Paracetamol Metabolites Research Articles

Electrochemical Sensor based on N-Doped Graphite/Aluminum Silicate Nanocomposite Modified Carbon Paste for Simultaneous Detection of Paracetamol and Pamabrom

We have developed an eco-friendly sensor through innovative modification of a carbon paste electrode with nanomaterials. This modification is based on employing a mixture of aluminum silicate and nitrogen-doped graphite nanocomposite (Al2SiO5/NG/CPE), introducing the first electrochemical approach for the voltammetric determination of a combination of paracetamol (PCM) and pamabrom (PAM), which is recognized as an over-the-counter remedy for menstrual cramp relief. N-doped graphite was prepared from graphite and urea using a metal-free soft nitriding method. The morphological characterization of the Al2SiO5/NG nanocomposite was investigated using transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The experimental conditions were optimized using square wave voltammetry and cyclic voltammetry techniques to explore the impact of scan rate, pH, and concentration. The results exhibited good linearity across a wide concentration range of 0.2 nM–100.0 μM for both drugs. The limits of detection for PCM and PAM were 25 and 24 pM, respectively, while the limits of quantification were 88.3 and 80.0 pM, showing the proposed sensor’s exceptional sensitivity. Furthermore, the proposed sensor was employed to determine the PCM/PAM mixture in bulk powder, pharmaceutical dosage forms, biological fluids, and in the presence of toxic paracetamol metabolites.

A triple cysteine motif as major determinant of the modulation of neuronal KV7 channels by the paracetamol metabolite N-acetyl-p-benzo quinone imine.

The analgesic action of paracetamol involves KV7 channels, and its metabolite N-acetyl-p-benzo quinone imine (NAPQI), a cysteine modifying reagent, was shown to increase currents through such channels in nociceptors. Modification of cysteine residues by N-ethylmaleimide, H2O2, or nitric oxide has been found to modulate currents through KV7 channels. The study aims to identify whether, and if so which, cysteine residues in neuronal KV7 channels might be responsible for the effects of NAPQI. To address this question, we used a combination of perforated patch-clamp recordings, site-directed mutagenesis, and mass spectrometry applied to recombinant KV7.1 to KV7.5 channels. Currents through the cardiac subtype KV7.1 were reduced by NAPQI. Currents through all other subtypes were increased, either by an isolated shift of the channel voltage dependence to more negative values (KV7.3) or by such a shift combined with increased maximal current levels (KV7.2, KV7.4, KV7.5). A stretch of three cysteine residues in the S2-S3 linker region of KV7.2 was necessary and sufficient to mediate these effects. The paracetamol metabolite N-acetyl-p-benzo quinone imine (NAPQI) modifies cysteine residues of KV7 subunits and reinforces channel gating in homomeric and heteromeric KV7.2 to KV7.5, but not in KV7.1 channels. In KV7.2, a triple cysteine motif located within the S2-S3 linker region mediates this reinforcement that can be expected to reduce the excitability of nociceptors and to mediate antinociceptive actions of paracetamol.

Analisis Studi Biofarmasetika dan Farmakokinetika tentang Pengeluaran Parasetamol Melalui Urin dan Saliva

The purpose of this study was to determine that Paracetamol, also known as acetaminophen, is a commonly used analgesic and antipyretic drug to relieve pain and reduce fever. The process of metabolism and elimination of paracetamol from the body is important to understand, especially in the context of the safe use of this drug. This study aims to analyze the biopharmaceutics and pharmacokinetics studies of paracetamol excretion through urine and saliva as important indicators in understanding the metabolic and elimination processes of this drug. Paracetamol is rapidly and efficiently absorbed through the gastrointestinal tract, reaches the highest concentration in plasma in a short time, and is dispersed throughout the body fluids. The metabolic process of paracetamol mainly occurs in the liver, through two main phases: oxidation and conjugation with glucuronic and sulfuric acids. Excretion of drugs and their metabolites can occur through urine and saliva, with the kidney as the main organ in the excretion process. Qualitative analytical methods were used in this study to identify paracetamol metabolite compounds in urine and saliva samples and to evaluate the metabolic pathways involved. Glucoronide, sulfate, and phenol conjugate assays were used to detect the presence of paracetamol metabolites in the samples. The assay results showed that urine was more effective in excreting paracetamol compared to saliva. In conclusion, this study provides a better understanding of the metabolic process and elimination of paracetamol from the human body through the analysis of biopharmaceutics and pharmacokinetics studies. These results are important for understanding the therapeutic effects and toxicity of paracetamol as well as for developing more effective and safe drug use management strategies.

