Oxidative Stress and Acute Hepatic Injury

Mapping of susceptibility loci for Ebola virus pathogenesis in mice

Ebola virus (EBOV), a major global health concern, causes severe, often fatal EBOV disease (EVD) in humans. Host genetic variation plays a critical role, yet the identity of host susceptibility loci in mammals remains unknown. Using genetic reference populations, we generate an F2 mapping cohort to identify host susceptibility loci that regulate EVD. While disease-resistant mice display minimal pathogenesis, susceptible mice display severe liver pathology consistent with EVD-like disease and transcriptional signatures associated with inflammatory and liver metabolic processes. A significant quantitative trait locus (QTL) for virus RNA load in blood is identified in chromosome (chr)8, and a severe clinical disease and mortality QTL is mapped to chr7, which includes the Trim5 locus. Using knockout mice, we validate the Trim5 locus as one potential driver of liver failure and mortality after infection. The identification of susceptibility loci provides insight into molecular genetic mechanisms regulating EVD progression and severity, potentially informing therapeutics and vaccination strategies.

Transcriptomic analysis of hydrogen peroxide-induced liver dysfunction in Cyprinus carpio: Insights into protein synthesis and metabolism

Hydrogen peroxide (H2O2), a prevalent reactive oxygen species (ROS) found in natural aquatic environments, has garnered significant attention for its potential toxicity in fish. However, the molecular mechanisms underlying this toxicity are not yet comprehensively understood. This study aimed to assess H2O2-induced liver dysfunction in common carp (Cyprinus carpio) and elucidate the underlying molecular mechanisms via biochemical and transcriptomic analyses. Common carp were divided into normal control (NC) and H2O2-treated groups (1 mM H2O2), the latter of which was exposed to H2O2 for 1 h per day over a period of 14 days. Serum biochemical analyses indicated that exposure to H2O2 resulted in moderate liver damage, characterized by elevated alanine aminotransferase (ALT) activity and lowered albumin (Alb) level. Concurrently, H2O2 exposure induced oxidative stress and modified the hepatic metabolic enzyme levels. Transcriptome analysis highlighted that 1358 and 1188 genes were significantly downregulated and upregulated, respectively, in the H2O2-treated group. These differentially expressed genes (DEGs) were significantly enriched in protein synthesis and a variety of metabolic functions such as peptide biosynthetic processes, protein transport, ribonucleoprotein complex biogenesis, oxoacid metabolic processes, and tricarboxylic acid metabolic processes. Dysregulation of protein synthesis is principally associated with the downregulation of three specific pathways: ribosome biogenesis, protein export, and protein processing in the endoplasmic reticulum (ER). Furthermore, metabolic abnormalities were primarily characterized by inhibition of the citrate cycle (TCA) and fatty acid biosynthesis. Significantly, anomalies in both protein synthesis and metabolic function may be linked to aberrant regulation of the insulin signaling pathway. These findings offer innovative insights into the mechanisms underlying H2O2 toxicity in aquatic animals, contributing to the assessment of ecological risks.

Protective effect of alpha‑lipoic acid against in utero cytarabine exposure-induced hepatotoxicity in rat female neonates

Cytarabine, an anti-metabolite drug, remains the mainstay of treatment for hematological malignancies. It causes various toxic effects including teratogenicity. Alpha lipoic acid (ALA) is a natural antioxidant reported to offer protection against hepatotoxicity induced by various pathological conditions, drugs, or chemicals. We investigated the protective effect of ALA against prenatal cytarabine exposure-induced hepatotoxicity in rat female neonates. A total of 30 dams were randomly assigned to five groups and received normal saline, ALA 200 mg/kg, cytarabine 12.5 mg/kg, cytarabine 25 mg/kg, and cytarabine 25 mg/kg + ALA 200 mg/kg, respectively, from gestational day (GD)8 to GD21. Cytarabine and ALA were administered via intraperitoneal and oral (gavage) routes, respectively. On postnatal day (PND)1, all the live female neonates (pups) were collected and weighed. The blood and liver from pups were carefully collected and used for histopathological, and biochemical evaluations. A significant and dose-dependent decrease in maternal food intake and weight gain was observed in the pregnant rats (dams) of the cytarabine groups as compared to the dams of the control group. The pups exposed to cytarabine showed a significant and dose-dependent (a) decrease in body weight, liver weight, hepatosomatic index, catalase, superoxide dismutase, glutathione, glutathione peroxidase, serum albumin levels and (b) increase in malondialdehyde, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, AST/ALT ratio, and histopathological anomalies. Maternal co-administration of ALA ameliorated these biochemical changes and histopathological abnormalities by combating oxidative stress. Future studies are warranted to explore the molecular mechanisms involved in the ALA's protective effects against prenatal cytarabine-induced hepatotoxicity.

Antioxidant nanozymes as next-generation therapeutics to free radical-mediated inflammatory diseases: A comprehensive review

Recent developments in exploring the biological enzyme mimicking properties in nanozymes have opened a separate avenue, which provides a suitable alternative to the natural antioxidants and enzymes. Due to high and tunable catalytic activity, low cost of synthesis, easy surface modification, and good biocompatibility, nanozymes have garnered significant research interest globally. Several inorganic nanomaterials have been investigated to exhibit catalytic activities of some of the key natural enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase, peroxidase, and oxidase, etc. These nanozymes are used for diverse biomedical applications including therapeutics, imaging, and biosensing in various cells/tissues and animal models. In particular, inflammation-related diseases are closely associated with reactive oxygen and reactive nitrogen species, and therefore effective antioxidants could be excellent therapeutics due to their free radical scavenging ability. Although biological enzymes and other artificial antioxidants could perform well in scavenging the reactive oxygen and nitrogen species, however, suffer from several drawbacks such as the requirement of strict physiological conditions for enzymatic activity, limited stability in the environment beyond their optimum pH and temperature, and high cost of synthesis, purification, and storage make then unattractive for broad-spectrum applications. Therefore, this review systematically and comprehensively presents the free radical-mediated evolution of various inflammatory diseases (inflammatory bowel disease, mammary gland fibrosis, and inflammation, acute injury of the liver and kidney, mammary fibrosis, and cerebral ischemic stroke reperfusion) and their mitigation by various antioxidant nanozymes in the biological system. The mechanism of free radical scavenging by antioxidant nanozymes under in vitro and in vivo experimental models and catalytic efficiency comparison with corresponding natural enzymes has also been presented.

Mapping Interindividual Variability of Toxicodynamics Using High-Throughput Transcriptomics and Primary Human Hepatocytes from Fifty Donors

BACKGROUND

Understanding the variability across the human population with respect to toxicodynamic responses after exposure to chemicals, such as environmental toxicants or drugs, is essential to define safety factors for risk assessment to protect the entire population. Activation of cellular stress response pathways are early adverse outcome pathway (AOP) key events of chemical-induced toxicity and would elucidate the estimation of population variability of toxicodynamic responses.

OBJECTIVES

We aimed to map the variability in cellular stress response activation in a large panel of primary human hepatocyte (PHH) donors to aid in the quantification of toxicodynamic interindividual variability to derive safety uncertainty factors.

METHODS

High-throughput transcriptomics of over 8,000 samples in total was performed covering a panel of 50 individual PHH donors upon 8 to 24 h exposure to broad concentration ranges of four different toxicological relevant stimuli: tunicamycin for the unfolded protein response (UPR), diethyl maleate for the oxidative stress response (OSR), cisplatin for the DNA damage response (DDR), and tumor necrosis factor alpha (TNF α ) for NF- κ B signaling. Using a population mixed-effect framework, the distribution of benchmark concentrations (BMCs) and maximum fold change were modeled to evaluate the influence of PHH donor panel size on the correct estimation of interindividual variability for the various stimuli.

RESULTS

Transcriptome mapping allowed the investigation of the interindividual variability in concentration-dependent stress response activation, where the average of BMCs had a maximum difference of 864-, 13-, 13-, and 259-fold between different PHHs for UPR, OSR, DDR, and NF- κ B signaling-related genes, respectively. Population modeling revealed that small PHH panel sizes systematically underestimated the variance and gave low probabilities in estimating the correct human population variance. Estimated toxicodynamic variability factors of stress response activation in PHHs based on this dataset ranged between 1.6 and 6.3.

DISCUSSION

Overall, by combining high-throughput transcriptomics and population modeling, improved understanding of interindividual variability in chemical-induced activation of toxicity relevant stress pathways across the human population using a large panel of plated cryopreserved PHHs was established, thereby contributing toward increasing the confidence of in vitro-based prediction of adverse responses, in particular hepatotoxicity. https://doi.org/10.1289/EHP11891.

