Acetaminophen-induced liver injury: Molecular mechanism and treatments from natural products

NLRP3 inflammasome: structure, mechanism, drug-induced organ toxicity, therapeutic strategies, and future perspectives

Drug-induced toxicity is an important issue in clinical medicine, which typically results in organ dysfunction and adverse health consequences. The family of NOD-like receptors (NLRs) includes intracellular proteins involved in recognizing pathogens and triggering innate immune responses, including the activation of the NLRP3 inflammasome. The NLRP3 (nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3) inflammasome is a critical component for both innate and adaptive immune responses and has been implicated in various drug-induced toxicities, including hepatic, renal, and cardiovascular diseases. The unusual activation of the NLRP3 inflammasome causes the release of pro-inflammatory cytokines, such as IL-1β and IL-18, which can lead to more damage to tissues. Targeting NLRP3 inflammasome is a potential therapeutic endeavour for suppressing drug-induced toxicity. This review provides insights into the mechanism, drug-induced organ toxicity, therapeutic strategies, and prospective therapeutic approaches of the NLRP3 inflammasome and summarizes the developing therapies that target the inflammasome unit. This review has taken up one of the foremost endeavours in understanding and inhibiting the NLRP3 inflammasome as a means of generating safer pharmacological therapies.

Deciphering per- and polyfluoroalkyl substances mode of action: comparative gene expression analysis in human liver spheroids

Understanding the mechanisms by which environmental chemicals cause toxicity is necessary for effective human health risk assessment. High-throughput transcriptomics (HTTr) can be used to inform risk assessment on toxicological mechanisms, hazards, and potencies. We applied HTTr to elucidate the molecular mechanisms by which per- and polyfluoroalkyl substances (PFAS) cause liver perturbations. We contrasted transcriptomic profiles of PFOA, PFBS, PFOS, and PFDS against transcriptomic profiles from established liver-toxic and non-toxic reference compounds, alongside peroxisome proliferator-activated receptors (PPARs) agonists. Our analysis was conducted on metabolically competent 3-D human liver spheroids produced from primary cells from 10 donors. Pathway analysis showed that PFOS and PFDS perturb many of the same pathways as the known liver-toxic compounds in the spheroids, and that the cholesterol biosynthesis pathways are significantly affected by exposure to these compounds. PFOA alters lipid metabolism-related pathways but its expression profile does not closely match reference compounds. PFBS upregulates many degradation-related pathways and targets many of the same pathways as the PPAR agonists and acetaminophen. Our transcriptional analysis does not support the claim that these PFAS are DNA-damaging in this model. A multidimensional scaling (MDS) analysis revealed that PFOS, PFOA, and PFDS cluster together in the same multidimensional space as liver-damaging compounds, whereas PFBS clusters more closely with the non-liver-damaging compounds. Benchmark concentration-response modeling predicts that all the PFAS are bioactive in the liver. Overall, our results show that these PFAS produce unique transcriptional changes but also alter pathways associated with established liver-toxic chemicals in this liver spheroid model.

Alpha-pinene protects rat liver against acetaminophen-induced oxidative stress and apoptosis

Acetaminophen (APA) is a commonly used antipyretic and analgesic medication worldwide. The current study aims to investigate the relationship between alpha-pinene, oxidative stress factors, genes involved in the apoptotic pathway, and liver damage caused by PAR. Thirty Wistar rats were divided into five groups: a control group and four treatment groups receiving APA (0.640 g/kg/day), APA+alpha-pinene (75 mg/kg), APA+alpha-pinene (125 mg/kg), and APA+ silymarin (50 mg/kg). The treatment groups were injected with APA for 2 weeks, while the control group received distilled water. The study assessed liver enzymes, oxidative stress factors, and apoptotic gene expression. We found that alpha-pinene decreased the ALT, AST, and ALP levels in the liver of PAR-treated rats. Alpha-pinene restored GSH, MDA, SOD, and CAT activities in the liver of PAR-treated rats. Real-time PCR analysis showed that alpha-pinene inhibited apoptosis by suppressing Bax and caspase-3 and upregulating Bcl-2 in the liver of APA-treated rats. Moreover, alpha-pinene downregulates PPARγ in the liver of APA-treated rats. Alpha-pinene has been discovered to have protective properties against liver damage caused by the use of APA. This protection is achieved by reducing oxidative stress and apoptosis. Alpha-pinene increases the expression of Bcl-2, which has an anti-apoptotic effect and reduces the levels of Bax and caspase-3.

