Dose Of APAP Research Articles

Acetaminophen effects upon formalin-evoked flinching, postformalin, and postincisional allodynia and conditioned place preference.

We explored in mice, the analgesic, tolerance, dependency, and rewarding effects of systemic acetaminophen (APAP). Studies employed adult mice (C57Bl6). (1) Intraplantar formalin flinching + post formalin allodynia. Mice were given intraperitoneal APAP in a DMSO (5%)/Tween 80 (5%) or a water-based formulation before formalin flinching on day 1 and tactile thresholds assessed before and after APAP at day 12. (2) Paw incision. At 24 hours and 8 days after hind paw incision in male mice, effects of intraperitoneal APAP on tactile allodynia were assessed. (3) Repeated delivery. Mice received daily (4 days) analgesic doses of APAP or vehicle and tested upon formalin flinching on day 5. (4) Conditioned place preference. For 3 consecutive days, vehicle was given in the morning in either of 2 chambers and in each afternoon, an analgesic dose of morphine or APAP in the other chamber. On days 5 and 10, animals were allowed to select a "preferred" chamber. Formalin in male mice resulted in biphasic flinching and an enduring postformalin tactile allodynia. Acetaminophen dose dependently decreased phase 2 flinching, and reversed allodynia was observed postflinching. At a comparable APAP dose, female mice showed similarly reduced phase 2 flinching. Incision allodynia was transiently reversed by APAP. Repeated APAP delivery showed no loss of effect after sequential injections or signs of withdrawal. Morphine, but not APAP or vehicle, resulted in robust place preference. APAP decreased flinching and allodynia observed following formalin and paw incision and an absence of tolerance, dependence, or rewarding properties.

Prenatal cigarette smoke exposure sensitizes acetaminophen-induced liver injury by modulating miR-34a-5p in male offspring mice.

Introduction: Cigarette smoke (CS) exacerbates the severity of diseases not only in lungs, but also in systemic organs having no direct contact with smoke. In addition, smoking during pregnancy can have severe health consequences for both the mother and the fetus. Therefore, our aim was to evaluate effects of prenatal exposure to CS on acetaminophen (APAP)-induced acute liver injury (ALI) in offspring. Methods: Female C57BL/6 mice on day 6 of gestation were exposed to mainstream CS (MSCS) at 0, 150, 300, or 600μg/L for 2h a day, 5days a week for 2weeks using a nose-only exposure system. At four weeks old, male offspring mice were injected intraperitoneally with a single dose of APAP at 300mg/kg body weight to induce ALI. Results: Maternal MSCS exposure significantly amplified pathological effects associated with ALI as evidenced by elevated serum alanine aminotransferase levels, increased hepatocellular apoptosis, higher oxidative stress, and increased inflammation. Interestingly, maternal MSCS exposure reduced microRNA (miR)-34a-5p expression in livers of offspring. Moreover, treatment with a miR-34a-5p mimic significantly mitigated the severity of APAP-induced hepatotoxicity. Overexpression of miR-34a-5p completely abrogated adverse effects of maternal MSCS exposure in offspring with ALI. Mechanistically, miR-34a-5p significantly decreased expression levels of hepatocyte nuclear factor 4 alpha, leading to down-regulated expression of cytochrome P450 (CYP)1A2 and CYP3A11. Discussion: Prenatal exposure to MSCS can alter the expression of miRNAs, even in the absence of additional MSCS exposure, potentially increasing susceptibility to APAP exposure in male offspring mice.

Association of Acetaminophen (Paracetamol) Use With Severity and Outcomes in Patients With Viral Hepatitis-Associated Acute Liver Failure.