Protective effects of jervine purified from Veratrum album on paracetamol-induced liver toxicity in rats

Purpose: Since paracetamol toxicity is a very common type of poisoning, we planned to investigate whether Jervine has an effect on paracetamol toxicity by utilizing its anti-inflammatory effect.
 Materials and Methods: In our study, 42 Sprague Dawley rats of 8 weeks of age were used. Seven groups were formed with 6 animals in each group. At the 24th hour of the study, all groups underwent laparotomy under anesthesia, and liver dissection was performed. Hematoxylin and Eosin (H&E) staining was performed to evaluate liver histopathology. SOD, CAT, GSH, and MDA levels were analyzed biochemically.
 Results: Histopathological, while liver tissues were normal in the control group, we observed degeneration areas, inflammation, and hemorrhage in the paracetamol group. Jervine reduced the severity of paracetamol toxicity and prevented liver damage. Jervine significantly increased SOD levels. Paracetamol administration significantly decreased CAT levels. Paracetamol significantly decreased GSH levels compared to the control group. 
 Conclusion: Jervine reduced the adverse effects of paracetamol toxicity on liver tissue, such as degeneration, inflammation, and hemorrhage. Jervine increased antioxidant activity and reduced the harmful effects of NAPQI, the toxic metabolite of paracetamol, on liver tissue.

Investigation of catalytic properties of glutathione reductase obtained by chromatographic methods from the liver of rats with paracetamol-induced liver damage upon administration of 6-hydroxy-2,2,2,4-trimethyl-1,2-dihydroquinoline

The aim of the present study was to analyze some catalytic and regulatory properties of the enzyme preparation of glutathione reductase (GR, EC 1.6.4.2.) obtained from rat liver using gel filtration and ion exchange chromatography under conditions of paracetamol-induced liver injury (PILI) and administration of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline (DHQ). Laboratory animals (Rattus norvegicus rats of the Wistar line) were divided into 3 groups. The animals of the control group were orally administered vaseline oil. The second group consisted of rats with PILI induced by a single oral administration of paracetamol at a dose of 1000 mg/kg body weight dissolved in 1 cm3 of vaseline oil. Animals of the third group were modeled by PILI and orally administered with DHQ at a dose of 50 mg per 1 kg body weight dissolved in 1 cm3 of 1% starch, 1 hour and 12 hours after paracetamol administration. Liver and serum were collected 24 hours after paracetamol administration. GR activity was measured on a spectrophotometer at 340 nm wavelength. The enzyme was purified from rat liver by ammonium sulfate fractionation, gel filtration through Sephadex G-25, and ion exchange chromatography on DEAE-cellulose. The total amount of protein in the samples was measured using the BCA protein assay kit. GR was obtained from the liver of rats treated with DHQ on the background of PILI with a 32-fold purification degree. Using the method of double inverse Lineweaver-Burk coordinates it was shown that administration of DHQ to rats was accompanied by a decrease in the affinity of the enzyme for NADPH, as compared to the indicators at pathology. The introduction of isocitrate into the spectrophotometric medium resulted in a less pronounced increase in the activity of GR from the liver of animals treated with DHQ on the background of PILI, compared to the second group of rats. The enzyme from the liver of animals of the third group was characterized by a more significant decrease in activity when glucose-6-phosphate was introduced into the reaction medium. Citrate had a less pronounced regulatory effect on GR from the liver of rats treated with DHQ on the background of pathology, relative to the indicators of animals with PILI. The changes in enzyme properties demonstrated may be due to conformational changes in the molecule resulting from the inhibition effect of DHQ on the intensity of free radical-induced oxidation, which develops against the background of the toxic effect of paracetamol metabolites.

Paracetamol (acetaminophen) poisoning: The early years.

