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Phytochemical investigation on the roots of Kadsura coccinea led to the isolation five previously unknown dibenzocyclooctadiene lignans, named heilaohusuins A-E (1-5). Their structures determined by NMR spectroscopy, HR-ESI-MS, and ECD spectra. Hepatoprotection effects of a series of dibenzocyclooctadiene derivatives (1-68) were investigated against acetaminophen (APAP) induced HepG2 cells. Compounds 2, 10, 13, 21, 32, 41, 46, and 49 showed remarkable protective effects, increasing the viabilities to > 52.2% (bicyclol, 52.1 ± 1.3%) at 10 μM. The structure-activity relationships (SAR) for hepatoprotective activity were summarized, according to the activity results of dibenzocyclooctadiene derivatives. Furthermore, we found that one new dibenzocyclooctadiene lignan heilaohusuin B attenuates hepatotoxicity, the mechanism might be closely correlated with oxidative stress inhibition via activating the Nrf2 pathway., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Phoenix dactylifera L. (date palm) seeds have been mentioned in the Moroccan pharmacopoeia as efficient remedies against a wide range of diseases including hepatic and gastrointestinal disorders and countless infections. The current work was performed to assess the phenolic profile and hepatoprotective potential of two date seed varieties, locally known as Jihl and Majhoul , aqueous extracts against paracetamol- (PCM-) driven liver toxicity in 42 Wistar rats. The polyphenol profile was built by means of an HPLC analysis. Hepatic damage was provoked by exposing rats to PCM at a dose of 1.5 g/kg once a week. Besides PCM, Jihl and Majhoul date seed extracts (200 and 400 mg/kg) were administered orally in a day-to-day routine. Our findings showed that among the examined polyphenol compounds, p -coumaric acid, quercetin, caffeic acid, and rutin were the most abundant phytochemicals. Date pits significantly ( p < 0.001) stabilized the PCM-driven alterations in liver function parameters (AST, ALT, ALP, LDH, total protein, direct bilirubin, and total bilirubin). Moreover, Phoenix dactylifera pits enhanced considerably ( p < 0.001) the activities of antioxidant enzymes (SOD, CAT, and GPx) as well as the level of reduced glutathione (GSH). The established hepatoprotective effect may be due to the date seeds antioxidant effect and their ability to trap free radicals. The main outcomes of the present study could validate the traditional use of these date seeds to manage various health conditions., Competing Interests: The authors declare that they have no conflicts of interest regarding the publication of this paper., (Copyright © 2021 Eimad Dine Tariq Bouhlali et al.)

The study was carried out to evaluate the hepatoprotective potential of aqueous methanolic extract of Heliotropium strigosum (HSME) against paracetamol induced hepatotoxicity in Swiss albino mice. The plant powder (1.5Kg) was macerated in aqueous methanol (30:70) for 7 days. The extract was evaluated for the presence of different phytochemicals and High-performance liquid chromatography (HPLC) analysis. HSME was orally administered to mice at 125, 250 and 500mg/kg for 8 days followed by paracetamol intoxication (500mg/kg orally) on the 8th day using silymarin as standard control. All the therapy was administered by oral gavage. The liver biochemical parameters and histopathological evaluation were carried out to assess changes in liver function and histology. HPLC analysis confirmed the presence of quercetin, kaempferol, and other phenolic compounds. Treatment with the extract resulted in notable (p<0.05) reduction in liver parameters in dose dependent manner. The action of HSME 500mg/kg dose was comparable to silymarin. The effect of HSME against paracetamol induced hepatotoxicity was demonstrated by protective changes in the liver histopathological which proved the traditional uses of the plant.

Present study is aimed to investigate the hepatoprotective and hematopoietic effect of Typha elephantina leaves aqueous (T.E.AQ), extract in paracetamol (PCM) intoxicated rabbits. Experimental animals were divided into various groups. The blood was taken on day 7th (W1=Week 1), day 14th (W2 = week 2) and day 21st (W3 = week 3) of treatments and was analyzed for all hematological and serum biochemical markers. PCM administration caused marked increase in the levels of serum biochemical and hematological parameters. The leaves of T.E.AQ extract at dose rate 300mg/kg body weight significantly (P<0.05) reduced the elevated levels of serum biochemical and hematological indices towards normal values on third week (day 21st) of treatment while treatment in the first two weeks revealed non-significant effects even at all doses of extract. The levels of glutathione (GSH) and radical scavenging activity (RSA) were reduced and thiobarbituric acid reactive substances (TBARS) levels was high in the PCM feed animals. Administration of (T.E.AQ) extract at high dose (300mg/kg) significantly regulated and normalized these antioxidant values. The antioxidant capacity of (TE.AQ) extract, showed increase inhibition against various extract concentrations on the basis of percent scavenging of (DPPH) free radical. The histological sections of liver further supported the hepatoprotective activity of extract.

Introduction: Liver disease is common and often life-threatening. Sinomenine (SIN) is an active ingredient extracted from  Sinomenium acutum . This study investigated the protective effect and mechanism of sinomenine (SIN) on acetaminophen (APAP)-induced liver injury from in vitro and in vivo., Methods: In vivo experiments, mice were randomly divided into six groups (n=10): control group, model group, SIN (25 mg/kg) group, SIN (50 mg/kg) group, SIN (100 mg/kg) group and SIN (100 mg/kg) + SRI-011381 group. Alanine transaminases (ALT), aspartate transaminases (AST) and alkaline phosphatase (ALP) were detected. The pathological lesion was measured by HE staining. Apoptosis was measured by TUNEL staining. In vitro experiments, BRL-3A cells were treated with APAP (7.5 mM) and then subjected to various doses of SIN (10, 50 and 100 μg/mL) at 37°C for 24 h. Inflammatory factors and oxidative stress index were measured by ELISA. The expression of proteins was detected by Western blot., Results: The results showed that compared with the control group, the levels of ALT, AST and ALP in the serum of APAP-induced mice were significantly increased, followed by liver histological damage and hepatocyte apoptosis. Besides, APAP reduced the activity of SOD and GSH-Px, while increasing the content of MDA and LDH. Notably, APAP also promoted the expression of NLRP3, ASC, caspase-1 and IL-1β. Interestingly, SIN treatment dose-dependently reduced APAP-induced liver injury and oxidative stress, inhibited the activation of NLRP3 inflammasomes, and reduced the levels of inflammatory cytokines. In vitro studies have shown that SIN treatment significantly reduced the viability of BRL-3A cells and oxidative stress and inflammation. In addition, the Western blotting analysis showed that SIN inhibited the activation of TGF-β/Smad pathway in a dose-dependent manner in vitro and in vivo. These effects were significantly reversed by TGF-β/Smad activator SRI-011381 or TGF-β overexpression., Discussion: The study indicates that SIN attenuates APAP-induced acute liver injury by decreasing oxidative stress and inflammatory response via TGF-β/Smad pathway in vitro and in vivo., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Chen et al.)

Purpose: Dexmedetomidine [DEX; (S)-4-[1-(2,3-dimethylphenyl)ethyl]-3H-imidazole] is a selective α 2 -adrenergic receptor (α 2 -AR) agonist that attenuates the liver damage associated with local or systemic inflammation. However, it remains unclear whether DEX has protective effects against acetaminophen (Paracetamol, PARA)-induced liver toxicity (PILT)., Methods: PILT mice were established by intraperitoneal administration of a hepatotoxic dose of acetaminophen (300 mg/kg). Thirty minutes later, the mice were treated with DEX at a concentration of 0, 5, 25, or 50 μg/kg. Blood and liver samples were obtained for further analysis., Results: DEX treatment significantly attenuated PILT in mice, with the strongest beneficial effects at a dose of 25 μg/kg. The levels of hepatic cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), in addition to myeloperoxidase (MPO) activity, were significantly decreased following DEX treatment. Moreover, DEX treatment reduced macrophage recruitment around the area of hepatotoxicity and the expression levels of hepatic phosphorylated mitogen-activated protein kinase kinase 4 (MAP2K4), c-jun N-terminal kinase (JNK), and c-Jun expression induced by acetaminophen overdose., Conclusion: The data suggest that DEX likely downregulates the JNK signaling pathway and its downstream effectors to promote its hepatoprotective effect, providing a clinical application of DEX for the attenuation of PILT., Competing Interests: The authors declare no conflicts of interest in this work., (© 2019 Chou et al.)