4-Hydroxyestrogen metabolites strongly prevent chemically-induced ferroptotic hepatocyte injury in vitro and in vivo

Ferroptosis is a regulated cell death characterized by excessive accumulation of toxic lipid reactive oxygen species (ROS). Ferroptosis is an underlying cause in some human diseases, including the drug-induced liver injury. The present study aims to determine whether 4-hydroxyestrone (4-OH-E1) and 4-hydroxyestradiol (4-OH-E2), two endogenous catechol estrogens, can prevent chemically-induced ferroptotic hepatocyte injury in vitro and in vivo. The induction of ferroptotic cell death by erastin and RSL3 in rat H-4-II-E and human HuH-7 hepatoma cells is used as in vitro models. 4-OH-E1 and 4-OH-E2 each exhibit a strong protection against erastin/RSL3-induced ferroptosis in H-4-II-E hepatoma cells, and they also strongly abrogate erastin/RSL3-induced accumulation of cellular NO, ROS and lipid-ROS. A similar protective effect is observed with 4-OH-E1 and 4-OH-E2 in RSL3-induced ferroptosis in HuH-7 cells. Mechanistically, these two catechol estrogens protect hepatoma cells against chemically-induced ferroptosis mainly through binding to cellular PDI protein with a high affinity, which leads to inhibition of PDI-catalyzed NOS dimerization (activation), thereby preventing the accumulation of cellular NO, ROS and lipid-ROS. In addition, the direct antioxidant activity of these two estrogens may also partially contribute to their cytoprotective effect. In vivo animal studies show that 4-OH-E1 and 4-OH-E2 also have a strong protective effect against acetaminophen-induced liver injury in a mouse model. Together, the results of this study demonstrate that 4-OH-E1 and 4-OH-E2 are endogenous factors with a strong protective activity against chemically-induced hepatocyte injury both in vitro and in vivo.

SMND-309 activates Nrf2 signaling to alleviate acetaminophen-induced hepatotoxicity and oxidative stress

BACKGROUND

Acetaminophen (APAP) can be used for pain relief and fever alleviation, the overdose of which, however, may lead to the accumulation of N-acetyl-p-benzoquinone imine (NAPQI), inducing oxidative stress and liver damage. The natural compound SMND-309 has been shown to have hepatoprotective effects and potential antioxidant activity. However, its ability to alleviate acetaminophen-induced acute liver injury (AILI) has not been elucidated.

OBJECTIVE

To explore the protective effect of the natural compound SMND-309 against AILI and the potential mechanism.

METHODS

The AILI model was established using a mouse model and HepG2 cells for pathological evaluation and biochemical assays of mouse liver tissues to assess the level of liver injury. The effects of SMND-309 on cellular ROS levels and mitochondrial membrane potential were detected using DCFH-DA and JC-1 probes. Western blotting was performed to detect the expressions of Nrf2 signaling pathway and key proteins related to APAP metabolism in the combination of immunohistochemistry of liver tissues, with immunofluorescence assay used to detect whether Nrf2 undergoes nuclear translocation. Molecular docking, molecular dynamics simulation (MD) and biofilm layer interference (BLI) experiments were performed to detect the interaction of SMND-309 with Keap1.

RESULTS

SMND-309 improved histopathological changes in the liver, decreased alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels, as well as attenuated oxidative stress injury and mitochondrial dysfunction in the HepG2 cell line. Further studies revealed that SMND-309 promoted nuclear translocation of Nrf2 and upregulated the expressions of glutamate-cysteine ligase catalytic subunit (GCLC), heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1). In addition, molecular docking and MD suggested that SMND-309 could bind Keap1 and identified possible binding modes, with BLI experiments confirming that SMND-309 directly interacted with Keap1.

CONCLUSION

SMND-309 exerts hepatoprotective effects against AILI in an Nrf2-ARE signaling pathway-dependent manner.

A case report of liver failure caused by Tetrastigma hemsleyanum Diels et Gilg: A rare case report and literature review

RATIONALE

Tetrastigma hemsleyanum Diels et Gilg is a traditional Chinese medicinal plant recognized for its therapeutic properties, which include heat-clearing, toxicity-eliminating, anti-inflammatory, pain-relieving, blood circulation-promoting, blood stasis-resolving, wind-dispersing, and phlegm-resolving actions. It is predominantly used in clinical settings to manage inflammatory disorders, such as febrile convulsions, hepatitis, snakebites, and cellulitis. To date, no documented cases of liver failure attributable to T hemsleyanum Diels et Gilg have been reported.

PATIENT CONCERNS

A 50-year-old female patient presented with symptoms of xanthochromia, tea-colored urine, fatigue, and anorexia following a three-day course of T hemsleyanum Diels et Gilg. Liver function tests revealed elevated alanine aminotransferase (1386 U/L) and AST (405 U/L) levels.

DIAGNOSES

Liver failure induced by T hemsleyanum Diels et Gilg was diagnosed.

INTERVENTIONS

The patient received treatment that included discontinuation of hepatotoxic drugs, administration of N-acetylcysteine for liver protection, nutritional support, and correction of acid-base and electrolyte imbalances.

OUTCOMES

After 11 days of liver-protective and nutritional therapy, significant improvements in the patient's condition were noted. The symptoms of xanthochromia and tea-colored urine subsided, and liver function markers decreased markedly, returning to near-normal levels. No further complaints of discomfort were reported, and the patient was discharged with prescribed medications for follow-up.

LESSON

The possibility of liver failure following the use of T hemsleyanum Diels et Gilg should be considered. When patients present with symptoms such as fat intolerance, xanthochromia, poor appetite, nausea, and dark urine after consuming this herb, liver function tests should be promptly conducted to exclude the possibility of drug-induced liver injury. T hemsleyanum Diels et Gilg has the potential to induce liver failure. Liver-protective measures, including nutritional support, proved to be effective in managing the condition.