Paracetamol (acetaminophen) was marketed in the 1950s as a nonprescription analgesic/antipyretic without any preclinical toxicity studies. It became used increasingly for self-poisoning, particularly in the UK and was belatedly found to cause acute liver damage, which could be fatal. Management of poisoned patients was difficult as maximum abnormalities of liver function were delayed for 3days or more after an overdose. There was no treatment and the mechanism of hepatotoxicity was not known. The paracetamol half-life was prolonged with liver damage occurring when it exceeded 4h and the Rumack-Matthew nomogram was an important advance that allowed stratification of patients into separate zones of risk. It is used to guide prognosis and treatment and its predictive value could be increased by combining it with the paracetamol half-life. The problems of a sheep farmer in Australia in the early 1970s led to the discovery of the mechanism of paracetamol hepatotoxicity, and the first effective treatment of overdosage with intravenous (IV) cysteamine. This had unpleasant side effects and administration was difficult. N-acetylcysteine soon became the treatment of choice for paracetamol overdose and given early it was very effective when administered either IV or orally. N-acetylcysteine could cause anaphylactoid reactions, particularly early during IV administration when the concentrations were highest. Simpler and shorter regimes with slower initial rates of infusion have now been introduced with a reduced incidence of these adverse effects. In addition, there has been a move to use larger doses of N-acetylcysteine given over longer periods for patients who are more severely poisoned and those with risk factors. There has been much interest recently in the search for novel biomarkers such as microRNAs, procalcitonin and cyclophilin that promise to have greater specificity and sensitivity than transaminases. Paracetamol-protein adducts predict hepatotoxicity and are specific biomarkers of toxic paracetamol metabolite exposure. Another approach would be measurement of the plasma levels of cysteine and inorganic sulfate. It is 50 years since the first effective treatment for paracetamol poisoning and, apart from liver transplantation, there is still no effective treatment for patients who present late.

Chlorzoxazone reduced the paracetamol-induced toxicity via competitive inhibition of CYP2E1-mediated metabolism

BackgroundDrug metabolism is crucial to attaining the therapeutic index of any drug. The metabolism and elimination of the drugs are governed mainly by P-glycoprotein (P-gp) and Cytochrome P450 (CYP). Paracetamol is mostly used as analgesic and antipyretic agent. The metabolism of paracetamol is primarily via Glucuronidation and sulphation at therapeutic doses. About 5–10% of paracetamol is metabolized via CYP mediated pathway. Cytochrome P450 2E1 (CYP2E1) is primarily responsible for forming a toxic metabolite of paracetamol called N-acetyl-p-benzoquinoneimine (NAPQI). Even at therapeutic doses, long-term usage of paracetamol leads to the hepatic and nephrotoxicity because of NAPQI. Several in-vitro and in-vivo studies conducted by different research groups and reported that chlorzoxazone is a substrate and inhibitor of CYP2E1. However, the effect of chlorzoxazone on the paracetamol (CYP2E1 substrate) metabolism via the CYP2E1 has not yet been reported. This study investigated the effect of chlorzoxazone on the CYP2E1-mediated metabolism of Paracetamol and NAPQI formation in Wistar rats.ResultsFor 15 days, animals were orally administered with Paracetamol (300 mg/kg) with and without Silymarin (100 mg/kg) (standard CYP2E1 inhibitor) and Chlorzoxazone (50 and 100 mg/kg). Analysis was performed using RP-HPLC on the 15th day to determine paracetamol and NAPQI concentration in the plasma. Paracetamol combination with chlorzoxazone (50 and 100 mg/kg) showed a dose-dependent increase in the AUC0–∞ and the peak plasma concentration (Cmax) of Paracetamol and a dose-dependent decrease of AUC0–∞ and Cmax of NAPQI compared to paracetamol control (p < 0.001). Chlorzoxazone significantly decreased the elevated liver and renal markers compared to paracetamol control. Simultaneously, Hepatic and nephrotic tissue studies showed that compared to the paracetamol control group, the combination of chlorzoxazone significantly ameliorated paracetamol-induced hepatotoxicity and nephrotoxicity.ConclusionFinally, this study revealed that paracetamol in combination with chlorzoxazone led to a significant decrease in the plasma levels of NAPQI and enhanced absorption of paracetamol in rats via the inhibition of CYP2E1- mediated metabolism. In addition, chlorzoxazone significantly ameliorated paracetamol-induced hepatotoxicity and nephrotoxicity.

