Imatinib mesylate-induced acute hepatotoxicity

INTRODUCTION

Imatinib is a first-line selective tyrosine kinase inhibitor used for the treatment of chronic myeloid leukemia. Although imatinib-induced hepatotoxicity may aggravate the patient's clinical condition and alter the treatment plan, the mechanism of imatinib-induced hepatotoxicity has rarely been investigated.

CASE REPORT

We report a 51-year-old man, suffering from acute toxic hepatitis after 5 months of imatinib treatment for chronic myeloid leukemia.

MANAGEMENT AND OUTCOME

The outcome was favorable after discontinuation of treatment with normalization of biological liver function after 12 weeks. The treatment was switched to nilotinib without any incidents.

DISCUSSION

Regular liver function test monitoring is recommended during imatinib treatment. In fact of acute hepatic toxicity, treatment with imatinib should be stopped in the case of cytolysis more than five times the upper limit of normal.

Acute necrotic hepatotoxicity caused by Melanthera latifolia (Asteraceae) in cattle

This study aims to report a spontaneous and experimental intoxication in cattle by Melanthera latifolia (Asteraceae) for the first time, and to describe its epidemiological, clinical, and pathological findings. An outbreak of acute toxic hepatopathy in cattle occurred from December of 2021 to January of 2022 in a beef cattle farm from Rio Grande do Sul state, Southern Brazil, and resulted in 94 deaths from a herd of 430 animals. At necropsy, lesions consisted of enhanced lobular pattern of the liver, transmural gallbladder edema, and hemorrhages on the surface of multiple organs. The main microscopic lesion was marked hepatocellular necrosis in the centrilobular region associated with hemorrhage and infiltration of neutrophils. During the outbreak, multiple specimens of M. latifolia were noted in the paddocks where affected cattle were grazing and many showed signs of consumption. No other known acute hepatotoxic plants were found. Two 12-month-old steers were experimentally intoxicated with a single oral dose of the fresh plant (flowers, leaves, and less fibrous stalks). One bovine ingested a dose of 10  g/kg and was euthanized after 48 h, and the other ingested 15  g/kg and was euthanized 17 h later. Clinical signs, macroscopic, and microscopic lesions in both animals were similar to those observed in the spontaneous cases. Thus, this study demonstrates that M. latifolia was the cause of the outbreak of acute toxic hepatopathy with significant mortality in cattle. M. latifolia nor any plant of the genus Melanthera had ever been reported as toxic.

Galium aparine L. protects against acetaminophen-induced hepatotoxicity in rats

The toxicity of acetaminophen (N-acetyl-para-aminophenol (APAP)) is the most frequent cause of drug-induced liver damage. Galium aparine L. (GA) is traditionally used to treat jaundice. We aimed to investigate the hepatoprotective potential of GA in the APAP-induced hepatic encephalopathy (HE) rat model. Qualitative phytochemical characterization of GA was performed by LC/Q-TOF/MS analysis. Wistar rats were pretreated with GA (250 and 500 mg/kg b.wt. per oral) for five days. On the 6th day, the rats were exposed to APAP (1500 mg/kg b.wt. oral gavage) and behavioral tests (open field and passive avoidance tests) were applied on the 7th and 8th days. The animals were killed, and biochemical and histopathological parameters were assessed in blood and hepatic specimens. GA pretreated rats exhibited a significant reduction in APAP-induced liver damage, evidenced by the reduction in liver necrosis and alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin (BIL). GA demonstrated an anxiolytic effect, as seen in the acquisition trial and grooming behavior. The short-term memory performances of animals were not changed in all groups, suggesting that APAP intoxication did not affect hippocampal function. These results show that GA extract markedly exerts hepatoprotective activity, while its effect on hepatic encephalopathy was limited.