Two rarely phenolic acid-substituted alloses ( 1, 2 ) and one new glucoside ( 3 ), as well as nine known compounds ( 4-12 ) were isolated from rhizomes of Cibotium barometz (L.) J. Sm. Structures of 1-3 were established by extensively spectroscopic analyses (NMR, MS, etc.) and acid hydrolysis. All compounds were evaluated for the hepatoprotective activities against APAP-induced HepG2 cell damage. Compounds 1 , 4 - 7 , 10 exhibited significant hepatoprotective activities, even more strongly than positive control, bicycol. In addition, compounds 1 and 9 could reduce PC12 cell death induced by serum deprivation.

Drug-induced nephrotoxicity is a frequent serious adverse effect, contributing to morbidity and increased healthcare utilization. Prevention or reversal is key. Curcumin has useful biological features that include antioxidant, anti-inflammatory, and anticancer properties. This review covers aspects of curcumin in relation to prevention of drug-induced nephrotoxicity: dosage and schedule, effect on kidney biomarkers and histological changes, and mechanisms of curcumin's protective effects. Despite success in some animal models, human studies and clinical administration of curcumin for nephroprotection remains limited due to difficulty in achieving therapeutic levels following oral administration and in determining the optimal dosing schedule. Lack of sufficient evidence from animal studies, coupled with low systemic bioavailability, continues to limit the utilization of curcumin in addressing and controlling drug-induced nephrotoxicity. Therefore, human studies are required to fully assess and validate the therapeutic potential of curcumin., (© 2019 International Union of Biochemistry and Molecular Biology.)

Four undescribed cembrane-type diterpenoids, boscartins L-O, as well as five known compounds (1S, 3R, 11S, 12R, 7E)-1,12-epoxy-4-methylenecembr-7- ene- 3,11-diol, isoincensole oxide, incensole oxide, incensole acetate and incensole oxide acetate were isolated from the gum resin of Boswellia sacra Flueck. (Burseraceae). The structures of these compounds were elucidated by extensive 1D and 2D NMR spectroscopic and mass spectrometric analysis, as well as comparisons with known compounds. The absolute configurations of the known compound (1S, 3R, 7E, 11S, 12R)-1,12-epoxy-4-methylenecembr-7-ene-3,11-diol was unequivocally confirmed by single-crystal X-ray diffraction analysis with Cu Kα radiation. Incensole acetate exhibited significant hepatoprotective activity at 10 μM against paracetamol-induced HepG2 cell damage., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background and Purpose: Acetaminophen-induced acute liver injury (AILI) is the most frequent cause of acute liver failure in developed countries. Given the significant limitations associated with N-acetyl cysteine, the only antidote used to treat AILI, the development of novel therapeutic approaches that can offer a wide range of therapeutic time-windows is clearly needed. Glycycoumarin (GCM), a natural coumarin purified from liquorice, has been previously demonstrated to possess potent hepatoprotective effects. In the present study, we aimed to investigate the therapeutic potential of GCM against AILI., Experimental Approach: Acetaminophen (300 mg·kg -1 ) was administered to male C57BL/6 mice, with and without GCM. Serum transaminases, haematoxylin and eosin staining and Western blot were used to assess hepatic damage., Key Results: GCM (50 mg·kg -1 ) was highly effective against acetaminophen-induced hepatotoxicity. Moreover, GCM was superior to N-acetyl cysteine, in terms of the dosage and the therapeutic time-windows. Further mechanistic investigations revealed that the therapeutic action of GCM was not a result of inhibition of acetaminophen metabolic activation or associated with Nrf2. Instead, the protective effect of GCM appeared to be predominantly dependent on sustained activation of autophagy, which attenuated acetaminophen-induced mitochondrial oxidative stress and JNK activation., Conclusions and Implications: Collectively, our results indicate that GCM alleviated acetaminophen-induced oxidative stress through activating autophagy, thereby protecting against AILI. Our findings suggest that GCM has potential as a novel therapeutic agent for treating AILI., (© 2018 The British Pharmacological Society.)

Objectives: To determine that perioperative ondansetron reduces the analgesic efficacy of acetaminophen., Design: Randomized, double-blinded study., Patients: 120 patients ASA I-II who underwent abdominal hysterectomy., Interventions: All the patients were given 1g acetaminophen at skin closure. Patients were divided into two groups; ondansetron HCl (8mg, 2ml IV) (Group I, N=60) and saline (2ml IV) (Group II, N=60) at the skin closure., Measurement: Postoperative pain scores (VAS) while resting in bed and sitting, total opioid consumption were noted., Main Results: Patients randomized to ondansetron had significantly worse pain scores upon arrival to the recovery unit [by 1.7 (99.7% CI: 0.75, 2.59) cm] and at 1h [by 1.3 (0.5, 2.1) cm] while resting in bed. Pain scores while sitting were also significantly greater in ondansetron group at arrival in PACU by 0.6 (99.7% CI: 0.1, 1.0) cm. Thereafter, pain scores did not differ significantly. Median total opioid (tramadol) consumption was 441 [Q1, Q3: 280, 578] mg in the ondansetron group and 412 [309, 574] mg in the placebo group, P=0.95., Conclusions: Ondansetron significantly decreased the analgesic effect of acetaminophen during the initial postoperative period. Our results thus confirm that acetaminophen analgesia is partially mediated by serotonin receptors. However, the reduction was of marginal clinical importance and short-lived., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A new phenylpropanoid glycoside ( 1 ), and two new coumarin glycosides ( 2 , 3 ), together with two known compounds ( 4 , 5 ), have been isolated from the stems of Hydrangea paniculata Sieb. Their structures have been determined by spectroscopic and chemical methods. Furthermore, compound 1 (50 μM) exhibited significant hepatoprotective activity against N -acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in vitro assays.

