Drug-Induced Liver Injury in the Setting of Analgesic Use

Neutrophil extracellular traps promote acetaminophen-induced acute liver injury in mice via AIM2

Excessive acetaminophen (APAP) can induce neutrophil activation and hepatocyte death. Along with hepatocyte dysfunction and death, NETosis (a form of neutrophil-associated inflammation) plays a vital role in the progression of acute liver injury (ALI) induced by APAP overdose. It has been shown that activated neutrophils tend to migrate towards the site of injury and participate in inflammatory processes via formation of neutrophil extracellular traps (NETs). In this study we investigated whether NETs were involved in hepatocyte injury and contributed to APAP-induced ALI progression. ALI mouse model was established by injecting overdose (350 mg/kg) of APAP. After 24 h, blood and livers were harvested for analyses. We showed that excessive APAP induced multiple programmed cell deaths of hepatocytes including pyroptosis, apoptosis and necroptosis, accompanied by significantly increased NETs markers (MPO, citH3) in the liver tissue and serum. Preinjection of DNase1 (10 U, i.p.) for two consecutive days significantly inhibited NETs formation, reduced PANoptosis and consequently alleviated excessive APAP-induced ALI. In order to clarify the communication between hepatocytes and neutrophils, we induced NETs formation in isolated neutrophils, and treated HepaRG cells with NETs. We found that NETs treatment markedly increased the activation of GSDMD, caspase-3 and MLKL, while pre-treatment with DNase1 down-regulated the expression of these proteins. Knockdown of AIM2 (a cytosolic innate immune receptor) abolished NETs-induced PANoptosis in HepaRG cells. Furthermore, excessive APAP-associated ALI was significantly attenuated in AIM2KO mice, and PANoptosis occurred less frequently. Upon restoring AIM2 expression in AIM2KO mice using AAV9 virus, both hepatic injury and PANoptosis was aggravated. In addition, we demonstrated that excessive APAP stimulated mtROS production and mitochondrial DNA (mtDNA) leakage, and mtDNA activated the TLR9 pathway to promote NETs formation. Our results uncover a novel mechanism of NETs and PANoptosis in APAP-associated ALI, which might serve as a therapeutic target.

Mitochondrial Dysfunction and Chronic Liver Disease

Mitochondria are generally considered the powerhouse of the cell, a small subcellular organelle that produces most of the cellular energy in the form of adenosine triphosphate (ATP). In addition, mitochondria are involved in various biological functions, such as biosynthesis, lipid metabolism, oxidative phosphorylation, cell signal transduction, and apoptosis. Mitochondrial dysfunction is manifested in different aspects, like increased mitochondrial reactive oxygen species (ROS), mitochondrial DNA (mtDNA) damage, adenosine triphosphate (ATP) synthesis disorder, abnormal mitophagy, as well as changes in mitochondrial morphology and structure. Mitochondrial dysfunction is related to the occurrence and development of various chronic liver diseases, including hepatocellular carcinoma (HCC), viral hepatitis, drug-induced liver injury (DILI), alcoholic fatty liver (AFL), and non-alcoholic fatty liver (NAFL). In this review, we summarize and discuss the role and mechanisms of mitochondrial dysfunction in chronic liver disease, focusing on and discussing some of the latest studies on mitochondria and chronic liver disease.

European* clinical practice recommendations on opioids for chronic noncancer pain - Part 1: Role of opioids in the management of chronic noncancer pain

BACKGROUND

Opioid use for chronic non-cancer pain (CNCP) is complex. In the absence of pan-European guidance on this issue, a position paper was commissioned by the European Pain Federation (EFIC).

METHODS

The clinical practice recommendations were developed by eight scientific societies and one patient self-help organization under the coordination of EFIC. A systematic literature search in MEDLINE (up until January 2020) was performed. Two categories of guidance are given: Evidence-based recommendations (supported by evidence from systematic reviews of randomized controlled trials or of observational studies) and Good Clinical Practice (GCP) statements (supported either by indirect evidence or by case-series, case-control studies and clinical experience). The GRADE system was applied to move from evidence to recommendations. The recommendations and GCP statements were developed by a multiprofessional task force (including nursing, service users, physicians, physiotherapy and psychology) and formal multistep procedures to reach a set of consensus recommendations. The clinical practice recommendations were reviewed by five external reviewers from North America and Europe and were also posted for public comment.

RESULTS

The key clinical practice recommendations suggest: (a) first optimizing established non-pharmacological treatments and non-opioid analgesics and (b) considering opioid treatment if established non-pharmacological treatments or non-opioid analgesics are not effective and/or not tolerated and/or contraindicated. Evidence- and clinical consensus-based potential indications and contraindications for opioid treatment are presented. Eighteen GCP recommendations give guidance regarding clinical evaluation, as well as opioid treatment assessment, monitoring, continuation and discontinuation.

CONCLUSIONS

Opioids remain a treatment option for some selected patients with CNCP under careful surveillance.

SIGNIFICANCE

In chronic pain, opioids are neither a universal cure nor a universally dangerous weapon. They should only be used for some selected chronic noncancer pain syndromes if established non-pharmacological and pharmacological treatment options have failed in supervised pain patients as part of a comprehensive, multi-modal, multi-disciplinary approach to treatment. In this context alone, opioid therapy can be a useful tool in achieving and maintaining an optimal level of pain control in some patients.

