Oral magnesium prevents acetaminophen-induced acute liver injury by modulating microbial metabolism

Magnesium Deficiency: The Insidious Executor of the Liver Disease

Magnesium (Mg), which is predominantly present in cells as a micronutrient, is involved in numerous vital physiological processes, such as DNA repair and energy metabolism. Mg deficiency has been reported to contribute toward the advent and progression of a variety of liver diseases; in particular, these two pathological entities may synergistically act. Given the significant impact and increasing burden of liver diseases on global healthcare resources and economic expenditure, it is tempting to manage Mg insufficiency as novel promising therapeutic strategies. In this review, we comprehensively elaborate on the complicated relationship between Mg deficiency and several contextual liver diseases, with concentrating on the underlying molecular mechanisms.

Ammonium tetrathiomolybdate attenuates acetaminophen-induced acute liver failure by inhibiting the TRPV4/Calcium/NF-κB signaling pathway

Acute liver failure (ALF), characterized by fulminant hepatic necrosis and excessive inflammatory-oxidative cascades, remains a critical clinical challenge with limited therapeutic options. This study investigates the therapeutic potential of ammonium tetrathiomolybdate (ATTM)-a copper-chelating agent with multimodal anti-inflammatory and antioxidant properties-in acetaminophen (APAP)-induced ALF. Utilizing APAP-challenged C57BL/6J mice, we demonstrated that ATTM administration, whether prophylactic or delayed by 2 h post-exposure, significantly attenuated hepatotoxicity, as evidenced by reduced histopathological damage and improved survival rates. These therapeutic effects were further confirmed in AML12 hepatocytes, thereby reinforcing the observed in vivo findings. RNA sequencing revealed that calcium signaling is the predominant pathway modulated by ATTM. Subsequent mechanistic validation identified Transient Receptor Potential Cation Channel Subfamily V Member 4 (TRPV4)-mediated calcium influx as the critical therapeutic target. ATTM suppressed TRPV4-dependent calcium mobilization, thereby inhibiting the sequential phosphorylation of NF-κB pathway components in both murine liver tissue and AML12 cells. Crucially, TRPV4 agonism via RN-1747 reversed the hepatoprotective effects of ATTM, thereby confirming the centrality of this axis in mediating ATTM's therapeutic actions. These findings establish ATTM as a novel modulator of the TRPV4/calcium/NF-κB signaling cascade, capable of interrupting inflammatory-oxidative loops at multiple nodes. Our work not only elucidates a previously unrecognized mechanism for copper chelators in ALF management but also positions ATTM as a promising therapeutic candidate warranting clinical translation.

Chronic alcohol intake disrupts cytochrome P450 enzyme activity in alcoholic fatty liver disease: insights into metabolic alterations and therapeutic targets

Introduction

Alcoholic fatty liver disease (AFLD) is a common consequence of chronic alcohol consumption, characterized by lipid accumulation and oxidative stress in the liver. Cytochrome P450 (CYP450) enzymes play essential roles in metabolizing alcohol and other compounds. However, the specific long-term effects of alcohol on these enzymes remain unclear.

Methods

This study the examines influence of prolonged ethanol exposure on CYP450 activity and expression in AFLD using a rat model. Key enzymes such as CYP2E1, CYP2D6, and CYP3A1 were assessed in relation to lipid accumulation and oxidative stress.

Results

Significant alterations were identified in the expression and activity of CYP2E1, CYP2D6, and CYP3A1, which were associated with increased lipid accumulation and oxidative stress in the liver. Additionally, the expression of P-glycoprotein (P-gp) was elevated, suggesting that chronic alcohol intake may impact drug transport and excretion.

Discussion

These findings provide new insights into the molecular mechanisms of AFLD and highlight the potential of CYP450 modulation as a therapeutic target. By elucidating how long-term ethanol exposure disrupts hepatic CYP450 enzyme profiles, this research lays the groundwork for developing personalized therapeutic strategies to improve outcomes for patients with AFLD.

