Protective effect of Et-1 receptor antagonist bosentan on paracetamol induced acute liver toxicity in rats

Allicin and Omega-3 fatty acids attenuates acetaminophen mediated renal toxicity and modulates oxidative stress, and cell apoptosis in rats

Acetaminophen (APAP), a widely used medication known for its pain-relieving and fever-reducing effects, can cause kidney failure if taken in excess. To investigate the potential protective effects of allicin (ALC) and/or omega-3 fatty acids (O3FA) against acetaminophen-induced kidney damage, a study was conducted using 49 rats divided into seven groups. The control group was given saline, while the other groups received ALC, O3FA, APAP, ALC + APAP, O3FA + APAP, or ALC + O3FA + APAP. After administering APAP, the rats showed decreased levels of total protein and albumin in their blood, along with increased levels of creatinine and urea. The concentration of reduced glutathione (GSH), as well as the activity of superoxide dismutase (SOD) and catalase (CAT), decreased, while the level of malondialdehyde (MDA) in the renal tissues increased. The activation of caspase-3 and HSP70 also suggested an impact on kidney histopathology. Overall, the study found that ALC and/or O3FA may have a protective impact against acetaminophen-induced kidney damage through their anti-inflammatory, anti-apoptotic, and antioxidant defense systems.

Caesalpinia bonducella Counteracts Paracetamol-Instigated Hepatic Toxicity via Modulating TNF-α and IL-6/10 Expression and Bcl-2 and Caspase-8/3 Signalling

Paracetamol is the most predominantly used antipyretic and analgesic drug. As paracetamol is metabolised mostly in the liver, both deliberate and unintentional overdoses of paracetamol are reported to provoke severe hepatotoxicity, including liver failure. Caesalpinia bonducella seed is well known for its medicinal and therapeutic properties. However, there is no report on its potential protective effects against paracetamol-instigated hepatotoxicity. Therefore, we studied the protective effects of aqueous seed extract of Caesalpinia bonducella (ASECB) on paracetamol-instigated hepatotoxicity in rats. Thirty female albino rats were divided into five groups: control, paracetamol-intoxicated, ASECB + paracetamol, silymarin + paracetamol, and ASECB alone. The rats were assessed for liver enzyme markers (alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase), antioxidant activity (superoxide dismutase, catalase, reduced glutathione, glutathione peroxidase), lipid peroxidation (malondialdehyde), histopathological, cytokine levels (pro-inflammatory cytokines TNF-α and IL-6, and anti-inflammatory cytokine IL-10), and protein expression (pro-apoptotic markers caspase 3 and caspase 8 and anti-apoptotic marker Bcl-2) after the 8-day study period. Repercussions of paracetamol intoxication induced upregulation of liver enzyme markers, antioxidant depletion, malondialdehyde production, decreased expression of Bcl-2 and IL-10, and overexpression of apoptotic and pro-inflammatory mediators, which were attenuated by pre-treatment with ASECB. ASECB markedly mitigated paracetamol-instigated liver injury by suppressing caspase-8/3 signalling and inflammatory infiltration in liver tissue by significantly reducing TNF-α and IL-6. In conclusion, ASECB pre-treatment exerts potent liver protection against paracetamol-instigated hepatotoxicity evidenced by mitigation of oxidative stress, lipid peroxidation, inflammation, and apoptosis.

Fisetin Attenuates Paracetamol-Induced Hepatotoxicity by Regulating CYP2E1 Enzyme

Paracetamol is one of the drugs that cause hepatic damage. Fisetin has wide pharmacological effects such as anticancer, antiinflammatory and antioxidant. We aimed to evaluate the possible protective effect of fisetin on paracetamol-induced hepatotoxicity. Fisetin was administered at 25 and 50 mg/kg doses. Paracetamol was administered orally at a dose of 2 g/kg for induce hepatotoxicity 1 h after the fisetin and NAC treatments. The rats were sacrificed 24h after the Paracetamol administration. Tumor necrosis factor-alpha (TNF-α), NFκB and CYP2E1 mRNA levels and Superoxide dismutase (SOD) activity, glutathione (GSH) and malondialdehyde (MDA) levels of livers were determined. Serum ALT, AST and ALP levels were measured. Histopathological examinations were also performed. Fisetin administration significantly decreased the ALT, AST and ALP levels in a dose dependent manner. In addition, SOD activity and GSH levels increased, and the MDA level decreased with the treatment of fisetin. The TNF-α, NFκB and CYP2E1 gene expressions were significantly lower in both doses of the fisetin groups compared with the PARA group. Histopathological examinations showed that fisetin has hepatoprotective effects. This study showed that fisetin has the liver protective effects by increasing GSH, decreasing inflammatory mediators and CYP2E1.