Small molecules of plant origin offer presumptively safe opportunities to prevent carcinogenesis, mutagenesis and other forms of toxicity in humans. However, the mechanisms of action of such plant-based agents remain largely unknown. In recent years the stress responsive transcription factor Nrf2 has been validated as a target for disease chemoprevention. Withania somnifera (WS) is a herb used in Ayurveda (an ancient form of medicine in South Asia). In the recent past, withanolides isolated from WS, such as Withaferin A (WA) have been demonstrated to be preventive and therapeutic against multiple diseases in experimental models. The goals of this study are to evaluate withanolides such as WA as well as Withania somnifera root extract as inducers of Nrf2 signaling, to probe the underlying signaling mechanism of WA and to determine whether prevention of acetaminophen (APAP)-induced hepatic toxicity in mice by WA occurs in an Nrf2-dependent manner. We observed that WA profoundly protects wild-type mice but not Nrf2-disrupted mice against APAP hepatotoxicity. WA is a potent inducer of Nrf2-dependent cytoprotective enzyme expression both in vivo and in vitro. Unexpectedly, WA induces Nrf2 signaling at least in part, in a Keap1-independent, Pten/Pi3k/Akt-dependent manner in comparison to prototypical Nrf2 inducers, sulforaphane and CDDO-Im. The identification of WA as an Nrf2 inducer that can signal through a non-canonical, Keap1-independent pathway provides an opportunity to evaluate the role of other regulatory partners of Nrf2 in the dietary and pharmacological induction of Nrf2-mediated cytoprotection., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Acetaminophen (APAP) overdose accounts for the majority of acute liver failure cases, and oxidative stress plays a key role in its toxic effects. Esculentoside A (EsA) has anti-oxidant activities, but its therapeutic potential for APAP hepatotoxicity remains unknown. This study aimed to assess the protective effects and mechanism of EsA against APAP-induced hepatotoxicity in vitro and in vivo. In vitro, EsA treatment inhibited APAP- or H 2 O 2 -induced cytotoxicity, H 2 O 2 and O 2 - production, glutathione (GSH) depletion and apoptosis dependent on nuclear factor erythroid-2-related factor 2 (Nrf2) activation in HepG2 cells. Moreover, EsA significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and serine/threonine kinase (Akt), as well as glycogen synthase kinase 3 beta (GSK-3β) inhibitory phosphorylation at Ser9. Furthermore, an AMPK inhibitor (compound c) abolished the effects of EsA on AKT phosphorylation, GSK-3β inactivation, Nrf2 nuclear translocation and cytoprotection. With regard to APAP-induced acute liver injury, EsA attenuated the APAP-stimulated increases in the serum ALT and AST levels, as well as centrilobular necrosis and GSH depletion in the mice. In addition, it decreased the GSSG level, GSSG-to-GSH ratio, and the phosphorylation and mitochondrial translocation of c-Jun N-terminal kinase (JNK). Further, the protective potential of EsA against mitochondrial dysfunction was exhibited not only by inhibiting Bax mitochondrial translocation and the release of mitochondrial inter-membrane proteins, such as apoptosis-inducing factor (AIF), but also by activating Nrf2/HO-1. Collectively, our findings suggest that EsA has protective potential against APAP toxicity by potentiating the Nrf2-regulated survival mechanism through the AMPK/Akt/GSK3β pathway., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Methanol extract of Bauhinia purpurea L. (family Fabaceae) (MEBP) possesses high antioxidant and anti-inflammatory activities and recently reported to exert hepatoprotection against paracetamol (PCM)-induced liver injury in rats. In an attempt to identify the hepatoprotective bioactive compounds in MEBP, the extract was prepared in different partitions and subjected to the PCM-induced liver injury model in rats., Methods: Dried MEBP was partitioned successively to obtain petroleum ether (PEBP), ethylacetate (EABP) and aqueous (AQBP) partitions, respectively. All partitions were subjected to in vitro antioxidant (i.e. total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH)- and superoxide-radicals scavenging assay, and oxygen radical absorbance capacity (ORAC) assay) and anti-inflammatory (i.e. lipooxygenase (LOX) and xanthine oxidase (XO) assay) analysis. The partitions, prepared in the dose range of 50, 250 and 500 mg/kg, together with a vehicle (10 % DMSO) and standard drug (200 mg/kg silymarin) were administered orally for 7 consecutive days prior to subjection to the 3 mg/kg PCM-induced liver injury model in rats. Following the hepatic injury induction, blood samples and liver were collected for the respective biochemical parameter and histopathological studies. Body weight changes and liver weight were also recorded. The partitions were also subjected to the phytochemical screening and HPLC analysis., Results: Of all partitions, EABP possessed high TPC value and demonstrated remarkable antioxidant activity when assessed using the DPPH- and superoxide-radical scavenging assay, as well as ORAC assay, which was followed by AQBP and PEBP. All partitions also showed low anti-inflammatory activity via the LOX and XO pathways. In the hepatoprotective study, the effectiveness of the partitions is in the order of EABP>AQBP>PEBP, which is supported by the microscopic analysis and histopathological scoring. In the biochemical analysis, EABP also exerted the most effective effect by reducing the serum level of alanine transaminase (ALT) and aspartate transaminase (AST) at all doses tested in comparison to the other partitions. Phytochemical screening and HPLC analysis suggested the presence of: flavonoids, condensed tannins and triterpenes in EABP; flavonoids, condensed tannins and saponins in PEBP and; only saponins in AQBP., Conclusion: EABP demonstrates the most effective hepatoprotection against PCM-induced liver injury in rats. This observation could be attributed to its remarkable antioxidant activity and the presence of flavonoids that might probably act synergistically with other biocompounds to cause the hepatoprotection.

Acetaminophen (N-acetyl-para-aminophenol (APAP)) toxicity causes acute liver failure by inducing centrilobular hepatic damage as a consequence of mitochondrial oxidative stress. Sterile inflammation, triggered by hepatic damage, facilitates gut bacterial translocation leading to systemic inflammation; TLR4-mediated activation by LPS has been shown to have a critical role in APAP-mediated hepatotoxicity. In this study, we demonstrate significant protection mediated by chitohexaose (Chtx) in mice challenged with a lethal dose of APAP (400 mg/kg b.w.). Decreased mortality by Chtx was associated with reduced hepatic damage, increased peritoneal migration of neutrophils, decreased mRNA expression of IL-1β as well as inhibition of inflammasome activation in liver. Further, an alternate mouse model of co-administration of a sublethal doses of APAP (200 mg/kg b.w.) and LPS (5 mg/kg b.w.) operating synergistically and mediating complete mortality was developed. Overwhelming inflammation, characterized by increased inflammatory cytokines (TNF-α, IL-1β and so on) in liver as well as in circulation and mortality was demonstrable in this model. Also, Chtx administration mediated significant reversal of mortality in APAP+LPS co-administered mice, which was associated with reduced IL-1β in liver and plasma cytokines in this model. In conclusion, Chtx being a small molecular weight linear carbohydrate offers promise for clinical management of liver failure associated with APAP overdose.