Utilizing Nanoparticles of Hesperidin Loaded on Layered Double Hydroxide to Reduce Hepatotoxicity Caused by Paracetamol in Rats: Controlling of Biotransformation, Oxidative Stress, Inflammation, and Apoptosis

Background/Objectives: The most used antipyretic and pain relief treatment is paracetamol (acetaminophen), also known as N-acetyl-para-aminophenol (APAP). However, it is considered potentially hazardous if consumed repeatedly in large doses or over prolonged periods. This investigation explores the effectiveness of hesperidin (Hesp) and Hesp loaded on layered double hydroxide nanoparticles (Hesp-NPs) in inhibiting the progression of acute hepatotoxicity in rats induced by APAP. Methods: LDH-Hesp-NPs were prepared and characterized. Male Wistar rats were orally treated with Hesp and Hesp-NPs at the same adjusted dose (100 mg/kg) every other day for six weeks. After 2 h of the first doses of Hesp and Hesp-NPs, the rats received one oral dose of APAP (750 mg/kg). Results: Administering of Hesp and Hesp-NPs to APAP-treated rats significantly reduced oxidant parameter (malondialdehyde) and serum enzymes (ALT, AST, LDH, and ALP) associated with liver function. Antioxidant markers in the liver, such as catalase and glutathione, also increased notably. Moreover, Hesp and Hesp-NPs enhanced the mRNA expression of liver UGT1A6, IL-10, and HO-1. Conversely, the mRNA expressions of liver CYP1A1, KEAP1, TGF-β, P53, and BAX decreased. These improvements in biochemical and molecular markers were corroborated by liver histopathology. Conclusions: Hesp and Hesp-NPs protect significantly against APAP-induced hepatotoxicity in male Wistar rats. Hesp-NPs treatment was more potent. The protective effects may be mediated via modulation of APAP biotransformation, oxidative stress, inflammation and apoptosis.

A turn-on fluorescent probe for imaging of hydroxyl radicals in drug-induced liver injury

Hydroxyl radical is the most oxidizing type of reactive oxygen species (ROS), which is closely related to body health. In this work, a novel turn-on fluorescent probe BIJ-H for OH with high sensitivity was reported. BIJ-H was synthesized by a three-step reaction, and the pure product was obtained by only washing with poor solvents. In a neat aqueous solution containing BIJ-H, after adding OH, the probe was oxidized to BIJ, which produced fluorescence emission at 625 nm under the excitation with 550 nm. This sensing behavior can be achieved under physiological pH conditions. The detection limit of BIJ-H for OH was as low as 0.1379 μM. Thanks to the good analytical properties of BIJ-H, the probe has been applied to fluorescence imaging of OH in HepG2 cells and in acute liver injury induced by acetaminophen. The probe BIJ-H is expected to be used in the qualitative and quantitative detection of OH in physiological or pathological processes.

Property-Based Design of Xanthine Derivatives as Potent and Orally Available TRPC4/5 Inhibitors for Depression and Anxiety

Transient receptor potential canonical channels 4 and 5 (TRPC4/5) are nonselective cation channels involved in emotional regulation, positioning them to be promising targets for treating mental disorders such as anxiety and depression. HC-070, a potent TRPC4/5 inhibitor, exhibits significant anxiolytic and antidepressant effects in animal models, though its drug-like properties require optimization. In this study, we applied a property-based drug design (PBDD) approach to optimize HC-070, leading to the discovery of compound 32, which shows improved LipE and Fsp3 values, reduced hERG blocking activity, enhanced metabolic stability, increased aqueous solubility, and superior oral bioavailability. Oral administration of compound 32 in mouse models demonstrates anxiolytic and antidepressant efficacy comparable to fluoxetine. This study supports the therapeutic potential of TRPC4/5 inhibitors for mental disorders and identifies compound 32 as a promising candidate for further investigation. Furthermore, our work underscores the value of PBDD in optimizing lead compounds during drug discovery process.

Thonningianin A ameliorates acetaminophen-induced liver injury by activating GPX4 and modulating endoplasmic reticulum stress

Introduction

Acetaminophen (APAP) is widely used as an analgesic and antipyretic. However overdose APAP can lead to acute liver injury (ALI), representing a significant challenge for public health due to limited treatment options. Current research highlights the need for safer and more effective therapies for APAP-induced liver injury, especially those that target oxidative and endoplasmic reticulum (ER) stress pathways. This study investigates the protective effects of Thonningianin A (TA), a flavonoid compound derived from Penthorum chinense Pursh, in mitigating APAP-induced hepatotoxicity.

Methods

The experimental design involved administering TA at doses of 20 mg/kg and 40 mg/kg to C57BL/6 mice prior to inducing hepatotoxicity with APAP.

