serum transaminase (ALT and AST) activities, indexes of hepatic injury. These results suggest that suppressive effects of some dietary amino acids on the GalN-induced hepatitis are mediated by IL-18 reduction.

Pectolinarin and Pectolinarigenin of Cirsium setidens Prevent the Hepatic Injury in Rats Caused by D-Galactosamine via an Antioxidant Mechanism

To identify the hepatoprotective component from the leaves of Cirsium setidens (Compositae), the methanolic extract was divided into two fractions, chloroform and butanol fractions, and their hepatoprotective efficacy was evaluated in a rat model of hepatic injury caused by D-galactosamine (GalN). Hepatoprotective activity was measured by the activity of serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). Glutathione metabolism was measured via biochemical parameters such as glutathione (GSH), glutathione reductase (GR), gamma-glutamylcysteine synthetase (GCS), glutathione S-transferase (GST), and superoxide dismutase (SOD) levels. We subjected the butanol fraction, which had higher activity, to column chromatography to yield pectolinarin, which was further hydrolyzed to yield pectolinarigenin. Administration (10, 20 mg/kg, p.o.) of the main flavonoid glycoside component, pectolinarin, and its aglycone, pectolinarigenin, for 2 weeks significantly decreased the activity levels of AST, ALT, ALP and LDH, indicating that the two compounds have hepatoprotective activity. Pectolinarin and pectolinarigenin also increased activity levels of GSH, GR, GCS, and GST, as well as SOD. The significant effect was only seen in SOD activity. This suggests that the two components exhibit hepatoprotective activity mainly via SOD antioxidant mechanism.