Acute viral hepatitis (AVH) comprises 11% of acute liver failure (ALF) in North America while acetaminophen (APAP) toxicity represents 46%. The use of APAP to treat prodromal hepatitis symptoms is common. It is unknown if concurrent APAP use impacts liver injury in AVH-induced ALF. In this prospective, multicenter cohort study, 356 patients meeting criteria for AVH including hepatitis A, B, Epstein-Barr virus, and herpes simplex virus, all leading to ALF (hepatic encephalopathy after acute illness, international normalized ratio ≥1.5), or acute liver injury (acute liver injury, international normalized ratio >2.0, no hepatic encephalopathy) were reviewed for evidence of APAP use: APAP ingestion history or measurement of serum APAP level or APAP-CYS adducts, a specific biomarker released into blood with APAP injury. Patients were grouped by APAP exposure level, from high (measurable APAP levels or toxic APAP-CYS), medium (therapeutic APAP-CYS), low (history of APAP ingestion only and/or barely detectable APAP-CYS), or no exposure recorded. Two hundred five of 356 patients (57.5%) with AVH-ALF had evidence of APAP use: 87 out of 356 (24%) demonstrated high or medium exposures. The aminotransferase and bilirubin levels of high/medium group resembled a mixed APAP-viral injury. Mortality was the highest (51.6%, 21.4%, 28.8%, and 30.5%), and transplant-free survival was the lowest (22.6%, 44.6%, 41.5%, and 40.4%) in the high exposure group compared with medium, low, and no exposure groups. However, the specific comparisons of mortality and transplant-free survival between the high exposure and no exposure groups were not statistically different even after adjusting for baseline patient characteristics differences. APAP use in AVH-ALF is common and may negatively impact outcomes compared with little or no APAP exposure. Prospective studies of the safest and effective dose of APAP to use in patients with AVH are needed.

Exposure to Benzo(a)pyrene Enhances Acetaminophen-Induced Liver Injury in Mice at Non-Hepatotoxic Doses

Acetaminophen (APAP) is a widely used analgesic, especially for children. Its primary mechanism involves inhibiting cyclooxygenase enzymes and activating the endocannabinoid and TRPV1 systems. Though its toxicity is low, it can harm the liver in a dose-dependent manner. Low APAP doses can also increase pollutant-induced liver damage. Little is known about interactions between APAP and benzo[a]pyrene (B[a]P). This study aimed to assess if co-exposure to non-hepatotoxic doses of B[a]P and APAP causes liver injury in mice, exploring the underlying mechanisms. Female ICR mice received 50 mg/kg B[a]P or a vehicle for three days, followed by 200 mg/kg APAP or a vehicle. Liver injury was assessed through histopathological examination, serum transaminase activity, and gene expression analysis. In the B[a]P/APAP group, several histology changes were observed, including ballooning injury, steatosis, necrosis, inflammation, and apoptosis. Transaminase levels correlated with histopathological scores, and there was an increase in hepatic cytochrome P450 family 1 subfamily a member 1 (Cyp1a1) mRNA levels and a decrease in aryl hydrocarbon receptor (Ahr), cytochrome P450 family 2 subfamily e polypeptide 1 (Cyp2e1), superoxide dismutase 1 (Sod1), peroxisome proliferator activated receptor gamma (Ppar-γ), and caspase 3 (Casp3). This suggests that prior exposure to B[a]P makes mice more susceptible to APAP-induced liver injury, involving changes in gene expression related to metabolism, redox balance, and cell proliferation. Therefore, using therapeutic APAP doses after exposure to B[a]P could lead to liver injury.

Transcriptomic signature, bioactivity and safety of a non-hepatotoxic analgesic generating AM404 in the midbrain PAG region

Safe and effective pain management is a critical healthcare and societal need. The potential for acute liver injury from paracetamol (ApAP) overdose; nephrotoxicity and gastrointestinal damage from chronic non-steroidal anti-inflammatory drug (NSAID) use; and opioids’ addiction are unresolved challenges. We developed SRP-001, a non-opioid and non-hepatotoxic small molecule that, unlike ApAP, does not produce the hepatotoxic metabolite N-acetyl-p-benzoquinone-imine (NAPQI) and preserves hepatic tight junction integrity at high doses. CD-1 mice exposed to SRP-001 showed no mortality, unlike a 70% mortality observed with increasing equimolar doses of ApAP within 72 h. SRP-001 and ApAP have comparable antinociceptive effects, including the complete Freund’s adjuvant-induced inflammatory von Frey model. Both induce analgesia via N-arachidonoylphenolamine (AM404) formation in the midbrain periaqueductal grey (PAG) nociception region, with SRP-001 generating higher amounts of AM404 than ApAP. Single-cell transcriptomics of PAG uncovered that SRP-001 and ApAP also share modulation of pain-related gene expression and cell signaling pathways/networks, including endocannabinoid signaling, genes pertaining to mechanical nociception, and fatty acid amide hydrolase (FAAH). Both regulate the expression of key genes encoding FAAH, 2-arachidonoylglycerol (2-AG), cannabinoid receptor 1 (CNR1), CNR2, transient receptor potential vanilloid type 4 (TRPV4), and voltage-gated Ca2+ channel. Phase 1 trial (NCT05484414) (02/08/2022) demonstrates SRP-001’s safety, tolerability, and favorable pharmacokinetics, including a half-life from 4.9 to 9.8 h. Given its non-hepatotoxicity and clinically validated analgesic mechanisms, SRP-001 offers a promising alternative to ApAP, NSAIDs, and opioids for safer pain treatment.