Isolation of Novel Bacterial Strains Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 from Sewage Sludge for Paracetamol Biodegradation.

Paracetamol is one of the most used pharmaceuticals worldwide, but due to its widespread use it is detected in various environmental matrices, such as surface and ground waters, sediments, soils or even plants, where it is introduced mainly from the discharge of wastewater and the use of sewage sludge as fertilizer in agriculture. Its accumulation in certain organisms can induce reproductive, neurotoxic or endocrine disorders, being therefore considered an emerging pollutant. This study reports on the isolation, from sewage sludge produced in wastewater treatment plants (WWTPs), of bacterial strains capable of degrading paracetamol. Up to 17 bacterial strains were isolated, but only two of them, identified as Pseudomonas stutzeri CSW02 and Pseudomonas extremaustralis CSW01, were able to degrade very high concentrations of paracetamol in solution as a sole carbon and energy source, and none of them had been previously described as paracetamol degraders. These bacteria showed the ability to degrade up to 500 mg L-1 of paracetamol in only 6 and 4 h, respectively, much quicker than any other paracetamol-degrader strain described in the literature. The two main paracetamol metabolites, 4-aminophenol and hydroquinone, which present high toxicity, were detected during the degradation process, although they disappeared very quickly for paracetamol concentrations up to 500 mg L-1. The IC50 of paracetamol for the growth of these two isolates was also calculated, indicating that P. extremaustralis CSW01 was more tolerant than S. stutzeri CSW02 to high concentrations of paracetamol and/or its metabolites in solution, and this is the reason for the much lower paracetamol degradation by S. stutzeri CSW02 at 2000-3000 mg L-1. These findings indicate that both bacteria are very promising candidates for their use in paracetamol bioremediation in water and sewage sludge.

Mitophagy and endoplasmic reticulum-phagy accelerated by a p62 ZZ ligand alleviates paracetamol-induced hepatotoxicity.

Paracetamol (acetaminophen)-induced hepatotoxicity is the leading cause of drug-induced liver injury worldwide. Autophagy is a degradative process by which various cargoes are collected by the autophagic receptors such as p62/SQSTM1/Sequestosome-1 for lysosomal degradation. Here, we investigated the protective role of p62-dependent autophagy in paracetamol-induced liver injury. Paracetamol-induced hepatotoxicity was induced by a single i.p. injection of paracetamol (500 mg·kg-1 ) in C57/BL6 male mice. YTK-2205 (20 mg·kg-1 ), a p62 agonist targeting ZZ domain, was co- or post-administered with paracetamol. Western blotting and immunocytochemistry were performed to explore the mechanism. N-terminal arginylation of the molecular chaperone calreticulin retro-translocated from the endoplasmic reticulum (ER) was induced in the livers undergoing paracetamol-induced hepatotoxicity, and YTK-2205 exhibited notable therapeutic efficacy in acute hepatotoxicity as assessed by the levels of serum alanine aminotransferase and hepatic necrosis. This efficacy was significantly attributed to accelerated degradation of ubiquitin (Ub) conjugates as well as damaged mitochondria (mitophagy) and endoplasmic reticulum (ER-phagy). In primary murine hepatocytes treated with paracetamol, YTK-2205 induced the co-localization of p62+ LC3+ phagophores to the sites of mitophagy and ER-phagy. A similar activity of YTK-2205 was observed with N-acetyl-p-benzoquinone imine, a putative toxic metabolite of paracetamol in Hep3B cells. Our results elucidated that p62-dependent autophagy plays a key role in the removal of cytotoxic materials such as damaged mitochondria in paracetamol-induced hepatotoxicity. Small molecule ligands to p62 may be developed into drugs to treat this pathological condition.