Evaluation of analgesic and anti-inflammatory actions of indolealkylamines from toad venom in mice using lipidomics and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Toad venom is one of widely used traditional Chinese medicines due to its analgesic and anti-inflammatory activities. However, hydrophilic alkaloids from toad venom, which may have certain pharmacological activities, have not been systematic studied.

AIM OF THE STUDY

The aim of the study was to identify the indolealkylamines (IAAs) from toad venom and investigate the analgesic and anti-inflammatory actions.

MATERIALS AND METHODS

The alkaloids were extracted and identified by high-resolution mass spectrometry. The analgesic abilities were determined using hot-plate test, formalin test and von Frey test. High-sensitivity lipidomics was used to investigate the regulatory function of IAAs on inflammatory eicosanoids. Besides, network pharmacology and molecular docking were used to demonstrate the candidate targets of IAAs.

RESULTS

22 constituents have been characterized by high performance liquid chromatography (HPLC)-Triple TOF 5600, including six specific IAAs (serotonin, N-methyl serotonin, bufotenine, bufotenidine, bufothionine and dehydrobufotenine). Pharmacological studies showed that the IAAs from toad venom exerted significant analgesic activities at doses of 5, 15 and 45 mg/kg in vivo. Moreover, lipids analysis revealed IAAs might down-regulate inflammatory mediators from COX, LOX, DHA and LA pathways in formalin models, thus showing anti-inflammatory effect. The potent pharmacological function might because of the binding of IAAs and protein targets, such as sigma-1 receptor.

CONCLUSION

The studies provided a systemic evidence for the analgesic and anti-inflammatory activities of IAAs from toad venom. It suggested that IAAs might be a potential candidate to reduce inflammatory pain disorders.

S-allyl-L-cysteine protects hepatocytes from indomethacin-induced apoptosis by attenuating endoplasmic reticulum stress

Drug‐induced liver injury (DILI) can lead to acute liver failure, a lethal condition which may require liver transplantation. Hepatotoxicity associated with nonsteroidal anti‐inflammatory drugs (NSAIDs) accounts for ~ 10% of all DILI. In the current study, we determined whether indomethacin, one of the most commonly used NSAIDS, induced apoptosis in hepatocytes and investigated the underlying mechanism. Meanwhile, we investigated the protective effect of S‐allyl‐L‐cysteine (SAC), an active garlic derivative, on indomethacin‐induced hepatocyte apoptosis, and its implication on endoplasmic reticulum (ER) stress. We found that indomethacin triggered ER stress, as indicated by the elevated expression of phosphorylated eukaryotic translation initiation factor 2α (eIF2α), C/EBP homologous protein (CHOP) and spliced XBP1 in a rat liver BRL‐3A cell line. Following indomethacin treatment, caspase 3 activation and hepatocyte apoptosis were also observed. Inhibition of ER stress by chemical chaperone 4‐phenyl butyric acid alleviated cell apoptosis caused by indomethacin, indicating that ER stress is involved in indomethacin‐induced hepatocyte apoptosis. Moreover, SAC abated indomethacin‐induced eIF2α phosphorylation, inhibited CHOP upregulation and its nuclear translocation, abrogated the activation of caspase 3 and finally, protected hepatocytes from apoptosis. In conclusion, SAC protects indomethacin‐induced hepatocyte apoptosis through mitigating ER stress and may be suitable for development into a potential new therapeutic agent for the treatment of DILI.

Drug and herbal/dietary supplements-induced liver injury: A tertiary care center experience

BACKGROUND

Drug-induced liver injury (DILI) and herbal/dietary supplements (HDS) related liver injury present unique diagnostic challenges. Collaboration between the clinician and the pathologist is required for an accurate diagnosis and management.

AIM

To report our experience on the clinical-pathological findings of hepatic injury caused by drugs/HDS.

METHODS

A retrospective review of clinically proven cases of DILI/HDS who presented to our institution from January 1, 2013 to December 31, 2017 was performed. Slides were reviewed for histopathological patterns of injury and correlated with the causative agent. Out of 600 patients presenting with unexplained rise in liver enzymes undergoing biopsy, 107 were suspected to have DILI/HDS. Of these, 53 had a directly linked exposure to drug/herbal supplements. Fifteen patients were excluded for concurrent known liver disease. Thirty-eight patients with clinically proven DILI/HDS were finally included.

RESULTS

Thirty-eight cases of DILI/HDS with a male:female of 1:1.5 and mean age of 51 ± 3 years were identified. DILI was identified in 84.2% cases while HDS injury in 15.8%. Acute hepatitis (42.1%) was the most common pattern of injury while granulomatous hepatitis (2.6%) was the least common. We found one case of acute-cholestasis due to rivaroxaban and two cases of cholestatic-hepatitis due to rizatriptan and trimethobenzamide-hydrochloride that, to the best of our knowledge, have not been previously reported. One case of steatohepatitis due to trimethoprim-sulfamethoxazole and three unusual cases of cholestatic-hepatitis with bile duct injury and steatosis due to dronedarone, C4-Extreme and hydroxycut, were also seen. Of our cohort, 81.6% of the patients fared well with discontinuation of drug and 18.4% underwent transplant; of which 42.9% were deceased.

CONCLUSION

We describe the clinical findings, histopathological patterns of injury and clinical outcomes caused by drugs. In particular, we report a few previously unreported/ rarely observed clinical and histopathological patterns of hepatic injury.