Review of Metal-Polyphenol Self-Assembled Nanoparticles: Synthesis, Properties, and Biological Applications in Inflammatory Diseases

Polyphenols, which are compounds characterized by the presence of phenolic hydroxyl groups, are abundantly found in natural plants and exist in highly complex forms within living organisms. As some of the most prevalent compounds in nature, polyphenols possess significant medicinal value due to their unique structural features, particularly their therapeutic efficacy in antitumor, anti-inflammatory, and antibacterial applications. In the context of inflammation therapy, polyphenolic compounds can inhibit the excessive release of inflammatory mediators from inflammatory cells, thereby mitigating inflammation. Furthermore, these compounds exhibit strong antioxidant properties, enabling them to scavenge free radicals and reactive oxygen species (ROS), reduce oxidative stress-related damage, and exert anti-inflammatory effects. Due to their multiple phenolic hydroxyl groups and their ability to chelate various metals, polyphenols are extensively utilized in the synthesis of self-assembled nanoparticles for the treatment of various diseases. Numerous studies have demonstrated that the therapeutic profile of nanoparticles formed through self-assembly with metal ions surpasses that of polyphenolic compounds alone. This Review will focus on the self-assembly of different polyphenolic compounds with various metal ions to generate nanoparticles, their characterization, and their therapeutic applications in inflammation-related diseases, providing researchers with new insights into the synthetic study of metal-polyphenol nanocomposites and their biological applications.

Magnesium promoting OVX rats' rotator cuff tear repair with relieving stem cell senescence effect

The rotator cuff tear (RCT) repairing of tendon-to-bone junction (enthese) after surgery in osteoporotic patients is mainly hindered by poor bone formation at the damaged humeral tuberosity region. We found that long-term oral supplementation of Magnesium ions (Mg2+) can significantly promote humeral tuberosity bone formation and enthese regeneration after RCT surgery in ovariectomized (OVX) rats, attributing to the promotive effect of Mg2+ on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its inhibition of new bone mineralization. Meanwhile, the in vitro replicative senescent markers of BMSCs are significantly relieved by Mg2+. The BMSCs' RNA-seq data analysis and cell energy metabolism results indicate that Mg2+ significantly increase senescent BMSCs' mitochondrial transmembrane potential and intracellular ATP content, and reduce reactive oxygen species production.

Natural Polyphenol-Mediated Inhibition of Ferroptosis Alleviates Oxidative Damage and Inflammation in Acute Liver Injury

Acetaminophen (APAP) overdose has long been recognized as the main cause of drug-induced liver injury (DILI), characterized by glutathione (GSH) depletion and reactive oxygen species (ROS) accumulation, leading to ferroptosis and inflammatory responses. There is an urgent need for liver-protective agents to combat ferroptosis, modulate oxidative stress, and ameliorate inflammation. Catechin, a well-known polyphenol compound, has been shown to have antioxidant potential. However, its protective role on APAP-induced liver injury (AILI) has not been elucidated. In this study, we evaluated the modulating effects of catechin on AILI and observed that catechin attenuated liver injury by reducing inflammation. Mechanistically, catechin alleviated hepatic oxidative stress by inhibiting ROS accumulation, malondialdehyde (MDA) production, and GSH depletion. Furthermore, catechin, as a hepatic injury reparative agent, could counteract APAP-induced hepatocyte ferroptosis by activating the xCT/GPX4 pathway, and is expected to be a novel natural inhibitor of ferroptosis. Additionally, the transcriptomic results indicated that the inhibition of Stat1 by catechin is important for the management of AILI. Inhibition of signal transducer and activator of transcription 1 (STAT1) expression, achieved through the use of the STAT1 inhibitor fludarabine in vivo and small interfering RNA (siRNA) in vitro, was confirmed to attenuate APAP-induced ferroptosis. In conclusion, the present study identified a novel natural drug inhibitor of ferroptosis and revealed its mechanism of action to inhibit ferroptosis, regulate oxidative stress, and ameliorate inflammation in AILI. This further provides new insights into the novel natural ferroptosis inhibitors for the treatment of ROS-related inflammatory diseases.