Evaluation of the hepatoprotective effect of curcumin-loaded solid lipid nanoparticles against paracetamol overdose toxicity: Role of inducible nitric oxide synthase

Curcumin (Cur) is a natural compound that exhibited therapeutic effects against various liver injuries however Cur showed poor water solubility and bioavailability. This study aimed to design Cur-loaded solid lipid nanoparticles (SLNs) and to evaluate the hepatoprotective and antioxidant effects in a model of acute hepatotoxicity induced by paracetamol (PCM) overdose compared to the raw Cur and N-acetylcysteine (NAC). SLNs were prepared by emulsion/solvent evaporation method and 3² factorial design was employed. Wistar rats were divided into Control, PCM, PCM + NAC, PCM + raw Cur, and PCM + Cur-SLNs groups and treated orally for 14 days before receiving a single PCM dose. The Cur-loaded SLNs showed high entrapment efficiency % ranging between 69.1 and 92.1%, particle size (PS) between 217 and 506 nm, and zeta potential values between -17.9 and -25.5 mV. The in vivo results revealed that the PCM group exhibited deterioration of liver functions, pathological lesions on the liver tissues, severe oxidative stress, and increases in both the serum and hepatic iNOS levels. Remarkably, the PCM + Cur-SLNs group showed significantly better liver functions and tissue integrity compared to the PCM group. Furthermore, higher reduced glutathione and catalase but lower malondialdehyde and iNOS levels were observed. In conclusion, Cur-loaded SLNs effectively prevented the liver damage induced by PCM overdose through alleviating the oxidative stress and inhibiting the serum and hepatic iNOS expression in an effect comparable to NAC and better than raw Cur.

Aprepitant: an antiemetic drug, contributes to the prevention of acute lung injury with its anti-inflammatory and antioxidant properties

OBJECTIVES

We investigated, the effects of aprepitant (APRE) on the lung tissues of rats with an experimental polymicrobial sepsis model (CLP: cecal ligation and puncture) biochemically, molecularly and histopathologically.

METHODS

A total of 40 rats were divided into 5 groups with 8 animals in each group. Group 1 (SHAM), control group; Group 2 (CLP), cecal ligation and puncture; Group 3 (CLP + APRE10), rats were administered CLP + 10 mg/kg aprepitant; Group 4 (CLP + APRE20), rats were administered CLP + 20 mg/kg aprepitant; and Group 5 (CLP + APRE40), rats were administered CLP + 40 mg/kg aprepitant. A polymicrobial sepsis model was induced with CLP. After 16 h, lung tissues were taken for examination. Tumour necrosis factor α (TNF-α) and nuclear factor-kappa b (NFK-b) messenger ribonucleic acid (mRNA) expressions were analysed by real-time PCR (RT-PCR), biochemically antioxidant parameters such as superoxide dismutase (SOD) and glutathione (GSH) and oxidant parameters such as malondialdehyde (MDA) and lung damage histopathologically.

KEY FINDINGS AND CONCLUSIONS

The GSH level and SOD activity increased while the MDA level and the expressions of TNF-α and NFK-b were reduced in the groups treated with APRE, especially in the CLP + APRE40 group. The histopathology results supported the molecular and biochemical results.

Lignans from Schisandra chinensis ameliorate alcohol and CCl4-induced long-term liver injury and reduce hepatocellular degeneration via blocking ETBR

ETHNOPHARMACOLOGICAL RELEVANCE

Chemical hepatotoxicity, especially alcoholic liver injury (ALI), commonly occurs in young and middle-aged people who drink heavily. ALI is extremely harmful and can induce severe disease states, such as hepatitis, liver fibrosis, cirrhosis, or liver cancer, which are similar to CCl₄-induced liver disease states in animals. In recent studies, the pathological changes of hepatocytes and the hepatic stellate cell have shown a significant connection between endoplasmic reticulum (ER) stress and the development of liver pathology in patients. However, the detailed pathological mechanism needs to be further studied. Schisandra chinensis, (S. chinensis), a fruit-bearing vine used in Traditional Chinese Medicine (TCM), has been used to treat chronic or acute diseases, including liver disease. S. chinensis-derived lignans (SCDLs) in particular have been shown to alleviate liver pathological changes.

AIM OF THE STUDY

This study sought to elucidate the mechanisms underlying SCDL-mediated hepatoprotection.

MATERIALS AND METHODS

We first used in silico target prediction and computational simulation methods to identify putative lignan-binding targets relative to the hepatoprotective effect. A gene microarray analysis was performed to identify differently expressed genes that might have significance in the disease pathological process. We then used histological analyses in a mice hepatotoxicity model to test the effectiveness of SCDLs in vivo, and a hepatocellular toxicity model to analyze the candidate-compound-mediated hepatoprotection and expression states of the key targets in vitro.

