xCT-mediated glutamate excretion in white adipocytes stimulates interferon-γ production by natural killer cells in obesity.

Obesity-mediated hypoxic stress underlies inflammation, including interferon (IFN)-γ production by natural killer (NK) cells in white adipose tissue. However, the effects of obesity on NK cell IFN-γ production remain obscure. Here, we show that hypoxia promotes xCT-mediated glutamate excretion and C-X-C motif chemokine ligand 12 (CXCL12) expression in white adipocytes, resulting in CXCR4+ NK cell recruitment. Interestingly, this spatial proximity between adipocytes and NK cells induces IFN-γ production in NK cells by stimulating metabotropic glutamate receptor 5 (mGluR5). IFN-γ then triggers inflammatory activation of macrophages and augments xCT and CXCL12 expression in adipocytes, forming a bidirectional pathway. Genetic or pharmacological inhibition of xCT, mGluR5, or IFN-γ receptor in adipocytes or NK cells alleviates obesity-related metabolic disorders in mice. Consistently, patients with obesity showed elevated levels of glutamate/mGluR5 and CXCL12/CXCR4 axes, suggesting that a bidirectional pathway between adipocytes and NK cells could be a viable therapeutic target in obesity-related metabolic disorders.

Comprehensive transcriptomic analysis and meta-analysis identify therapeutic effects of N-acetylcysteine in nonalcoholic fatty liver disease.

Introduction: The continuous rise in the prevalence of nonalcoholic fatty liver disease (NAFLD) is emerging as a global health issue. Although the protective effects of N-acetylcysteine (NAC), an antioxidant, against various diseases have been reported, it is still unclear whether NAC has therapeutic potential in NAFLD. Thus, the present meta-analysis aimed to investigate the efficacy of NAC on NAFLD in preclinical studies. Methods: By searching PubMed, Web of Science, and Cochrane Library, 13 studies were included. The methodological quality was assessed based on the SYstematic Review Centre for Laboratory animal Experimentation guideline, and heterogeneity was evaluated with I 2 and p values. Publication bias was assessed by Egger's test and sensitivity analysis was performed. Results: The results showed that NAC treatment significantly improved systemic and hepatic lipid metabolism (p < 0.01), inflammation-related liver injury (p < 0.01), glucose intolerance (p < 0.05), and hepatic steatosis (p < 0.01) by restoring hepatic glutathione (GSH) (p < 0.05) and GSH reductase (p < 0.05) levels compared to controls in NAFLD-induced animals. Consistently, in bulk, single-cell, and spatial transcriptomics data, the abovementioned target pathways of NAC were strongly associated with NAFLD development in mice and patients. Conclusion: Our study suggests that NAC has therapeutic potential for NAFLD and should be considered for future clinical trials.

Isolation of Hepatic Stellate Cells and Lymphocytes for Co-culture Systems.

In contrast to quiescent hepatic stellate cells (HSCs), activated HSCs play crucial roles in the development of liver fibrosis by producing a huge amount of extracellular matrix such as collagen fibers. However, recent lines of evidence have also highlighted the immunoregulatory functions of HSCs, in which they interact with diverse hepatic lymphocytes to produce cytokines and chemokines, release extracellular vesicles, or express specific ligands. Therefore, to understand the exact interactions between HSCs and lymphocyte subsets in the pathogenesis of the liver disease, it is valuable to establish experimental procedures to isolate HSC and co-culture them with lymphocytes. Here, we introduce the efficient methods to isolate and purify mouse HSCs and hepatic lymphocytes using density gradient centrifugation, microscopic observation, and flow cytometry. Moreover, we provide the direct and indirect co-culturing methods of isolated mouse HSCs and hepatic lymphocytes based upon the purpose of the study.

Exosome-Based Delivery of Super-Repressor IκBα Alleviates Alcohol-Associated Liver Injury in Mice.