Activatable fluorescent probes for early diagnosis and evaluation of liver injury

With the increase in people's living standards, the number of patients suffering from liver injury keeps on increasing. Traditional diagnostic methods can no longer meet the needs of early and accurate diagnosis due to their limitations in application. However, fluorescent probes based on different fluorophores and nanomaterials have been gradually lighting up medical research due to their unique properties, such as high specificity and non-invasiveness. In addition, accurate identification of the different types of liver injury biomarkers can significantly improve the level of early diagnosis. Therefore, this review reviews the fluorescent probes used in the detection of biomarkers of liver injury over recent years and briefly summarizes the corresponding biomarkers of different types of liver injury. Impressively, this review also lists the structures and the response mechanisms of the different probes, and concludes with an outlook, suggesting directions in which improvements can be made. Finally, we hope that this review will contribute to the further development of fluorescent probes for the early diagnosis and assessment of liver injury.

Multi-faceted Anti-obesity Effects of N-Methyl-D-Aspartate (NMDA) Receptor Modulators: Central-Peripheral Crosstalk

Hypothalamus is central to food intake and satiety. Recent data unveiled the expression of N-methyl-D-aspartate receptors (NMDAR) on hypothalamic neurons and their interaction with GABAA and serotoninergic neuronal circuits. However, the precise mechanisms governing energy homeostasis remain elusive. Notably, in females, the consumption of progesterone-containing preparations, such as hormonal replacement therapy and birth control pills, has been associated with hyperphagia and obesity-effects mediated through the hypothalamus. To elucidate this phenomenon, we employed the progesterone-induced obesity model in female Swiss albino mice. Four NMDAR modulators were selected viz. dextromethorphan (Dxt), minocycline, d-aspartate, and cycloserine. Obesity was induced in female mice by progesterone administration for 4 weeks. Mice were allocated into 7 groups, group-1 as vehicle control (arachis oil), group-2 (progesterone + arachis oil), and group-3 as positive-control (progesterone + sibutramine); other groups were treated with test drugs + progesterone. Various parameters were recorded like food intake, thermogenesis, serum lipids, insulin, AST and ALT levels, organ-to-body weight ratio, total body fat, adiposity index, brain serotonin levels, histology of liver, kidney, and sizing of fat cells. Dxt-treated group has shown a significant downturn in body weight (p < 0.05) by a decline in food intake (p < 0.01), organ-to-liver ratio (p < 0.001), adiposity index (p < 0.01), and a rise in body temperature and brain serotonin level (p < 0.001). Dxt demonstrated anti-obesity effects by multiple mechanisms including interaction with hypothalamic GABAA channels and anti-inflammatory and free radical scavenging effects, improving the brain serotonin levels, and increasing insulin release from the pancreatic β-cells.

MnO2 Coated Mesoporous PdPt Nanoprobes for Scavenging Reactive Oxygen Species and Solving Acetaminophen-Induced Liver Injury

As one of the most widely used drugs, acetaminophen, is the leading cause of acute liver injury. In addition, acetaminophen-induced liver injury (AILI) has a strong relationship with the overproduced reactive oxygen species, which can be effectively eliminated by nanozymes. To address these challenges, mesoporous PdPt@MnO2 nanoprobes (PPM NPs) mimicking peroxide, catalase, and superoxide dismutase-like properties are synthesized. They demonstrate nontoxicity, high colloidal stability, and exceptional reactive oxygen species (ROS)-scavenging ability. By scavenging excessive ROS, decreasing inflammatory cytokines, and inhibiting the recruitment and activation of monocyte/macrophage cells and neutrophils, the pathology mechanism of PPM NPs in AILI is confirmed. Moreover, PPM NPs' therapeutic effect and good biocompatibility may facilitate the clinical treatment of AILI.

Development of a novel near-infrared molecule rotator for early diagnosis and visualization of viscosity changes in acute liver injury models

Acute liver injury leading to acute liver failure can be a life-threatening condition. Therefore, timely and accurate early diagnosis of the onset of acute liver injury in vivo is critical. Viscosity is one of the key parameters that can accurately reflect the levels of relevant active analytes at the cellular level. Herein, a novel near-infrared molecule rotator, DJM, was designed and synthesized. This probe exhibited a highly sensitive (461-fold from PBS solution to 95% glycerol solution) and selective response to viscosity with a maximum emission wavelength of 760 nm and a Stokes shift of 240 nm. Furthermore, DJM has exhibited a remarkable capacity to discern viscosity changes induced by nystatin in viable cells with sensitivity and selectivity and further applied in the zebrafish and mouse model of acute liver injury. Additionally, DJM may potentially offer direction for the timely observation and visualization of viscosity in more relevant disease models in the future.

Antioxidant and Hepatoprotective Potential of Echinops ritro L. Extracts on Induced Oxidative Stress In Vitro/In Vivo

Echinops ritro L. (Asteraceae) is traditionally used in the treatment of bacterial/fungal infections and respiratory and heart ailments. The aim of this study was to evaluate the potential of extracts from E. ritro leaves (ERLE) and flowering heads (ERFE) as antioxidant and hepatoprotective agents on diclofenac-induced lipid peroxidation and oxidative stress under in vitro and in vivo conditions. In isolated rat microsomes and hepatocytes, the extracts significantly alleviated oxidative stress by increasing cell viability and GSH levels and reducing LDH efflux and MDA production. During in vivo experiments, the administration of the ERFE alone or in combination with diclofenac resulted in a significant increase in cellular antioxidant protection and a decrease in lipid peroxidation witnessed by key markers and enzymes. A beneficial influence on the activity of the drug-metabolizing enzymes ethylmorphine-N-demetylase and aniline hydroxylase in liver tissue was found. In the acute toxicity test evaluation, the ERFE showed no toxicity. In the ultrahigh-performance liquid chromatography-high-resolution mass spectrometry analysis, 95 secondary metabolites were reported for the first time, including acylquinic acids, flavonoids, and coumarins. Protocatechuic acid O-hexoside, quinic, chlorogenic and 3, 5-dicaffeoylquinic acid, apigenin; apigenin 7-O-glucoside, hyperoside, jaceosidene, and cirsiliol dominated the profiles. The results suggest that both extracts should be designed for functional applications with antioxidant and hepatoprotective capacity.

Targeting Oxidative Stress with Polyphenols to Fight Liver Diseases

Reactive oxygen species (ROS) are important second messengers in many metabolic processes and signaling pathways. Disruption of the balance between ROS generation and antioxidant defenses results in the overproduction of ROS and subsequent oxidative damage to biomolecules and cellular components that disturb cellular function. Oxidative stress contributes to the initiation and progression of many liver pathologies such as ischemia-reperfusion injury (LIRI), non-alcoholic fatty liver disease (NAFLD), and hepatocellular carcinoma (HCC). Therefore, controlling ROS production is an attractive therapeutic strategy in relation to their treatment. In recent years, increasing evidence has supported the therapeutic effects of polyphenols on liver injury via the regulation of ROS levels. In the current review, we summarize the effects of polyphenols, such as quercetin, resveratrol, and curcumin, on oxidative damage during conditions that induce liver injury, such as LIRI, NAFLD, and HCC.

Fluorofenidone protects against acute liver failure in mice by regulating MKK4/JNK pathway

AIMS

Acute liver failure (ALF) is a life-threatening disease characterized by abrupt and extensive hepatic necrosis and apoptosis, resulting in high mortality. The approved drug, N-acetylcysteine (NAC), is only effective for acetaminophen (APAP)-associated ALF at the early stage. Thus, we investigate whether fluorofenidone (AKF-PD), a novel antifibrosis pyridone agent, protects against ALF in mice and explore its underlying mechanisms.

METHODS

ALF mouse models were established using APAP or lipopolysaccharide/D-galactosamine (LPS/D-Gal). Anisomycin and SP600125 were used as JNK activator and inhibitor, respectively, and NAC served as a positive control. Mouse hepatic cell line AML12 and primary mouse hepatocytes were used for in vitro studies.

RESULTS

AKF-PD pretreatment alleviated APAP-induced ALF with decreased necrosis, apoptosis, reactive oxygen species (ROS) markers, and mitochondrial permeability transition in liver. Additionally, AKF-PD alleviated mitochondrial ROS stimulated by APAP in AML12 cells. RNA-sequencing in the liver and subsequent gene set enrichment analysis showed that AKF-PD significantly impacted MAPK and IL-17 pathway. In vitro and in vivo studies demonstrated that AKF-PD inhibited APAP-induced phosphorylation of MKK4/JNK, while SP600125 only inhibited JNK phosphorylation. The protective effect of AKF-PD was abolished by anisomycin. Similarly, AKF-PD pretreatment abolished hepatotoxicity caused by LPS/D-Gal, decreased ROS levels, and diminished inflammation. Furthermore, unlike NAC, AKF-PD, inhibited the phosphorylation of MKK4 and JNK upon pretreatment, and improved survival in cases of LPS/D-Gal-induced mortality with delayed dosing.