Enzyme-Responsive Nanoparachute for Targeted miRNA Delivery: A Protective Strategy Against Acute Liver and Kidney Injury

MicroRNA (miRNA)-based therapy holds significant potential; however, its structural limitations pose a challenge to the full exploitation of its biomedical functionality. Framework nucleic acids are promising owing to their transportability, biocompatibility, and functional editability. MiRNA-125 is embedded into a nucleic acid framework to create an enzyme-responsive nanoparachute (NP), enhancing the miRNA loading capacity while preserving the attributes of small-scale framework nucleic acids and circumventing the uncertainty related to RNA exposure in conventional loading methods. An enzyme-sensitive sequence is designed in NP as a bioswitchable apparatus for cargo miRNAs release. NP is compared with conventional delivery modes and delivery vehicles, confirming its excellent transportability and sustained release properties. Moreover, NP confers good enzyme and serum resistance to the cargo miRNAs. Simultaneously, it can easily deliver miRNA-125 to liver and kidney lesions owing to its passive targeting properties. This allows for Keap1/Nrf2 pathway regulation and p53 protein targeting in the affected tissues. Additionally, NP negatively regulates the expression of Bax and Caspase-3. These combined actions help to inhibit oxidation, prevent cell cycle arrest, and reduce the apoptosis of liver and kidney cells. Consequently, this strategy offers a potential treatment for acute liver and kidney injury.

Maternal Gut Inflammation Aggravates Acute Liver Failure Through Facilitating Ferroptosis via Altering Gut Microbial Metabolism in Offspring

Microbial transmission from mother to infant is important for offspring microbiome formation and health. However, it is unclear whether maternal gut inflammation (MGI) during lactation influences mother-to-infant microbial transmission and offspring microbiota and disease susceptibility. In this study, it is found that MGI during lactation altered the gut microbiota of suckling pups by shaping the maternal microbiota in the gut and mammary glands. MGI-induced changes in the gut microbiota of suckling pups lasted into adulthood, resulting in the exacerbation of acute liver failure (ALF) caused by acetaminophen (APAP) in offspring. Specifically, MGI reduced the abundance of Lactobacillus reuteri (L. reuteri) and its metabolite indole-3-acetic acid (IAA) level in adult offspring. L. reuteri and IAA alleviated ALF in mice by promoting intestinal IL-22 production. Mechanistically, IL-22 limits APAP-induced excessive oxidative stress and ferroptosis by activating STAT3. The intestinal abundances of L. reuteri and IAA are inversely associated with the progression of patients with ALF. Overall, the study reveals the role of MGI in mother-to-infant microbial transmission and disease development in offspring, highlighting potential strategies for intervention in ALF based on the IAA-IL-22-STAT3 axis.

Bifidobacterium bifidum reduces oxidative stress and alters gut flora to mitigate acute liver injury caused by N-acetyl-p-aminophenol

Pharmacologically-induced liver injury from N-acetyl-p-aminophenol (APAP) overdose has become a leading cause of acute liver failure. Extensive research has elucidated the relationship between the intestinal microbiota and the pathophysiology of liver diseases. The growing body of evidence supporting the beneficial effects of probiotics, coupled with their established safety profile, has led to their widespread adoption in clinical practice. Among these, Bifidobacterium bifidum has garnered substantial attention due to its potential hepatoprotective properties, particularly in APAP-induced acute liver injury (AILI). However, the precise therapeutic effects and underlying mechanisms of its potential to alleviate drug-induced liver toxicity remain largely unexplored. To address this knowledge gap, the present study aimed to investigate the role of a new Bifidobacterium bifidum strain CGMCC No. 29,545 isolated from faeces on AILI. A mouse model was constructed through the administration of heat-killed or active B. bifidum CGMCC No. 29,545 preparations via gavage, followed by an intraperitoneal overdose of APAP. The results showed that the active B. bifidum could significantly reverse the increase in plasma transaminase levels and reduce the necrotic area of liver cells in AILI mice. A reduction in oxidative stress accompanied a reduction in this effect. Furthermore, B. bifidum attenuated plasma endotoxin levels and improved colonic inflammation, reducing hepatocyte apoptosis. The 16 S rRNA diversity of intestinal contents suggests that the involvement of B. bifidum in the regulation of the intestinal microbiota also plays a crucial role in the protection against AILI. The above results suggest that the amelioration of multiple injuries due to APAP overprocessing is closely related to active B. bifidum, which was confirmed by heat-killed B. bifidum preparations. Heat-killed B. bifidum preparations did not attenuate the degree of liver injury and oxidative stress caused by APAP treatment. The effects of two different active B. bifidum preparations provide new insights into the protective strategies of active B. bifidum as a probiotic against AILI.