Activation of Kupffer cells (KCs) by gut-derived lipopolysaccharide (LPS) instigates nuclear factor-κB (NF-κB)-mediated inflammatory responses in alcohol-associated liver diseases (ALD). Here, we utilized a novel optogenetically engineered exosome technology called 'exosomes for protein loading via optically reversible protein-protein interactions (EXPLOR)' to efficiently deliver the super-repressor IκB-loaded exosomes (Exo-srIκB) to the liver and examined its therapeutic potential in acute-on-chronic alcohol-associated liver injury. We detected enhanced uptake of DiI-labeled Exo-srIκB by LPS-treated inflammatory KCs, which suppressed LPS-induced inflammatory gene expression levels. In animal experiments, a single intravenous injection of Exo-srIκB prior to alcohol binge drinking significantly attenuated alcohol-associated hepatic steatosis and infiltration of neutrophils and macrophages but not a liver injury. Notably, three consecutive days of Exo-srIκB injection remarkably reduced alcohol-associated liver injury, steatosis, apoptosis of hepatocytes, fibrosis-related gene expression levels in hepatic stellate cells, infiltration of neutrophils and macrophages, and inflammatory gene expression levels in hepatocytes and KCs. In particular, the above effects occurred with inhibition of nuclear translocation of NF-κB in liver tissues, and these beneficial effects of Exo-srIκB on ALD were shown regardless of doses. Our results suggest an exosome-based modulation of NF-κB activity in KCs by Exo-srIκB as a novel and efficient therapeutic approach in ALD.

The Efficacy of Panax ginseng for the Treatment of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies.

Although tremendous research has reported the protective effects of natural compounds in nonalcoholic fatty liver disease (NAFLD), there is still no approved drug. This study aimed to examine the efficacy of Panax ginseng in NAFLD in preclinical studies. A total of 41 studies were identified by searching the PubMed, Web of Science, and Cochrane Library databases. The methodological quality was assessed by the risk of bias tool from the Systematic Review Center for Laboratory Animal Experimentation. The standardized mean difference (SMD) with a 95% confidence interval was calculated, and the random effects model was used to examine overall efficacy or heterogeneity. The publication bias was analyzed by Egger's test. The results showed that Panax ginseng treatment significantly reduced the systemic levels of alanine aminotransferase (SMD: -2.15 IU/L; p < 0.0001), aspartate aminotransferase (SMD: -2.86 IU/L; p < 0.0001), triglyceride (SMD: -2.86 mg/dL; p < 0.0001), total cholesterol (SMD: -1.69 mg/dL; p < 0.0001), low-density lipoprotein (SMD: -1.46 mg/dL; p < 0.0001), and fasting glucose (SMD: -1.45 mg/dL; p < 0.0001) while increasing high-density lipoprotein (SMD: 1.22 mg/dL; p = 0.0002) in NAFLD regardless of animal models or species. These findings may suggest that Panax ginseng is a promising therapeutic agent for NAFLD treatment.

Catecholamine induces Kupffer cell apoptosis via growth differentiation factor 15 in alcohol-associated liver disease.

Chronic alcohol consumption often induces hepatic steatosis but rarely causes severe inflammation in Kupffer cells (KCs) despite the increased hepatic influx of lipopolysaccharide (LPS), suggesting the presence of a veiled tolerance mechanism. In addition to LPS, the liver is affected by several gut-derived neurotransmitters through the portal blood, but the effects of catecholamines on KCs have not been clearly explored in alcohol-associated liver disease (ALD). Hence, we investigated the regulatory roles of catecholamine on inflammatory KCs under chronic alcohol exposure. We discovered that catecholamine levels were significantly elevated in the cecum, portal blood, and liver tissues of chronic ethanol-fed mice. Increased catecholamines induced mitochondrial translocation of cytochrome P450 2E1 in perivenous hepatocytes expressing the ß2-adrenergic receptor (ADRB2), leading to the enhanced production of growth differentiation factor 15 (GDF15). Subsequently, GDF15 profoundly increased ADRB2 expression in adjacent inflammatory KCs to facilitate catecholamine/ADRB2-mediated apoptosis. Single-cell RNA sequencing of KCs confirmed the elevated expression of Adrb2 and apoptotic genes after chronic ethanol intake. Genetic ablation of Adrb2 or hepatic Gdf15 robustly decreased the number of apoptotic KCs near perivenous areas, exacerbating alcohol-associated inflammation. Consistently, we found that blood and stool catecholamine levels and perivenous GDF15 expression were increased in patients with early-stage ALD along with an increase in apoptotic KCs. Our findings reveal a novel protective mechanism against ALD, in which the catecholamine/GDF15 axis plays a critical role in KC apoptosis, and identify a unique neuro-metabo-immune axis between the gut and liver that elicits hepatoprotection against alcohol-mediated pathogenic challenges.