Indole-3-carboxaldehyde alleviates acetaminophen-induced liver injury via inhibition of oxidative stress and apoptosis

Drug-induced liver injury (DILI) occurs frequently and can be life-threatening. Increasing researches suggest that acetaminophen (APAP) overdose is a leading cause of drug-induced liver injury. Indole-3-carboxaldehyde (I3A) alleviates hepatic inflammation, fibrosis and atherosclerosis, suggesting a potential role in different disease development. However, the question of whether and how I3A protects against acetaminophen-induced liver injury remains unanswered. In this study, we demonstrated that I3A treatment effectively mitigates acetaminophen-induced liver injury. Serum alanine/aspartate aminotransferases (ALT/AST), liver malondialdehyde (MDA) activity, liver glutathione (GSH), and superoxide dismutase (SOD) levels confirmed the protective effect of I3A against APAP-induced liver injury. Liver histological examination provided further evidence of I3A-induced protection. Mechanistically, I3A reduced the expression of apoptosis-related factors and oxidative stress, alleviating disease symptoms. Finally, I3A treatment improved survival in mice receiving a lethal dose of APAP. In conclusion, our study demonstrates that I3A modulates hepatotoxicity and can be used as a potential therapeutic agent for DILI.

The Modulation of Phospho-Extracellular Signal-Regulated Kinase and Phospho-Protein Kinase B Signaling Pathways plus Activity of Macrophage-Stimulating Protein Contribute to the Protective Effect of Stachydrine on Acetaminophen-Induced Liver Injury.

Stachydrine, a prominent bioactive alkaloid derived from Leonurus heterophyllus, is a significant herb in traditional medicine. It has been noted for its anti-inflammatory and antioxidant characteristics. Consequently, we conducted a study of its hepatoprotective effect and the fundamental mechanisms involved in acetaminophen (APAP)-induced liver injury, utilizing a mouse model. Mice were intraperitoneally administered a hepatotoxic dose of APAP (300 mg/kg). Thirty minutes after APAP administration, mice were treated with different concentrations of stachydrine (0, 2.5, 5, and 10 mg/kg). Animals were sacrificed 16 h after APAP injection for serum and liver tissue assays. APAP overdose significantly elevated the serum alanine transferase levels, hepatic pro-inflammatory cytokines, malondialdehyde activity, phospho-extracellular signal-regulated kinase (ERK), phospho-protein kinase B (AKT), and macrophage-stimulating protein expression. Stachydrine treatment significantly decreased these parameters in mice with APAP-induced liver damage. Our results suggest that stachydrine may be a promising beneficial target in the prevention of APAP-induced liver damage through attenuation of the inflammatory response, inhibition of the ERK and AKT pathways, and expression of macrophage-stimulating proteins.