Aims: Acetaminophen (APAP) overdose leads to severe hepatotoxicity. Isoquercitrin exhibited potential hepatoprotective effect in our previous study. The present investigation aimed to evaluate the effect of isoquercitrin against APAP induced liver injury and to explore its possible mechanism., Main Methods: Mice were treated intragastrically with isoquercitrin (10, 20, or 50mg/kg) for 3days before APAP (300mg/kg) injection. After 24h from APAP treatment, the levels of serum aminotransferase, hepatic oxidative stress and nitrosative stress biomarkers were determined by commercial kits or western bolt. Activities of UDP-glucuronosyltransferases (UGTs), sulfotransferases (SULTs) and cytochrome 2E1 (CYP2E1) were evaluated using ELISA methods and standard biochemical procedures. Subsequently, the protein and mRNA levels of inflammatory factors including TNF-α, IL-1β, IL-6 and iNOS were determined using ELISA methods, western blot or real-time PCR. The effect of isoquercitrin on APAP activated NFκB/MAPK pathway was assessed by western bolt., Key Findings: Isoquercitrin pretreatments markedly attenuated APAP induced hepatic oxidative stress, nitrosative stress and centrilobular necrosis. In addition to potent antioxidant activity, isoquercitrin was able to regulate the activities of SULTs and CYP2E1, therefore promoted APAP hepatic detoxification. The anti-inflammatory activity of isoquercitrin which involved in the amelioration of iNOS, TNF-α, IL-1β and IL-6 production via the blockade of NF-κB and MAPK pathways also responsible for its hepatoprotective effect., Significance: Our data evidenced that isoquercitrin protected liver from APAP induced injury though inhibition of oxidative stress, nitrosative stress and inflammation, as well as regulation of APAP metabolism, suggesting that isoquercitrin could be a potential hepatoprotective agent., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Acetaminophen (N-acetyl-p-aminophenol, APAP) is one of the most widely used over the counter antipyretic and analgesic medications. It is safe at therapeutic doses, but its overdose can result in severe hepatotoxicity, a leading cause of drug-induced acute liver failure in the USA. Depletion of glutathione (GSH) is one of the initiating steps in APAP-induced hepatotoxicity; therefore, one strategy for restricting organ damage is to restore GSH levels by using GSH prodrugs. N-acetylcysteine (NAC), a GSH precursor, is the only currently approved antidote for an acetaminophen overdose. Unfortunately, fairly high doses and longer treatment times are required due to its poor bioavailability. In addition, oral and I.V. administration of NAC in a hospital setting are laborious and costly. Therefore, we studied the protective effects of N-acetylcysteine amide (NACA), a novel antioxidant with higher bioavailability, and compared it with NAC in APAP-induced hepatotoxicity in C57BL/6 mice. Our results showed that NACA is better than NAC at a low dose (106mg/kg) in preventing oxidative stress and protecting against APAP-induced damage. NACA significantly increased GSH levels and the GSH/GSSG ratio in the liver to 66.5% and 60.5% of the control, respectively; and it reduced the level of ALT by 30%. However, at the dose used, NAC was not effective in combating the oxidative stress induced by APAP. Thus, NACA appears to be better than NAC in reducing the oxidative stress induced by APAP. It would be of great value in the health care field to develop drugs like NACA as more effective and safer options for the prevention and therapeutic intervention in APAP-induced toxicity., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Withaferin-A (WA) has anti-oxidant activities however, its therapeutic potential in acetaminophen (APAP) hepatotoxicity is unknown. We performed a proof-of-concept study to assess the therapeutic potential of WA in a mouse model that mimics APAP-induced liver injury (AILI) in humans. Overnight fasted C57BL/6NTac (5-6 wk. old) male mice received 200 mg/kg APAP intraperitoneally (i.p.). After 1 h mice were treated with 40 mg/kg WA or vehicle i.p., and euthanized 4 and 16 h later; their livers were harvested and serum collected for analysis. At 4 h, compared to vehicle-treated mice, WA-treated mice had reduced serum ALT levels, hepatocyte necrosis and intrahepatic hemorrhage. All APAP-treated mice had reduced hepatic glutathione (GSH) levels however, reduction in GSH was lower in WA-treated when compared to vehicle-treated mice. Compared to vehicle-treated mice, livers from WA-treated mice had reduced APAP-induced JNK activation, mitochondrial Bax translocation, and nitrotyrosine generation. Compared to vehicle-treated mice, WA-treated mice had increased hepatic up-regulation of Nrf2, Gclc and Nqo1, and down-regulation of Il-6 and Il-1β. The hepatoprotective effect of WA persisted at 16 h. Compared to vehicle-treated mice, WA-treated mice had reduced hepatocyte necrosis and hepatic expression of Il-6, Tnf-α and Il-1β, increased hepatic Gclc and Nqo1 expression and GSH levels, and reduced lipid peroxidation. Finally, in AML12 hepatocytes, WA reduced H₂O₂-induced oxidative stress and necrosis by preventing GSH depletion. Collectively, these data show mechanisms whereby WA reduces necrotic hepatocyte injury, and demonstrate that WA has therapeutic potential in AILI., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Oxidative stress plays a major part in the pathogenesis of drug-induced liver injury. Yet, overcoming it with other xenobiotics impose additional risks. In this study, we consider the use of natural-occurring and purified Vitamin E analogs as hepatoprotective agents. Vitamin E is well-known for its intrinsic antioxidant property even though the differential effect of specific analogs of tocopherol (TP) and tocotrienol (T3) is still not ascertained. This study investigates the protective effect of T3 analogs (α-, δ-, γ-) in comparison with α-TP followed by assessing the underlying mechanisms of the cytoprotective T3 analog(s) in two xenobiotics-induced liver injury models using (1) acetaminophen (APAP)- and (2) hydrogen peroxide (H2O2). Both α-TP and α-T3 exerted cytoprotective effects while only lower concentration of γ-T3 was effective in inhibiting both toxicants induced injury. α-TP/α-T3 protected hepatocytes from APAP and H2O2-induced liver injury through arresting free radicals and inhibiting oxidative stress (inhibition of reactive oxygen species, lipid peroxidation and mitochondrial permeability transition). There was also demonstrable inhibition of the apoptotic pathway (inhibition of caspse-3 activity and overexpression of Bcl-XL), accompanied with an induction of liver regeneration (PCNA and NF-kB). The cellular uptake of α-T3 was higher than α-TP at the same treatment dosage after 24h. Overall, α-T3 seems to be a more potent hepatoprotective analog among the tocotrienols and α-TP at the same in vitro treatment dosage. In summary, these results suggest that α-TP/α-T3 elicit hepatoprotective effects against toxicants-induced damage mainly through activation of antioxidant responses at an early stage to prevent the exacerbation of injury., (Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.)

Paracetamol has an extensive first-pass metabolism that highly affects its bioavailability (BA); thus, dose may be repeated several times a day in order to have longer efficacy. However, hepatotoxicity may arise because of paracetamol metabolism. Therefore, this project aimed to increase paracetamol BA in rats by glucosamine (GlcN). At GlcN-paracetamol racemic mixture ratio of 4:1 and paracetamol dose of 10 mg/kg, paracetamol area under the curve (AUC) and maximum concentration (Cmax ) were significantly increased by 99% and 66%, respectively (p < 0.05). Furthermore, paracetamol AUC and Cmax levels were increased by 165% and 88% in rats prefed with GlcN for 2 days (p < 0.001). Moreover, GlcN significantly reduced phase Ι and phase I/ΙΙ metabolic reactions in liver homogenate by 48% and 54%, respectively. Furthermore, GlcN molecule was found to possess a good in silico binding mode into the CYP2E1 active site-forming bidentate hydrogen bonding with the Thr303 side chain. Finally, serum ALT and AST levels of rats-administered high doses of paracetamol were significantly reduced when rats were prefed with GlcN (p < 0.01). In conclusion, GlcN can increase the relative BA of paracetamol through reducing its metabolism. This phenomenon is associated with reduction in hepatocytes injury following ingestion of high doses of paracetamol., (© 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.)

Overdose of acetaminophen (APAP) can cause acute liver injury that is sometimes fatal, requiring efficient pharmacological intervention. The traditional Chinese herb Bupleurum falcatum has been widely used for the treatment of several liver diseases in eastern Asian countries, and saikosaponin d (SSd) is one of its major pharmacologically-active components. However, the efficacy of Bupleurum falcatum or SSd on APAP toxicity remains unclear. C57/BL6 mice were administered SSd intraperitoneally once daily for 5days, followed by APAP challenge. Biochemical and pathological analysis revealed that mice treated with SSd were protected against APAP-induced hepatotoxicity. SSd markedly suppressed phosphorylation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) and reversed the APAP-induced increases in the target genes of NF-κB, such as pro-inflammatory cytokine Il6 and Ccl2, and those of STAT3, such as Socs3, Fga, Fgb and Fgg. SSd also enhanced the expression of the anti-inflammatory cytokine Il10 mRNA. Collectively, these results demonstrate that SSd protects mice from APAP-induced hepatotoxicity mainly through down-regulating NF-κB- and STAT3-mediated inflammatory signaling. This study unveils one of the possible mechanisms of hepatoprotection caused by Bupleurum falcatum and/or SSd., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Unlabelled: Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5mM, 10mM or 20mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24h, which correlated with the clinical onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24h and 48h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6h after APAP and a partial protection when given at 15 h., Conclusion: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Paracetamol poisoning is common worldwide. It is treated with intravenous acetylcysteine, but the standard regimen is complex and associated with frequent adverse effects related to concentration, which can cause treatment interruption. We aimed to ascertain whether adverse effects could be reduced with either a shorter modified acetylcysteine schedule, antiemetic pretreatment, or both., Methods: We undertook a double-blind, randomised factorial study at three UK hospitals, between Sept 6, 2010, and Dec 31, 2012. We randomly allocated patients with acute paracetamol overdose to either the standard intravenous acetylcysteine regimen (duration 20·25 h) or a shorter (12 h) modified protocol, with or without intravenous ondansetron pretreatment (4 mg). Masking was achieved by infusion of 5% dextrose (during acetylcysteine delivery) or saline (for antiemetic pretreatment). Randomisation was done via the internet and included a minimisation procedure by prognostic factors. The primary outcome was absence of vomiting, retching, or need for rescue antiemetic treatment at 2 h. Prespecified secondary outcomes included a greater than 50% increase in alanine aminotransferase activity over the admission value. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov (identifier NCT01050270)., Findings: Of 222 patients who underwent randomisation, 217 were assessable 2 h after the start of acetylcysteine treatment. Vomiting, retching, or need for rescue antiemetic treatment at 2 h was reported in 39 of 108 patients assigned to the shorter modified protocol compared with 71 of 109 allocated to the standard acetylcysteine regimen (adjusted odds ratio 0·26, 97·5% CI 0·13-0·52; p<0·0001), and in 45 of 109 patients who received ondansetron compared with 65 of 108 allocated placebo (0·41, 0·20-0·80; p=0·003). Severe anaphylactoid reactions were recorded in five patients assigned to the shorter modified acetylcysteine regimen versus 31 who were allocated to the standard protocol (adjusted common odds ratio 0·23, 97·5% CI 0·12-0·43; p<0·0001). The proportion of patients with a 50% increase in alanine aminotransferase activity did not differ between the standard (9/110) and shorter modified (13/112) regimens (adjusted odds ratio 0·60, 97·5% CI 0·20-1·83); however, the proportion was higher with ondansetron (16/111) than with placebo (6/111; 3·30, 1·01-10·72; p=0·024)., Interpretation: In patients with paracetamol poisoning, a 12 h modified acetylcysteine regimen resulted in less vomiting, fewer anaphylactoid reactions, and reduced need for treatment interruption. This study was not powered to detect non-inferiority of the shorter protocol versus the standard approach; therefore, further research is needed to confirm the efficacy of the 12 h modified acetylcysteine regimen., Funding: Chief Scientist Office of the Scottish Government., (Copyright © 2014 Bateman et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd. All rights reserved.)