Roles of diclofenac and its metabolites in immune activation associated with acute hepatotoxicity in TgCYP3A4/hPXR-humanized mice

Diclofenac (DCF) is a widely used nonsteroidal anti-inflammatory drug, but it comes with a high risk of drug-induced liver injury (DILI). Despite the quinone-imine adduct pathways, the immunotoxicity is recently considered as another factor for DILI. However, such immune responses are still elusive. In the present study, investigation of the immune response in the acute hepatotoxicity model of TgCYP3A4/hPXR-humanized mice was conducted by administration of DCF and DCF metabolites, respectively. In a single dose intraperitoneal injection of 80 mg/kg DCF, the pharmacokinetic results showed the major DCF metabolites, including 4'-hydroxy-diclofenac (4'-OH-DCF), 5-hydroxy-diclofenac (5-OH-DCF) and diclofenac glucuronide (DCF-G) were generated after DCF treatment. Not only DCF, but those DCF metabolites could also directly cause different degrees of acute liver injury as significantly increased the serum ALT levels in a short time period in the TgCYP3A4/hPXR-humanized mice. Furthermore, the three DCF metabolites could directly stimulate the significant elevation of serum immune-related factors in varying degrees. Transcriptome analysis revealed the differentially expressed genes in the liver of DCF-G treated mice were mostly involved with the "immune system process" and "cell death" and related to "IL-17 signaling pathway" and "TNF-α signaling pathway", but 5-OH-DCF had little effect on the expressions of those genes. These results indicate that the metabolite DCF-G plays an important role in the activation of the hepatic immune system, which might be involved in the pathogenesis of DCF-induced acute liver injury.

Comparative biochemical and histopathological evaluations proved that receptacle is the most effective part of Cynara scolymus against liver and kidney damages

ETHNOPHARMACOLOGICAL RELEVANCE

The liver and kidney are among the most important organs in the body, where metabolic and elimination functions take place. During this process, liver and kidneys may suffer damage due to ingestion or formation of toxic metabolites leading to organ loss and even death. Artichoke (Cynara scolymus L.) leaf has long been recognized as a popular herbal remedy in traditional medicines with beneficial effects on liver.

AIM OF THE STUDY

In phytotherapy leaves are the part used to support the liver functions and for treatment of damage induced by various toxins, while fleshy receptacle is cooked as meal to support liver homeostasis. However, effects of other plant parts on liver such as stems, bracts have not much attracted the attention of scientific community so far. In this study we investigated comparatively the hepatoprotective and nephroprotective effects of different plant parts of artichoke, i.e. receptacles, outer bracts, inner bracts, and stems with that of leaves upon paracetamol-induction in rats.

MATERIALS AND METHODS

Aqueous ethanol (80%) extracts obtained from the different parts of artichoke were administered for five consecutive days after paracetamol induction to rats. At the end of experimental period blood samples from the experimental animals were taken for biochemical tests, while livers and kidneys were removed for further histopathological evaluation.

RESULTS

The histopathological examinations of liver and kidney tissues revealed that the receptacle and stem extracts of the artichoke were the most effective parts by improving the experimentally induced pathology in both liver and kidney. Biochemical tests also supported the histopathological data; receptacle, stem and bract extracts reduced serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, but not alkaline phosphatase (ALP), creatinine and blood urea nitrogen (BUN) levels.

CONCLUSIONS

Histopathological and biochemical studies have shown that receptacle and stem extracts of artichoke were found to exert higher protective activity on liver and kidney damage induced by paracetamol comparing to its bract and leaf extracts, the latest is officially recognized as herbal remedy.

Acute hepatotoxicity of multimodal targeted imaging contrast agent NaLuF4:Gd,Yb,Er-PEG/PEI-FA in mice

In the past few decades, upconversion nanoparticles (abbreviated as UCNPs) have been more widely applied in the biomedical fields, such as in vitro and in vivo upconversion fluorescent bioimaging, photodynamic therapy, biological macromolecular detection, imaging mediated drug delivery and so on. But meanwhile, there is still not much research on the acute toxicity of upconversion nanoparticles in vivo, such as acute hepatotoxicity. In this work, we studied the in vivo biodistribution and acute hepatotoxicity of multimodal targeted contrast agent NaLuF₄:Gd,Yb,Er-PEG/PEI-FA nanoprobe, which were synthesized by the solvothermal method and modified with Polyethylene glycol (PEG), Polyetherimide (PEI), folic acid (FA) on the surface. The acute hepatotoxicity in mice was systematically assessed after tail vein injection of different concentration of UCNPs. The results showed that NaLuF₄:Gd,Yb,Er-PEG/PEI-FA nanoparticles with an average diameter of 44.5 ± 10.4 nm, and three typical upconversion fluorescence emission bands at 520 nm, 540 nm and 660 nm under the excitation of 980 nm laser. In vivo distribution experiments results demonstrated that approximately 87% of UCNPs injected through the tail vein accumulate in the liver. In the acute hepatotoxicity test, the intravenously injection dose of UCNPs was 10, 40, 70 and 100 mg/kg, respectively. The body weight, blood routine, serum biochemistry, histomorphology and liver oxidative stress were detected and observed no significant acute hepatotoxicity damage under the injection dose of 100 mg/kg. In conclusion, NaLuF₄:Gd,Yb,Er-PEG/PEI-FA nanoprobes are safe and reliable, and have potential applications in the field of tumor targeted multimodal imaging.