Effects of Concomitant Use of N-acetylcysteine and Cyclosporine A on Acetaminophen-induced Acute Kidney Injury in Mice

Background: Acetaminophen (APAP), a commonly used analgesic, causes acute kidney injury (AKI) in overdose although it is rare. Mitochondrial dysfunction plays a major role in the pathophysiology of renal damage, although the exact molecular mechanism is unknown. This study aimed to evaluate the potential therapeutic effect of cyclosporin A (CsA), a mitochondrial membrane permeability transition pore (MPTP) inhibitor, with N-acetylcysteine (NAC) in APAP-induced AKI. Methods: Male BALB/c mice were divided into control, APAP, APAP+NAC, APAP+CsA and APAP+NAC+CsA groups (n=6). A single dose of APAP (400 mg/kg) was administered intraperitoneally. All other treatments (1200 mg/kg NAC, 50 mg/kg CsA) were performed intraperitoneally 3 h after APAP administration. All animals were decapitated and blood samples and kidney tissue samples were collected for evaluation. Serum creatinine (Cr) and blood urea nitrogen (BUN) levels were measured. The kidney tissue 8-hydroxy-deoxyguanosine (8-OHdG), cytochrome c (Cytc) and 3-nitrotyrosine (3-NT) levels and cytochrome c (Cytc) expressions were determined. Result: Increased Cr and BUN levels, histopathological examinations and expressions of 8-OHdG, 3-NT and Cytc were detected in the APAP group. Combined NAC+CsA treatment sufficiently reversed oxidative stress, serum Cr and BUN levels and histopathological alterations induced by APAP. Moreover, cytc levels and renal tubular injury were remarkably reduced by combined drug treatment compared to the APAP+NAC group. These data suggest that the therapeutic effect of combined NAC+CsA treatment in mice with APAP-induced nephrotoxicity can be related to the combination of the antioxidant effect of NAC and the mitochondrial MPTP inhibitor effect of CsA.

Hepatocyte miR-21-5p-deficiency alleviates APAP-induced liver injury by inducing PPARγ and autophagy.

Acetaminophen (APAP)-induced liver injury is one of the most frequent causes of acute liver failure worldwide. Significant increases in the levels of miRNA-21 in both liver tissues and plasma have been observed in APAP-overdosed animals and humans. However, the mechanistic effect of miRNA-21 on acute liver injury remains unknown. In this study, we generated a new hepatocyte-specific miRNA-21 knockout (miR-21-HKO) mouse line. miR-21-HKO and the background-matched sibling wild-type (WT) mice were treated with a toxic dose of APAP. Compared with WT mice, miR-21 HKO mice showed an increased survival, a reduction of necrotic hepatocytes, and an increased expression of light chain 3 beta, which suggested an autophagy activation. The expression of PPARγ was highly induced in the livers of miR-21-HKO mice after a 2-h APAP treatment, which preceded the activation of LC3B at the 12 h APAP treatment. miR-21 negatively regulated PPARγ protein expression by targeting its 3'-UTR. When PPARγ function was blocked by a potent antagonist GW9662 in miR-21-HKO mice, the autophage activation was significantly diminished, suggesting an indispensable role of PPARγ signaling pathway in miR-21-mediated hepatotoxicity. Taken together, hepatocyte-specific depletion of miRNA-21 alleviated APAP-induced hepatotoxicity by activating PPARγ and autophagy, demonstrating a crucial new regulatory role of miR-21 in APAP-mediated liver injury.

Ameliorative effects of umbelliferone against acetaminophen-induced hepatic oxidative stress and inflammation in mice.

Acetaminophen (APAP) is a commonly used antipyretic and pain reliever that its overdose causes acute liver toxicity. Umbelliferone (UMB) has many pharmacological effects. In this study, the hepatoprotective effect of UMB on acute hepatotoxicity induced by APAP was investigated. Forty-nine male mice were separated into seven groups. The control received vehicle (i.p.), UMB group received UMB (120 mg/kg, i.p.), APAP group was treated with a single dose of APAP (350 mg/kg, i.p.), and pretreated groups received N-acetylcysteine (NAC, 200 mg/kg, i.p.) or different doses of UMB (30, 60, and 120 mg/kg, i.p.), respectively before APAP. Twenty-four hours after APAP injection, mice were sacrificed and blood and liver samples were collected. Then, serum and tissue samples were investigated for biochemical and histological studies. A single dose of APAP caused elevation in the serum liver enzymes, including alanine aminotransferase, aspartate transaminase, and alkaline phosphatase. The amounts of thiobarbituric acid reactive substances, tumor necrosis factor-alpha, and nitric oxide increased in the mice's liver tissue. Moreover, the amount of total thiol and the activity of antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase) significantly diminished in the APAP group. Histological results confirmed the hepatotoxicity induced by APAP. However, UMB (more effective at 60 and 120 mg/kg) lessened APAP-induced hepatic injuries, which is comparable with NAC effects. The findings of this study provided evidence that UMB ameliorates liver injury induced by APAP through its antioxidant and anti-inflammatory effects.