Overdoses of acetaminophen (paracetamol, N-acetyl-p-aminophenol; APAP) cause severe liver injury, yet there is no common or high throughput in vitro human APAP model. This study examined the characteristics and usefulness of HepG2 cells grown in a nano culture plate (NCP) system, a three-dimensional culture method, as an in vitro human model for APAP-induced hepatotoxicity. The NCP-cultured HepG2 cells showed higher expression of mRNA and protein levels of cytochrome P450 2E1, which metabolizes APAP to a toxic metabolite, APAP-cysteine adduct formation, and higher sensitivity against APAP-induced cell injury compared with conventionally cultured cells. We demonstrated that treatment of APAP in NCP-cultured HepG2 cells shows key mechanistic features of APAP-induced hepatotoxicity, such as decreases in intracellular glutathione and mitochondrial membrane potential, activation of JNK, and cellular injury; and pharmacological agents, such as Cyclosporine A (a mitochondrial permeability transition inhibitor) and SP600125 (a JNK inhibitor), prevented cell injury induced by APAP exposure. In addition, the antidote of APAP-induced hepatotoxicity, N-acetylcysteine, could attenuate cellular injury induced by APAP in NCP-cultured HepG2 cells. We suggest that cellular injury induced by APAP treatment using an NCP-HepG2 system is a useful human model to study mechanisms and screen drug candidates of APAP-induced hepatotoxicity.

Context: Haemodialysis is sometimes used for patients with massive acetaminophen overdose when signs of "mitochondrial paralysis" (lactic acidosis, altered mental status, hypothermia and hyperglycaemia) are present. The role of haemodialysis is debated, in part because the evidence base is weak and the endogenous clearance of acetaminophen is high. There is also concern because the antidote acetylcysteine is also dialyzable. We prospectively measured serum acetylcysteine concentrations during haemodialysis in three such cases., Case Details: Three adults each presented comatose and acidemic 10 to ~18 h after ingesting > 1000mg/kg of acetaminophen. Two were hypothermic and hyperglycaemic. Serum lactate concentrations ranged from 7 mM to 12.5 mM. All three were intubated, and initial acetaminophen concentrations were as high as 5980 μM (900 μg/mL). An intravenous loading dose of 150 mg/kg acetylcysteine was initiated between 10.8 and ~18 h post ingestion, and additional doses were empirically administered during haemodialysis to compensate for possible antidote removal. A single run of 3-4 h of haemodialysis removed 10-20 g of acetaminophen (48-80% of remaining body burden), reduced serum acetaminophen concentrations by 56-84% (total clearance 3.4-7.8 mL/kg/min), accelerated native acetaminophen clearance (mean elimination half-life 580 min pre-dialysis, 120 min during and 340 min post-dialysis) and corrected acidemia. Extraction ratios of acetylcysteine across the dialysis circuit ranged from 73% to 87% (dialysance 3.0 to 5.3 mL/kg/min). All three patients recovered fully, and none developed coagulopathy or other signs of liver failure., Discussion: When massive acetaminophen ingestion is accompanied by coma and lactic acidosis, emergency haemodialysis can result in rapid biochemical improvement. As expected, haemodialysis more than doubles the clearance of both acetaminophen and acetylcysteine. Because acetylcysteine dosing is largely empirical, we recommend doubling the dose during haemodialysis, with an additional half-load when dialysis exceeds 6 h.

The aim of the present study was to validate the antioxidant effect of whey protein hydrolysate (WPH) using a small animal model. Paracetamol is common drug that is safe at therapeutic levels; however, an overdose causes oxidative stress, which may lead to potential hepatic and renal necrosis. The protective effect of WPH against paracetamol-induced hepato-nephrotoxicity in mice was investigated in this study. The WPH was prepared by hydrolyzing ultrafiltered retentate of mozzarella cheese whey with commercial food-grade alcalase; the resulting WPH had substantial in vitro antioxidant activity. Male albino mice were treated with WPH for 4 d [intraperitoneally at 4 mg/kg of body weight (BW) per day or orally at 8 mg/kg of BW per day] before or after oral administration of paracetamol (300 mg/kg of BW) for 2 d. Two control groups were used; the negative control mice were administered water only; the paracetamol group was administered paracetamol at 300 mg/kg of BW but received no WPH. Levels of different marker enzymes (glutamate pyruvate transaminase and alkaline phosphatase), creatinine, and blood urea nitrogen were measured in the experimental animal blood sera. The WPH successfully mitigated the increase in the concentration of oxidative biomarkers such as glutathione pyruvate transaminase, alkaline phosphatase, and creatinine, and restored the level of blood urea nitrogen to normal in sera of mice in which oxidative stress was induced with an overdose of paracetamol. Furthermore, the indices of different antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase, and lipid peroxidation end-products were determined in liver homogenate. The mice that were given WPH, either intraperitoneally or orally, showed increased activities of antioxidant enzymes and a reduction in thiobarbituric acid reactive substances (TBARS) compared with the paracetamol control group. The protective effect of WPH was less when administered orally than intraperitoneally. We concluded that WPH is the potential protector against paracetamol-induced hepato-nephrotoxicity and can be effectively used in health-promoting foods as a biofunctional ingredient., (Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

A new flavonoid C-glycoside, kaempferol 8-C-beta-galactoside, along with twelve known glycosidic flavonoids was isolated from the aqueous methanolic extract of Solanum elaeagnifolium Cav. (Solanaceae), by conventional chromatographic methods; their structure elucidation was achieved using UV, ESI-MS, and NMR spectral analyses. Groups of six mice were administered S. elaeagnifolium extracts at 25, 50, and 75 mg/kg body weight (BW) prior to or post administration of a single dose of paracetamol (500 mg/kg BW). The extract showed significant hepatoprotective and curative effects against histopathological and histochemical damage induced by paracetamol in liver. The extract also ameliorated the elevation in glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), and alkaline phosphatase (ALP) levels. These findings were accompanied by a nearly normal architecture of the liver in the treated groups, compared to the paracetamol control group. As a positive control, silymarin was used, an established hepatoprotective drug against paracetamol-induced liver injury. This study provides the first validation of the hepatoprotective activity of S. elaeagnifolium.

Acetaminophen (APAP)-induced liver injury is the leading cause of acute liver failure in many countries. This study determined the extent of liver protein sulfhydryl depletion not only in whole liver homogenate but also in the zonal pattern of sulfhydryl depletion within the liver lobule. A single oral gavage dose of 150 or 300 mg/kg APAP in B6C3F1 mice produced increased serum alanine aminotransferase levels, liver necrosis, and glutathione depletion in a dose-dependent manner. Free protein sulfhydryls were measured in liver protein homogenates by labeling with maleimide linked to a near infrared fluorescent dye followed by SDS-polyacrylamide gel electrophoresis. Global protein sulfhydryl levels were decreased significantly (48.4%) starting at 1 hour after the APAP dose and maintained at this reduced level through 24 hours. To visualize the specific hepatocytes that had reduced protein sulfhydryl levels, frozen liver sections were labeled with maleimide linked to horseradish peroxidase. The centrilobular areas exhibited dramatic decreases in free protein sulfhydryls while the periportal regions were essentially spared. These protein sulfhydryl-depleted regions correlated with areas exhibiting histopathologic injury and APAP binding to protein. The majority of protein sulfhydryl depletion was due to reversible oxidation since the global- and lobule-specific effects were essentially reversed when the samples were reduced with tris(2-carboxyethy)phosphine before maleimide labeling. These temporal and zonal pattern changes in protein sulfhydryl oxidation shed new light on the importance that changes in protein redox status might play in the pathogenesis of APAP hepatotoxicity.