Oral administration of astilbin mitigates acetaminophen-induced acute liver injury in mice by modulating the gut microbiota

Acetaminophen (APAP) overdose-induced acute liver injury (ALI) is characterized by extensive oxidative stress, and the clinical interventions for this adverse effect remain limited. Astilbin is an active compound found in the rhizome of Smilax glabra Roxb. with anti-inflammatory and antioxidant activities. Due to its low oral bioavailability, astilbin can accumulate in the intestine, which provides a basis for the interaction between astilbin and gut microbiota (GM). In the present study we investigated the protective effects of astilbin against APAP-induced ALI by focusing on the interaction between astilbin and GM. Mice were treated with astilbin (50 mg·kg-1·d-1, i.g.) for 7 days. After the last administration of astilbin for 2 h, the mice received APAP (300 mg/kg, i.g.) to induce ALI. We showed that oral administration of astilbin significantly alleviated APAP-induced ALI by altering the composition of GM and enriching beneficial metabolites including hydroxytyrosol (HT). GM depletion using an "antibiotics cocktail" or paraoral administration of astilbin abolished the hepatoprotective effects of astilbin. On the other hand, administration of HT (10 mg/kg, i.g.) caused similar protective effects in APAP-induced ALI mice. Transcriptomic analysis of the liver tissue revealed that HT inhibited reactive oxygen species and inflammation-related signaling in APAP-induced ALI; HT promoted activation of the Nrf2 signaling pathway to combat oxidative stress following APAP challenge in a sirtuin-6-dependent manner. These results highlight that oral astilbin ameliorates APAP-induced ALI by manipulating the GM and metabolites towards a more favorable profile, and provide an alternative therapeutic strategy for alleviating APAP-induced ALI.

Akkermansia muciniphila Mediated the Preventive Effect of Disulfiram on Acute Liver Injury via PI3K/Akt Pathway

Acetaminophen induced acute liver injury (ALI) has a high incidence and is a serious medical problem, but there is a lack of effective treatment. The enterohepatic axis is one of the targets of recent attention due to its important role in liver diseases. Disulfiram (DSF) is a multitarget drug that has been proven to play a role in a variety of liver diseases and can affect intestinal flora, but whether it can alleviate ALI is not clear. We utilised bacterial 16S rRNA gene profiling, antimicrobial treatments, and faecal microbiota transplantation tests to explore whether DSF therapy for ALI is dependent on gut microbiota. Our findings indicate that DSF primarily restores intestinal microbiome balance by modulating the abundance of Akkermansia muciniphila (A. muciniphila), leading to significant alleviation of ALI symptoms in a gut microbiota dependent manner. We also found that A. muciniphila can promote the activation of PI3K/Akt pathway, correct the Bcl-2/Bax ratio, and further inhibit hepatocyte apoptosis. In conclusion, DSF ameliorates ALI by modulating the intestinal microbiome and activating the PI3K/AKT pathway through A. muciniphila.

Pharma[e]cology: How the Gut Microbiome Contributes to Variations in Drug Response

Drugs represent our first, and sometimes last, line of defense for many diseases, yet despite decades of research we still do not fully understand why a given drug works in one patient and fails in the next. The human gut microbiome is one of the missing puzzle pieces, due to its ability to parallel and extend host pathways for drug metabolism, along with more complex host-microbiome interactions. Herein, we focus on the well-established links between the gut microbiome and drugs for heart disease and cancer, plus emerging data on neurological disease. We highlight the interdisciplinary methods that are available and how they can be used to address major remaining knowledge gaps, including the consequences of microbial drug metabolism for treatment outcomes. Continued progress in this area promises fundamental biological insights into humans and their associated microbial communities and strategies for leveraging the microbiome to improve the practice of medicine.

Zinc promotes microbial p-coumaric acid production that protects against cholestatic liver injury

Cholestatic liver disease (CLD) is a common liver disorder with limited treatment options. Here, we demonstrate that zinc (Zn) supplementation can alter the gut microbiome to mitigate cholestatic liver injury. Oral Zn altered the microbiota of mice and humans (this study was registered at clinicaltrials.gov [NCT05597137]), increasing the abundance of Blautia producta (B. producta) and promoting the generation of p-coumaric acid. Additionally, p-coumaric acid concentrations were negatively correlated with liver injury parameters in CLD patients. In mice, the protective effects of Zn were partially mediated by p-coumaric acid, which directly bound to nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) and suppressed the production of reactive oxygen species (ROS) in hepatocytes, thus preventing hepatocyte cell death and liver damage. Additionally, knocking out the histidine ammonia-lyase, which catalyzes the conversion of tyrosine to p-coumaric acid in B. producta, blunted the protective effects of Zn. These findings highlight a host-microbiota interaction that is stimulated by Zn supplementation, providing potential benefits for CLD.