Clinical Pharmacology of Paracetamol in Infants and Children

Paracetamol (acetaminophen) has analgesic and antipyretic effects similar to those of aspirin but has only weak anti-inflammatory effects. It is a nonselective cyclooxygenase inhibitor which acts at the peroxidase site of the enzyme and is thus distinct among the nonsteroidal anti-inflammatory drugs. The major metabolites of paracetamol are paracetamol glucuronide and paracetamol sulphate and the minor metabolites are mercapturic acid cysteine conjugates and N-acetyl-p-benzoquinone imine. The last is a highly reactive intermediate and it reacts with sulfhydryl groups in glutathione and is harmless. Paracetamol may be administered orally, rectally, or intravenously. In infants, the oral dosing of paracetamol consist in a loading dose of 20 mg/kg following by subsequent doses of 10 to 15 mg/kg, and in children, the dose varies with the child age and body-weigh. Paracetamol has been found efficacy and safe in infants and children but it may induce adverse-effects. The elimination half-life of paracetamol is 11.0 and 4.38 hours in more immature preterm infants and in less immature preterm infants, respectively, and it is 3.45 hours in children. Propranolol interacts with drugs. The prophylaxis, treatment, and trials with paracetamol have been investigated in infants and children. Paracetamol may induce toxicity and it crosses the human placenta and migrates into the breast milk in significant amounts. The aim of this study in the review of paracetamol dosing, efficacy and safety, adverse-effects, metabolism, pharmacokinetics, drug interaction, prophylaxis, treatment, trials, toxicity in infants and children, and paracetamol transfer across the human placenta and migration into the breast milk.

Human sperm cells can form paracetamol metabolite AM404 that directly interferes with sperm calcium signalling and function through a CatSper-dependent mechanism

Abstract STUDY QUESTION Do paracetamol (N-acetyl-para-aminophenol (APAP) or acetaminophen) and/or its metabolites affect human sperm Ca2+-signalling and function? SUMMARY ANSWER While APAP itself does not interact with Ca2+-signalling in human sperm, its metabolite N-arachidonoyl phenolamine (AM404), produced via fatty acid amide hydrolase (FAAH), interferes with human sperm Ca2+-signalling and function through a suggested CatSper channel-dependent action. WHAT IS KNOWN ALREADY Studies have shown that adult men with high urinary levels of over-the-counter mild analgesic APAP have impaired sperm motility and increased time-to-pregnancy. STUDY DESIGN, SIZE, DURATION This study consists of (i) an in vivo human pharmaceutical APAP exposure experiment to understand to what degree APAP reaches the sperm cells in the seminal fluid; (ii) in vitro calcium imaging and functional experiments in freshly donated human sperm cells to investigate CatSper channel-dependent activation by APAP and its metabolites; and (iii) experiments to understand the in situ capabilities of human sperm cells to form APAP metabolite AM404. PARTICIPANTS/MATERIALS, SETTING, METHODS Three healthy young males participated in the in vivo human exposure experiment after prior consent. Human semen samples were provided by healthy young volunteer donors after prior consent on the day of the in vitro experiments. MAIN RESULTS AND THE ROLE OF CHANCE Pharmaceutical APAP exposure reaches the seminal plasma in high micromolar concentrations and accumulates in the seminal plasma between 3 and 5 days of exposure (P-value 0.023). APAP and its primary metabolite 4-aminophenol (4AP) do not interact with human sperm Ca2+-signalling. Instead, the APAP metabolite AM404 produced via FAAH interferes with human sperm Ca2+-signalling through a CatSper-dependent action. Also, AM404 significantly increases sperm cell penetration into viscous mucous (P-value of 0.003). FAAH is functionally expressed in human sperm cells in the neck/midpiece region, as evidenced by immunohistochemical staining and the ability of human sperm cells to hydrolyse the fluorogenic FAAH substrate arachidonyl 7-amino, 4-methyl coumarin amide in an FAAH-dependent manner. Importantly, human sperm cells have the capacity to form AM404 in situ after exposure to 4AP (P-value 0.0402 compared to vehicle-treated sperm cells). LIMITATIONS, REASONS FOR CAUTION The experiments were conducted largely in vitro. Future studies are needed to test whether APAP can disrupt human sperm function in vivo through the action of AM404. WIDER IMPLICATIONS OF THE FINDINGS We hypothesize that these observations could, at least in part, be responsible for the negative association between male urinary APAP concentrations, sperm motility and time-to-pregnancy. STUDY FUNDING/COMPETING INTEREST(S) D.M.K. is funded by the Lundbeck Foundation, grant number R324-2019-1881, and the Svend Andersen Foundation. A.R. is funded by a BRIDGE—Translational Excellence Programme grant funded by the Novo Nordisk Foundation, grant agreement number: NNF18SA0034956. All authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A.