Results and discussion

TA treatment significantly lowered plasma ALT and AST levels, inhibited the production of inflammatory cytokines, and reduced oxidative stress markers in liver tissues. Furthermore, TA modulated apoptosis-related proteins by increasing BCL-2 expression while decreasing CHOP and BAX levels. It alleviated endoplasmic reticulum (ER) stress by downregulating GRP78, p-PERK, and ATF4. Notably, liver-specific GPX4 knockdown, achieved through AAV-8-mediated shRNA delivery, abolished the hepatoprotective effects of TA, underscoring GPX4's essential role in mediating TA-induced hepatoprotection. These findings suggest TA as a promising therapeutic agent in managing APAP-induced liver injury, with its unique action on both oxidative and ER stress pathways contributing to its hepatoprotective efficacy.

Sakuranetin Prevents Acetaminophen-Induced Liver Injury via Nrf2-Induced Inhibition of Hepatocyte Ferroptosis

Introduction

Oxidative stress is an important cause of acetaminophen (APAP)-induced liver injury (AILI). Sakuranetin (Sak) is an antitoxin from the cherry flavonoid plant with good antioxidant effects. However, whether sakuranetine has a protective effect on APAP-induced liver injury is not clear.

Methods

Mouse and HepG2 cell models of APAP injury were used to investigate the effect of sakuranetin on AILI and its mechanism. Serum transaminase levels, histological changes, inflammatory mediators, oxidative stress, ferroptosis-related markers and Nrf2 signaling pathway proteins were analyzed.

Results

Sakuranetin significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as inflammatory factor; increased HepG2 activity and decreased cell death; inhibited ROS production, increased glutathione (GSH) content, expression of Glutathione Peroxidase 4 (GPX4) and Solute Carrier Family 7 Member 11 (SLC7A11), and decreased malondialdehyde and Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) expression in mice and HepG2 cells after APAP treatment. Further analysis showed that sakuranetin induced the activation of the NFE2 Like BZIP Transcription Factor 2 (Nrf2) signaling pathway in liver tissue and HepG2 cells and promoted the nuclear translocation of Nrf2. Moreover, the hepatoprotective effect of sakuranetin and its inhibitory effect on ferroptosis were significantly attenuated by the Nrf2 inhibitor ML385.

Conclusion

Sakuranetin alleviates AILI by activating the Nrf2 signaling pathway and inhibiting ferroptosis, and sakuranetin may be a potential therapeutic agent for the treatment of AILI.

Ehretia laevis mitigates paracetamol- induced hepatotoxicity by attenuating oxidative stress and inflammation in rats

Hepatotoxicity is caused due to intake of drug or any chemical above the therapeutic range or as overdose. Current therapies for the management of hepatotoxicity are associated with several side effects. The present study was envisaged to explore the hepatoprotective potential of Ehretia laevis (E. laevis) in paracetamol (PCM) induced hepatotoxicity. All the plant extracts and fractions were evaluated for antioxidant and antiproliferative potential using various in vitro assays. Hepatotoxicity was induced in rats using a standardized single oral dose of PCM (3 g/kg). The aqueous fraction of E. laevis (AFEL) exhibited significant antioxidant and antiproliferative activity as compared to methanol extract of E. laevis (MEEL) in vitro. Moreover, treatment with AFEL (25, 50 and 100 mg/kg) decreased serum hepatic markers, attenuate the oxidative stress, inflammation and histopathological changes. LC-MS analysis of AFEL showed the presence of rutin, quercetin and kaempferol. Rutin was found to be in higher concentration, therefore it was docked on TNF-α. Its overall binding mode supports its capability to make complex with TNF-α. The finding of the study suggested significant antioxidant, antiproliferative, and hepatoprotective potential of E. laevis in paracetamol induced hepatotoxicity which could be attributed to the presence of various polyphenols.

A novel "ON-OFF-ON" colorimetric and fluorescence dual-signal sensing APAP based on TSPP-Fe3

Acetaminophen, also known as paracetamol (APAP), is a commonly used over-the-counter medication that is often used to treat headaches, toothaches, joint pain, muscle pain, and to lower body temperature. However, overdose can lead to liver damage, gastrointestinal distress, kidney damage, and cardiovascular disease. Therefore, it is very important to establish a method to quickly detect APAP. A novel "ON-OFF-ON" colorimetric and fluorescence dual-signal sensing system was constructed for the quantitative detection of APAP based on 5,10,15,20-tetrakis(4-sulphonatophenyl) porphyrin (TSPP) dual-signal probe. The absorbance and fluorescence intensity of TSPP respectively were quenched when Fe3+ was introduced into TSPP solution. At this point, the color of the corresponding solution changed from red to green. The absorbance and fluorescence intensity of TSPP respectively were restored when APAP was added to the TSPP-Fe3+ system. At this time, the color of the solution changed from green to colorless. Therefore, an "ON-OFF-ON" dual-signal sensing study of APAP were constructed using TSPP as the colorimetric and fluorescent probe. The proposed colorimetric sensing system had a wide linear range in the 13.12 mM ∼ 23.20 mM with 0.11 mM of limit of detection (LOD, S/N = 3). And the proposed fluorescence sensing system had a wide linear range in the 3.45 mM ∼ 12.50 mM and 41.67 mM ∼ 65.22 mM with 0.83 mM of limit of detection (LOD, S/N = 3). The dual-signal sensing system were applied to the APAP detection of real samples.