Evaluation of the Acute Toxicity of Acetaminophen in Mice

Acetaminophen (N-acetyl-para-aminophenol, APAP), widely used for pain relief across specie, poses significant toxicity risks. This study ‎aimed to assess the acute toxicity profile of APAP by determining the median toxic dose ‎‎(TD50) in a ‎‎murine model. Sixty male Balb/c mice, aged 8 weeks and weighing 20-30 ‎g, were randomized into six equal groups. Five groups received single oral doses of APAP (150, 200, 300, 500, and 700 mg/kg BW), while the control group received distilled water. The TD50 was ‎computed utilizing the probit method. Animals were ‎‎monitored for 24 h for ‎any sign indicative of clinical toxicity. Post-exposure, liver and kidney necropsies were conducted for histopathological analysis. Predominant symptoms of toxicity included prostration, hematuria, heightened agitation, lacrimation, cyanosis, and recumbency across doses from 150 to 700 mg/kg BW. The TD50 for APAP was estimated to be 732 ‎mg/kg BW. The liver histopathological examination of mice treated ‎‎with 700 mg/kg BW APAP ‎revealed severe multifocal hyper eosinophilic hepatocytes, indicating areas of centrilobular ‎necrosis, disorganized ‎‎hepatic cords, and multiple hemorrhage regions. The kidney ‎examination exhibited no pathological changes in treated mice with 700 mg/kg BW ‎‎APAP. In ‎conclusion this investigation provides critical insights into the acute toxicity profile of APAP. The findings not only highlight the ‎‎potential risk associated with APAP usage but also the ‎necessity of strict monitoring for stringent dosage control. Further research is also ‎‎needed to ‎understand the underlying mechanism of APAP-induced toxicity and pave the way for the ‎development of efficacious therapeutic ‎strategies to counter APAP overdose‎‎‎‎.

Effect of Nutrition on Drug-Induced Liver Injury: Insights from a High-Fat Diet Mouse Model.

Literature suggests that a high-fat diet (HFD) potentially increases the risk of chemical/drug-induced toxicity after an acute overdose. Drug/chemical-induced hepatotoxicity has been well studied, and the mechanism that regulates this toxicity has been extensively examined using different experimental animal models. Our study focuses on drug-induced hepatotoxicity in HFD-fed female Balb/C mice. This study addresses the effect of nutrition on the magnitude of acetaminophen (APAP)-induced hepatotoxicity at different time intervals. Female Balb/C mice, after the weaning period separated into two different groups, normal diet (ND) and HFD receiving groups; after 15 weeks, they were dosed with a single dose (300 mg/kg per os (p.o.) of APAP. Blood samples were collected at different time intervals (0, 6 and 24 hours), and liver samples were collected at the end time point. Liver injury parameters [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)], antioxidant assay (sodium dismutase, glutathione, and catalase), and histopathology study were conducted. Pharmacokinetic (PK) analysis was done using the RP-HPLC system and Phoenix WinNonlin 8.3 software. APAP-induced liver injury decreased AST and ALT in the HFD group compared with the ND group at 6 and 24 hours (p < 0.01 and p < 0.001), respectively. Antioxidant enzyme levels remained constant in the HFD group, whereas histopathology showed remarkable changes. The PK's of APAP in HFD indicate lower plasma concentrations of APAP (p < 0.05), with two-fold higher clearance and volume of distribution. HFD significantly reduced susceptibility to APAP-mediated liver injury in Balb/C mice compared with ND mice. Our study mimics the clinical scenario where the same dose of the drug is prescribed to the normal and obese population. Our results suggest the potential need for dose titration to assess an individual's nutritional state in a clinical scenario.

Interleukin-10 disrupts liver repair in acetaminophen-induced acute liver failure.