Efflux transporters in rat placenta and developing brain: transcriptomic and functional response to paracetamol

Adenosine triphosphate binding cassette (ABC) transporters transfer lipid-soluble molecules across cellular interfaces either directly or after enzymatic metabolism. RNAseq analysis identified transcripts for ABC transporters and enzymes in rat E19, P5 and adult brain and choroid plexus and E19 placenta. Their functional capacity to efflux small molecules was studied by quantitative analysis of paracetamol (acetaminophen) and its metabolites using liquid scintillation counting, autoradiography and ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Animals were treated acutely (30 min) and chronically (5 days, twice daily) with paracetamol (15 mg/kg) to investigate ability of brain and placenta barriers to regulate ABC transport functionality during extended treatment. Results indicated that transcripts of many efflux-associated ABC transporters were higher in adult brain and choroid plexus than at earlier ages. Chronic treatment upregulated certain transcripts only in adult brain and altered concentrations of paracetamol metabolites in circulation of pregnant dams. Combination of changes to metabolites and transport system transcripts may explain observed changes in paracetamol entry into adult and fetal brains. Analysis of lower paracetamol dosing (3.75 mg/kg) indicated dose-dependent changes in paracetamol metabolism. Transcripts of ABC transporters and enzymes at key barriers responsible for molecular transport into the developing brain showed alterations in paracetamol pharmacokinetics in pregnancy following different treatment regimens.

Pengaruh Pemberian Curcumin Terhadap Perbaikan Fungsi Hepar Tikus Putih (Rattus Novergicus) yang diinduksi Parasetamol Dosis Tinggi

Paracetamol has analgesic properties comparable to NSAIDs, but paracetamol have minimal side effects. Paracetamol is metabolized via sulfation and glucuronidation conjugation which is then excreted in the urine. A small part of the paracetamol has been changed to NAPQI. NAPQI will be detoxified by gluthathione. In high doses, there in an increase in NAPQI and a decrease in glutathione levels that results in oxidative stress and liver cell necrosis. Curcumin is often used as a traditional medicine to treat liver disease where it contains phenolic groups capable to scavenge free radicals. Curcumin extract can improve cellular responses to oxidative stress such as increasing the expression of Nrf2, SOD, and gluthathione. The purpose of this research was to know the effect of curcumin on the improvement of liver function in white rats (Rattus novergicus) induced by high dose paracetamol. The design of this research was a descriptive research using literature studies from at least 15 international journals indexed by Scimago or national journals indexed by Sinta published in 2015-2020. Based on the journals used in this research, giving curcumin at a dose of 200 mg/kg BW/day for 2 weeks was effective in significantly increasing gluthathione levels in rats receiving high dose paracetamol. Giving curcumin at a dose of 100 mg/kg BW/day for 7 days can reduce AST and ALT activity in rats receiving high dose paracetamol, but the dose of curcumin that was more effective in reducing AST and ALT activity was 200 mg/kg BW/day for 2 weeks. This is because of curcumin which functions as a hepatoprotector that bind directly to the toxic metabolite of paracetamol, thereby reducing the use of glutathione and quench free radicals, so that oxidative stress in the liver decreased and gluthathione levels increased, AST and ALT activity decreased.

N-acetylcysteine in clinical practice – properties, use and adverse effects

N-acetylcysteine is a simple chemical compound with antioxidant and mucolytic properties. Currently, it is the primary treatment for acetaminophen poisoning. Prior to the introduction of acetylcysteine, acetaminophen overdose was associated with high mortality due to acute liver failure. Owing to its antioxidant properties, acetylcysteine maintains appropriate levels of glutathione, thereby protecting the liver from damage by toxic metabolites of paracetamol. Acetylcysteine is also used for infections with excess respiratory secretions. The mechanism of action of cysteine derivatives involves cleavage of disulfide bonds between the macromolecules present in the mucus and, consequently, reduction of mucus viscosity. Clinical trials have shown that N-acetylcysteine also plays an important role in relieving cough by eliminating mucus from the airways. Owing to its antioxidant properties, it can also prevent contrast-induced nephropathy. It was shown that prophylactic doses of acetylcysteine administered the day before and at the day of contrast administration are effective in preventing contrastinduced nephropathy in patients with chronic kidney disease. The compound can also modulate pathophysiological processes involved in many mental and neurological disorders. There is also evidence supporting the efficacy of acetylcysteine in mental disorders such as autism, schizophrenia, Alzheimer’s disease, psychoactive substance dependence or bipolar disorder. However, in addition to its therapeutic activity, the drug may also induce adverse effects. Adverse effects of varying severity have been reported since the introduction of acetylcysteine into clinical use.