RESULTS

The in silico analysis results indicated that endothelin receptor B (ETBR/EDNRB) is likely a significant node during the liver pathological change process and a promising key target for the SCDL compound schisantherin D on the hepatoprotective effect; experimental studies showed that schisantherin D alleviated the EtOH- and ET-1-induced HL-7702 cell (belongs to liver parenchymal cell lines) injury ratio, decreased the expression of ETBR, and inhibited ECMs and ET-1 secretion in LX-2 cells (one form of hepatic stellate cells). SCDLs ameliorated EtOH- and CCl₄-induced fibrosis formation in mice liver tissue. Liver tissue western blots of SCDL-treated mice showed downregulated α-SMA, ETBR, PLCβ, CHOP, Bax, and the apoptotic factors of cleaved-caspase 12, cleaved-caspase 9, and cleaved-caspase 3 hinted at an anti-apoptosis and hepatoprotective effect. The SCDL treatment also elevated serum glutathione (GSH) and reduced the serum-transforming growth factor-β1 (TGF-β1) level.

CONCLUSION

The findings indicated that SCDLs prevent hepatotoxicity via their anti-fibrotic, anti-oxidant, and anti-apoptosis properties. ETBR may be the key factor in promoting chemical hepatotoxicity.

A novel effect of Aprepitant: Protection for cisplatin-induced nephrotoxicity and hepatotoxicity

Cisplatin is widely used chemotherapeutic drug and have some serious side effects as tissue toxicity and nausea and vomiting. Aprepitant is used in clinic as an anti-emetic drug for cisplatin treated patient to prevent nausea and vomiting. We aimed to investigate the protective effects of Aprepitant on cisplatin-induced nephrotoxicity and hepatotoxicity. In total 42 male rats were separated into six groups (n = 7). A single dose of cisplatin (10 mg/kg i.p.) was administered to induce toxicity on first day. Different doses of Aprepitant (5, 10 and 20 mg/kg, p.o.) were given to treatment groups during 3 days. After the experimental procedures serum enzymes (ALT, AST, ALP, BUN and Creatinin), kidney and liver oxidative parameters (SOD, GSH and MDA), inflammatory cytokines (TNF-α and NF-κB) and Cyp2e1 expressions analyzed. Histopathological investigations also performed for all groups. Cisplatin caused tissue toxicity in both kidney and liver. Serum enzymes, tissue cytokines and oxidative stress were increased after the Cis treatment. Aprepitant treatment normalized all parameters compared to cisplatin treated group. Cisplatin significantly increased the Cyp2e1 expression in the kidney while significantly decreased in the liver compared to Healthy group. Histopathologically, it was shown that cisplatin causes a lot of abnormal structures as inflammatory infiltration and necrosis on the liver and kidney. Similar the biochemical and molecular results, aprepitant showed positive effects on tissue pathological parameters. With its main anti-emetic effect, Aprepitant treatment may be an effective option for cancer patients if they have additional injury as nephrotoxicity and hepatotoxicity due to cisplatin.

Nobiletin attenuates acetaminophen-induced hepatorenal toxicity in rats

The study aimed to examine the effects of nobiletin on the toxicity model induced with acetaminophen (APAP). For this purpose, 24 adult male rats were equally divided into four groups. The groups were the control group (group 1); dimethyl sulfoxide only, the APAP group (group 2) received a single dose of APAP 1000 mg/kg on the 10th day of experiment; the Nobiletin group (group 3), nobiletin (10 mg/kg) for 10 days; and the APAP + Nobiletin group (group 4), nobiletin (10 mg/kg) for 10 days with a single dose of APAP (1000 mg/kg) administered on the 10th day and the experiment ended after 48 hours. At the end of the study, a significant increase in malondialdehyde, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels and a significant decrease in glutathione levels, glutathione peroxidase activities and nuclear factor erythroid-derived 2-like 2 (Nrf-2) and heme oxygenase-1 (HO-1) expressions were observed with APAP application in liver and kidney tissues. Serum aspartate transaminase (AST), alanine transaminase (ALT), urea, and creatinine levels were also significantly increased in the APAP group. However, nobiletin treatment in group 4 reversed oxidative stress and inflammatory and histopathological signs caused by APAP. It is concluded that nobiletin may be a beneficial substance that confers hepatorenal protection to APAP-induced toxicity via antioxidant and anti-inflammatory mechanisms.