Sirtuin 5-Mediated Desuccinylation of ALDH2 Alleviates Mitochondrial Oxidative Stress Following Acetaminophen-Induced Acute Liver Injury

Acetaminophen (APAP) overdose is a major cause of drug-induced liver injury. Sirtuins 5 (SIRT5) has been implicated in the development of various liver diseases. However, its involvement in APAP-induced acute liver injury (AILI) remains unclear. The present study aimed to explore the role of SIRT5 in AILI. SIRT5 expression is dramatically downregulated by APAP administration in mouse livers and AML12 hepatocytes. SIRT5 deficiency not only exacerbates liver injury and the inflammatory response, but also worsens mitochondrial oxidative stress. Conversely, the opposite pathological and biochemical changes are observed in mice with SIRT5 overexpression. Mechanistically, quantitative succinylome analysis and site mutation experiments revealed that SIRT5 desuccinylated aldehyde dehydrogenase 2 (ALDH2) at lysine 385 and maintained the enzymatic activity of ALDH2, resulting in the suppression of inflammation and mitochondrial oxidative stress. Furthermore, succinylation of ALDH2 at lysine 385 abolished its protective effect against AILI, and the protective effect of SIRT5 against AILI is dependent on the desuccinylation of ALDH2 at K385. Finally, virtual screening of natural compounds revealed that Puerarin promoted SIRT5 desuccinylase activity and further attenuated AILI. Collectively, the present study showed that the SIRT5-ALDH2 axis plays a critical role in AILI progression and might be a strategy for therapeutic intervention.

Synthesis of Acetaminophen-Based Coumarins as Selective COX-2 Inhibitors: An in vitro-in silico Study

Acetaminophen, a centrally-acting old analgesic drug, is a weak inhibitor of cyclooxygenase (COX) isoforms with some selectivity toward COX-2. This compound was used in this work as a precursor to create nine acetaminophen based coumarins (ACFs). To satisfy the aim of this work, which states the synthesis of acetaminophen-based coumarins as selective COX-2 inhibitors, the ACFs were subjected to two types of investigation: in vitro and in silico. Given the former type, the ACFs capacity to block COX-1 and COX-2 was investigated in lab settings. On the other hand, the in silico investigation included docking the chemical structures of ACFs into the active sites of these enzymes, predicting their anticipated toxicities, and determining the ADME characteristics. The results of the in vitro study revealed that the synthesized ACFs demonstrated good-to-excellent inhibitory properties against the enzymes under study. Also, these ACFs exhibited a high level of COX-2 selectivity, which improved as the capacity of the aromatic substitute for withdrawing electrons was enhanced. Results of docking were comparable to the in vitro investigation in case of COX-2. On the other hand, the in silico investigations indicated that the synthesized ACFs are safer than their precursor, acetaminophen, with a high potential to consider oral-administrated candidates.

Protein disulfide isomerase plays a crucial role in mediating chemically-induced, glutathione depletion-associated hepatocyte injury in vitro and in vivo

Recently we have shown that protein disulfide isomerase (PDI or PDIA1) is involved in mediating chemically-induced, glutathione (GSH) depletion-associated ferroptotic cell death through NOS activation (dimerization) and NO accumulation. The present study aims to determine the role of PDI in mediating chemically-induced hepatocyte injury in vitro and in vivo and whether PDI inhibitors can effectively protect against chemically-induced hepatocyte injury. We show that during the development of erastin-induced ferroptotic cell death, accumulation of cellular NO, ROS and lipid-ROS follows a sequential order, i.e., cellular NO accumulation first, followed by accumulation of cellular ROS, and lastly cellular lipid-ROS. Cellular NO, ROS and lipid-ROS each play a crucial role in mediating erastin-induced ferroptosis in cultured hepatocytes. In addition, it is shown that PDI is an important upstream mediator of erastin-induced ferroptosis through PDI-mediated conversion of NOS monomer to its dimer, which then leads to accumulation of cellular NO, ROS and lipid-ROS, and ultimately ferroptotic cell death. Genetic manipulation of PDI expression or pharmacological inhibition of PDI function each can effectively abrogate erastin-induced ferroptosis. Lastly, evidence is presented to show that PDI is also involved in mediating acetaminophen-induced liver injury in vivo using both wild-type C57BL/6J mice and hepatocyte-specific PDI conditional knockout (PDIfl/fl Alb-cre) mice. Together, our work demonstrates that PDI is an important upstream mediator of chemically-induced, GSH depletion-associated hepatocyte ferroptosis, and inhibition of PDI can effectively prevent this injury.