NAMPT mitigates colitis severity by supporting redox-sensitive activation of phagocytosis in inflammatory macrophages.

Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in the nicotinamide adenine dinucleotide (NAD+) salvage pathway and plays a crucial role in the maintenance of the NAD+ pool during inflammation. Considering that macrophages are essential for tissue homeostasis and inflammation, we sought to examine the functional impact of NAMPT in inflammatory macrophages, particularly in the context of inflammatory bowel disease (IBD). In this study, we show that mice with NAMPT deletion within the myeloid compartment (Namptf/fLysMCre+/-, Nampt mKO) have more pronounced colitis with lower survival rates, as well as numerous uncleared apoptotic corpses within the mucosal layer. Nampt-deficient macrophages exhibit reduced phagocytic activity due to insufficient NAD+ abundance, which is required to produce NADPH for the oxidative burst. Nicotinamide mononucleotide (NMN) treatment rescues NADPH levels in Nampt mKO macrophages and sustains superoxide generation via NADPH oxidase. Consequently, Nampt mKO mice fail to clear dead cells during tissue repair, leading to substantially prolonged chronic colitis. Moreover, systemic administration of NMN, to supply NAD+, effectively suppresses the disease severity of DSS-induced colitis. Collectively, our findings suggest that activation of the NAMPT-dependent NAD+ biosynthetic pathway, via NMN administration, is a potential therapeutic strategy for managing inflammatory diseases.

Metabotropic Glutamate Receptor 5 in Natural Killer Cells Attenuates Liver Fibrosis by Exerting Cytotoxicity to Activated Stellate Cells.

BACKGROUND AND AIMS: The important roles of glutamate and metabotropic glutamate receptor 5 (mGluR5) in HSCs have recently been reported in various liver diseases; however, the mechanism linking the glutamine/glutamate metabolism and mGluR5 in liver fibrosis remains unclear. Here, we report that mGluR5 activation in natural killer (NK) cells attenuates liver fibrosis through increased cytotoxicity and interferon-γ (IFN-γ) production in both mice and humans. APPROACH AND RESULTS: Following 2-week injection of carbon tetrachloride (CCl4 ) or 5-week methionine-deficient and choline-deficient diet, liver fibrosis was more aggravated in mGluR5 knockout mice with significantly decreased frequency of NK cells compared with wild-type mice. Consistently, NK cell-specific mGluR5 knockout mice had aggravated CCl4 -induced liver fibrosis with decreased production of IFN-γ. Conversely, in vitro activation of mGluR5 in NK cells significantly increased the expression of anti-fibrosis-related genes including Ifng, Prf1 (perforin), and Klrk1 (killer cell lectin like receptor K1) and the production of IFN-γ through the mitogen-activated extracellular signal-regulated kinase/extracellular signal-related kinase pathway, contributing to the increased cytotoxicity against activated HSCs. However, we found that the uptake of glutamate was increased in activated HSCs, resulting in shortage of extracellular glutamate and reduced stimulation of mGluR5 in NK cells. Consequently, this could enable HSCs to evade NK cell cytotoxicity in advanced liver fibrosis. In vivo, pharmacologic activation of mGluR5 accelerated CCl4 -induced liver fibrosis regression by restoring NK cell cytotoxicity. In humans, mGluR5 activation enhanced the cytotoxicity of NK cells isolated from healthy donors, but not from patients with cirrhosis with significantly reduced mGluR5 expression in NK cells. CONCLUSIONS: mGluR5 plays important roles in attenuating liver fibrosis by augmenting NK cell cytotoxicity, which could be used as a potential therapeutic target for liver fibrosis.