CONCLUSIONS

In summary, AKF-PD can protect against ALF caused by APAP or LPS/D-Gal, in part, via regulating MKK4/JNK pathway. AKF-PD might be a novel candidate drug for ALF.

Long-Term Paracetamol Treatment Impairs Cognitive Function and Brain-Derived Neurotrophic Factor in Adult Rat Brain

Paracetamol (acetaminophen, APAP) is known as a safe pain reliever; however, its negative effects on the central nervous system have gradually been reported. We examined alterations in learning and memory, and brain-derived neurotrophic factor (BDNF) expression in the frontal cortex and hippocampus at different durations of APAP treatment in rats. Novel object recognition (NOR) and Morris water maze (MWM) paradigms were used to assess learning and memory in rats fed with 200 mg/kg APAP at single-dose, 15-day or 30-day treatments. BDNF expression was evaluated through immunohistochemistry and Western blotting. The single-dose APAP treatment did not alter the NOR performance. However, deficits in the NOR and MWM capacities were detected in the rats with longer durations of APAP treatment. An analysis of BDNF expression revealed no significant change in BDNF expression in the single-dose APAP treatment, while rats given APAP for extended periods as treatment showed a significant decrement in this protein in the frontal cortex and hippocampus. Short-term APAP treatment has no effect on learning and memory, or BDNF expression; however, long-term APAP exposure causes cognitive impairment. The diminishment of the BDNF level in the frontal cortex and hippocampus due to the long period of treatment with APAP may at least in part be involved in altered learning and memory in rats.

Ketogenic Diet and Ketone Bodies against Ischemic Injury: Targets, Mechanisms, and Therapeutic Potential

The ketogenic diet (KD) has been used as a treatment for epilepsy since the 1920s, and its role in the prevention of many other diseases is now being considered. In recent years, there has been an intensive investigation on using the KD as a therapeutic approach to treat acute pathologies, including ischemic ones. However, contradictory data are observed for the effects of the KD on various organs after ischemic injury. In this review, we provide the first systematic analysis of studies conducted from 1980 to 2022 investigating the effects and main mechanisms of the KD and its mimetics on ischemia-reperfusion injury of the brain, heart, kidneys, liver, gut, and eyes. Our analysis demonstrated a high diversity of both the composition of the used KD and the protocols for the treatment of animals, which could be the reason for contradictory effects in different studies. It can be concluded that a true KD or its mimetics, such as β-hydroxybutyrate, can be considered as positive exposure, protecting the organ from ischemia and its negative consequences, whereas the shift to a rather similar high-calorie or high-fat diet leads to the opposite effect.

Structure design mechanisms and inflammatory disease applications of nanozymes

Nanozymes are artificial enzymes with high catalytic activity, low cost, and good biocompatibility, and have received ever-increasing attention in recent years. Various inorganic and organic nanoparticles have been found to exhibit enzyme-like activities and are used as nanozymes for diverse biomedical applications ranging from tumor imaging and therapeutics to detection. However, their further clinical applications are hindered by the potential toxicity and long-term retention of nanomaterials in vivo. Clarifying the catalytic mechanism of nanozymes and identifying the key factors responsible for their behavior can guide the design of nanozyme structure, enlighten the ways to improve their enzyme-like activities, and minimize the dosage of nanozymes, leading to reduced toxicity to the human body for a real biomedical application prospect. In particular, inflammation occurring in numerous diseases is closely related to reactive oxygen species, and the active oxygen scavenging ability of nanozymes potentially exerts excellent therapeutic effects on inflammatory diseases. In this review, we systematically summarize the structure-activity relationship of nanozymes, including regulation strategies for size and morphology, surface structure, and composition. Based on the structure-activity mechanisms, a series of chemically designed nanozymes developed to target various inflammatory diseases are briefly summarized.

Alanyl-Glutamine Protects against Lipopolysaccharide-Induced Liver Injury in Mice via Alleviating Oxidative Stress, Inhibiting Inflammation, and Regulating Autophagy

Acute liver injury is a worldwide problem with a high rate of morbidity and mortality, and effective pharmacological therapies are still urgently needed. Alanyl-glutamine (Ala-Gln), a dipeptide formed from L-alanine and L-glutamine, is known as a protective compound that is involved in various tissue injuries, but there are limited reports regarding the effects of Ala-Gln in acute liver injury. This present study aimed to investigate the protective effects of Ala-Gln in lipopolysaccharide (LPS)-induced acute liver injury in mice, with a focus on inflammatory responses and oxidative stress. The acute liver injury induced using LPS (50 μg/kg) and D-galactosamine (D-Gal) (400 mg/kg) stimulation in mice was significantly attenuated after Ala-Gln treatment (500 and 1500 mg/kg), as evidenced by reduced plasma alanine transaminase (ALT) (p < 0.01, p < 0.001), aspartate transaminase (AST) (p < 0.05, p < 0.001), and lactate dehydrogenase (LDH) (p < 0.01, p < 0.001) levels, and accompanied by improved histopathological changes. In addition, LPS/D-Gal-induced hepatic apoptosis was also alleviated by Ala-Gln administration, as shown by a greatly decreased ratio of TUNEL-positive hepatocytes, from approximately 10% to 2%, and markedly reduced protein levels of cleaved caspase-3 (p < 0.05, p < 0.001) in liver. Moreover, we found that LPS/D-Gal-triggered oxidative stress was suppressed after Ala-Gln treatment, the effect of which might be dependent on the elevation of SOD and GPX activities, and on GSH levels in liver. Interestingly, we observed that Ala-Gln clearly inhibited LPS/D-Gal exposure-induced macrophage accumulation and the production of proinflammatory factors in the liver. Furthermore, Ala-Gln greatly regulated autophagy in the liver in LPS/D-Gal-treated mice. Using RAW264.7 cells, we confirmed the anti-inflammatory role of Ala-Gln-targeting macrophages.

Effect of infection with Aeromonas hydrophila on antioxidant capacity, inflammation response, and apoptosis proteins in Chinese mitten crab (Eriocheir sinensis)

Aeromonas hydrophila (A. hydrophila) as a serious bacterial disease endangering aquaculture and the Chinese mitten crabs (Eriocheir sinensis) industry. The present study was conducted to investigate the effects of A. hydrophila on the antioxidant, inflammation, immunity and apoptosis of the E. sinensis. The E. sinensis (female: 150 crabs and male: 150 crabs; 67.11 ± 0.76 g) were randomly divided into the control group (Foot injection with 200 μl PBS) and infection group (Foot injection with 200 μl A. hydrophila of 10⁶ cfu/mL). The hepatopancreas and serum was collected to detect the related indicators after injection 24 h. The results showed that A. hydrophila significantly reduced the malondialdehyde (MDA) level and gamma-glutamyl-cysteine synthetase (γ-GCS) activity in the hepatopancreas of male and female crabs (P < 0.05). A.hydrophila also significantly decreased the total-superoxide dismutase (T-SOD) activity while the levels of total antioxidant capacity (T-AOC) and total glutathione (T-GSH) were significantly increased in the hepatopancreas and serum of male crabs (P < 0.05). At the transcriptional level, the expression of catalase (CAT) and glutathione peroxidases (GPx), Glutathione S-transferase (GST) in the hepatopancreas of male and female crabs was significantly reduced compared to the control group (P < 0.05). However, A. hydrophila could not significantly change the Kelch-like ECH-associated protein 1 (Keap1) gene expression level in both of male and female carbs. A. hydrophila injection for 24 h, the lysozyme (LZM) and phenoloxidase (PO) activity was significantly increased in the hepatopancreas and serum of the male and female crabs (P < 0.05). Simultaneous increase of immune-related enzyme activity (acid phosphatase and alkaline phosphatase) was found in the serum of male and female crabs (P < 0.05). However, the acid phosphatase (ACP) and alkaline phosphatase (ALP) activity was significantly decreased in the hepatopancreas of male and female crabs (P < 0.05). Meanwhile, the LZM mRNA level was significantly decreased in the hepatopancreas of E. sinensis (P < 0.05). Furthermore, A. hydrophila significantly inhibited the mRNA expression of immune regulated factors (Interleukin enhancer binding factor 2: ILF2, interleukin-16: IL-16, Toll-like receptor: TLR) in the male and female crabs. The levels of inflammatory cytokines (interleukin-1β: IL-1β, interleukin-6: IL-6, interleukin-8: IL-8, interleukin-10: IL-10) were significantly increased in the hepatopancreas of male and female crabs. Moreover, A.hydrophila increased the mRNA expression of apoptosis - related genes in male crabs (p38 mitogen-activated protein kinase: p38, adamalysin 17: ADAM17, Cysteine-aspartic acid protease 3: Caspase 3, and Bcl-2-associated X: BAX), but reduced the expression of p38, ADAM17, Caspase 3 and BAX genes in female crabs. In conclusion, A. hydrophila could induce oxidative stress and the response of inflammation and immunity, and also trigger the mRNA expression changes of apoptosis related-genes in E. sinensis. This study provides a theoretical basis for the study of E. sinensis diseases.