Phytic acid attenuates acetaminophen-induced hepatotoxicity via modulating iron-mediated oxidative stress and SIRT-1 expression in mice

Introduction: Administration of high doses of acetaminophen (APAP) results in liver injury. Oxidative stress and iron overload play roles in the pathogenesis of APAP-induced hepatotoxicity. The present study assessed the potential hepatoprotective effects of phytic acid (PA), a natural antioxidant and iron chelator, on APAP-induced hepatotoxicity and the possible underlying mechanism through its effects on CYP2E1 gene expression, iron homeostasis, oxidative stress, and SIRT-1 expression levels. Methods: Twenty-four adult male albino mice were used in this study. Mice were divided into four groups (six mice in each group): control, APAP-treated, PA-treated and APAP + PA-treated groups. Liver function tests, serum and liver tissue iron load were evaluated in all the study groups. Hepatic tissue homogenates were used to detect oxidative stress markers, including malondialdehyde (MDA) and reduced glutathione (GSH). Histological hepatic evaluation and immunohistochemistry of SIRT-1 were performed. Quantitative real-time PCR was used for the assessment of CYP2E1 and SIRT-1 gene expressions. APAP-induced biochemical and structural hepatic changes were reported. Results: PA administration showed beneficial effects on APAP-induced hepatotoxicity through improvements in liver functions, decreased CYP2E1 gene expression, decreased serum and liver iron load, decreased MDA, increased GSH, increased SIRT-1 expression level and improvement in hepatic architecture. Conclusion: Conclusively, PA can be considered a potential compound that can attenuate acetaminophen-induced hepatotoxicity through its role as an iron chelator and antioxidant, as well as the up-regulation of SIRT-1 and down-regulation of CYP2E1.

The evidence-based multifaceted roles of hepatic stellate cells in liver diseases: A concise review

Hepatic stellate cells (HSCs) play central roles in liver disease pathogenesis, spanning steatosis to cirrhosis and hepatocellular carcinoma. These cells, located in the liver's sinusoidal space of Disse, transition from a quiescent, vitamin A-rich state to an activated, myofibroblast-like phenotype in response to liver injury. This activation results from a complex interplay of cytokines, growth factors, and oxidative stress, leading to excessive collagen deposition and liver fibrosis, a hallmark of chronic liver diseases. Recently, HSCs have gained recognition for their dynamic, multifaceted roles in liver health and disease. Attention has shifted toward their involvement in various liver conditions, including acute liver injury, alcoholic and non-alcoholic fatty liver disease, and liver regeneration. This review aims to explore diverse functions of HSCs in these acute or chronic liver pathologies, with a focus on their roles beyond fibrogenesis. HSCs exhibit a wide range of actions, including lipid storage, immunomodulation, and interactions with other hepatic and extrahepatic cells, making them pivotal in the hepatic microenvironment. Understanding HSC involvement in the progression of liver diseases can offer novel insights into pathogenic mechanisms and guide targeted therapeutic strategies for various liver conditions.

The protective effect of Thai rice bran on N-acetyl-ρ-aminophen-induced hepatotoxicity in mice

Background and purpose

N-acetyl-ρ-aminophen (APAP) is a widely used medication with analgesic and antipyretic characteristics. High paracetamol doses can damage the liver. Thai-pigmented rice may treat numerous liver disorders due to its antioxidant, anti-inflammatory, and glutathione-restoring capabilities. This study aimed to evaluate the phenolic components in three Thai rice bran extracts and their antioxidant and hepatoprotective activities in an animal model.

Experimental approach

Fifty male mice were randomly assigned to the control and APAP studies. Each study was divided into 5 groups (n = 5) treated with distilled water, Hom Mali, Hang-Ngok, and Hom Nil (HN) rice compared with N-acetylcysteine with/without 60 mg/kg/day of APAP orally once a day for two weeks. Blood and liver sampling were collected for analysis.

Findings/Results

HN rice bran exhibited higher contents of total phenolic, total flavonoid, total anthocyanin, ferric-reducing antioxidant, and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities than Hom Mali and Hang-Ngok. Anthocyanin was merely detected in HN. Following APAP administration, mice exhibited significant increases in hepatic enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)), and malondialdehyde (MDA), but lower levels of antioxidant enzymes and glutathione profiles. Amongst the three cultivars, HN rice was the only compound that decreased MDA, ALT, AST, TNF-α, and IL-6 while increasing antioxidant enzyme activity such as superoxide dismutase, catalase, and glutathione peroxidase that was very close to that of N-acetylcysteine groups.

Conclusion and implications

Given the hepatoprotective and antioxidant properties, HN has the potential to be used as a health supplement.

Comparative analysis of gene expression between mice and humans in acetaminophen-induced liver injury by integrating bioinformatics analysis

OBJECTIVE

Mice are routinely utilized as animal models of drug-induced liver injury (DILI), however, there are significant differences in the pathogenesis between mice and humans. This study aimed to compare gene expression between humans and mice in acetaminophen (APAP)-induced liver injury (AILI), and investigate the similarities and differences in biological processes between the two species.

METHODS

A pair of public datasets (GSE218879 and GSE120652) obtained from GEO were analyzed using "Limma" package in R language, and differentially expressed genes (DEGs) were identified, including co-expressed DEGs (co-DEGs) and specific-expressed DEGS (specific-DEGs). Analysis of Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed analyses for specific-DEGs and co-DEGs. The co-DEGs were also used to construct transcription factor (TF)-gene network, gene-miRNA interactions network and protein-protein interaction (PPI) network for analyzing hub genes.