Marine macro-algae attenuates nephrotoxicity and hepatotoxicity induced by cisplatin and acetaminophen in rats

Cisplatin is considered one of the best anticancer medications often used for the treatment of various cancers even with its adverse effects. Acetaminophen (paracetamol) is a widely used analgesic-antipyretic drug that causes hepatotoxicity at higher than the effective doses. The present study assesses the nephroprotective and hepatoprotective effects of two seaweeds against cisplatin and acetaminophen toxicity in rats. Damage to the liver and kidney was induced by administering a single intraperitoneal dose of acetaminophen (600 mg/kg) or cisplatin (7 mg/kg) to groups of rats. The damage to the liver and kidney was assessed by the elevated liver (ALT, AST, ALP, LDH, electrolytes) and kidney (urea, creatinine) biomarkers. The ethanol extract of brown seaweed reversed the elevated levels of kidney and liver biomarkers along with triglycerides, cholesterol, and glucose. Among the two seaweeds, Sargassum ilicifolium showed better nephroprotective and hepatoprotective effects than the standard drug N-Acetyl-cysteine, Halymenia porphyroides showed only limited protection. Findings of this study provide evidence of nephroprotective and hepatoprotective effects of S. ilicifolium. Seaweed could be a beneficial dietary supplement to attenuate nephrotoxicity and hepatotoxicity.

Acute and 28-days repeated dose sub-acute toxicity study of gallic acid in albino mice

Gallic acid is a phenolic acid ubiquitously present in numerous medicinal plants and food beverages. Gallic acid is also a potent anti-oxidant phytochemical possessing numerous medicinal potentials against various ailments such as diabetes, hypercholesterolemia and other life-threatening diseases including malignancy. Present study was aimed to evaluate acute and sub-acute toxicity of gallic acid in albino mice. The primary aim of the study was to investigate gallic acid prompted PPAR-α/γ activation associated adverse events. Acute toxicity of gallic acid was determined in albino mice and 28-days sub-acute toxicity study was carried out in male and female albino mice at three dose levels, 100, 300 and 900 mg/kg/day, p.o. LD₅₀ of gallic acid was found to be greater than 2000 mg/kg in mice. Hematological investigation did not show any alteration in transaminases and other blood homeostasis parameters. Gross necropsy showed non-significant alteration upon gallic acid administration. Histopathological finding suggested no significant alteration in tissue histology with slight fatty cells in bone marrow indicating non-significant bone marrow suppression, also no obvious effect was observed on hematological parameters. High dose of gallic acid (900 mg/kg/day) for 28 days did not produce any significant alteration in morphological and behavioral parameters. Histopathological finding also supports safety of gallic acid in mice.

Protective Effect of Gemfibrozil on Hepatotoxicity Induced by Acetaminophen in Mice: the Importance of Oxidative Stress Suppression

Purpose: Gemfibrozil (GEM) apart from agonist activity at peroxisome proliferator-activated receptor-alpha (PPAR-α) has antioxidant and anti-inflammatory properties. Accordingly, the present study was designed to investigate the protective effect of GEM on acute liver toxicity induced by acetaminophen (APAP) in mice.

Methods: In this study, mice divided in seven groups include, control group, APAP group, GEM group, three APAP groups pretreated with GEM at the doses of 25, 50 and 100 mg/kg respectively and APAP group pretreated with N-Acetyl cysteine. GEM, NAC or vehicle were administered for 10 days. In last day, GEM and NAC were gavaged 1 h before and 1 h after APAP injection. Twenty four hours after APAP, mice were sacrificed. Serum parameters include alanine aminotransferase (ALT), aspartate aminotransferase (AST) and liver tissue markers including catalase enzyme activity, reactive oxygen species (ROS), malondialdehyde and reduced glutathione (GSH) levels determined and histopathological parameters measured.

Results: GEM led to significant decrease in serum ALT and AST activities and increase in catalase activity and hepatic GSH level and reduces malondialdehyde and ROS levels in the liver tissue. In confirmation, histopathological findings revealed that GEM decrease degeneration, vacuolation and necrosis of hepatocytes and infiltration of inflammatory cells.

Conclusion: Present data demonstrated that GEM has antioxidant properties and can protect the liver from APAP toxicity, just in the same pathway that toxicity occurs by toxic ROS and that GEM may be an alternative therapeutic agent to NAC in APAP toxicity.

Protective effect of an L-type calcium channel blocker, amlodipine, on paracetamol-induced hepatotoxicity in rats

Paracetamol (P), one of the most popular and commonly used analgesic and antipyretic agents, causes hepatotoxicity in overdoses. Amlodipine (AML), an L-type calcium channel blocker, has been shown to have anti-inflammatory activity by reversing the effect of calcium in the inflammation pathogenesis. In this study, the hepatoprotective activity of AML on P-induced hepatotoxicity was evaluated. Thirty male albino Wistar rats were divided into five groups: (1) control, (2) 2 g/kg of P, (3) 2 g/kg of P + 5 mg/kg of AML, (4) 2 g/kg of P + 10 mg/kg of AML, and (5) 10 mg/kg of AML. Some liver enzymes, oxidative parameters, cytokine mRNA expressions, histopathology, and immunohistochemical studies were performed in liver and blood samples. The serum levels of alanine aminotransferase and aspartate aminotransferase and the mRNA expression of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta in the liver tissues were significantly increased in the group treated with P. The superoxide dismutase and glutathione parameters decreased and malondialdehyde levels increased in the livers of the rats treated with P. All these parameters were increased with both doses of the AML similar to the control group. A histopathological examination of the liver showed that AML administration ameliorated the P-induced inflammatory liver damage. In immunohistochemical staining, the expression of TNF-α in the cytoplasm of the hepatocytes was increased in the P group but not in other treatment groups when compared to the control. In conclusion, AML treatment showed significant protective effects against P-induced hepatotoxicity by increasing the activity of antioxidants and reducing inflammatory cytokines.