A ROS-Sensitive Nanozyme-Augmented Photoacoustic Nanoprobe for Early Diagnosis and Therapy of Acute Liver Failure

Early diagnosis of acute liver failure (ALF) is critical for curable treatment of patients, because most existing ALF therapies have narrow therapeutic time windows after disease onset. Reactive oxygen species (ROS), which lead to the sequential occurrences of hepatocyte necrosis and the leakage of alanine aminotransferase (ALT), represent early biomarkers of ALF. Photoacoustic imaging is emerging as a powerful tool for in vivo imaging of ROS. However, high-performance imaging probes that can boost the photoacoustic signals of the short-lived ROS of ALF are yet to be developed, and there remains a great challenge for ROS-based imaging of ALF. Herein, a ROS-sensitive nanozyme-augmented photoacoustic nanoprobe for successful in vivo imaging of ALF is presented. The deep-penetrating photoacoustic signals of the nanoprobe can be activated by the overexpressed ROS in ALF due to the synergy between nanocatalytic bubbles generation and thermoelastic expansion. Impressively, the nanozyme-augmented ROS imaging enables earlier diagnosis of ALF than the clinical ALT method, and the ROS-activated catalytic activity of nanoprobe permits timely nanocatalytic therapy of ALF.

Hybrid skin chips for toxicological evaluation of chemical drugs and cosmetic compounds

Development of drugs and cosmetics for topical application require safety tests in skin models. However, current skin models, such as skin cell sheets and artificial tissue-engineered skin, do not allow sophisticated toxicological evaluations (e.g., sensory irritation, hepatotoxicity). Animal models are prohibited worldwide for testing cosmetics. Therefore, reliable human skin models that recapitulate physiological events in skin tissue need to be established under in vitro settings. In this study, hybrid human skin models that enable delicate toxicological evaluations of drugs and cosmetic compounds are demonstrated. To recapitulate skin cornification, keratinocytes in the top layer of a vertical microfluidic chip were cultured at the air-liquid interface. For the skin-nerve hybrid model, differentiated neural stem cells in 3D collagen were positioned adjacent to and right below the skin layer. This model enables real-time quantitative skin sensitization analysis following chemical treatments by detecting alterations in neuronal activity in combination with a calcium imaging technique. For the skin-liver model, hepatic cells derived from pluripotent stem cells were cultured in 3D collagen distant from the skin layer. Potential hepatotoxicity of cutaneously applied chemicals in this model can be evaluated by quantification of glutathione and reactive oxygen species. Our study suggests that 3D hybrid skin chips would provide useful human skin models in pharmaceutical and cosmetic industries.

Preclinical models of idiosyncratic drug-induced liver injury (iDILI): Moving towards prediction

Idiosyncratic drug-induced liver injury (iDILI) encompasses the unexpected harms that prescription and non-prescription drugs, herbal and dietary supplements can cause to the liver. iDILI remains a major public health problem and a major cause of drug attrition. Given the lack of biomarkers for iDILI prediction, diagnosis and prognosis, searching new models to predict and study mechanisms of iDILI is necessary. One of the major limitations of iDILI preclinical assessment has been the lack of correlation between the markers of hepatotoxicity in animal toxicological studies and clinically significant iDILI. Thus, major advances in the understanding of iDILI susceptibility and pathogenesis have come from the study of well-phenotyped iDILI patients. However, there are many gaps for explaining all the complexity of iDILI susceptibility and mechanisms. Therefore, there is a need to optimize preclinical human in vitro models to reduce the risk of iDILI during drug development. Here, the current experimental models and the future directions in iDILI modelling are thoroughly discussed, focusing on the human cellular models available to study the pathophysiological mechanisms of the disease and the most used in vivo animal iDILI models. We also comment about in silico approaches and the increasing relevance of patient-derived cellular models.

Veratric acid alleviates liver ischemia/reperfusion injury by activating the Nrf2 signaling pathway

Oxidative stress following liver ischemia/reperfusion (I/R) is an important pathological mechanism responsible for liver injury. Veratric acid (VA) is a phenolic benzoic acid that has been reported to have antioxidant properties. However, whether VA has protective effects against liver I/R injury remains unclear. In the present study, a mouse liver I/R injury model was established. VA was administered intragastrically for one week before liver I/R. Biochemical indicators, histological analysis, cell apoptosis, oxidative stress, and pathway proteins were tested to evaluate the protective effects of VA on liver I/R injury. Furthermore, a mouse AML12 hepatocyte hypoxia/reoxygenation (H/R) model was used to explore the underlying mechanism. VA alleviated liver I/R injury, as manifested by decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, liver necrotic area, oxidative stress, and hepatocyte apoptosis. VA pretreatment increased the expression of Nrf2 and its downstream antioxidant proteins heme oxygenase-1 (HO-1) and NADPH quinone oxidoreductase 1 (NQO-1). In addition, VA pretreatment increased AML12 cell activity and decreased oxidative stress; it also decreased the apoptosis induced by H/R. Moreover, the protective effect of VA on hepatocytes was related to the activation of the Nrf2 signaling pathway, and to increases in the Nrf2, HO-1, and NQO-1 protein expression. The inhibition of Nrf2 with ML385 offseted VA-mediated protection in AML12 cells. In conclusion, these results suggest that VA protects the liver from oxidative stress and apoptosis induced by liver I/R injury by activating the Nrf2 signaling pathway.

Phytoantioxidant Functionalized Nanoparticles: A Green Approach to Combat Nanoparticle-Induced Oxidative Stress

Nanotechnology is gaining significant attention, with numerous biomedical applications. Silver in wound dressings, copper oxide and silver in antibacterial preparations, and zinc oxide nanoparticles as a food and cosmetic ingredient are common examples. However, adverse effects of nanoparticles in humans and the environment from extended exposure at varied concentrations have yet to be established. One of the drawbacks of employing nanoparticles is their tendency to cause oxidative stress, a significant public health concern with life-threatening consequences. Cardiovascular, renal, and respiratory problems and diabetes are among the oxidative stress-related disorders. In this context, phytoantioxidant functionalized nanoparticles could be a novel and effective alternative. In addition to performing their intended function, they can protect against oxidative damage. This review was designed by searching through various websites, books, and articles found in PubMed, Science Direct, and Google Scholar. To begin with, oxidative stress, its related diseases, and the mechanistic basis of oxidative damage caused by nanoparticles are discussed. One of the main mechanisms of action of nanoparticles was unearthed to be oxidative stress, which limits their use in humans. Secondly, the role of phytoantioxidant functionalized nanoparticles in oxidative damage prevention is critically discussed. The parameters for the characterization of nanoparticles were also discussed. The majority of silver, gold, iron, zinc oxide, and copper nanoparticles produced utilizing various plant extracts were active free radical scavengers. This potential is linked to several surface fabricated phytoconstituents, such as flavonoids and phenols. These phytoantioxidant functionalized nanoparticles could be a better alternative to nanoparticles prepared by other existing approaches.

Heliconia rostrata rhizomes mitigate chemical-induced liver injury by debilitating oxidative stress in HepG2 cells and rats

ETHNOPHARMACOLOGICAL RELEVANCE

Heliconia rostrata Ruiz and Pav. belongs to the family Heliconiaceae. Plant was traditionally used to cure jaundice, intestinal pain, diabetes and hypertension.

AIM OF THE EXPERIMENT

Present study evaluated hepatoprotective efficacy of ethanol (REE) and methanol (RME) extracts of H. rostrata rhizomes in HepG2 cell lines and rats. Antioxidant efficacy of extracts was determined using ex vivo and in vivo methods.

MATERIALS AND METHODS

Before conducting efficacy studies, safety of REE and RME was established using toxicity studies which included Oral acute-fixed dose toxicity using OECD TG420, 28-days repeated dose oral toxicity by OECD TG407 and cytotoxicity studies by brine shrimp lethality (BSL) bioassay and MTT assay taking HepG2 cell line. Ex vivo (Extracts: 0-250 μg/ml) and in vivo (Extracts: 50, 100 and 200 mg/kg) antioxidant studies were performed on fresh goat liver and rats (N = 45) of either sex, respectively. In vitro hepatoprotective efficacy of extracts was evaluated against ethanol induced toxicity in HepG2 cell line. In vivo study was performed at 50, 100 and 200 mg/kg/day doses in rats by CCl₄-induced hepatotoxicity study.