Poisons affecting the blood

Blood circulates as a liquid containing cells and numerous chemicals; it functions to transport nutrients, chemicals, oxygen and waste products to and from cells, and is involved in defence and wound repair to tissues. Numerous toxic substances can disrupt the normal function of the blood through various mechanisms resulting in clinical signs of poisoning. Some of the substances that commonly cause adverse effects on the blood in companion animals are described. These include onions and related food plants which cause oxidative damage to red blood cells and the formation of Heinz bodies, and zinc which causes haemolytic anaemia. Haemoglobin is also subject to oxidative damage from paracetamol metabolites resulting in the formation of methaemoglobin which is non-functioning, resulting in tissue hypoxia. Disruption of the clotting cascade by anticoagulant rodenticides results in delayed-onset haemorrhage and the drug 5-fluorouracil disrupts the formation of blood cells causing bone marrow depression.

Hepatotoxicity in a child following an accidental overdose of liquid paracetamol

Introduction: Accidental pediatric liquid paracetamol exposure is common. Most children do not require treatment with acetylcysteine and acute liver injury is rare.Case report: An otherwise well 3-year-old (15.4 kg) girl with recent vomiting and low-grade fever presented 1 h post-accidental ingestion of up to 150 mL of 24 mg/mL (240 mg/kg) of liquid paracetamol. Paracetamol concentrations 2 and 4 h post-ingestion were 105 and 97 mg/L, respectively, both below the nomogram treatment threshold so acetylcysteine was not administered. The ALT was elevated to 52 U/L 4 h post-ingestion, and then 219 U/L at 17 h, so intravenous acetylcysteine was commenced at 25 h. ALT peaked at 1393 U/L 5d post-ingestion, and INR peaked at 1.5 at 44 h post-ingestion. Acetylcysteine continued for 64 h and she made an uneventful recovery. Paracetamol metabolites were measured including, nontoxic glucuronide and sulphate conjugates and toxic cytochrome P450 (CYP) metabolites (cysteine and mercapturate). The apparent paracetamol half-life was 6.3 h. Her CYP metabolites were higher than usual, 11% of total metabolites. Glucuronide and sulphate conjugates accounted for 71 and 18% of total metabolites, respectively.Conclusion: This uncommon case of hepatotoxicity in a child following accidental liquid paracetamol ingestion may have been due to increased susceptibility from a recent viral illness with decreased oral intake, as evidenced by the higher proportion of CYP metabolites.

Neuroprotective Effect of AM404 Against NMDA-Induced Hippocampal Excitotoxicity

Different studies have demonstrated that inflammation and alterations in glutamate neurotransmission are two events contributing to the pathophysiology of neurodegenerative or neurological disorders. There are evidences that N-arachidonoylphenolamine (AM404), a cannabinoid system modulator and paracetamol metabolite, modulates inflammation and exerts neuroprotective effects on Huntington’s (HD) and Parkinson’s diseases (PD), and ischemia. However, the effects of AM404 on the production of inflammatory mediators and excitotoxicity in brain tissue stimulated with N-methyl-D-aspartic acid (NMDA) are not elucidated. In this present study, we investigated the effects of AM404 on the production of inflammatory mediators and neuronal cell death induced by NMDA in organotypic hippocampal slices cultures (OHSC) using qPCR, western blot (WB), and immunohistochemistry. Moreover, to comprehend the mechanism of excitotoxicity, we evaluated the effects of AM404 on glutamate release in hippocampal synaptosomes and the NMDA-induced calcium responses in acute hippocampal slices. Our results showed that AM404 led to a significant decrease in cell death induced by NMDA, through a mechanism possibly involving the reduction of glutamate release and the calcium ions responses. Furthermore, it decreased the expression of the interleukin (IL)-1β. This study provides new significant insights about the anti-inflammatory and neuroprotection effects of AM404 on NMDA-induced excitotoxicity. To understand the effects of AM404 in these processes might contribute to the therapeutic potential of AM404 in diseases with involvement of neuroinflammation and neurodegeneration and might lead to a possible future treatment of neurodegenerative diseases.