Paracetamol: overdose-induced oxidative stress toxicity, metabolism, and protective effects of various compounds in vivo and in vitro

Paracetamol (APAP) is one of the most widely used and popular over-the-counter analgesic and antipyretic drugs in the world when used at therapeutic doses. APAP overdose can cause severe liver injury, liver necrosis and kidney damage in human beings and animals. Many studies indicate that oxidative stress is involved in the various toxicities associated with APAP, and various antioxidants were evaluated to investigate their protective roles against APAP-induced liver and kidney toxicities. To date, almost no review has addressed the APAP toxicity in relation to oxidative stress. This review updates the research conducted over the past decades into the production of reactive oxygen species (ROS), reactive nitrogen species (RNS), and oxidative stress as a result of APAP treatments, and ultimately their correlation with the toxicity and metabolism of APAP. The metabolism of APAP involves various CYP450 enzymes, through which oxidative stress might occur, and such metabolic factors are reviewed within. The therapeutics of a variety of compounds against APAP-induced organ damage based on their anti-oxidative effects is also discussed, in order to further understand the role of oxidative stress in APAP-induced toxicity. This review will throw new light on the critical roles of oxidative stress in APAP-induced toxicity, as well as on the contradictions and blind spots that still exist in the understanding of APAP toxicity, the cellular effects in terms of organ injury and cell signaling pathways, and finally strategies to help remedy such against oxidative damage.

Proteomics analysis of human placenta reveals glutathione metabolism dysfunction as the underlying pathogenesis for preeclampsia

Hypertensive disorder in pregnancy (HDP) refers to a series of diseases that cause the hypertension during pregnancy, including HDP, preeclampsia (PE) and eclampsia. This study screens differentially expressed proteins of placenta tissues in PE cases using 2D LC-MS/MS quantitative proteomics strategy. A total of 2281 proteins are quantified, of these, 145 altering expression proteins are successfully screened between PE and control cases (p<0.05). Bioinformatics analysis suggests that these proteins are mainly involved in many biological processes, such as oxidation reduction, mitochondrion organization, and acute inflammatory response. Especially, the glutamine metabolic process related molecules, GPX1, GPX3, SMS, GGCT, GSTK1, NFκB, GSTT2, SOD1 and GCLM, are involved in the switching process from oxidized glutathione (GSSG) conversion to the reduced glutathione (GSH) by glutathione, mercapturic acid and arginine metabolism process. Results of this study revealed that glutathione metabolism disorder of placenta tissues may contribute to the occurrence of PE disease.

Paracetamol-induced nephrotoxicity and oxidative stress in rats: the protective role of Nigella sativa

Context Nigella sativa L. (Ranunculaceae) (NS) is traditionally used to treat many conditions such as inflammation. Objective This study evaluates the effects of NS seeds ethanol extract in paracetamol-induced acute nephrotoxicity in rats. Materials and methods Forty-eight female Wistar Albino rats were divided into eight groups: I = sham; II = sham + 1000 mg/kg NS; III = sham + 140 mg/kg (N-acetyl cysteine) NAC; IV = 2 g/kg paracetamol; V = 2 g/kg paracetamol + 140 mg/kg NAC; VI, VII and VIII = 2 g/kg paracetamol + 250, 500 and 1000 mg/kg NS, respectively. Paracetamol administration (oral) was carried out 1 h after NS and NAC administrations (oral), and all animals were sacrificed 24 h later. Results Paracetamol administration significantly increased serum urea (88.05 U/L) and creatinine (0.80 U/L) when compared with the sham group (49.80 and 0.31 U/L, respectively). However, serum urea level was reduced to 65.60, 56.00 and 54.18 U/L, with 250, 500 and 1000 mg/kg doses of the extract, respectively. Also, serum creatinine level was reduced to 0.64, 0.57 and 0.52 U/L with 250, 500 and 1000 mg/kg doses of the extract, respectively. NS administration increased superoxide dismutase and glutathione, and decreased malondialdehyde levels in the kidneys. Kidney histopathological examinations showed that NS administration antagonized paracetamol-induced kidney pathological damage. Discussion and conclusions The results suggest NS has a significant nephroprotective activity on paracetamol-induced nephrotoxicity. It may be suggested that the antiinflammatory and antioxidant effects of NS ethanolic extract originated from different compounds of its black seeds.