RESULTS

No mortality was observed during single and repeated dose toxicity studies. 50% lethal dose >2000 mg/kg, confirmed category 5 toxicity level of extracts, according to Globally Harmonized System. No signs of toxicity and treatment or dose related changes recorded in rats under repeated dose toxicity study. No-observed-adverse effect-level of 200 mg/kg/day was observed for both extracts. Median lethal concentration of REE and RME were 1291.30 and 1045.89 μg/ml, respectively in BSL bioassay and 50% cytotoxicity concentration >1000 μg/ml was obtained for both extracts from MTT assay. Calculated 50% inhibitory concentration and median effective dose of extracts obtained from different antioxidant assays in ex vivo and in vivo antioxidant studies, respectively indicated REE has more antioxidant efficacy than RME. In in vitro hepatoprotective efficacy study, extracts demonstrated dose dependent protection against ethanol induced hepatotoxicity. At 400 μg/ml, REE and RME demonstrated percentage protection of 65.53% and 57.98%, respectively. Results of liver function test and histopathological evaluation of liver in in vivo hepatoprotective study confirmed dose dependent protection provided by the extracts against CCl₄ -induced hepatotoxicity.

CONCLUSION

Both REE and RME were found safe to be considered for therapeutic uses. Both REE and RME were found to exhibit antioxidant efficacy in ex vivo and in vivo models. Results ascertained that H. rostrata rhizomes possess significant hepatoprotective potency.

The Role of Mitochondria in Liver Ischemia-Reperfusion Injury: From Aspects of Mitochondrial Oxidative Stress, Mitochondrial Fission, Mitochondrial Membrane Permeable Transport Pore Formation, Mitophagy, and Mitochondria-Related Protective Measures

Ischemia-reperfusion injury (IRI) has indeed been shown as a main complication of hepatectomy, liver transplantation, trauma, and hypovolemic shock. A large number of studies have confirmed that microvascular and parenchymal damage is mainly caused by reactive oxygen species (ROS), which is considered to be a major risk factor for IRI. Under normal conditions, ROS as a kind of by-product of cellular metabolism can be controlled at normal levels. However, when IRI occurs, mitochondrial oxidative phosphorylation is inhibited. In addition, oxidative respiratory chain damage leads to massive consumption of adenosine triphosphate (ATP) and large amounts of ROS. Additionally, mitochondrial dysfunction is involved in various organs and tissues in IRI. On the one hand, excessive free radicals induce mitochondrial damage, for instance, mitochondrial structure, number, function, and energy metabolism. On the other hand, the disorder of mitochondrial fusion and fission results in further reduction of the number of mitochondria so that it is not enough to clear excessive ROS, and mitochondrial structure changes to form mitochondrial membrane permeable transport pores (mPTPs), which leads to cell necrosis and apoptosis, organ failure, and metabolic dysfunction, increasing morbidity and mortality. According to the formation mechanism of IRI, various substances have been discovered or synthesized for specific targets and cell signaling pathways to inhibit or slow the damage of liver IRI to the body. Here, based on the development of this field, this review describes the role of mitochondria in liver IRI, from aspects of mitochondrial oxidative stress, mitochondrial fusion and fission, mPTP formation, and corresponding protective measures. Therefore, it may provide references for future clinical treatment and research.

The potential effect of phytochemicals and herbal plant remedies for treating drug-induced hepatotoxicity: a review

Drug-induced liver injury significantly caused by synthetic drugs, and other xenobiotics contribute to clinical hepatic dysfunction, which has been a substantial challenge for both patients and physicians. Traditional medicines used as an alternative therapy because of their pharmacological benefits, less or no side effects, and enormous availability in nature. Phytochemicals are essential ingredients of plants that reduce necrotic cell death, restore the antioxidant defence mechanism, limit oxidative stress, and prevent the inflammation of tissue and dysfunction of the mitochondria. In this review, we principally focused on the potential effect of the herbal plants and their phytochemicals in treating drug-induced hepatotoxicity.

Protective Effects of Morus nigra and Its Phytochemicals against Hepatotoxicity: A Review of Preclinical Studies

BACKGROUND

Our liver has a variety of vital functions including removing poisons, storing energy, immunological roles, and secretory and excretory functions. It may face some kinds of diseases caused by viruses, hepatotoxic chemicals, drugs, alcohol, and inherited disorders. Oxidative stress and inflammation are in the core of mechanisms of liver damages induced by viruses or chemical agents.

SUMMARY

Morus nigra (M. nigra), generally known as black mulberry, exhibited wide-spectrum pharmacological effects including antidiabetic, antinociceptive, anticancer, and hepatoprotective activities. Different parts of this plant particularly the fruit and leaf have shown beneficial effects on hepatocytes in cell culture and animal models of liver damages induced by chemicals (e.g., CCl4), drugs (e.g., paracetamol), diet (e.g., high fat), diabetes, etc. The beneficial effects of M. nigra on the liver are attributed to the presence of considerable amounts of phenolic compounds such as anthocyanins, flavonols, and phenolic acids. The present review is aimed to focus on the hepatoprotective activities of M. nigra and its phytochemicals and the mechanisms responsible for these activities. Key Messages: The evidence reviewed in this study can help design clinical trials on M. nigra in patients with liver disorders and develop a hepatoprotective herbal medicine.

Idiosyncratic Drug-Induced Liver Injury: Mechanistic and Clinical Challenges

Idiosyncratic drug-induced liver injury (IDILI) remains a significant problem for patients and drug development. The idiosyncratic nature of IDILI makes mechanistic studies difficult, and little is known of its pathogenesis for certain. Circumstantial evidence suggests that most, but not all, IDILI is caused by reactive metabolites of drugs that are bioactivated by cytochromes P450 and other enzymes in the liver. Additionally, there is overwhelming evidence that most IDILI is mediated by the adaptive immune system; one example being the association of IDILI caused by specific drugs with specific human leukocyte antigen (HLA) haplotypes, and this may in part explain the idiosyncratic nature of these reactions. The T cell receptor repertoire likely also contributes to the idiosyncratic nature. Although most of the liver injury is likely mediated by the adaptive immune system, specifically cytotoxic CD8+ T cells, adaptive immune activation first requires an innate immune response to activate antigen presenting cells and produce cytokines required for T cell proliferation. This innate response is likely caused by either a reactive metabolite or some form of cell stress that is clinically silent but not idiosyncratic. If this is true it would make it possible to study the early steps in the immune response that in some patients can lead to IDILI. Other hypotheses have been proposed, such as mitochondrial injury, inhibition of the bile salt export pump, unfolded protein response, and oxidative stress although, in most cases, it is likely that they are also involved in the initiation of an immune response rather than representing a completely separate mechanism. Using the clinical manifestations of liver injury from a number of examples of IDILI-associated drugs, this review aims to summarize and illustrate these mechanistic hypotheses.

Investigations of drug-induced liver injury by a peroxynitrite activatable two-photon fluorescence probe

Drug-induced liver injury (DILI) is a prevalent liver disease and the leading cause for acute liver failure (ALF) worldwide. Screening of DILI in patients is central to ensure drug safety and improve therapy efficiency. Mounting evidences revealed that peroxynitrite (ONOO^-) is involved in the DILI process and can be a potential biomarker for DILI. Thus far, there are few two-photon fluorescence probes for ONOO^- that can accomplish this challenging task in DILI liver tissues. Hereby, a peroxynitrite activatable two-photon fluorescence probe BN-PN for the imaging of ONOO^- in mice liver was elaborately constructed. The probe specifically reacted with peroxynitrite to furnish 140-fold fluorescence increase in vitro, which elucidated a high sensitivity for ONOO^-. Thus, subtle changes of ONOO^- levels in live cells can be sensitively imaged with this probe by two-photon microscopy. The probe also denoted the overproduction of ONOO^- in APAP-induced liver injury, and proved that administration with NAC can effectively alleviate DILI and reduce ONOO^- production in mouse liver. Further, the probe demonstrated the rapid rise of ONOO^- level in the liver of DILI mice administrated with alcohol. This work disclosed the rational construction of a two-photon fluorescence probe-based DILI screening method, which would help the estimation of drug safety and new drug development.