HEPATOPROTECTIVE EFFECT OF A 70% ETHANOL EXTRACT OF GOD'S CROWN FRUIT (PHALERIA MACROCARPA) AGAINST PARACETAMOL HEPATOTOXICITY IN SWISS WEBSTER MICE

Background: The god’s crown fruits have properties as antioxidants and anti-inflammatory. Toxic doses of paracetamol can injure the liver through toxic metabolite bonds with cytoplasmic proteins that cause free radicals to form. The aim of this research is to know the effect of the crown of gods extracts on paracetamol hepatotoxicity.&#x0D; Method: A total of 30 of Webster swiss mice with a weight of ± 20 grams, age 3 months were randomly assigned to five groups, negative control, positive control, treatment 1,2 and 3. A 70% ethanol extract of god’s crown fruit given in doses 60mg, 120mg and 240mg per kgBB mice. The extract was administered for 14 days in the treatment groups, then on day 15 paracetamol ware administered in a given dose 300mg/kgBB for 1 day for the positive control group and treatment groups. On day 16, the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were examined from the orbital sinuses and animals terminated liver tissues taken and immediately fixed in 10% buffer formalin for histological examination.&#x0D; Results and Discussion: The 70% ethanol extract of the god’s crown fruits decreased blood serum levels of AST and ALT, and these results were supported by histopathologic scores of the liver in which histopathologic scores were improved with the increasing doses (p &lt; 0.05). The secondary metabolite contents of the god’s crown fruit extract served as an antioxidant and anti-inflammatory, protecting hepatic injury from the toxic metabolite of paracetamol. &#x0D; Conclusion: A 70% ethanol extract of god’s crown fruit (Phaleria macrocarpa) have hepatoprotective properties that effectively prevent hepatic injury due to paracetamol toxic dose.

Quercetin reduced the formation of N-acetyl-p-benzoquinoneimine, a toxic metabolite of paracetamol in rats and isolated rat hepatocytes.

N-acetyl-p-benzoquinoneimine (NAPQI) is toxic metabolite of paracetamol formed primarily by cytochrome P4502E1 (CYP2E1) metabolic pathway when administered at therapeutic doses or overdose. The influence of quercetin (flavonoid) on the bioactivation of paracetamol to NAPQI was investigated using rat liver microsomes and rats in vivo. Paracetamol (80mg/kg) was administered orally without or with silymarin (100mg/kg), a known inhibitor of CYP2E1, CYP3A4 and quercetin (10 and 20mg/kg) to rats for 15 consecutive days. Area under the plasma concentration-time curve (AUC0-∞ ) and the peakplasma concentration (Cmax ) of paracetamol were dose-dependently increased with quercetin (10 and 20mg/kg) compared to paracetamol control group (p<0.001). On the other hand, the AUC0-∞ and Cmax of NAPQI were decreased significantly with quercetin. The same results were observed with silymarin also. The elevated liver and kidney functional enzymes/compounds were significantly reduced by quercetin and silymarin compared to paracetamol control group. The formation of NAPQI was reduced in the incubation samples in presence of quercetin in experiment using isolated rat hepatocytes. The presentstudy results revealed that quercetin might be inhibited the CYP2E1-mediated metabolism of paracetamol; thereby decreased the formation of NAPQI and protected the liver and kidney.

Poisons affecting the blood

Blood circulates as a liquid containing cells and numerous chemicals; it functions to transport nutrients, chemicals, oxygen and waste products to and from cells, and is involved in defence and wound repair to tissues. Numerous toxic substances can disrupt the normal function of the blood through various mechanisms resulting in clinical signs of poisoning. Some of the substances that commonly cause adverse effects on the blood in companion animals are described. These include onions and related food plants which cause oxidative damage to red blood cells and the formation of Heinz bodies, and zinc which causes haemolytic anaemia. Haemoglobin is also subject to oxidative damage from paracetamol metabolites resulting in the formation of methaemoglobin which is non-functioning, resulting in tissue hypoxia. Disruption of the clotting cascade by anticoagulant rodenticides results in delayed-onset haemorrhage and the drug 5-fluorouracil disrupts the formation of blood cells causing bone marrow depression.