Evolving roles of circadian rhythms in liver homeostasis and pathology

Circadian clock in mammals is determined by a core oscillator in the suprachiasmatic nucleus (SCN) of the hypothalamus and synchronized peripheral clocks in other tissues. The coherent timing systems could sustain robust output of circadian rhythms in response to the entrainment controlled environmentally. Disparate approaches have discovered that clock genes and clock-controlled genes (CCGs) exist in nearly all mammalian cell types and are essential for establishing the mechanisms and complexity of internal time-keeping systems. Accumulating evidence demonstrates that the control of homeostasis and pathology in the liver involves intricate loops of transcriptional and post-translational regulation of clock genes expression. This review will focus on the recent advances with great importance concerning clock rhythms linking liver homeostasis and diseases. We particularly highlight what is currently known of the evolving insights into the mechanisms underlying circadian clock . Eventually , findings during recent years in the field might prompt new circadian-related chronotherapeutic strategies for the diagnosis and treatment of liver diseases by coupling these processes.

A novel approach to contrast-induced nephrotoxicity: the melatonergic agent agomelatine

OBJECTIVE

To study the potential nephroprotective role of agomelatine in rat renal tissue in cases of contrast-induced nephrotoxicity (CIN). The drug's action on the antioxidant system and proinflammatory cytokines, superoxide dismutase (SOD) activity, levels of glutathione (GSH) and malondialdehyde (MDA) and the gene expression of interleukin-6 (IL-6), tumour necrosis factor (TNF)-α and nuclear factor kappa B (NF-κB) was measured. Tubular necrosis and hyaline and haemorrhagic casts were also histopathologically evaluated.

METHODS

The institutional ethics and local animal care committees approved the study. Eight groups of six rats were put on the following drug regimens: Group 1: healthy controls, Group 2: GLY (glycerol), Group 3: CM (contrast media--iohexol 10 ml kg(-1)), Group 4: GLY+CM, Group 5: CM+AGO20 (agomelatine 20 mg kg(-1)), Group 6: GLY+CM+AGO20, Group 7: CM+AGO40 (agomelatine 40 mg kg(-1)) and Group 8: GLY+CM+AGO40. The groups were evaluated by one-way analysis of variance and Duncan's multiple comparison test.

RESULTS

Agomelatine administration significantly improved the serum levels of blood urea nitrogen (BUN) and creatinine, SOD activity, GSH and MDA. The use of agomelatine had substantial downregulatory consequences on TNF-α, NF-κB and IL-6 messenger RNA levels. Mild-to-severe hyaline and haemorrhagic casts and tubular necrosis were observed in all groups, except in the healthy group. The histopathological scores were better in the agomelatine treatment groups.

CONCLUSION

Agomelatine has nephroprotective effects against CIN in rats. This effect can be attributed to its properties of reducing oxidative stress and inhibiting the secretion of proinflammatory cytokines (NF-κB, TNF-α and IL-6).

ADVANCES IN KNOWLEDGE

CIN is one of the most important adverse effects of radiological procedures. Renal failure, diabetes, malignancy, old age and non-steroidal anti-inflammatory drug use pose the risk of CIN in patients. Several clinical studies have investigated ways to avoid CIN. Theophylline/aminophylline, statins, ascorbic acid and iloprost have been suggested for this purpose. Agomelatine is one of the melatonin ligands and is used for affective disorders and has antioxidant features. In this study, we hypothesized that agomelatine could have nephroprotective, antioxidant and anti-inflammatory effects against CIN in rats.

The protective effects of carvacrol and thymol against paracetamol-induced toxicity on human hepatocellular carcinoma cell lines (HepG2)

Acetaminophen (APAP) overdose could induce liver damage and lead to acute liver failure. The treatment of APAP overdoses could be improved by new therapeutic strategies. Thymus spp., which has many beneficial effects and has been used in folk medicine, is one such potential strategy. In the present study, the hepatoprotective activity of the main constituents of Thymus spp., carvacrol and thymol, were evaluated in light of APAP-induced hepatotoxicity. We hoped to understand the hepatoprotective mechanism of these agents on the antioxidant system and pro-inflammatory cytokines in vitro. Dose-dependent effects of thymol and carvacrol (25, 50, and 100 µM) were tested on cultured HepG2 cells. N-Acetylcysteine (NAC) was tested as positive control. We showed that APAP inhibited HepG2 cell growth by inducing inflammation and oxidative stress. Incubating APAP-exposed HepG2 cells with carvacrol and thymol for 24 h ameliorated this inflammation and oxidative stress. We also evaluated alanine transaminase and lactate dehydrogenase levels of HepG2 cells. We found that thymol and carvacrol protected against APAP-induced toxicity in HepG2 cells by increasing antioxidant activity and reducing pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 1β. Taking together high-dose thymol and carvacrol treatment has an effect close to NAC treatment in APAP toxicity, but thymol has better treatment effect than carvacrol.