Alisma plantago-aquatica polysaccharides ameliorate acetaminophen-induced acute liver injury by regulating hepatic metabolic profiles and modulating gut microbiota

Acetaminophen (APAP) has emerged as a predominant contributor to acute liver failure (ALF) in United States. Alismatis rhizoma, a commonly used traditional herbal medicine, contains small molecular components with extensive hepatoprotective activity. However, the specific role of Alismatis rhizoma polysaccharide (ARP) in liver protection remains unclear. ARP50 and ARP70, derived through graded alcohol precipitation and refinement, predominantly consisted of varying proportions of glucose, galactose, and arabinose. In vitro experiments on free radical scavenging demonstrated notable antioxidant capabilities of ARP50 and ARP70. To investigate the hepatoprotective effects, an APAP-induced acute liver injury (ALI) model was established in mice. ARP50 and ARP70 exerted dose-dependent therapeutic effects on APAP-induced liver injury. Further analysis of liver metabolites revealed that ARPs facilitated the reconstruction of the liver antioxidant system by modulating the metabolism network centered on l-glutamine. In addition, the abundance of gut microbiota was altered under the influence of ARPs. ARP50 significantly reduced the levels of Pseudarthrobacter and markedly increased the levels of Faecalibacterium，At the same time, ARP50 could increase the levels of acetic acid in the liver and serum. Meanwhile, ARP70 significantly increased the abundance of Dubosiella, Muribaculum, Ileibacterium, and Prevotellaceae UCG 001, while reducing the abundance of Escherichia Shigella and Pseudarthrobacter. The results indicated that ARPs could exert a protective effect against APAP-induced acute liver injury by reshaping the liver metabolic profile and modulating the gut microbiota.

Host-derived Lactobacillus plantarum alleviates hyperuricemia by improving gut microbial community and hydrolase-mediated degradation of purine nucleosides

The gut microbiota is implicated in the pathogenesis of hyperuricemia (HUA) and gout. However, it remains unclear whether probiotics residing in the host gut, such as Lactobacillus, can prevent HUA development. Herein, we isolated Lactobacillus plantarum SQ001 from the cecum of HUA geese and conducted in vitro assays on uric acid (UA) and nucleoside co-culture. Metabolomics and genome-wide analyses, revealed that this strain may promote nucleoside uptake and hydrolysis through its nucleoside hydrolase gene. The functional role of iunH gene was confirmed via heterologous expression and gene knockout studies. Oral administration of L. plantarum SQ001 resulted in increased abundance of Lactobacillus species and reduced serum UA levels. Furthermore, it downregulated hepatic xanthine oxidase, a key enzyme involved in UA synthesis, as well as renal reabsorption protein GLUT9, while enhancing the expression of renal excretion protein ABCG2. Our findings suggest that L. plantarum has potential to ameliorate gut microbial dysbiosis with HUA, thereby offering insights into its potential application as a probiotic therapy for individuals with HUA or gout.

Metabolic Dysregulation and Metabolite Imbalances in Acute-on-chronic Liver Failure: Impact on Immune Status

Liver failure encompasses a range of severe clinical syndromes resulting from the deterioration of liver function, triggered by factors both within and outside the liver. While the definition of acute-on-chronic liver failure (ACLF) may vary by region, it is universally recognized for its association with multiorgan failure, a robust inflammatory response, and high short-term mortality rates. Recent advances in metabolomics have provided insights into energy metabolism and metabolite alterations specific to ACLF. Additionally, immunometabolism is increasingly acknowledged as a pivotal mechanism in regulating immune cell functions. Therefore, understanding the energy metabolism pathways involved in ACLF and investigating how metabolite imbalances affect immune cell functionality are crucial for developing effective treatment strategies for ACLF. This review methodically examined the immune and metabolic states of ACLF patients and elucidated how alterations in metabolites impact immune functions, offering novel perspectives for immune regulation and therapeutic management of liver failure.