Disease-specific eQTL screening reveals an anti-fibrotic effect of AGXT2 in non-alcoholic fatty liver disease.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) poses an increasing clinical burden. Genome-wide association studies have revealed a limited contribution of genomic variants to the disease, requiring alternative but robust approaches to identify disease-associated variants and genes. We carried out a disease-specific expression quantitative trait loci (eQTL) screen to identify novel genetic factors that specifically act on NAFLD progression on the basis of genotype. METHODS: We recruited 125 Korean patients (83 with biopsy-proven NAFLD and 42 without NAFLD) and performed eQTL analyses using 21,272 transcripts and 3,234,941 genotyped and imputed single nucleotide polymorphisms. We then selected eQTLs that were detected only in the NAFLD group, but not in the control group (i.e., NAFLD-eQTLs). An additional cohort of 162 Korean individuals with NAFLD was used for replication. The function of the selected eQTL toward NAFLD development was validated using HepG2, primary hepatocytes and NAFLD mouse models. RESULTS: The NAFLD-specific eQTL screening yielded 242 loci. Among them, AGXT2, encoding alanine-glyoxylate aminotransferase 2, displayed decreased expression in patients with NAFLD homozygous for the non-reference allele of rs2291702, compared to no-NAFLD individuals with the same genotype (p = 4.79 × 10-6). This change was replicated in an additional 162 individuals, yielding a combined p value of 8.05 × 10-8 from a total of 245 patients with NAFLD and 42 controls. Knockdown of AGXT2 induced palmitate-overloaded hepatocyte death by increasing endoplasmic reticulum stress, and exacerbated NAFLD diet-induced liver fibrosis in mice, while overexpression of AGXT2 attenuated liver fibrosis and steatosis. CONCLUSIONS: We identified a new molecular role for AGXT2 in NAFLD. Our overall approach will serve as an efficient tool for uncovering novel genetic factors that contribute to liver steatosis and fibrosis in patients with NAFLD. LAY SUMMARY: Elucidating causal genes for non-alcoholic fatty liver disease (NAFLD) has been challenging due to limited tissue availability and the polygenic nature of the disease. Using liver and blood samples from 125 Korean individuals (83 with NAFLD and 42 without NAFLD), we devised a new analytic method to identify causal genes. Among the candidates, we found that AGXT2-rs2291702 protects against liver fibrosis in a genotype-dependent manner with the potential for therapeutic interventions. Our approach enables the discovery of causal genes that act on the basis of genotype.

Ginsenoside F2 attenuates chronic-binge ethanol-induced liver injury by increasing regulatory T cells and decreasing Th17 cells.

BACKGROUND: Recently, beneficial roles of ginsenoside F2 (GF2), a minor constituent of Panax ginseng, have been demonstrated in diverse inflammatory diseases. However, its roles in alcoholic liver inflammation and injury have not been clearly understood. Here, we investigated the underlying mechanism by which GF2 ameliorated alcoholic liver injury. METHODS: To induce alcoholic liver injury, C57BL/6J wild type (WT) or interleukin (IL)-10 knockout (KO) mice were orally administered with ethanol (3 g/kg) or ethanol-containing GF2 (50 mg/kg) for 2 wk. Liver injury and infiltration of macrophages and neutrophils were evaluated by serum biochemistry and immunohistochemistry, respectively. The changes of hepatic immune cells were assessed by flow cytometry and polymerase chain reaction analysis. In vitro differentiation of naïve T cells was performed. RESULTS: GF2 treatment significantly attenuated alcoholic liver injury, in which infiltrations of inflammatory macrophages and neutrophils were decreased. Moreover, the frequencies of Foxp3+ regulatory T cells (Tregs) increased but IL-17-producing T (Th17) cells decreased in GF2-treated mice compared to controls. Furthermore, the mRNA expression of IL-10 and Foxp3 was significantly increased, whereas IL-17 mRNA expression was suppressed in GF2-treated mice. However, these beneficial roles of GF2 were not observed in GF2-treated IL-10 KO mice, suggesting a critical role of IL-10. Similarly, GF2 treatment suppressed differentiation of naïve T cells into Th17 cells by inhibiting RORγt expression and stimulating Foxp3 expression. CONCLUSION: The present study suggests that GF2 treatment attenuates alcoholic liver injury by increasing IL-10 expression and Tregs and decreasing IL-17 expression and Th17 cells.

Oxidative stress and glutamate excretion in alcoholic steatosis: Metabolic synapse between hepatocyte and stellate cell.