Detection Technologies for Reactive Oxygen Species: Fluorescence and Electrochemical Methods and Their Applications

Reactive oxygen species (ROS) have been found in plants, mammals, and natural environmental processes. The presence of ROS in mammals has been linked to the development of severe diseases, such as diabetes, cancer, tumors, and several neurodegenerative conditions. The most common ROS involved in human health are superoxide (O2•-), hydrogen peroxide (H2O2), and hydroxyl radicals (•OH). Organic and inorganic molecules have been integrated with various methods to detect and monitor ROS for understanding the effect of their presence and concentration on diseases caused by oxidative stress. Among several techniques, fluorescence and electrochemical methods have been recently developed and employed for the detection of ROS. This literature review intends to critically discuss the development of these techniques to date, as well as their application for in vitro and in vivo ROS detection regarding free-radical-related diseases. Moreover, important insights into and further steps for using fluorescence and electrochemical methods in the detection of ROS are presented.

Oleoylethanolamide Protects Against Acute Liver Injury by Regulating Nrf-2/HO-1 and NLRP3 Pathways in Mice

Acute liver injury is a rapidly deteriorating clinical condition with markedly high morbidity and mortality. Oleoylethanolamide (OEA) is an endogenous lipid messenger with multiple bioactivities, and has therapeutic effects on various liver diseases. However, effects of OEA on acute liver injury remains unknown. In this study, effects and mechanisms of OEA in lipopolysaccharide (LPS)/d-galactosamine (D-Gal)-induced acute liver injury in mice were investigated. We found that OEA treatment significantly attenuated LPS/D-Gal-induced hepatocytes damage, reduced liver index (liver weight/body weight), decreased plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels. Moreover, mechanism study suggested that OEA pretreatment significantly reduced hepatic MDA levels, increased Superoxide dismutase (SOD) and Glutathione peroxidase (GSH-PX) activities via up-regulate Nrf-2 and HO-1 expression to exert anti-oxidation activity. Additionally, OEA markedly reduced the expression levels of Bax, Bcl-2 and cleaved caspase-3 to suppress hepatocyte apoptosis. Meanwhile, OEA remarkedly reduced the number of activated intrahepatic macrophages, and alleviated the mRNA expression of pro-inflammatory factors, including TNF-α, IL-6, MCP1 and RANTES. Furthermore, OEA obviously reduced the expression of IL-1β in liver and plasma through inhibit protein levels of NLRP3 and caspase-1, which indicated that OEA could suppress NLRP3 inflammasome pathway. We further determined the protein expression of PPAR-α in liver and found that OEA significantly increase hepatic PPAR-α expression. In addition, HO-1 inhibitor ZnPP blocked the therapeutic effects of OEA on LPS/D-Gal-induced liver damage and oxidative stress, suggesting crucial role of Nrf-2/HO-1 pathway in the protective effects of OEA in acute liver injury. Together, these findings demonstrated that OEA protect against the LPS/D-Gal-induced acute liver injury in mice through the inhibition of apoptosis, oxidative stress and inflammation, and its mechanisms might be associated with the Nrf-2/HO-1 and NLRP3 inflammasome signaling pathways.

A reactive oxygen species-responsive antioxidant nanotherapy for the treatment of drug-induced tissue and organ injury

Drug-induced tissue injury has become a growing public health problem. Gastrointestinal injury and liver dysfunction are the most common side effects related to drug therapies, resulting in high morbidity and mortality in recent years. The overproduction of reactive oxygen species (ROS) is critically involved in the pathogenesis of drug-induced tissue injury. Consequently, antioxidant therapy represents a very promising strategy for the treatment of drug-induced tissue injury. Herein, a multifunctional antioxidant nanotherapy (TON) is engineered from a cyclodextrin-derived ROS-responsive material and a radical scavenger tempol, and is capable of eliminating a broad spectrum of ROS. After oral administration, TON can passively accumulate in the inflamed gastrointestinal tissues in mice with indomethacin-induced gastrointestinal injury. Correspondingly, TON shows superior efficacy in two representative murine models of indomethacin-induced gastrointestinal injury and acetaminophen-induced hepatic injury via attenuating oxidative stress and mitigating inflammatory responses. Additionally, preliminary in vitro and in vivo experiments demonstrate the good safety profile of TON. Consequently, the ROS-responsive antioxidant nanotherapy TON is promising for the treatment of drug-induced tissue and organ injury.

Selenoprotein V protects against endoplasmic reticulum stress and oxidative injury induced by pro-oxidants

Selenoprotein V (SELENOV) contains a thioredoxin-like fold and a conserved CxxU motif with a potential redox function. This study was to assess its in vivo and in vitro roles and mechanisms in coping with different oxidant insults. In Experiment (Expt.)1, SELENOV knockout (KO) and wild type (WT) mice (male, 8-wk old) were given an ip injection of saline, diquat (DQ, 12.5 mg/kg), or N-acetyl-para-aminophenol (APAP, 300 mg/kg) (n = 10), and killed 5 h after the injection. In Expt. 2, primary hepatocytes of WT and KO were treated with DQ (0-0.75 mM) or APAP (0-6 mM) for 12 h. In Expt. 3, 293 T cells overexpressing Selenov gene (OE) were treated with APAP (0-4 mM) for 24 h or H₂O₂ (0-0.4 mM) for 12 h. Compared with the WT, the DQ- and APAP-injected KO mice had higher (P < 0.05) serum alanine aminotransferase activities and hepatic malondialdehyde (MDA), protein carbonyl, endoplasmic reticulum (ER) stress-related proteins (BIP and CHOP), apoptosis-related proteins (FAK and caspase-9), and 3-nitrotyrosine, along with lower total anti-oxidizing-capability (T-AOC) and severer hepatic necrosis. Likewise, the DQ and APAP-treated KO hepatocytes had elevated (P < 0.05) cell death (10-40%), decreased (P < 0.05) T-AOC (63-83%), glutathione (26-87%), superoxide dismutase (SOD) activity (28-36%), mRNA levels of redox enzymes (Cat, Gcs, Gpx3, and Sod) and (or) sharper declines (P < 0.05) in cellular respiration and ATP production than that of the WT cells. In contrast, the OE cells had greater viability and T-AOC and lower MDA, and carbonyl contents after the APAP and H₂O₂ exposures (all at P < 0.05) than the controls. Moreover, the OE cells had greater (P < 0.05) redox enzyme activities (GPX, TrxR, and SOD), and lower (P < 0.05) expressions of ER stress-related genes (Atf4, Atf6, Bip, Xbp1t, Xbp1s, and Chop) and proteins (BIP, CHOP, FAK, and caspase-9) than the control cells after the treatment of H₂O₂ (0.4 mM). In conclusion, SELENOV conferred protections in vivo and in vitro against the reactive oxygen and nitrogen species-mediated ER stress-related signaling and oxidative injuries.

Echinochrome Pigment Improves Male Rats' Fertility

Background::

Infertility is the first-rate public health trouble affecting one in five married couples globally, male causes embody a significant proportion. Natural products could be an alternative or complementary inexpensive treatment for such matters. Echinochrome (Ech) is a natural quinone pigment obtained from sea urchin, and it was confirmed to possess many pharmacological properties due to its chemical activity.

Objective::

The current research paper was targeted to evaluate the potential effects of Ech on male fertility, and to highlight the possible involved mechanisms.

Methods::

Eighteen adult male rats were randomly distributed into three groups: control (1 ml of 2% DMSO, p.o.), low dose Ech (0.1 mg/kg, p.o.), and high dose Ech (1 mg/kg p.o.).

Results::

The high dose Ech caused a significant decline in the levels of glucose, ALT, AST, ALP, urea, Cr, uric acid, TG, TC and LDL-C and testicular tissue MDA, while it caused a significant rise in the levels of albumin, TP, HDL-C, FSH, LH, testosterone and testicular tissue GSH activity. Moreover, it showed a significant positive effect on the testis weight, caudal epididymis weight, sperm count, sperm motility, sperm morphology, fructose concentration, and α-glucosidase activity. However, no significant changes were observed in histological examination of testicular tissue among all groups.

Conclusion::

High dose Ech improved male rat-fertility either directly by activating the pituitary gonadal axis, and or indirectly via enhancing: the renal and hepatic functions, the lipid profile and or the antioxidant pathways.