RESULTS

Mouse samples contained 1052 up-regulated genes and 1064 down-regulated genes, while human samples contained 1156 up-regulated genes and 1557 down-regulated genes. After taking the intersection between the DEGs, only 154 co-down-regulated and 89 co-up-regulated DEGs were identified, with a proportion of less than 10%. It was suggested that significant differences in gene expression between mice and humans in drug-induced liver injury. Mouse-specific-DEGs predominantly engaged in processes related to apoptosis and endoplasmic reticulum stress, while human-specific-DEGs were concentrated around catabolic process. Analysis of co-regulated genes reveals showed that they were mainly enriched in biosynthetic and metabolism-related processes. Then a PPI network which contains 189 nodes and 380 edges was constructed from the co-DEGs and two modules were obtained by Mcode. We screened out 10 hub genes by three algorithms of Degree, MCC and MNC, including CYP7A1, LSS, SREBF1, FASN, CD44, SPP1, ITGAV, ANXA5, LGALS3 and PDGFRA. Besides, TFs such as FOXC1, HINFP, NFKB1, miRNAs like mir-744-5p, mir-335-5p, mir-149-3p, mir-218-5p, mir-10a-5p may be the key regulatory factors of hub genes.

CONCLUSIONS

The DEGs of AILI mice models and those of patients were compared, and common biological processes were identified. The signaling pathways and hub genes in co-expression were identified between mice and humans through a series of bioinformatics analyses, which may be more valuable to reveal molecular mechanisms of AILI.

Flaxseed Lignan Alleviates the Paracetamol-Induced Hepatotoxicity Associated with Regulation of Gut Microbiota and Serum Metabolome

This study examined the protective effect of flaxseed lignans on liver damage caused by an overdose of paracetamol (PAM). The findings demonstrated that administering 800 mg/kg/d flaxseed lignan prior to PAM significantly decreased the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBi) levels, while it increased liver superoxide dismutase (SOD) and glutathione (GSH) levels in mice. Flaxseed lignan renovated the gut microbiota dysbiosis induced by PAM by promoting the proliferation of sulfonolipid (SL) producing bacteria such as Alistipes and lignan-deglycosolating bacteria such as Ruminococcus while inhibiting the growth of opportunistic pathogen bacteria such as Acinetobacter and Clostridium. Furthermore, flaxseed lignan modulated the serum metabolomic profile after PAM administration, specifically in the taurine and hypotaurine metabolism, phenylalanine metabolism, and pyrimidine metabolism. The study identified eight potential biomarkers, including enterolactone, cervonyl carnitine, acutilobin, and PC (20:3(5Z, 8Z, 11Z)/20:0). Overall, the results suggest that flaxseed lignan can alleviate PAM-induced hepatotoxicity and may be beneficial in preventing drug-induced microbiome and metabolomic disorders.

Phytolacca Dodecandra (L' Herit) (Phytolaccaceae) Methanol Root Extract Protects Liver from Acetaminophen-Induced Injury in Rats

Phytolacca dodecandra (L' Herit), or 'Endod', is one of the widely known medicinal plants in Ethiopia. Berries of the endod have been used as a detergent for centuries. The present study was aimed to test the hepatoprotective effects of the plant against acetaminophen (APAP)-induced liver injury in rats. Mice of either sex were used for oral acute toxicity tests and APAP-induced lethality tests. Hepatoprotective experiments were done on male rats using 2 g/kg of APAP to induce liver damage. Liver enzymes, total bilirubin (TB), and lipid profile were determined. Liver tissues were also examined histopathologically to see a morphologic change in the control and experiment groups. The protective effect of the plant extract was also tested through sodium pentobarbital (SPB)-induced sleeping time. A significant increase in serum levels of liver enzymes, TB, low-density lipoprotein (LDL), and triglycerides (TGs) was seen from oral administration of 2 g/kg APAP. Total cholesterol (TC) and high-density lipoprotein (HDL) levels were decreased. Serum levels of all parameters were reversed to normal after administration of silymarin 100 mg/kg and, 100, 200, and 400 mg/kg doses of the extract. A significant dose-dependent hepatoprotective effect of Phytolacca dodecandra Methanol Root Extract (PDME) was seen in terms of LDL. Histopathological investigations and SPB-induced sleeping time confirmed the findings of biochemical analysis. The findings of the present study indicate that PDME protected the liver from APAP injury.

Prospective Application of Tannic Acid in Acetaminophen (APAP)-Induced Acute Liver Failure

This study investigated the effect of tannic acid (TA), a natural plant-derived polyphenol, on hepatocyte viability and function, focusing on both hepatoprotective and hepatocurative aspects within liver failure models. In an in vitro prevention model, the TA-containing group exhibited 1.5-fold and 59-fold higher relative cell viability and albumin synthesis, respectively, in injured mature hepatocytes (MHs) and 1.14-fold and 1.10-fold higher values in injured small hepatocytes (SHs), compared with the TA-free group. In the in vitro curative model, the TA-containing group exhibited 3.25-fold and 113-fold higher relative cell viability and albumin synthesis, respectively, in injured MHs and 0.36-fold and 3.55-fold higher values in injured SHs, compared with the TA-free group. In the in vivo disease model, the administration of 300 μL of 1 μg/mL TA significantly mitigated acute liver failure damage and post-APAP toxicity in mice. This was evident in serum analysis, where the levels of alanine transaminase, aspartate aminotransferase, and total bilirubin notably decreased, in agreement with histological observations. The study findings reveal that TA can enhance hepatic function at specific additive concentrations. Furthermore, even when injured by APAP, hepatocytes could revert to their preinjury state after additional TA supplementation. Additionally, pretreating hepatocytes with TA can alleviate subsequent damage. Thus, TA holds clinical potential in the treatment of APAP-induced liver failure.