Current and future directions in the treatment and prevention of drug-induced liver injury: a systematic review

While the pace of discovery of new agents, mechanisms and risk factors involved in drug-induced liver injury (DILI) remains brisk, advances in the treatment of acute DILI seems slow by comparison. In general, the key to treating suspected DILI is to stop using the drug prior to developing irreversible liver failure. However, predicting when to stop is an inexact science, and commonly used ALT monitoring is an ineffective strategy outside of clinical trials. The only specific antidote for acute DILI remains N-acetylcysteine (NAC) for acetaminophen poisoning, although NAC is proving to be beneficial in some cases of non-acetaminophen DILI in adults. Corticosteroids can be effective for DILI associated with autoimmune or systemic hypersensitivity features. Ursodeoxycholic acid, silymarin and glycyrrhizin have been used to treat DILI for decades, but success remains anecdotal. Bile acid washout regimens using cholestyramine appear to be more evidenced based, in particular for leflunomide toxicity. For drug-induced acute liver failure, the use of liver support systems is still investigational in the United States and emergency liver transplant remains limited by its availability. Primary prevention appears to be the key to avoiding DILI and the need for acute treatment. Pharmacogenomics, including human leukocyte antigen genotyping and the discovery of specific DILI biomarkers offers significant promise for the future. This article describes and summarizes the numerous and diverse treatment and prevention modalities that are currently available to manage DILI.

Nephroprotective potential of carnitine against glycerol and contrast-induced kidney injury in rats through modulation of oxidative stress, proinflammatory cytokines, and apoptosis

OBJECTIVE

Contrast media (CM) are a major cause of nephropathy in high-risk patients. The aim of this study was to examine the effects of carnitine (CAR) in advanced nephrotoxicity due to CM administration in rats with glycerol-induced renal functional disorder.

METHODS

40 rats were divided randomly into five groups (n = 8): (1) healthy group; (2) glycerol only (GLY); (3) glycerol and CM (GLY + CM); (4) glycerol, CM and 200 mg kg(-1) carnitine (CAR200, Carnitene(®); Sigma-tau/Santa Farma, Istanbul, Turkey); and (5) glycerol, CM and 400 mg kg(-1) carnitine (CAR400). Kidney injury was induced with a single-dose, intramuscular injection of 10 ml kg(-1) body weight (b.w.) of GLY. CAR was administered intraperitoneally. CM (8 ml kg(-1) b.w. iohexol, Omnipaque™; Opakim Medical Products, Istanbul, Turkey) was infused via the tail vein to the rats in Groups 3-5.

RESULTS

l-carnitine administration significantly decreased serum creatinine and blood urea nitrogen levels. Superoxide dismutase and glutathione activity increased significantly in the treatment groups compared with the nephrotoxic groups. CAR400 significantly reduced malondialdehyde levels to healthy levels. In the treatment groups, tumour necrosis factor (TNF)-α, transforming growth factor 1β, interleukin 1β and caspase-3 gene expression decreased compared with the nephrotoxic groups. TNF-α and nuclear factor kappa-beta (NF-κB) protein expression increased after CM and CAR administration reduced both TNF-α and NF-κB expressions. Histopathologically, hyaline and haemorrhagic casts and necrosis in proximal tubules increased in the nephrotoxicity groups and decreased in the CAR groups.

CONCLUSION

The results reveal that l-carnitine protects the oxidant/antioxidant balance and decreases proinflammatory cytokines and apoptosis in CM-induced nephrotoxicity in rats with underlying pathology.

ADVANCES IN KNOWLEDGE

Depending on the underlying kidney pathologies, the incidence of CM-induced nephropathy (CIN) increases. Therefore, this is the best model to represent clinically observed CIN.

The lung endothelin system: a potent therapeutic target with bosentan for the amelioration of lung alterations in a rat model of diabetes mellitus

PURPOSE

The aim of this study is to show the effect of a new mechanism on endothelin (ET) receptors in the physiopathology of diabetes-related pulmonary injury. We tested the hypothesis that dual ET-1 receptor antagonism via bosentan can reverse diabetes-induced lung injury.

METHODS

The rats (24 male) were separated into four groups: group 1 (HEALTHY): Control group; group 2 (DM): Streptozotocin 60 mg/kg (i.p.); group 3 (DM + BOS-1): Diabetes + bosentan 50 mg/kg per-os; group 4 (DM + BOS-2): Diabetes + bosentan 100 mg/kg per-os. The bosentan treatment was initiated immediately after the onset of STZ-induced diabetes and continued for 6 weeks.

