Autophagy alleviates amiodarone-induced hepatotoxicity

The lipidome landscape of amiodarone toxicity: An in vivo lipid-centric multi-omics study

Amiodarone is an effective therapy for arrhythmias, its prolonged management may lead to significant adverse drug reactions. Amiodarone-induced hepatotoxicity is described by phospholipidosis, hepatic steatosis, cholestatic hepatitis, and cirrhosis. However, the systemic and hepatic lipidome disturbances and underlying toxicological mechanisms remain comprehensively elucidated. Untargeted lipidomics were utilized to analyze serum and liver samples from the rats orally administered a daily dose of amiodarone of either 100 or 300 mg/kg for one week. Changes in the expression of hepatic lipid-related genes were also examined utilizing transcriptomics. We found a higher magnitude of lipidome alterations in the 300 mg/kg than those in the 100 mg/kg groups. Treated animals showed elevated abundances of phosphatidylcholines, ether-linked phosphatidylcholines, sphingomyelins, and ceramides, and decreased levels of triacylglycerols, ether-linked triacylglycerols, and fatty acids. We also found 199 lipid-related differentially expressed hepatic genes between the 300 mg/kg group versus controls, implying lipid metabolism and signaling pathways disturbances. Specifically, elevation of serum phosphatidylcholines and ether-linked phosphatidylcholines, as well as hepatic bismonoacylglycerophosphates might be associated with reduced expression of phospholipase genes and elevated expression of glycerophospholipid biosynthesis genes, possibly driving phospholipidosis. Perturbations of sphingolipid metabolism might also be the key events for amiodarone-induced toxicity. Alterations in gene expression levels related to lipid storage and metabolism, mitochondria functions, and energy homeostasis were also found. Collectively, our study characterized the sophisticated perturbations in the lipidome and transcriptome of amiodarone-treated rats and suggested potential mechanisms responsible for amiodarone-induced hepatotoxicity.

Diacerein counteracts amiodarone‑induced hepatotoxicity in rats via targeting TLR4/NF-kB/NLRP3 pathways

This study investigates the protective effects of diacerein (DCN) against amiodarone (AMIO)-induced hepatotoxicity in a rat model. AMIO administration resulted in significant elevations of liver enzymes, ALT and AST, indicating hepatocellular membrane disruption and oxidative stress, as demonstrated by elevated levels of malondialdehyde (MDA) and decreased glutathione (GSH). Additionally, pro-inflammatory cytokines including TNF-α and IL-1β were expressed more when AMIO triggered the Toll-like receptor 4/nuclear factor kappa B/inflammasome 3 (TLR4/NF-κB/NLRP3) inflammatory pathway, along with elevated caspase-1 (CASP1) levels, which promoted apoptosis. In contrast, oral administration of DCN for two weeks effectively mitigated these effects by reducing liver enzyme levels and improving histopathological alterations. DCN also demonstrated anti-oxidant properties by decreasing MDA levels and increasing nuclear factor erythroid 2-related factor 2 (Nrf2) and GSH content. Furthermore, DCN downregulated the hepatic content of TLR4, NF-κB p65, NLRP3, CASP1, and pro-inflammatory cytokines, thereby inhibiting the activation of the inflammatory cascade. Moreover, DCN reduced protein expression of caspase 3. Those findings suggest that DCN exerts its hepatoprotective effects through its anti-oxidant activity, modulation of TLR4/NF-κB/NLRP3 inflammatory pathways, and reduction of apoptosis. These results provide new insights into potential therapeutic strategies for managing AMIO-induced hepatotoxicity, warranting further investigation into the underlying molecular mechanisms of DCN's protective effects.

Livogrit prevents Amiodarone-induced toxicity in experimental model of human liver (HepG2) cells and Caenorhabditis elegans by regulating redox homeostasis