Background: Treatment of single-time-point ingestion acute paracetamol (acetaminophen) poisoning with N-acetylcysteine (NAC) is guided by plotting a timed plasma paracetamol concentration on established nomograms. Guidelines in the UK differ from those in the U.S. and Australasia by having two treatment lines on the nomogram. Patients deemed to be at 'normal' risk of hepatotoxicity are treated using the treatment line starting at 200 mg/L at 4 h post-ingestion; those at higher risk are treated using the 'high risk' treatment line starting at 100 mg/L at 4 h post-ingestion., Aim: To examine the effect on treatment numbers if UK guidelines were to adopt a single treatment line nomogram or lower, risk-stratified treatment lines., Methods: We undertook a retrospective analysis of a series of acute single-time-point paracetamol poisonings presenting to our inner city emergency department. Treatment numbers and effect on treatment costs were modelled for three alternative scenarios: a 150 line-a combined single treatment line starting at a 4 h concentration of 150 mg/L, a 100 line-a combined single treatment line starting at a 4 h concentration of 100 mg/L, and a 150/75 line-a double treatment line at the lower concentrations of 150 mg/L for normal risk and 75 mg/L for high risk patients., Results: A total of 1,214 cases were identified. Under current UK guidance, 133 (11.0%) high risk cases and 98 (8.1%) normal risk cases needed treatment (total 231, 19.0%). A 150 line would result in 87 (7.2%) high risk cases and 155 (12.8%) normal risk cases needing treatment (total 242, 19.9%). A 100 line would result in 133 (11.0%) high risk and 251 (20.7%) normal risk cases needing treatment (total 384, 31.6%). A 150/75 line would result in 153 (12.6%) high risk and 155 (12.8%) normal risk cases needing treatment (total 308, 25.4%)., Conclusions: Both a 100 line and a 150/75 line would result in a large increase in the number of patients being treated and an associated increase in the costs of treatment. A single 150 mg/L treatment line would simplify treatment algorithms and lead to a similar number of patients being treated with NAC overall. A potential concern however is whether any of the high risk cases that would no longer be treated might develop significant hepatotoxicity. After consideration of the evidence for dual treatment lines, we feel that these risks are small and that it is worth reconsidering a change of treatment recommendations to a single 150 line.

Inflammation contributes to liver injury in acetaminophen (APAP) hepatotoxicity in mice and is triggered by stimulation of immune cells. The purinergic receptor P2X7 is upstream of the nod-like receptor family, pryin domain containing-3 (NLRP3) inflammasome in immune cells and is activated by ATP and NAD that serve as damage-associated molecular patterns. APAP hepatotoxicity was assessed in mice genetically deficient in P2X7, the key inflammatory receptor for nucleotides (P2X7-/-), and in wild-type mice. P2X7-/- mice had significantly decreased APAP-induced liver necrosis. In addition, APAP-poisoned mice were treated with the specific P2X7 antagonist A438079 or etheno-NAD, a competitive antagonist of NAD. Pre- or posttreatment with A438079 significantly decreased APAP-induced necrosis and hemorrhage in APAP liver injury in wild-type but not P2X7-/- mice. Pretreatment with etheno-NAD also significantly decreased APAP-induced necrosis and hemorrhage in APAP liver injury. In addition, APAP toxicity in mice lacking the plasma membrane ecto-NTPDase CD39 (CD39-/-) that metabolizes ATP was examined in parallel with the use of soluble apyrase to deplete extracellular ATP in wild-type mice. CD39-/- mice had increased APAP-induced hemorrhage and mortality, whereas apyrase also decreased APAP-induced mortality. Kupffer cells were treated with extracellular ATP to assess P2X7-dependent inflammasome activation. P2X7 was required for ATP-stimulated IL-1β release. In conclusion, P2X7 and exposure to the ligands ATP and NAD are required for manifestations of APAP-induced hepatotoxicity.

Drug induced hepatotoxicity is a major problem where phytochemicals hold promise for its abrogation. This study was carried out to explore cytoprotective potential of lupeol, a triterpene, against acetaminophen (AAP)-induced toxicity in rat hepatocytes. AAP exposure significantly (p<0.05) reduced cell viability, disturbed Bcl-2 family pro/anti-apoptotic protein balance, increased ROS production and altered redox homeostasis. It also induced mitochondria-mediated hepatocellular injury by significant mitochondrial depolarization, caspase-9/3 activation and subsequent DNA fragmentation. Our results suggest that lupeol pre-treatment effectively restored antioxidant enzyme levels, decreased lipid peroxidation, inhibited ROS generation and depolarization of mitochondria. Lupeol also attenuated mitochondria-mediated signaling pathway and DNA damage as evident from TUNEL assay and cell cycle studies leading to prevention of cytotoxicity. This study confirms the efficacy of lupeol, a food derived antioxidant, in abrogating ROS generation, maintaining redox balance and providing significant protection against mitochondria-mediated cell death during AAP-induced toxicity., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, but at high dose it leads to undesirable side effects, such as hepatotoxicity and nephrotoxicity. The present study demonstrates the comparative hepatoprotective and nephroprotective activity of hesperidin (HD), a naturally occurring bioflavonoid against APAP induced toxicity. APAP induces hepatotoxicity and nephrotoxicity as was evident by abnormal deviation in the levels of antioxidant enzymes. Moreover, APAP induced renal damage by inducing apoptotic death and inflammation in renal tubular cells, manifested by an increase in the expression of caspase-3, caspase-9, NFkB, iNOS, Kim-1 and decrease in Bcl-2 expression. These results were further supported by the histopathological examination of kidney. All these features of APAP toxicity were reversed by the co-administration of HD. Therefore, our study favors the view that HD may be a useful modulator in alleviating APAP induced oxidative stress and toxicity., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The present study examined effects of caffeine on antinociception by acetaminophen in the formalin test in mice. It demonstrates that caffeine 10mg/kg inhibits antinociception produced by acetaminophen 300 mg/kg i.p. against phase 2 flinches. Chronic administration of caffeine in the drinking water (0.1, 0.3g/l) for 8 days also inhibits the action of acetaminophen. The selective adenosine A(1) receptor antagonist DPCPX 1mg/kg i.p. mimics the action of caffeine, but the selective adenosine A(2A) receptor antagonist SCH58261 3mg/kg i.p. does not. While acetaminophen produced the same effect in mice that were +/+, +/- and -/- for adenosine A(1) receptors, inhibition of antinociception by caffeine was seen only in +/+ and +/- mice. A higher dose of caffeine, 40 mg/kg, produced an intrinsic antinociception against formalin-evoked flinches, an effect also seen when caffeine was administered intrathecally. SCH58261 30 nmol, but not DPCPX 10 nmol, also produced antinociception when administered intrathecally indicating involvement of adenosine A(2A) receptors in spinal antinociception. Caffeine reversal of acetaminophen results from actions in the spinal cord, as intrathecal DPCPX 10 nmol inhibited antinociception by systemic acetaminophen; this was also observed in +/+ but not in -/- adenosine A(1) receptor mice. We propose that spinal adenosine A(1) receptors contribute to the action of acetaminophen secondarily to involvement of descending serotonin pathways and release of adenosine within the spinal cord. Inhibition of acetaminophen antinociception by doses of caffeine relevant to dietary human intake levels suggests a more detailed consideration of acetaminophen-caffeine interactions in humans is warranted., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Acetaminophen is an analgesic drug that is used safely in therapeutic doses. At high doses, it causes hepatotoxicity, resulting in hepatic necrosis. Some medications and methods are available for treatment of acetaminophen overdose. However, results are inconsistent, and sufficient outcomes cannot always be obtained., Objective: The mechanism of action of acetaminophen has not been fully understood. It has been suggested that it exerts its effects on GABA receptors. Flumazenil has been experimentally proven to produce an antagonism on acetaminophen's analgesic effect.The purpose of this study was to determine whether flumazenil antagonized the toxic effects of acetaminophen overdose in rats., Methods: A total of 49 Wistar albino rats weighing between 250 - 350 g were used in the study. Nine rats were examined for a preliminary study, and the other rats were randomly divided into five groups with eight subjects in each., Control Group: Saline; Acetaminophen group: 3 g/kg acetaminophen; Experimental Group F1: 3 g/kg acetaminophen + 0.1 mg/kg flumazenil; Experimental group F2: 3 g/kg acetaminophen + 1 mg/kg flumazenil; Experimental group F3: 3 g/kg acetaminophen + 10 mg/kg flumazenil. Acetaminophen was administered in a 3 ml saline solution by way of gastric catheter. Flumazenil was administered by way of intraperitoneal injections. Serum levels of acetaminophen, AST, ALT, LDH, ALP and bilirubin were recorded over a 24-hour period., Results: Serum acetaminophen levels were similar between the groups. The AST, ALT, ALP, LDH, total bilirubin and direct bilirubin levels of Group A were significantly higher compared with the Group C, Group F1, Group F2 and Group F3. There was not a statistically significant difference in the AST, ALT, ALP, LDH, total bilirubin or direct bilirubin levels of the flumazenil-administered groups., Conclusion: Flumazenil's prevention of the acetaminophen-induced increase in liver enzymes is promising. There is some indication that flumazenil could be used in treatment of acetaminophen intoxication (Tab. 2, Ref. 25).