TRPM2 channel-mediated cell death: An important mechanism linking oxidative stress-inducing pathological factors to associated pathological conditions

Oxidative stress resulting from the accumulation of high levels of reactive oxygen species is a salient feature of, and a well-recognised pathological factor for, diverse pathologies. One common mechanism for oxidative stress damage is via the disruption of intracellular ion homeostasis to induce cell death. TRPM2 is a non-selective Ca2+-permeable cation channel with a wide distribution throughout the body and is highly sensitive to activation by oxidative stress. Recent studies have collected abundant evidence to show its important role in mediating cell death induced by miscellaneous oxidative stress-inducing pathological factors, both endogenous and exogenous, including ischemia/reperfusion and the neurotoxicants amyloid-β peptides and MPTP/MPP+ that cause neuronal demise in the brain, myocardial ischemia/reperfusion, proinflammatory mediators that disrupt endothelial function, diabetogenic agent streptozotocin and diabetes risk factor free fatty acids that induce loss of pancreatic β-cells, bile acids that damage pancreatic acinar cells, renal ischemia/reperfusion and albuminuria that are detrimental to kidney cells, acetaminophen that triggers hepatocyte death, and nanoparticles that injure pericytes. Studies have also shed light on the signalling mechanisms by which these pathological factors activate the TRPM2 channel to alter intracellular ion homeostasis leading to aberrant initiation of various cell death pathways. TRPM2-mediated cell death thus emerges as an important mechanism in the pathogenesis of conditions including ischemic stroke, neurodegenerative diseases, cardiovascular diseases, diabetes, pancreatitis, chronic kidney disease, liver damage and neurovascular injury. These findings raise the exciting perspective of targeting the TRPM2 channel as a novel therapeutic strategy to treat such oxidative stress-associated diseases.

Hepatic 31 P-magnetic resonance spectroscopy identified the impact of melatonin-pretreated mitochondria in acute liver ischaemia-reperfusion injury

Acute liver ischaemia-reperfusion injury (IRI), commonly encountered during liver resection and transplantation surgery, is strongly associated with unfavourable clinical outcome. However, a prompt and accurate diagnosis and the treatment of this entity remain formidable challenges. This study tested the hypothesis that ³¹ P-magnetic resonance spectroscopy (³¹ P-MRS) findings could provide reliable living images to accurately identify the degree of acute liver IRI and melatonin-pretreated mitochondria was an innovative treatment for protecting the liver from IRI in rat. Adult male SD rats were categorized into group 1 (sham-operated control), group 2 (IRI only) and group 3 (IRI + melatonin [ie mitochondrial donor rat received intraperitoneal administration of melatonin] pretreated mitochondria [10 mg/per rat by portal vein]). By the end of study period at 72 hours, ³¹ P-MRS showed that, as compared with group 1, the hepatic levels of ATP and NADH were significantly lower in group 2 than in groups 1 and 3, and significantly lower in group 3 than in group 1. The liver protein expressions of mitochondrial-electron-transport-chain complexes and mitochondrial integrity exhibited an identical pattern to ³¹ P-MRS finding. The protein expressions of oxidative stress, inflammatory, cellular stress signalling and mitochondrial-damaged biomarkers displayed an opposite finding of ³¹ P-MRS, whereas the protein expressions of antioxidants were significantly progressively increased from groups 1 to 3. Microscopic findings showed that the fibrotic area/liver injury score and inflammatory and DNA-damaged biomarkers exhibited an identical pattern of cellular stress signalling. Melatonin-pretreated mitochondria effectively protected liver against IRI and ³¹ P-MRS was a reliable tool for measuring the mitochondrial/ATP consumption in living animals.

Hepatoprotective effect of limonene against chronic immobilization induced liver damage in rats

Prolonged immobilization may impair the physiological functions of various organs of the body, including the liver, brain, and heart. In this study, we investigated the hepatoprotective effect of limonene (a monoterpene) in male rats exposed to chronic immobilization. Rats were exposed to immobilization stress (6 h/21 days) and received limonene (10 mg/kg, oral gavage) during this period. Chronic immobilization increased the levels of liver enzymes alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase in serum. Increased levels of malondialdehyde and decreased glutathione content were also observed in the liver tissue of immobilized rats. Expression of TNF-α, IL-1β, IL-6, and NF-κB mRNA was increased, and infiltrated cells were also observed in the liver parenchyma in rats exposed to chronic immobilization. Limonene prevented all these changes in immobilized rats. These results suggest that limonene, due to its antioxidant and anti-inflammatory effects, rescues the liver from damages caused by chronic immobilization.

Enhanced Keap1-Nrf2/Trx-1 axis by daphnetin protects against oxidative stress-driven hepatotoxicity via inhibiting ASK1/JNK and Txnip/NLRP3 inflammasome activation

BACKGROUND

Oxidative stress-triggered fatal hepatotoxicity is an essential pathogenic factor in acute liver failure (ALF).

AIMS

To investigate the protective effect of daphnetin (Daph) on tert-butyl hydroperoxide (t-BHP) and acetaminophen (APAP)-induced hepatotoxicity through altering Nrf2/Trx-1 pathway activation.

MATERIALS AND METHODS

In vivo, male C57BL/6 mice with Wild-type (WT) and Nrf2^-/- were divided into five groups and acute liver injury model were established by APAP or LPS/GalN after injection with Daph (20, 40, or 80 mg/kg), seperately. Then, liver tissue and serum were collected for biochemical determination, TUNEL and H & E staining, and western blot analysis. In vitro, HepG2 cells were used to investigate the protective effect and mechanism of daphnetin against ROS and apoptosis induced by t-BHP via apoptosis detection, western blot, immunofluorescence analysis, and sgRNA transfection.

RESULTS

Our results indicated that Daph efficiently inhibited t-BHP-stimulated hepatotoxicity, and modulated Trx-1 expression and Nrf2 activation which decreased Keap1-overexpression in HepG2 cells. Moreover, Daph inhibited t-BHP-excited hepatotoxicity and enhanced Trx-1 expression, which was reversed in Nrf2^-/- HepG2 cells. In vivo, a survival rate analysis first suggested that Daph significantly reduced the lethality induced by APAP or GalN/LPS in a Nrf2-dependent or -independent manner by using Nrf2^-/- mice, respectively. Next, further results implicated that Daph not only effectively alleviated APAP-induced an increase of ALT and AST levels, histopathological changes, ROS overproduction, malondialdehyde (MDA) formation and GSH/GSSG reduction, but it also relieved hepatic apoptosis by strengthening the suppression of cleaved-caspase-3 and expression of P53 protein. Additionally, Daph attenuated mitochondrial dysfunction by suppressing ASK1/JNK activation and decreasing apoptosis-inducing factor (AIF) and Cytochrome c release and Bax mitochondrial translocation. Daph inhibited inflammatory responses by inactivating the thioredoxin-interacting protein (Txnip)/NLRP3 inflammasome. Furthermore, Daph efficiently enhanced Nrf2 nuclear translocation and Trx-1 expression. However, these effects in WT mice were eliminated in Nrf2^-/- mice.

CONCLUSIONS

These investigations demonstrated that Daph treatment has protective potential against oxidative stress-driven hepatotoxicity by inhibition of ASK1/JNK and Txnip/NLRP3 activation, which may be strongly related to the Nrf2/Trx-1 upregulation.

Liver injury induced by paracetamol and challenges associated with intentional and unintentional use

Drug induced liver injury (DILI) is a common cause of acute liver injury. Paracetamol, also known as acetaminophen, is a widely used anti-pyretic that has long been established to cause liver toxicity once above therapeutic levels. Hepatotoxicity from paracetamol overdose, whether intentional or non-intentional, is the most common cause of DILI in the United States and remains a global issue. Given the increased prevalence of combination medications in the form of pain relievers and antihistamines, paracetamol can be difficult to identify and remains a significant cause of acute hepatotoxicity, as evidenced by its contribution to over half of all acute liver failure cases in the United States. This is especially concerning given that, when co-ingested with other medications, the rise in serum paracetamol levels may be delayed past the 4-hour post-ingestion mark that is currently used to determine patients that require medical therapy. This review serves to describe the clinical and pathophysiologic features of hepatotoxicity secondary to paracetamol and provide an update on current available knowledge and treatment options.

Detection of biomarkers to differentiate endocrine disruption from hepatotoxicity in zebrafish (Danio rerio) using proteomics

Measurement of specific biomarkers identified by proteomics provides a potential alternative method for risk assessment, which is required to discriminate between hepatotoxicity and endocrine disruption. In this study, adult zebrafish (Danio rerio) were exposed to the hepatotoxic substance acetaminophen (APAP) for 21 days, in a fish short-term reproduction assay (FSTRA). The molecular changes induced by APAP exposure were studied in liver and gonads by applying a previously developed combined FSTRA and proteomics approach. We observed a significant decrease in egg numbers, an increase in plasma hyaluronic acid, and the presence of single cell necrosis in liver tissue. Furthermore, nine common biomarkers (atp5f1b, etfa, uqcrc2a, cahz, c3a.1, rab11ba, mettl7a, khdrbs1a and si:dkey-108k21.24) for assessing hepatotoxicity were detected in both male and female liver, indicating hepatic damage. In comparison with exposure to fadrozole, an endocrine disrupting chemical (EDC), three potential biomarkers for liver injury, i.e. cahz, c3a.1 and atp5f1b, were differentially expressed. The zebrafish proteome response to fadrozole exposure indicated a significant regulation in estrogen synthesis and perturbed binding of sperm to zona pellucida in the ovary. This study demonstrates that biomarkers identified and quantified by proteomics can serve as additional weight-of-evidence for the discrimination of hepatotoxicity and endocrine disruption, which is necessary for hazard identification in EU legislation and to decide upon the option for risk assessment.