Current progress on the microbial therapies for acute liver failure

Acute liver failure (ALF), associated with a clinical fatality rate exceeding 80%, is characterized by severe liver damage resulting from various factors in the absence of pre-existing liver disease. The role of microbiota in the progression of diverse liver diseases, including ALF, has been increasingly recognized, with the interactions between the microbiota and the host significantly influencing both disease onset and progression. Despite growing interest in the microbiological aspects of ALF, comprehensive reviews remain limited. This review critically examines the mechanisms and efficacy of microbiota-based treatments for ALF, focusing on their role in prevention, treatment, and prognosis over the past decade.

Magnesium Matters: A Comprehensive Review of Its Vital Role in Health and Diseases

Magnesium (Mg), an essential mineral abundantly present within the human body, is intricately involved in a multitude of biochemical processes vital for maintaining health and overall well-being. This review aims to delve into the multifaceted impact of Mg on human health, exploring its physiological functions, dietary sources, and potential health implications of deficiency or insufficiency. Mg plays a pivotal role in various physiological processes, including energy metabolism, muscle contraction, protein synthesis, and DNA synthesis. It acts as a cofactor for more than 300 enzymatic reactions, facilitating the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) for energy production. Moreover, Mg is essential for the proper functioning of ion channels, particularly calcium channels, influencing nerve transmission and muscle relaxation. Mg is naturally found in a wide array of foods, with green leafy vegetables, whole grains, nuts, seeds, and legumes being particularly rich sources. Additionally, certain fortified foods and dietary supplements provide supplemental Mg intake. Deficiency or insufficiency of mg can have profound implications for health. Inadequate mg levels have been associated with increased risks of various chronic diseases, including hypertension, type 2 diabetes, osteoporosis, and cardiovascular diseases. Furthermore, mg deficiency may manifest as symptoms such as muscle weakness, fatigue, tremors, and irregular heartbeat. Numerous studies have elucidated the relationship between mg intake and the risk of developing chronic diseases. For instance, epidemiological evidence suggests that higher mg intake is associated with a reduced risk of hypertension, possibly due to its vasodilatory effects and influence on blood pressure regulation mechanisms. Similarly, mg has been implicated in the pathophysiology of type 2 diabetes, with mg deficiency contributing to insulin resistance and impaired glucose metabolism. Furthermore, adequate mg intake is crucial for maintaining bone density and reducing the risk of osteoporosis, as mg plays a vital role in bone mineralization and bone health. Understanding the importance of mg in human physiology underscores the significance of ensuring adequate mg intake through diet or supplementation. Healthcare professionals play a critical role in educating individuals about the importance of incorporating mg-rich foods into their diets and considering mg supplementation when necessary, particularly for individuals at risk of deficiency or those with chronic diseases. Mg is an indispensable mineral with far-reaching implications for human health. Its involvement in various physiological processes underscores its importance in maintaining overall health and well-being. Ensuring adequate mg intake is essential for preventing deficiency-related health complications and reducing the risk of chronic diseases. Further research is warranted to elucidate the optimal strategies for mg supplementation and its potential therapeutic applications in disease prevention and management.

Akkermansia muciniphila Metabolite Inosine Inhibits Castration Resistance in Prostate Cancer

Prostate cancer (PCa) is initially sensitive to androgen deprivation therapy (ADT) but ultimately develops resistance and progresses to castration-resistant prostate cancer (CRPC) with a poor prognosis. This study indicated that some PCa patients and mice were more sensitive to ADT and entered CRPC later, which was related to the gut microbiota, especially the enrichment of Akkermansia muciniphila (AKK). Untargeted metabolomics analysis found that serum inosine level was upregulated in the treatment-sensitive group and significantly correlated with AKK. Furthermore, we revealed that intestinal permeability and serum lipopolysaccharide (LPS) levels increased in treatment-resistant mice. LPS stimulated the upregulation of p-NF-κB p65 and AR in tumors. Supplementing AKK metabolite inosine could alleviate intestinal barrier damage and reduce serum LPS level, ultimately inhibiting castration resistance via the LPS/NF-κB/AR axis. Finally, we constructed a predictive model for CRPC combining gut microbiota and clinical information (AUC = 0.729). This study revealed the potential mechanism of gut microbiota on CRPC and provided potential therapeutic targets and prognostic indicators.