Natural Products for Acetaminophen-Induced Acute Liver Injury: A Review

The liver plays a vital role in metabolism, synthesis, and detoxification, but it is susceptible to damage from various factors such as viral infections, drug reactions, excessive alcohol consumption, and autoimmune diseases. This susceptibility is particularly problematic for patients requiring medication, as drug-induced liver injury often leads to underestimation, misdiagnosis, and difficulties in treatment. Acetaminophen (APAP) is a widely used and safe drug in therapeutic doses but can cause liver toxicity when taken in excessive amounts. This study aimed to investigate the hepatotoxicity of APAP and explore potential treatment strategies using a mouse model of APAP-induced liver injury. The study involved the evaluation of various natural products for their therapeutic potential. The findings revealed that natural products demonstrated promising hepatoprotective effects, potentially alleviating liver damage and improving liver function through various mechanisms such as oxidative stress and inflammation, which cause changes in signaling pathways. These results underscore the importance of exploring novel treatment options for drug-induced liver injury, suggesting that further research in this area could lead to the development of effective preventive and therapeutic interventions, ultimately benefiting patients with liver injury caused by medicine.

Hepatoprotective Effects of Four Brazilian Savanna Species on Acetaminophen-Induced Hepatotoxicity in HepG2 Cells

We investigated four Cerrado plant species, i.e., Cheiloclinium cognatum (Miers) A.C.Sm, Guazuma ulmifolia Lam., Hancornia speciosa Gomes, and Hymenaea stigonocarpa Mart. ex Hayne, against acetaminophen toxicity using an in vitro assay with HepG2 cells. The activity against acetaminophen toxicity was evaluated using different protocols, i.e., pre-treatment, co-treatment, and post-treatment of the cells with acetaminophen and the plant extracts. HepG2 cell viability after treatment with acetaminophen was 39.61 ± 5.59% of viable cells. In the pre-treatment protocol, the extracts could perform protection with viability ranging from 50.02 ± 15.24% to 78.75 ± 5.61%, approaching the positive control silymarin with 75.83 ± 5.52%. In the post-treatment protocol, all extracts and silymarin failed to reverse the acetaminophen damage. In the co-treatment protocol, the extracts showed protection ranging from 50.92 ± 11.14% to 68.50 ± 9.75%, and silymarin showed 77.87 ± 4.26%, demonstrating that the aqueous extracts of the species also do not increase the toxic effect of acetaminophen. This protection observed in cell viability was accompanied by a decrease in ROS. The extracts' hepatoprotection can be related to antioxidant compounds, such as rutin and mangiferin, identified using HPLC-DAD and UPLC-MS/MS. The extracts were shown to protect HepG2 cells against future APAP toxicity and may be candidates for supplements that could be used to prevent liver damage. In the concomitant treatment using the extracts with APAP, it was demonstrated that the extracts do not present a synergistic toxicity effect, with no occurrence of potentiation of toxicity. The extracts showed considerable cytoprotective effects and important antioxidant characteristics.

Solarplast®-An Enzymatically Treated Spinach Extract

In the modern world we are constantly bombarded by environmental and natural stimuli that can result in oxidative stress. Antioxidant molecules and enzymes help the human body scavenge reactive oxygen species and prevent oxidative damage. Most organisms possess intrinsic antioxidant activity, but also benefit from the consumption of antioxidants from their diet. Leafy green vegetables such as spinach are a well-researched rich source of dietary antioxidant molecules. However, plant cell walls are difficult to digest for many individuals and the bio-accessibility of nutrients and antioxidants from these sources can be limited by the degree of digestion and assimilation. Through a specific enzymatic process, Solarplast^® contains organic spinach protoplasts without the cell wall, which may facilitate higher yield and efficacy of beneficial antioxidant molecules. In this study, analytical techniques coupled to in vitro bioassays were used to determine the potential antioxidant activity of Solarplast^® and determine its antioxidant enzymatic capabilities. Solarplast^® demonstrated superior antioxidant activity when compared to frozen spinach leaves in TOC, FRAP and TEAC antioxidant assays. Several antioxidant enzymes were also increased in Solarplast^®, when compared to frozen spinach. As a functional readout, Solarplast^® attenuated hydrogen peroxide-, ethanol- and acetaminophen-induced increases in oxidative stress and cytotoxicity in both intestinal (HT-29) and liver (HepG2) cell lines. These findings suggest that Solarplast^® may represent a non-GMO, plant-based food supplement to help reduce oxidative stress in the human body.