Systemic levels of the anti-inflammatory cytokine interleukin 10 (IL-10) are highest in acetaminophen (APAP)-induced acute liver failure (ALF) patients with the poorest prognosis. The mechanistic basis for this counterintuitive finding is not known, as induction of IL-10 is hypothesized to temper the pathological effects of immune cell activation. Aberrant production of IL-10 after severe liver injury could conceivably interfere with the beneficial, pro-reparative actions of immune cells, such as monocytes. To test this possibility, we determined whether IL-10 levels are dysregulated in mice with APAP-induced ALF and further evaluated whether aberrant production of IL-10 prevents monocyte recruitment and/or the resolution of necrotic lesions by these cells. Our studies demonstrate that in mice challenged with 300 mg/kg acetaminophen (APAP), a hepatotoxic dose of APAP that fails to produce ALF (i.e., APAP-induced acute liver injury; AALI), Ly6Chi monocytes were recruited to the liver and infiltrated the necrotic lesions by 48 hours coincident with the clearance of dead cell debris. At 72 hours, IL-10 was upregulated, culminating in the resolution of hepatic inflammation. By contrast, in mice treated with 600 mg/kg APAP, a dose that produces clinical features of ALF (i.e., APAP-induced ALF; AALF), IL-10 levels were markedly elevated by 24 hours. Early induction of IL-10 was associated with a reduction in the hepatic numbers of Ly6Chi monocytes resulting in the persistence of dead cell debris. Inhibition of IL-10 in AALF mice, beginning at 24 hours after APAP treatment, increased the hepatic numbers of monocytes which coincided with a reduction in the necrotic area. Moreover, pharmacologic elevation of systemic IL-10 levels in AALI mice reduced hepatic myeloid cell numbers and increased the area of necrosis. Collectively, these results indicate that during ALF, aberrant production of IL-10 disrupts the hepatic recruitment of monocytes, which prevents the clearance of dead cell debris. These are the first studies to document a mechanistic basis for the link between high IL-10 levels and poor outcome in patients with ALF.

LPCAT3/LPLAT12 deficiency in the liver ameliorates acetaminophen-induced acute liver injury.

Acetaminophen (APAP) is a double-edged sword, mainly depending on the dosage. A moderate dose of APAP is effective for fever and pain relief; however, an overdose induces acute liver injury. The mechanism underlying APAP-induced acute liver failure is unclear, and its treatment is limited. A recent report has shown that several oxidized phospholipids are associated with APAP-induced acute liver failure. Lysophosphatidylcholine acyltransferase 3 (Lpcat3, Lplat12), which is highly expressed in the liver, preferentially catalyzes the incorporation of arachidonate into lysophospholipids (PLs). In the present study, we investigated the roles of Lpcat3 on APAP-induced acute liver injury using liver-specific Lpcat3-knockout mice. Hepatic Lpcat3 deficiency reduced the degree of APAP-induced necrosis of hepatocytes around Zone 3 and ameliorated the elevation of hepatic injury serum marker levels, and prolonged survival. Lipidomic analysis showed that the accumulation of oxidized and hydroperoxidized phospholipids was suppressed in Lpcat3-knockout mice. The amelioration of APAP-induced acute liver injury was due not only to the reduction in the lipid synthesis of arachidonic acid PLs because of Lpcat3 deficiency, but also to the promotion of the APAP detoxification pathway by facilitating the conjugation of glutathione and N-acetyl-p-benzoquinone imine. Our findings suggest that Lpcat3 is a potential therapeutic target for treating APAP-induced acute liver injury.

ERK/NF-kB/COX-2 Signaling Pathway Plays a Key Role in Curcumin Protection against Acetaminophen-Induced Liver Injury.