The Discovery of Gut Microbial Metabolites as Modulators of Host Susceptibility to Acetaminophen-Induced Hepatotoxicity

The mammalian gut microbiota plays diverse and essential roles in modulating host physiology. Key mediators determining the outcome of the microbiota-host interactions are the small molecule metabolites produced by the gut microbiota. The liver is a major organ exposed to gut microbial metabolites, and it serves as the nexus for maintaining healthy interactions between the gut microbiota and the host. At the same time, the liver is the primary target of potentially harmful gut microbial metabolites. In this review, we provide an up-to-date list of gut microbial metabolites that have been identified to either increase or decrease host susceptibility to acetaminophen (APAP)-induced liver injury. The signaling pathways and molecular factors involved in the progression of APAP-induced hepatotoxicity are well-established, and we propose that the mouse model of APAP-induced hepatotoxicity serves as a model system for uncovering gut microbial metabolites with previously unknown functions. Furthermore, we envision that gut microbial metabolites identified to alter APAP-induced hepatotoxicity likely have broader implications in other liver diseases. SIGNIFICANCE STATEMENT: This review provides an overview of the role of the gut microbiota in modulating the host susceptibility to acetaminophen (APAP)-induced liver injury. It focuses on the roles of gut bacterial small molecule metabolites as mediators of the interaction between the gut microbiota and the liver. It also illustrates the utility of APAP-induced liver injury as a model to identify gut microbial metabolites with biological function.

Hericium erinaceus polysaccharides ameliorate nonalcoholic fatty liver disease via gut microbiota and tryptophan metabolism regulation in an aged laying hen model

Polysaccharides extracted from Hericium erinaceus (HEP) exhibit hepatoprotective activity in the alleviation of non-alcoholic fatty liver disease (NAFLD); however, the mechanisms underlying whether and how HEP regulation of the gut microbiota to alleviate liver-associated metabolic disorders are not well understood. This study used an aged laying hen model to explore the mechanisms through which HEP alleviates NAFLD, with a focus on regulatory function of HEP in the gut microbiome. The results showed that HEP ameliorated hepatic damage and metabolic disorders by improving intestinal barrier function and shaping the gut microbiota and tryptophan metabolic profiles. HEP increased the abundance of Lactobacillus and certain tryptophan metabolites, including indole-3-carboxylic acid, kynurenic acid, and tryptamine in the cecum. These metabolites upregulated the expression of ZO-1 and Occludin by activating the AhR and restoring the intestinal barrier integrity. The increased intestinal barrier functions decreased LPS transferring from the intestine to the liver, inhibited hepatic LPS/TLR4/MyD88/NF-κB pathway activation, and reduced hepatic inflammatory response and apoptosis. Fecal microbiota transplantation experiments further confirmed that the hepatoprotective effect is likely mediated by HEP-altered gut microbiota and their metabolites. Overall, dietary HEP could ameliorate the hepatic damage and metabolic disorders of NAFLD through regulating the "gut-liver" axis.

Magnesium alleviates extracellular histone-induced apoptosis and defective bacterial phagocytosis in macrophages by regulating intracellular calcium signal

Extracellular histones have been determined as important mediators of sepsis, which induce excessive inflammatory responses in macrophages and impair innate immunity. Magnesium (Mg2+), one of the essential nutrients of the human body, contributes to the proper regulation of immune function. However, no reports indicate whether extracellular histones affect survival and bacterial phagocytosis in macrophages and whether Mg2+ is protective against histone-induced macrophage damage. Our clinical data revealed a negative correlation between circulating histone and monocyte levels in septic patients, and in vitro experiments confirmed that histones induced mitochondria-associated apoptosis and defective bacterial phagocytosis in macrophages. Interestingly, our clinical data also indicated an association between lower serum Mg2+ levels and reduced monocyte levels in septic patients. Moreover, in vitro experiments demonstrated that Mg2+ attenuated histone-induced apoptosis and defective bacterial phagocytosis in macrophages through the PLC/IP3R/STIM-mediated calcium signaling pathway. Importantly, further animal experiments proved that Mg2+ significantly improved survival and attenuated histone-mediated lung injury and macrophage damage in histone-stimulated mice. Additionally, in a cecal ligation and puncture (CLP) + histone-induced injury mouse model, Mg2+ inhibited histone-mediated apoptosis and defective phagocytosis in macrophages and further reduced bacterial load. Overall, these results suggest that Mg2+ supplementation may be a promising treatment for extracellular histone-mediated macrophage damage in sepsis.