Treatment with cationic amphiphilic drugs like Amiodarone leads to development of phospholipidosis, a type of lysosomal storage disorder characterized by excessive deposition of phospholipids. Such disorder in liver enhances accumulation of drugs and its metabolites, and dysregulates lipid profiles, which subsequently leads to hepatotoxicity. In the present study, we assessed pharmacological effects of herbal medicine, Livogrit, against hepatic phospholipidosis-induced toxicity. Human liver (HepG2) cells and in vivo model of Caenorhabditis elegans (N2 and CF1553 strains) were used to study effect of Livogrit on Amiodarone-induced phospholipidosis. In HepG2 cells, Livogrit treatment displayed enhanced uptake of acidic pH-based stains and reduced phospholipid accumulation, oxidative stress, AST, ALT, cholesterol levels, and gene expression of SCD-1 and LSS. Protein levels of LPLA2 were also normalized. Livogrit treatment restored Pgp functionality which led to decreased cellular accumulation of Amiodarone as observed by UHPLC analysis. In C. elegans, Livogrit prevented ROS generation, fat-6/7 gene overexpression, and lysosomal trapping of Amiodarone in N2 strain. SOD-3::GFP expression in CF1553 strain normalized by Livogrit treatment. Livogrit regulates phospholipidosis by regulation of redox homeostasis, phospholipid anabolism, and Pgp functionality hindered by lysosomal trapping of Amiodarone. Livogrit could be a potential therapeutic intervention for amelioration of drug-induced phospholipidosis and prevent hepatotoxicity.

The possible effects of chronic administration of amiodarone hydrochloride on the seminiferous tubules of adult male albino rats: histological and biochemical study

Amiodarone hydrochloride is an antiarrhythmic agent that is widely prescribed. However, it has serious side effects that approximately affect the whole body organs. In our study, we aimed to assess the possible effects of chronic administration of two different doses of amiodarone hydrochloride on the oxidative and inflammatory parameters as well as the histological morphology and ultrastructure of the seminiferous tubules of adult male albino rats. Forty rats were divided into four groups; Control group 1: each rat did not receive any drugs at all. Control group 2: each rat received 3 ml of 0.16% methylcellulose, orally and daily for 4 weeks. Low dose amiodarone group: each rat received 3 ml of 0.16% methylcellulose contained 3.6 mg amiodarone, orally and daily for 4 weeks. High dose amiodarone group: each rat received 3 ml of 0.16% methylcellulose contained 7.2 mg amiodarone, orally and daily for 4 weeks. Blood samples were collected for measuring serum levels of malondialdehyde, superoxide dismutase, interleukin-6 and tumor necrosis factor-alpha. Testes specimens were examined to assess the morphological changes and the level of expression of caspase-3 apoptotic marker. The results indicated that; amiodarone hydrochloride could induce a dose-dependent toxicity, causing oxidative stress, inflammation, cellular degeneration, deposition of collagen and enhanced apoptosis in the seminiferous tubules.

Insights gained into the injury mechanism of drug and herb induced liver injury in the hepatic microenvironment

Drug-Induced Liver Injury (DILI) and herb Induced Liver Injury (HILI) continues to pose a substantial challenge in both clinical practice and drug development, representing a grave threat to patient well-being. This comprehensive review introduces a novel perspective on DILI and HILI by thoroughly exploring the intricate microenvironment of the liver. The dynamic interplay among hepatocytes, sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, cholangiocytes, and the intricate vascular network assumes a central role in drug metabolism and detoxification. Significantly, this microenvironment is emerging as a critical determinant of susceptibility to DILI and HILI. The review delves into the multifaceted interactions within the liver microenvironment, providing valuable insights into the complex mechanisms that underlie DILI and HILI. Furthermore, we discuss potential strategies for mitigating drug-induced liver injury by targeting these influential factors, emphasizing their clinical relevance. By highlighting recent advances and future prospects, our aim is to shed light on the promising avenue of leveraging the liver microenvironment for the prevention and mitigation of DILI and HILI. This deeper understanding is crucial for advancing clinical practices and ensuring patient safety in the realm of DILI and HILI.

Amiodarone-Induced Liver Attenuation on CT Scan: Alarming Signal for Toxicity and Prompt Discontinuation

Amiodarone, a class III antiarrhythmic drug, is commonly used for the management of life-threatening ventricular arrhythmias, atrial fibrillation, and other refractory supra-ventricular arrhythmias. Factors like a large volume of distribution, lipophilic property, deposition in tissues in large amounts, etc. have led to the development of amiodarone-induced multisystem adverse events. We report a case of amiodarone-induced hepatic attenuation on computed tomography (CT) of the abdomen in an elderly female patient. Amiodarone with a composition of 40% iodine by weight deposits in the liver, leading to characteristically increased radiodensity reported as increased attenuation on CT scan. Surprisingly, the severity and extent of hepatic attenuation on CT scans do not necessarily correlate with the total exposure to amiodarone over time. Individual factors may influence the liver's response to the drug, leading to varying degrees of hepatic changes. To minimize the risk of adverse events associated with amiodarone, clinicians should carefully adjust the dosage to the lowest effective level and regularly monitor liver function tests in patients. This proactive approach enables early detection of liver dysfunction and facilitates timely adjustments or discontinuation of amiodarone, thereby reducing potential harm.