Recent experimental studies have highlighted the beneficial effects of curcumin on liver injury induced by acetaminophen (APAP). However, the specific molecular mechanisms underlying curcumin's hepatoprotective effects against APAP-induced liver injury remain to be fully elucidated. This study aimed to investigate the therapeutic effect of curcumin on APAP-induced liver injury using a mouse model. In the experiment, mice were subjected to an intraperitoneal hepatotoxic dose of APAP (300 mg/kg) to induce hepatotoxicity. After 30 min of APAP administration, the mice were treated with different concentrations of curcumin (0, 10, 25, or 50 mg/kg). After 16 h, mice with hepatotoxicity showed elevated levels of serum alanine transaminase (ALT), aspartate transaminase (AST), hepatic myeloperoxidase (MPO), TNF-α, and IL-6, and decreased levels of glutathione (GSH). Moreover, there was an increased infiltration of neutrophils and macrophages following intraperitoneal injection of APAP. However, curcumin-treated mice displayed a pronounced reduction in serum ALT, AST, hepatic MPO, TNF-α, and IL-6 levels, coupled with a notable elevation in GSH levels compared to the APAP-treated hepatotoxic mice. Moreover, curcumin treatment led to reduced infiltration of neutrophils and macrophages. Additionally, curcumin inhibited the phosphorylation of ERK and NF-kB proteins while reducing the expression of cyclooxygenase-2 (COX-2). These findings highlight the hepatoprotective potential of curcumin against APAP-induced liver injury through the suppression of the ERK, NF-kB, and COX-2 signaling pathways.

Ethyl gallate concurrent administration protects against acetaminophen-induced acute liver injury in mice: An in vivo and in silico approach.

Acetaminophen (APAP) in high doses causes acute liver injury and acute liver failure. Ethyl gallate (EG) is a natural polyphenol, possessing antioxidant, anti-inflammatory, and anti-microbial properties. Therefore, in this study, we evaluated the protective role of EG against APAP-induced acute liver injury in mice. Acute liver injury was induced by a single dose of APAP (400 mg/kg., i.p.). In separate groups, EG (10 mg/kg), EG (20 mg/kg), and N-acetylcysteine (NAC; 1200 mg/kg., i.p.) were administered concurrently with APAP. The mice were sacrificed after 24 h of treatment. Liver marker enzymes of hepatotoxicity, antioxidant markers, inflammatory markers, and histopathological studies were done. APAP administration caused a significant elevation of marker enzymes of hepatotoxicity and lipid peroxidation. APAP administration also decreased enzymic and nonenzymic antioxidants. Acute APAP intoxication induced nuclear factor κ B, tumor necrosis factor-α, interleukin-1, p65, and p52 and downregulated IκB gene expressions. Our histopathological studies have confirmed the presence of centrilobular necrosis, 24 h after APAP intoxication. All the above abnormalities were significantly inhibited in groups of mice that were concurrently administered with APAP + EG and APAP + NAC. Our in silico analysis further confirms that hydroxyl groups of EG interact with the above inflammatory proteins at the 3,4,5-trihydroxybenzoic acid region. These effects of EG against APAP-induced acute liver injury could be attributed to its antioxidative, free radical scavenging, and anti-inflammatory potentials. Therefore, this study suggests that EG can be an efficient therapeutic approach to protect the liver from APAP intoxication.

A systems approach reveals species differences in hepatic stress response capacity.

To minimize the occurrence of unexpected toxicities in early phase preclinical studies of new drugs, it is vital to understand fundamental similarities and differences between preclinical species and humans. Species differences in sensitivity to acetaminophen (APAP) liver injury have been related to differences in the fraction of the drug that is bioactivated to the reactive metabolite N-acetyl-p-benzoquinoneimine (NAPQI). We have used physiologically based pharmacokinetic modeling to identify oral doses of APAP (300 and 1000 mg/kg in mice and rats, respectively) yielding similar hepatic burdens of NAPQI to enable the comparison of temporal liver tissue responses under conditions of equivalent chemical insult. Despite pharmacokinetic and biochemical verification of the equivalent NAPQI insult, serum biomarker and tissue histopathology analyses revealed that mice still exhibited a greater degree of liver injury than rats. Transcriptomic and proteomic analyses highlighted the stronger activation of stress response pathways (including the Nrf2 oxidative stress response and autophagy) in the livers of rats, indicative of a more robust transcriptional adaptation to the equivalent insult. Components of these pathways were also found to be expressed at a higher basal level in the livers of rats compared with both mice and humans. Our findings exemplify a systems approach to understanding differential species sensitivity to hepatotoxicity. Multiomics analysis indicated that rats possess a greater basal and adaptive capacity for hepatic stress responses than mice and humans, with important implications for species selection and human translation in the safety testing of new drug candidates associated with reactive metabolite formation.