Rosa damascena (RD) is a widely cultivated ornamental plant. It acts as an astringent, aperients, carminative, and refrigerant and is used in respiratory disorders, tonsillitis, eye disorders, migraines, gynecological disorders, and menopausal symptoms. The aim of this study is to investigate the hepatoprotective activity of the aqueous extract of RD flowers at different oral dose levels (250, 500, and 1000 mg/kg body weight) on acetaminophen (2 g/kg oral N-acetyl-p-aminophenol [APAP])-induced toxicity in rats. APAP administration altered various biochemical parameters, including serum transaminases, serum alkaline phosphatase, lactate dehydrogenase, albumin, bilirubin, urea and creatinine, hepatic lipid peroxidation, and reduced glutathione levels. Adenosine triphosphatase and glucose-6-phosphatase activity in the liver was decreased significantly in animals treated with APAP. These values are retrieved significantly by treatment with RD extract at all 3 doses in dose-dependant manner. Apart from these, histopathological changes also reveal the protective nature of the RD extract against acetaminophen-induced necrotic damage of hepatic tissues. In conclusion, these data suggest that the aqueous extract of RD may prevent hepatic damage from APAP-induced toxicity in rats and is likely to be mediated through its antioxidant activities.

The present investigation was planned to evaluate the nephroprotective activity of jaggery against acetaminophen (APAP)-induced renal damage in rats. The protective activity of jaggery at different doses (250, 500, and 750 mg/kg, orally) was evaluated against oxidative damage induced by APAP administration (2 g/kg, once orally in acute exposure; 20 mg/kg, orally for 21 days in subchronic exposure) in rats. APAP administration significantly increased the levels of serum urea, creatinine, and renal lipid peroxidation (LPO), whereas substantial decreases were observed in levels of glutathione (GSH), adenosine triphosphatase (ATPase), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GPx) enzymatic activities after APAP administration. Administration of jaggery significantly moved the studied parameters toward normal levels and also reversed the histopathologic alterations. Thus, jaggery can be used to reduce renal damage and may serve as an alternative medicine in the treatment of renal etiologies.

This study was carried out to compare the hepatoprotective effect of methionine on paracetamol treated rats at both the peaks of toxicity and absorption. Female Wistar rats were divided into 17 groups consisting of eight rats per group and treated with different doses of paracetamol/methionine (5:1). Each control rat received 5 ml of physiologic saline. The study was terminated at two different end points -the 4th and 16th hours. Results show that rats administered with toxic doses (1000 mg/kg, 3000 mg/kg, 5000 mg/kg BW) of paracetamol exhibited significant increases in the levels of ALT, AST, γ- GT compared with controls. These increases were much higher at the 16th than 4th hour but serum total protein, albumin and globulin were significantly decreased by the end of the 16th hour. Histology results of rats in the 3000 and 5000 mg/kg (by the end of the 16th hour) confirmed hepatic damage, light microscopic evaluation of liver showed remarkable centrilobular necrosis. Moreover, the presence of mononuclear cells in liver section of rats intoxicated with APAP (5000 mg/kg) suggests a possible involvement of inflammatory process which resulted in regurgitation of bilirubin leading to its elevated level as well as increase activity of ALP. The hepatoprotective effect of methionine, on the other hand, was demonstrated in these rats at the 4th and 16th hours, and both results were comparable and therefore not significantly different but elevation in GGT level still persisted. In conclusion, data obtained from this study suggest that these agents may be capable of inducing GGT, although further study is required to establish a possible relationship between methionine and this enzyme in some other animal species.

Background: Acetaminophen is one of the most commonly encountered medications in self-poisoning, with a high rate of morbidity. The prevalence and characteristics of acetaminophen intoxication associated with long hospital stay in patients are not well defined., Objectives: This study aims to identify the clinical and demographic factors associated with the length of in-hospital stay (LOS), and to evaluate the effect of early treatment of acetaminophen overdose patients (≤8 hours) by intravenous N-acetylcysteine (IV-NAC) on hospital stay., Methods: This is a retrospective cohort study of hospital admissions for acetaminophen overdose conducted over a period of 5 years from 1 January 2004 to 31 December 2008. Patients were divided into two groups: LS group patients had a long hospital stay (> median hours stay in hospital) and SS group patients had a short hospital stay (≤ median hours stay in hospital). Variables were abstracted from medical records for comparison between the two groups. A total of 20 variables were identified for comparison. Parametric and non-parametric tests were used to test differences between groups depending on the normality of the data. SPSS 15 was used for data analysis., Results: Of the 305 patients, 11 factors were identified in the univariate analysis as associated with LS. Three independent factors were found to be significant predictors of LS in the multivariate analysis. The factors associated with LS were seen among patients with a history of abdominal pain after ingestion of acetaminophen (p = 0.04), who were on IV-NAC administration (p < 0.001) and had an acutely depressed mood (p = 0.003). Late time to NAC infusion of more than 8 hours was associated with LS rather than SS (96 patients [57%] and 6 [24%], respectively; p = 0.003)., Conclusion: Patients with long hospital stay have different clinical characteristics compared to patients with short hospital stay. We identified time to IV-NAC administration is a potentially modifiable factor that may lead to prolonged hospital stay. When risk assessment indicates that NAC is required, it is highly recommended that NAC be started in the first hours of admission to reduce the LOS.