Targeting gut microbiota to counteract acetaminophen-induced acute liver injury

Acetaminophen (N-acetyl-p-aminophenol; APAP) overdose-induced acute liver injury (AILI) is a huge threat to public health worldwide. Recent research clearly shows that the intestinal microbiota (IM) is a key modulator in AILI. Herein, I discuss the latest findings on how the IM regulates AILI and the potential interventions to combat AILI by targeting the IM.

Mg and the microbiome: A liver-protective duo

Acute liver failure continues to carry high morbidity and mortality with limited therapeutic options. In this issue of Cell Host & Microbe, Li et al. demonstrate that oral magnesium can protect against acetaminophen-induced liver injury through alterations in the microbiome.

Dietary modulation of gut microbiota affects susceptibility to drug-induced liver injury

The rising incidence of drug-induced liver injury (DILI) parallels contemporary dietary shifts that have transformed the composition of human gut microbiota. The relationship between these phenomena remains unknown. Here, it is unveiled that a high fiber diet (HFiD) provides substantial protection against DILI, whereas a western style diet (WSD) significantly exacerbates DILI. Gut microbiota transplantation further confirms these differing outcomes are mediated by diet-induced variations in gut microbiota. Mechanistically, Lactobacillus acidophilus, enriched by HFiD, alleviates DILI through its metabolite indole-3-lactic acid (ILA), which activates the AhR/Nrf2 signaling pathway, thus enhancing hepatocellular antioxidant defenses and detoxification capacity. In the clinical intervention of subjects with prediabetes (N = 330), dietary fiber intervention enriches intestinal L. acidophilus, elevates serum ILA levels, and improves liver function. Conversely, WSD induces disturbance in bile acid metabolism and dysbiosis in gut microbiota, which impairs the intestinal barrier and facilitates the translocation of lipopolysaccharides (LPS) to the liver, thus triggering inflammatory responses and exacerbating DILI. These results demonstrate that dietary patterns significantly influence the onset of DILI by modulating gut microbiota. This novel insight expands the understanding of DILI risk factors and highlights the potential of dietary modifications as a preventive strategy against DILI.

Gut microbiota-mediated C-sulfonate metabolism impairs the bioavailability and anti-cholestatic efficacy of andrographolide

Cholestatic liver injury results from the accumulation of toxic bile acids in the liver, presenting a therapeutic challenge with no effective treatment available to date. Andrographolide (AP) has exhibited potential as a treatment for cholestatic liver disease. However, its limited oral bioavailability poses a significant obstacle to harnessing its potent therapeutic properties and restricts its clinical utility. This limitation is potentially attributed to the involvement of gut microbiota in AP metabolism. In our study, employing pseudo-germ-free, germ-free and strain colonization animal models, along with 16S rRNA and shotgun metagenomic sequencing analysis, we elucidate the pivotal role played by gut microbiota in the C-sulfonate metabolism of AP, a process profoundly affecting its bioavailability and anti-cholestatic efficacy. Subsequent investigations pinpoint a specific enzyme, adenosine-5'-phosphosulfate (APS) reductase, predominantly produced by Desulfovibrio piger, which catalyzes the reduction of SO42- to HSO3-. HSO3- subsequently interacts with AP, targeting its C=C unsaturated double bond, resulting in the formation of the C-sulfonate metabolite, 14-deoxy-12(R)-sulfo andrographolide (APM). Inhibition of APS reductase leads to a notable enhancement in AP bioavailability and anti-cholestatic efficacy. Furthermore, employing RNA sequencing analysis and farnesoid X receptor (FXR) knockout mice, our findings suggest that AP may exert its anti-cholestatic effects by activating the FXR pathway to promote bile acid efflux. In summary, our study unveils the significant involvement of gut microbiota in the C-sulfonate metabolism of AP and highlights the potential benefits of inhibiting APS reductase to enhance its therapeutic effects. These discoveries provide valuable insights into enhancing the clinical applicability of AP as a promising treatment for cholestatic liver injury.