RESULTS

In the treatment group, SOD activity was significantly increased, although GSH and MDA levels and TNF-α and TGF-β gene expression were decreased. Bosentan 50 mg/kg and bosentan 100 mg/kg showed a significantly down-regulatory effect on ET-1, ET-A, and ET-B mRNA expression.

CONCLUSIONS

In conclusion, increased endothelin levels in the lung associated with diabetes may be one cause of endothelial dysfunction, cytokine increase, and oxidant/antioxidant imbalance in the pathogenesis of complications that may develop during diabetes. With its multiple effects, bosentan therapy may be an effective option against complications that may develop in association with diabetes.

What is the role of bosentan in healing of femur fractures in a rat model?

The purpose of this study was to examine the effects bosentan (which is a strong vasoconstrictor) on bone fracture pathophysiology, and investigate the roles of the nonselective endothelin 1 receptor blocker bosentan on the bone fractures formed in rats through radiographic, histopathologic, and immunohistochemical methods. The rats were divided into three groups (six rats in each group): a femoral fracture control group, a femoral fracture plus bosentan at 50 mg/kg group, and a femoral fracture plus bosentan at 100 mg/kg group. The femoral fracture model was established by transversely cutting the femur at the midsection. After manual reduction, the fractured femur was fixed with intramedullary Kirschner wires. The radiographic healing scores of the bosentan 100 and 50 mg/kg groups were significantly better that those of the fracture control group. The fracture callus percent of new bone in the bosentan 100 mg/kg group was significantly greater than that in the control group. Also, semiquantitative analysis showed higher positive vascular endothelial growth factor and osteocalcin staining and lower positive endothelin receptor type A staining in the treatment groups than in the control group. Bosentan treatment also decreased tissue endothelin 1 expression relative to that in the fracture control group. As a result of our study, the protective effect of bosentan was shown in experimental femoral fracture healing in rats by radiographic, histopathologic, and molecular analyses.

Bosentan, a mixed endothelin receptor antagonist, inhibits superoxide anion-induced pain and inflammation in mice

Bosentan is a mixed endothelin receptor antagonist widely used to treat patients with pulmonary arterial hypertension, and the emerging literature suggests bosentan as a potent anti-inflammatory drug. Superoxide anion is produced in large amounts during inflammation, stimulates cytokine production, and thus contributes to inflammation and pain. However, it remains to be determined whether endothelin contributes to the inflammatory response triggered by the superoxide anion. The present study investigated the effects of bosentan in a mouse model of inflammation and pain induced by potassium superoxide, a superoxide anion donor. Male Swiss mice were treated with bosentan (10-100 mg/kg) by oral gavage, 1 h before potassium superoxide injection, and the inflammatory response was evaluated locally and at spinal cord (L4-L6) levels. Bosentan (100 mg/kg) inhibited superoxide anion-induced mechanical and thermal hyperalgesia, overt pain-like behavior (abdominal writhings, paw flinching, and licking), paw edema, myeloperoxidase activity (neutrophil marker) in the paw skin, and leukocyte recruitment in the peritoneal cavity. Bosentan also inhibited superoxide anion-induced interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) production, while it enhanced IL-10 production in the paw skin and spinal cord. Bosentan inhibited the reduction of antioxidant capacity (reduced glutathione, ferric reducing antioxidant power, and ABTS radical scavenging ability) induced by the superoxide anion. Finally, we demonstrated that intraplantar injection of potassium superoxide induces the mRNA expression of prepro-endothelin-1 in the paw skin and spinal cord. In conclusion, our results demonstrated that superoxide anion-induced inflammation, pain, cytokine production, and oxidative stress depend on endothelin; therefore, these responses are amenable to bosentan treatment.

Tnf-α inhibition by infliximab as a new target for the prevention of glycerol-contrast-induced nephropathy

Contrast medium-induced nephropathy (CIN) remains as a problem with high incidence and mortality rates. The aim of this study is to examine the roles of infliximab (INF) in the glycerol (GLY) and CIN model in rats. The rats were separated into five groups (n=8): Healthy, GLY, GLY+CM, GLY+CM+INF 5mg/kg intraperitoneally (i.p.), and GLY+CM+INF 7 mg/kg (i.p.). Antioxidant levels in the therapy groups were observed to be quite similar to those in the healthy group. In this study, while the kidney TNF-α, IL-1β, TGF-1β and Caspase 3 gene expressions' levels increased in the nephrotoxic groups, these levels were found to have decreased in the treatment groups. Moreover, histopathologic examination showed that hyaline, haemorrhagic casts and necrosis were increased in nephrotoxicity group, whereas they decreased in the therapy group. Furthermore, TNF-α and NF-κB expression were decreased with infliximab administrated groups similar to control group. In conclusion, we suggest that infliximab have protective roles on CIN.