Endoplasmic reticulum stress regulates autophagic response that is involved in Saikosaponin a-induced liver cell damage

Saikosaponin a (Ssa) is an active ingredient of the Chinese herbal plant Radix Bupleuri (RB) and has severe hepatotoxicity. However, biomolecular mechanisms involved in Ssa-induced hepatotoxicity are not yet entirely clear. Previous studies reported that Ssd (an isomer of Ssa) as a sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) inhibitor can induce autophagy in apoptotic defective cells, leading to autophagy-dependent cell death. Therefore, we speculate that endoplasmic reticulum (ER) stress and autophagy may also play an important role in Ssa-induced hepatocyte death. This study aimed to explore the connection between ER stress and autophagy and Ssa-induced hepatotoxicity. Experiments in vitro showed that the cell viability of L-02 cells in the Ssa treatment group decreased, the level of autophagy marker LC3-II/LC3-I and Beclin1 increased, the level of p62 decreased, the colocalization of autophagosome and lysosome increased, and the cell viability was significantly increased after the application of autophagy inhibitors 3-MA. In addition, SSa can induce ER stress in L-02 cells in vitro. Further studies demonstrated that SSa activated the PERK/eIF2α/ATF4/CHOP pathway, IRE1-TRAF2 pathway, ATF6 pathway, and AMPK/mTOR pathway associated with ER stress. Application of ER stress inhibitors 4-PBA can significantly down-regulate the level of autophagy and improve cell viability. Results of in vivo experiments showed that treatment with 150 and 300 mg/kg Ssa significantly elevated the liver/body weight ratio and caused histological injury in mice liver. Furthermore, Ssa treatment induced significantly downregulated p62 expression but upregulated LC3-II, CHOP, and GRP78 expression in mice livers. Taken together, our results showed that SSa can activate endoplasmic reticulum stress, promote toxic autophagy, and then induce cell death. We revealed an alternative mechanism involving autophagy and ERs, by which Ssa induced hepatotoxicity.

Protective Role of Amiodarone on Reperfusion Arrhythmia in Patients of Acute Myocardial Infarction with Percutaneous Coronary Intervention Treatment

With the development and popularity of percutaneous coronary intervention (PCI), ischemia-reperfusion injury (IRI) has attracted more and more clinical attention. Reperfusion arrhythmia (RA), one of the common manifestations during and after PCI, can affect the postoperative cardiac function of patients with acute myocardial infarction (AMI). Therefore, effective intervention on RA has important clinical significance. This study observed the effect of amiodarone on reperfusion arrhythmia (RA) after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) and explored its possible mechanism. The results showed that amiodarone had good clinical efficacy in the prevention of RA in patients with AMI after PCI, and it could reduce the levels of serum IL-6, hs-CRP, CK-MB, and cTnI in patients and reduce the damage caused by reperfusion, thereby reducing the occurrence of RA.

FOXO3 mutation predicting gefitinib-induced hepatotoxicity in NSCLC patients through regulation of autophagy

Hepatotoxicity is a common side effect for patients treated with gefitinib, but the related pathogenesis is unclear and lacks effective predictor and management strategies. A multi-omics approach integrating pharmacometabolomics, pharmacokinetics and pharmacogenomics was employed in non-small cell lung cancer patients to identify the effective predictor for gefitinib-induced hepatotoxicity and explore optional therapy substitution. Here, we found that patients with rs4946935 AA, located in Forkhead Box O3 (FOXO3) which is a well-known autophagic regulator, had a higher risk of hepatotoxicity than those with the GA or GG variant (OR = 18.020, 95%CI = 2.473 to 459.1784, P = 0.018) in a gefitinib-concentration dependent pattern. Furthermore, functional experiments identified that rs4946935_A impaired the expression of FOXO3 by inhibiting the promotor activity, increasing the threshold of autophagy initiation and inhibiting the autophagic activity which contributed to gefitinib-induced liver injury. In contrast, erlotinib-induced liver injury was independent on the variant and expression levels of FOXO3. This study reveals that FOXO3 mutation, leading to autophagic imbalance, plays important role in gefitinib-induced hepatotoxicity, especially for patients with high concentration of gefitinib. In conclusion, FOXO3 mutation is an effective predictor and erlotinib might be an appropriately and well-tolerated treatment option for patients carrying rs4946935 AA.