Hepatotoxicity and immunotoxicity of MC-LR on silver carp

Microcystins produced by some cyanobacteria can cause damages to the liver and kidneys of aquatic animals. In the natural water with cyanobacterial blooms, silver carp may suffer from the most serious affect of the bloom due to their filtering these cyanobacteria and ingesting them as food. In the present study, silver carp was exposed to microcystin-LR by using the method of intraperitoneal injection first to determine the acute toxicity of microcystin-LR on silver carp and then to determine the activity of inflammatory protein and content of inflammatory factors from the serum of silver carp following a subacute exposure of microcystin-LR at doses of 104.9 μg kg^-1 (1/5 of LD₅₀) or 262.1 μg kg^-1 (1/2 of LD₅₀). The results showed that MC-LR exposure increased fish liver index and promoted the activities of fish serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating the hepatotoxicity of MC-LR on the fish. Moreover, MC-LR exposure also increased the number of leukocytes, complement C3 level, lysozyme activity (at the first 9 h of exposure), and the contents of cytokines TNF-α, IL-1β and IFN-γ in fish serum. In addition, a significant increase in IgM level was observed in the serum and head kidney of silver carp following MC-LR exposure. This result suggests that semi-lethal doses of MC-LR exposure is not only hepatotoxic but also immunotoxic to silver carp.

Toxicoproteomic assessment of liver responses to acute pyrrolizidine alkaloid intoxication in rats

A toxicoproteomic study was performed on liver of rats treated with retrorsine (RTS), a representative hepatotoxic pyrrolizidine alkaloid at a toxic dose (140 mg/kg) known to cause severe acute hepatotoxicity. By comparing current data with our previous findings in mild liver lesions of rats treated with a lower dose of RTS, seven proteins and three toxicity pathways of vascular endothelial cell death, which was further verified by observed sinusoidal endothelial cell losses, were found uniquely associated with retrorsine-induced hepatotoxicity. This toxicoproteomic study of acute pyrrolizidine alkaloid intoxication lays a foundation for future investigation to delineate molecular mechanisms of pyrrolizidine alkaloid-induced hepatotoxicity.

Identification of a metabolic biomarker panel in rats for prediction of acute and idiosyncratic hepatotoxicity

It has been estimated that 10% of acute liver failure is due to “idiosyncratic hepatotoxicity”. The inability to identify such compounds with classical preclinical markers of hepatotoxicity has driven the need to discover a mechanism-based biomarker panel for hepatotoxicity. Seven compounds were included in this study: two overt hepatotoxicants (acetaminophen and carbon tetrachloride), two idiosyncratic hepatotoxicants (felbamate and dantrolene), and three non-hepatotoxicants (meloxicam, penicillin and metformin). Male Sprague–Dawley rats were orally gavaged with a single dose of vehicle, low dose or high dose of the compounds. At 6 h and 24 h post-dosing, blood was collected for metabolomics and clinical chemistry analyses, while organs were collected for histopathology analysis. Forty-one metabolites from previous hepatotoxicity studies were semi-quantified and were used to build models to predict hepatotoxicity. The selected metabolites were involved in various pathways, which have been noted to be linked to the underlying mechanisms of hepatotoxicity. PLS models based on all 41 metabolite or smaller subsets of 6 (6 h), 7 (24 h) and 20 (6 h and 24 h) metabolites resulted in models with an accuracy of at least 97.4% for the hold-out test set and 100% for training sets. When applied to the external test sets, the PLS models predicted that 1 of 9 rats at both 6 h and 24 h treated with idiosyncratic liver toxicants was exposed to a hepatotoxic chemical. In conclusion, the biomarker panel might provide information that along with other endpoint data (e.g., transcriptomics and proteomics) may diagnose acute and idiosyncratic hepatotoxicity in a clinical setting.