HIF-1α is a nuclear factor important in the transcription of genes controlling angiogenesis including vascular endothelial growth factor (VEGF). Both hypoxia and oxidative stress are known mechanisms for the induction of HIF-1α. Oxidative stress and mitochondrial permeability transition (MPT) are mechanistically important in acetaminophen (APAP) toxicity in the mouse. MPT may occur as a result of oxidative stress and leads to a large increase in oxidative stress. We previously reported the induction of HIF-1α in mice with APAP toxicity and have shown that VEGF is important in hepatocyte regeneration following APAP toxicity. The following study was performed to examine the relative contribution of hypoxia versus oxidative stress to the induction of HIF-1α in APAP toxicity in the mouse. Time course studies using the hypoxia marker pimonidazole showed no staining for pimonidazole at 1 or 2h in B6C3F1 mice treated with APAP. Staining for pimonidazole was present in the midzonal to periportal regions at 4, 8, 24 and 48h and no staining was observed in centrilobular hepatocytes, the sites of the toxicity. Subsequent studies with the MPT inhibitor cyclosporine A showed that cyclosporine A (CYC; 10mg/kg) reduced HIF-1α induction in APAP treated mice at 1 and 4h and did not inhibit the metabolism of APAP (depletion of hepatic non-protein sulfhydryls and hepatic protein adduct levels). The data suggest that HIF-1α induction in the early stages of APAP toxicity is secondary to oxidative stress via a mechanism involving MPT. In addition, APAP toxicity is not mediated by a hypoxia mechanism., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: The aim of this study was to assess any interaction between ondansetron and paracetamol on a model of post-fracture pain in mice., Methods: In protocol A, after fracture of the tibia, mice were assigned to four groups: paracetamol 30 mg kg⁻¹, paracetamol 50 mg kg⁻¹, paracetamol 100 mg kg⁻¹, or a saline vehicle i.p. In protocol B, after fracture of the tibia, mice were randomized to receive either paracetamol (100 mg kg⁻¹) plus saline (vehicle), paracetamol (100 mg kg⁻¹) plus ondansetron (1 mg kg⁻¹), paracetamol (100 mg kg⁻¹) plus ondansetron (2 mg kg⁻¹), saline plus ondansetron (2 mg kg⁻¹), or saline plus saline i.p. Three tests were used to assess pain behaviour: von Frey filament application, hot-plate test, and a subjective pain scale. Rescue analgesia with morphine was administered as necessary., Results: In protocol A, paracetamol (100 mg kg⁻¹)-treated animals had less mechanical nociception, thermal nociception, and a lower subjective pain scale rating, when compared with those receiving paracetamol at 30 or 50 mg kg⁻¹ or saline [ED₅₀ paracetamol=46.3 (6.34) mg kg⁻¹]. No difference was found between paracetamol (30 mg kg⁻¹) and saline-treated animals. In protocol B, the mechanical withdrawal threshold, the thermal withdrawal latency, and the subjective pain scale were lower after injection of paracetamol (100 mg kg⁻¹)+saline, paracetamol (100 mg kg⁻¹)+ondansetron (1 mg kg⁻¹), and paracetamol (100 mg kg⁻¹)+ondansetron (2 mg kg⁻¹), whereas in mice receiving saline+ondansetron (2 mg kg⁻¹) or saline+saline, there was no difference., Conclusion: We found that paracetamol 100 mg kg⁻¹ blocked the development of hyperalgesia and allodynia after fracture pain and ondansetron did not modify the antinociceptive effect of paracetamol in this model.

Extracts of Boerhaavia diffusa leaves were evaluated for antioxidant and hepatoprotective properties in the acetaminophen-induced liver damage model. Antioxidative evaluation of ethanolic extract gave total phenolic content, total flavonoid content, vitamin C content and vitamin E content and the levels of selenium and zinc as 6.6+/-0.2mg/g tannic acid equivalent, 0.092+/-0.003 mg/g quercetin equivalent, 0.21+/-0.03 mg/g, 0.054+/-0.002 mg/g, 0.52+/-0.05 ppm and 9.28+/-0.16 ppm, respectively. The DPPH scavenging capacity and the reductive potential were 78.32+/-2.41% and 0.65+/-0.02 mg/g ascorbic acid, respectively. Pretreatment with aqueous and ethanolic extracts decreased the activities of alkaline phosphatase, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, and the level of bilirubin in the serum that were elevated by acetaminophen. The two extracts also ameliorated the elevation in the activities of the enzymes in the liver. Acetaminophen intoxication led to reduction in serum and liver albumin levels which were not significantly increased by pretreatment with the extracts. The extracts also protected against acetaminophen induced lipid peroxidation. These results indicated that leaf extracts from B. diffusa possess hepatoprotective property against acetaminophen-induced liver damage which may be mediated through augmentation of antioxidant defenses., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

This study was undertaken to evaluate the protective effect of thymoquinone (TQ) against acetaminophen-induced hepatotoxicity. Mice were given TQ orally at three different doses (0.5, 1 and 2mg/kg/day) for 5 days before a single hepatotoxic dose of acetaminophen (500 mg/kg i.p.). TQ supplementation dramatically reduced acetaminophen-induced hepatotoxicity, in a dose-dependent manner, as evidenced by decreased serum alanine aminotransferase (ALT) activities. Acetaminophen (500 mg/kg i.p.) resulted in a significant increase in serum ALT and total nitrate/nitrite, hepatic lipid peroxides and a significant decrease in hepatic reduced glutathione (GSH) and ATP in a time-dependent manner. Interestingly, supplementation of TQ (2mg/kg/day) for 5 days before acetaminophen administration resulted in reversal of acetaminophen-induced increase in ALT, total nitrate/nitrite, lipid peroxide and a decrease in GSH and ATP. Moreover, TQ did not affect acetaminophen-induced early decrease in hepatic GSH indicating lack of the effect on the metabolic activation of acetaminophen. In conclusion, TQ is effective in protecting mice against acetaminophen-induced hepatotoxicity possibly via increased resistance to oxidative and nitrosative stress as well as its ability to improve the mitochondrial energy production., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Association of paracetamol (PARA) and diclofenac (DiCF) is the aim of our study. 60 male rats "Albinos wistar" were treated by oral gavage (per os) during seven days. A control group was treated by mineral water (0+0) mg/kg and a second group was treated with only a toxic dose of 100 mg/kg of PARA (100+0). Remaining lots were treated with a combination of different toxic doses of PARA and a therapeutic dose of DiCF (15+3, 100+3, 200+3 and 400+3) mg/kg. Plasma concentration of amiotransferases (ASAT, ALAT), alkalines phosphatase (ALP), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione (GSH), glucose, cholesterol, creatinin, direct and total bilirubin, significantly varied in the treated rats regarding to the witness's rats. The toxicity of PARA revealed by a dose dependant blood increases of ASAT, ALAT, ALP, GPx, GR, glucose, creatinin, bilirubin, and by decreases of cholesterol concentration and tissue GSH in comparisons to controls. The depletion of GSH and the increase of the oxidative stress enzymes (GPx and GR) suggest a detoxification function of the glutathione system. The association (PARA + DiCF) revealed a protective effect, resulting in the increase of the concentrations of ASAT, ALAT, ALP, GPx, GR, bilirubin and the increase of GSH. Regarding to all these results, it has been suggested that DiCF has a protective action towards the toxic effects of PARA.

Acetaminophen (APAP) can cause life-threatening renal damages and there is no specific treatment for APAP-induced renal damage. The aim of this study was to investigate the protective effects of curcumin (CMN) on APAP-induced nephrotoxicity. Nephrotoxicity was induced in male Wistar Albino rats by the administration of a single dose of 1000 mg/kg APAP intraperitoneally (i.p.). Some of these rats also received i.p. CMN (200mg/kg) at 30 min after the administration of APAP. Twenty-four hours after the administration of APAP, all the rats were sacrificed with a high dose of ketamine. Urea and creatinine levels were measured in the blood, and the levels of malondialdehyde (MDA) and glutathione (GSH), and antioxidant enzyme activity were determined in the renal tissue. Histopathological changes were studied. APAP administration caused elevated levels of renal MDA, and marked depletion of GSH levels and antioxidant enzyme activity, and deteriorated the renal functions as assessed by the increased plasma urea and creatinine levels as compared to control rats. CMN markedly reduced the elevated MDA levels, significantly increased the antioxidant enzyme activity and normalized the altered renal morphology in rats treated with APAP. CMN might be a potential candidate agent against APAP-induced nephrotoxicity, but further studies are required to identify this issue before clinical application becomes possible.

Certain disease conditions can modify drug-induced toxicities, which, in turn, may cause a medication-related health crisis. Therefore, preclinical investigations into the alterations in drug-induced toxicities using appropriate disease animal models are very important. This paper reviews the reported data related to the effects of diabetes and hypertriglyceridemia, common lifestyle-related diseases in a modern society, on acetaminophen (APAP)-induced hepatotoxicity and nephrotoxicity in rats and mice. It has generally been reported that diabetes protects rats and mice from APAP-induced hepatotoxicity and there are several reports that help to speculate on the effects of diabetes on APAP-induced nephrotoxicity. In fructose-induced hypertriglyceridemic rats, hepatotoxicity of APAP becomes apparently less severe, whereas nephrotoxicity of APAP becomes significantly more severe. The mechanisms of alteration of APAP-induced hepatorenal toxicity under diabetic and hypertriglyceridemic conditions are also discussed in this paper.