Cell Models and Omics Techniques for the Study of Nonalcoholic Fatty Liver Disease: Focusing on Stem Cell-Derived Cell Models

Nonalcoholic fatty liver disease (NAFLD) is now the leading cause of chronic liver disease in western countries. The molecular mechanisms leading to NAFLD are only partially understood, and effective therapeutic interventions are clearly needed. Therefore, preclinical research is required to improve knowledge about NAFLD physiopathology and to identify new therapeutic targets. Primary human hepatocytes, human hepatic cell lines, and human stem cell-derived hepatocyte-like cells exhibit different hepatic phenotypes and have been widely used for studying NAFLD pathogenesis. In this paper, apart from employing the different in vitro cell models for the in vitro assessment of NAFLD, we also reviewed other approaches (metabolomics, transcriptomics, and high-content screening). We aimed to summarize the characteristics of different cell types and methods and to discuss their major advantages and disadvantages for NAFLD modeling.

BH3-only protein expression determines hepatocellular carcinoma response to sorafenib-based treatment

Hepatocellular carcinoma (HCC) represents a global health challenge with limited therapeutic options. Anti-angiogenic immune checkpoint inhibitor-based combination therapy has been introduced for progressed HCC, but improves survival only in a subset of HCC patients. Tyrosine-kinase inhibitors (TKI) such as sorafenib represent an alternative treatment option but have only modest efficacy. Using different HCC cell lines and HCC tissues from various patients reflecting HCC heterogeneity, we investigated whether the sorafenib response could be enhanced by combination with pro-apoptotic agents, such as TNF-related apoptosis-inducing ligand (TRAIL) or the BH3-mimetic ABT-737, which target the death receptor and mitochondrial pathway of apoptosis, respectively. We found that both agents could enhance sorafenib-induced cell death which was, however, dependent on specific BH3-only proteins. TRAIL augmented sorafenib-induced cell death only in NOXA-expressing HCC cells, whereas ABT-737 enhanced the sorafenib response also in NOXA-deficient cells. ABT-737, however, failed to augment sorafenib cytotoxicity in the absence of BIM, even when NOXA was strongly expressed. In the presence of NOXA, BIM-deficient HCC cells could be in turn strongly sensitized for cell death induction by the combination of sorafenib with TRAIL. Accordingly, HCC tissues sensitive to apoptosis induction by sorafenib and TRAIL revealed enhanced NOXA expression compared to HCC tissues resistant to this treatment combination. Thus, our results suggest that BH3-only protein expression determines the treatment response of HCC to different sorafenib-based drug combinations. Individual profiling of BH3-only protein expression might therefore assist patient stratification to certain TKI-based HCC therapies.

New Avenues for Treatment and Prevention of Drug-Induced Steatosis and Steatohepatitis: Much More Than Antioxidants

Drug-induced lipid accumulation in the liver may induce two clinically relevant conditions, drug-induced steatosis (DIS) and drug-induced steatohepatitis (DISH). The list of drugs that may cause DIS or DISH is long and heterogeneous and includes therapeutically relevant molecules that cannot be easily replaced by less hepatotoxic medicines, therefore making specific strategies necessary for DIS/DISH prevention or treatment. For years, the only available tools to achieve these goals have been antioxidant drugs and free radical scavengers, which counteract drug-induced mitochondrial dysfunction but, unfortunately, have only limited efficacy. In the present review we illustrate how in vitro preclinical research unraveled new key players in the pathogenesis of specific forms of DISH, and how, in a few cases, proof of concept of the beneficial effects of their pharmacological modulation has been obtained in vivo in animal models of this condition. The key issue emerging from these studies is that, in selected cases, liver toxicity depends on mechanisms unrelated to those responsible for the desired, primary pharmacological effects of the toxic drug and, therefore, specific strategies can be designed to overcome steatogenicity without making the drug ineffective. In particular, the hepatotoxic drug could be given in combination with a second molecule intended to selectively antagonize its liver toxicity whilst, ideally, potentiating its desired pharmacological activity. Although most of the evidence that we discuss is from in vitro or animal models and will need to be further explored and validated in humans, it highlights new avenues to be pursued in order to improve the safety of steatogenic drugs.