Concurrent administration of farnesol protects acetaminophen-induced acute hepatic necrosis in mice.

Acetaminophen (APAP) is known to cause acute liver injury and acute liver failure in Western countries. This study investigates the protective role of farnesol (FAR) (C15 H26 O), a natural sesquiterpene alcohol in essential oils, against APAP-induced acute liver necrosis in mice. Mice were injected with a single dose of APAP (300 mg/kg) via an intraperitoneal route. Different groups of mice were concurrently treated with a single dose of FAR 25 mg/kg, FAR 50 mg/kg, and N-acetylcysteine. APAP administration caused a significant increase in transaminase activities and malondialdehyde (MDA) levels in the serum and liver tissue, respectively, with a concomitant decrease inintracellular antioxidants, including reduced glutathione (GSH) in the liver tissue. APAP intoxication upregulated proinflammatory cytokines such as tumor necrosis factor-α, interleukin-1β(IL-1β), IL-6, nuclear factor-κB (NF-κB), and IκB kinase β in the liver tissue. FAR and N-acetylcysteine (NAC) administrations concurrently with APAP preventedserum transaminase increase in serum and MDA levels in the liver tissue. A high dose of FAR and NAC treatments significantly inhibited GSH and other antioxidant depletion. FAR and NAC treatments also downregulated the expression of proinflammatory markers. FAR treatments protects against APAP-induced acute liver injury and offers antioxidant and anti-inflammatory effects by inhibiting the NF-κB pathway involved in the transcription of genes responsible for inflammatory cytokine synthesis.

Sodium Pentaborate Prevents Acetaminophen-Induced Hepatorenal Injury by Suppressing Oxidative Stress, Lipid Peroxidation, Apoptosis, and Inflammatory Cytokines in Rats.

Acetaminophen (N-acetyl-p-aminophenol, APAP, or paracetamol) is one of the drugs that may be damaging to the kidneys and liver when used in excess. In this context, it is vital to treat these side effects on the liver and kidneys with various antioxidants. Diseases have been treated using herbal and mineral remedies since ancient times. The mineral boron, found in rocks and water, is a crucial ingredient with multiple positive biological effects. The primary objective of this research is to determine whether or not boron has a protective effect against the toxicity generated by APAP in rats. Male Sprague-Dawley rats were pretreated orally with boron-source sodium pentaborate (B50 and B100 mg/kg) for 6 days by gastric gavage in order to counteract the toxicity caused by a single dose of APAP (1g/kg). APAP increased lipid peroxidation as well as serum BUN, creatinine concentrations, and serum activities of AST, ALP, and ALT by consuming GSH in liver and kidney tissues. In addition, the activity of antioxidative enzymes, including SOD, CAT, and GPx, was diminished. Inflammatory indicators such as TNF-α, IL-1β, and IL-33 were elevated in conjunction with APAP toxicity. In kidney and liver tissues, APAP dramatically increased the activity of caspase-3 and triggered apoptosis. Sodium pentaborate therapy on a short-term basis reduced biochemical levels despite these effects of APAP. This study showed that boron protects rats from the harmful effects of APAP by acting as an anti-inflammatory, antioxidant, and anti-apoptotic agent.

USP25 regulates KEAP1-NRF2 anti-oxidation axis and its inactivation protects acetaminophen-induced liver injury in male mice

Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor responsible for mounting an anti-oxidation gene expression program to counter oxidative stress. Under unstressed conditions, Kelch-like ECH-associated protein 1 (KEAP1), an adaptor protein for CUL3 E3 ubiquitin ligase, mediates NRF2 ubiquitination and degradation. We show here that the deubiquitinase USP25 directly binds to KEAP1 and prevents KEAP1’s own ubiquitination and degradation. In the absence of Usp25 or if the DUB is inhibited, KEAP1 is downregulated and NRF2 is stabilized, allowing the cells to respond to oxidative stress more readily. In acetaminophen (APAP) overdose-induced oxidative liver damage in male mice, the inactivation of Usp25, either genetically or pharmacologically, greatly attenuates liver injury and reduces the mortality rates resulted from lethal doses of APAP.