Elimination of Intracellular Calcium Overload by BAPTA-AM-Loaded Liposomes: A Promising Therapeutic Agent for Acute Liver Failure

In the past few decades, intracellular calcium overload has been shown to induce cell death through multiple signaling pathways. In this study, we used BAPTA-AM, a well-known membrane-permeable Ca²⁺ chelator, to prevent cell injury by allaying the intracellular calcium overload. We explored the clinical potentials of BAPTA-AM-loaded liposome (BAL) in the treatment of the acute liver failure (ALF) mouse model, which is characterized by severe hepatic necrosis and apoptosis. We discovered that BAL can significantly inhibit D-GalN-induced LO2 cell damage as it increased cell viability by 60% and downregulated the LPS-stimulated inflammatory response in RAW 264.7 macrophages by reversing the morphological change and modulating TNF-α and NF-κB expressions. Through systemic administration, BAL can rapidly accumulate in damaged liver tissue and exhibit excellent treatment effects on the D-GalN/LPS-induced ALF mouse model, including elevation of the survival rate (from 10 to 80%), recovery of normal liver indexes and liver health indicators, improvement of liver blood microcirculation (increased the blood flow volume by 80% and flow rate by 60%), and blood coagulation. The underlying hepatoprotective effect of BAL is presumably based on the antinecrosis and antiapoptosis abilities attributed to its inhibition on oxidative stress, restriction on TNF-α receptor, and mitochondria-mediated apoptotic pathway by effectively clearing the overloaded intercellular calcium. BAL holds great potential as a new therapeutic strategy for ALF treatment, and its prominent cell rescue ability provides ample opportunities for the treatment of many other diseases that are characterized by rapid and massive cell damage.

Anti-oxidative, anti-inflammatory and hepatoprotective effects of Radix Bupleuri extract against oxidative damage in tilapia (Oreochromis niloticus) via Nrf2 and TLRs signaling pathway

Radix Bupleuri extract (RBE) is one of the most popular oriental herbal medicines, which has anti-oxidative and anti-inflammatory properties. However, its protective effects and underlying molecular mechanisms on oxidative damage in tilapia are still unclear. The aims of the study were to explore the anti-oxidative, anti-inflammatory and hepatoprotective effects of RBE against oxidative damage, and to elucidate underlying molecular mechanisms in fish. Tilapia received diet containing three doses of RBE (0, 1 and 3 g/kg diet) for 60 days, and then were given an intraperitoneal injection of H₂O₂ or saline. Before injection, RBE treatments improved growth performance and partial anti-oxidative capacity in tilapia. After oxidative damage, RBE pretreatments were able to signally reduce the higher serum aminotransferases, alkaline phosphatase (AKP) and liver necrosis. In serum and liver, the abnormal lipid peroxidation level and antioxidant status induced by H₂O₂ injection were restored by RBE treatments. Furthermore, RBE treatments activated erythroid 2-related factor 2 (Nrf2) signaling pathway, which promoted the gene expression of heme oxygenase 1 (HO-1), NAD(P) H:quinone oxidoreductase 1 (NQO-1), glutathione-S-transferase (GST) and catalase (CAT). Meanwhile, RBE treatments reduced inflammatory response by inhibiting TLRs-MyD88-NF-κB signaling pathway, accompanied by the lower interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-8 mRNA levels. In addition, RBE treatments upregulated complement (C3) gene expression and downregulated heat shock protein (HSP70) gene expression. In conclusion, the current study suggested that RBE pretreatments protected against H₂O₂-induced oxidative damage in tilapia. The beneficial activity of RBE may be due to the modulation of Nrf2/ARE and TLRs-Myd88-NF-κB signaling pathway.

Disodium Guanylate Alleviates Acute Hepatic Injury Induced by Carbon Tetrachloride Via Antioxidative Stress and Antiapoptosis In Vivo and In Vitro

Hepatic injury is one of the most common digestive system diseases worldwide in clinic. Guanylic acid or guanosine monophosphate (GMP) was an important component of nucleotides, which is mainly in the form of sodium salt (disodium guanylate, GMP-Na₂ ). However, its effect on hepatic injury has not yet been investigated. This study is to investigate the protective effects of GMP-Na₂ on acute hepatic injury induced by carbon tetrachloride (CCl₄ ), and to explore its mechanism. The hepatic injury models of mice and HL-7702 cells were induced by CCl₄ . The alanine transaminase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), total antioxidant capacity (T-AOC) were determined by biochemical method. Hematoxylin-eosin staining were used to determine the morphological changes on liver tissue in mice. The mRNA and protein expressions of caspase-3, Bax, and Bcl-2 were detected by RT-PCR and Western blot analysis. Our results show that GMP-Na₂ treatment significantly decreased the activities of ALT and AST, and the levels of MDA as well as increased the levels of SOD, GSH-Px, and T-AOC. Importantly, GMP-Na₂ effectively enhanced the antiapoptosis function by upregulating Bcl-2 expression and downregulating caspase-3 and Bax expressions in vivo and in vitro. Moreover, the histopathological changes of liver tissue were obviously improved after GMP-Na₂ treatment. These findings suggest that GMP-Na₂ has protective effects on hepatic injury, and its mechanisms may be associated with antioxidative stress and antiapoptosis.

RORα suppresses interleukin-6-mediated hepatic acute phase response

Acute liver failure (ALF) is characterized by loss of liver function in response to sustained augmentation of the acute-phase response (APR) in the liver, which can progress even to death. Although the inflammatory interleukin-6 (IL-6)–axis is a crucial factor that drives the hepatic APR by releasing diverse acute-phase proteins (APPs), therapeutic strategies to block the IL-6–STAT3-mediated APR are not well developed. Here, we show that the nuclear receptor retinoic acid-related orphan receptor α (RORα) limits APR-mediated liver injury by inhibiting the hepatic IL-6–STAT3 signaling pathway. Administration of JC1-40, an RORα activator, diminished diethylnitrosamine-induced acute liver injury and repressed transcriptional expression of APPs such as CXCL1 and LCN2 in mice. IL-6-mediated activation of STAT3 was repressed after RORα activation by either adenoviral infusion of RORα or JC1-40 treatment in primary hepatocytes. Activation of RORα decreased transcriptional expression of IL-6 receptor α, an upstream activator of STAT3, both in vitro and in vivo. This may be one mechanism underlying the RORα-mediated inhibition of STAT3. Taken together, our results suggest that RORα is a regulator of the hepatic IL-6–STAT3 signaling pathway and may be a new therapeutic target for treating APR-associated inflammatory ALF.

Acetaminophen Responsive miR-19b Modulates SIRT1/Nrf2 Signaling Pathway in Drug-Induced Hepatotoxicity

Previous studies suggest that activation of SIRT1 protects liver from acetaminophen (APAP)-induced injury; however, the detailed mechanism of SIRT1 modulation in this process is still incomplete. Therefore, this study was to investigate the pathophysiological role of SIRT1 in APAP-mediated hepatotoxicity. We found that SIRT1 mRNA and protein were markedly upregulated in human LO2 cells and mouse liver upon APAP exposure. In vitro, the specific knockdown of SIRT1 expression ultimately aggravated APAP-evoked cellular antioxidant defense in LO2 cells. Moreover, lentivirus-mediated knockdown of hepatic SIRT1 expression exacerbated APAP-induced oxidative stress and liver injury, especially reduction of Nrf2 and subsequent downregulation of several antioxidant genes. Intriguingly, 30 mg/kg SRT1720, the specific SIRT1 activator, which greatly enhanced Nrf2 expression and antioxidant defense, and then eventually reversed APAP-induced hepatic liver injury in mice. Furthermore, APAP responsive miR-19b played an important role in regulating SIRT1 expression, whereas overexpression miR-19b largely abolished the induction of SIRT1 by APAP in vitro and in vivo. Specific SIRT1 3′-UTR mutation, which disrupted the interaction of miRNA-3′UTR, and successfully abrogated the modulation by miR-19b. Notably, hepatic miR-19b overexpression worsened the APAP-induced hepatotoxicity. In general, our results support the notion that the strong elevation of SIRT1 by APAP responsive miR-19b may represent a compensatory mechanism to protect liver against the drug-induced damage, at least in part by enhancing Nrf2-mediated antioxidant capacity in the liver.