Chronic alcohol consumption induces the development of alcoholic steatosis in the liver, which is one of the most widespread liver diseases worldwide. During general alcohol metabolism, hepatocytes generate mitochondria- and cytochrome P450 2E1 (CYP2E1)-mediated reactive oxygen species (ROS) whose accumulation elicits activation of the hepatic anti-oxidant system, including glutathione (GSH). However, chronic alcohol consumption decreases GSH generation through cysteine deficiency by suppressing the methionine cycle and trans-sulfuration system, whereas it turns on an alternative defense pathway, such as the xCT transporter, to compensate for GSH shortage. The xCT transporter mediates the uptake of cystine coupled to the efflux of glutamate, leading to an increase in blood glutamate. In response to the elevated glutamate in the liver, the expression of metabotropic glutamate receptor 5 (mGluR5) is up-regulated in hepatic stellate cells (HSCs) along with enhanced production of 2-arachidonoylglycerol, which in turn stimulates cannabinoid receptor 1 (CB1R) on neighboring hepatocytes to increase de novo lipogenesis. On the other hand, blockade of mGluR5 and CB1R attenuates alcoholic steatosis. Interestingly, although the increased expression of CYP2E1-mediated xCT and ROS generation are mainly observed at the perivenous area (zone 3), fat accumulation is mostly detected at hepatic zone 2. To resolve this discrepancy, this review summarizes recent advances on glutamate/mGluR5-derived alcoholic steatosis and zone-dependently different responses to alcohol intake. In addition, the bidirectional loop pathway and its unique metabolic synapse between hepatocytes and HSCs are discussed.

Mitochondrial Double-Stranded RNA in Exosome Promotes Interleukin-17 Production Through Toll-Like Receptor 3 in Alcohol-associated Liver Injury.

BACKGROUND AND AIMS: Mitochondrial double-stranded RNA (mtdsRNA) and its innate immune responses have been reported previously; however, mtdsRNA generation and its effects on alcohol-associated liver disease (ALD) remain unclear. Here, we report that hepatic mtdsRNA stimulates toll-like receptor 3 (TLR3) in Kupffer cells through the exosome (Exo) to enhance interleukin (IL)-17A (IL-17A) production in ALD. APPROACH AND RESULTS: Following binge ethanol (EtOH) drinking, IL-17A production primarily increased in γδ T cells of wild-type (WT) mice, whereas the production of IL-17A was mainly facilitated by CD4+ T cells in acute-on-chronic EtOH consumption. These were not observed in TLR3 knockout (KO) or Kupffer cell-depleted WT mice. The expression of polynucleotide phosphorylase, an mtdsRNA-restricting enzyme, was significantly decreased in EtOH-exposed livers and hepatocytes of WT mice. Immunostaining revealed that mtdsRNA colocalized with the mitochondria in EtOH-treated hepatocytes from WT mice and healthy humans. Bioanalyzer analysis revealed that small-sized RNAs were enriched in EtOH-treated Exos (EtOH-Exos) rather than EtOH-treated microvesicles in hepatocytes of WT mice and humans. Quantitative real-time PCR and RNA sequencing analyses indicated that mRNA expression of mitochondrial genes encoded by heavy and light strands was robustly increased in EtOH-Exos from mice and humans. After direct treatment with EtOH-Exos, IL-1ß expression was significantly increased in WT Kupffer cells but not in TLR3 KO Kupffer cells, augmenting IL-17A production of γδ T cells in mice and humans. CONCLUSIONS: EtOH-mediated generation of mtdsRNA contributes to TLR3 activation in Kupffer cells through exosomal delivery. Consequently, increased IL-1ß expression in Kupffer cells triggers IL-17A production in γδ T cells at the early stage that may accelerate IL-17A expression in CD4+ T cells in the later stage of ALD. Therefore, mtdsRNA and TLR3 may function as therapeutic targets in ALD.

Glutamate Signaling in Hepatic Stellate Cells Drives Alcoholic Steatosis.

Activation of hepatocyte cannabinoid receptor-1 (CB1R) by hepatic stellate cell (HSC)-derived 2-arachidonoylglycerol (2-AG) drives de novo lipogenesis in alcoholic liver disease (ALD). How alcohol stimulates 2-AG production in HSCs is unknown. Here, we report that chronic alcohol consumption induced hepatic cysteine deficiency and subsequent glutathione depletion by impaired transsulfuration pathway. A compensatory increase in hepatic cystine-glutamate anti-porter xCT boosted extracellular glutamate levels coupled to cystine uptake both in mice and in patients with ALD. Alcohol also induced the selective expression of metabotropic glutamate receptor-5 (mGluR5) in HSCs where mGluR5 activation stimulated 2-AG production. Consistently, genetic or pharmacologic inhibition of mGluR5 or xCT attenuated alcoholic steatosis in mice via the suppression of 2-AG production and subsequent CB1R-mediated de novo lipogenesis. We conclude that a bidirectional signaling operates at a metabolic synapse between hepatocytes and HSCs through xCT-mediated glutamate-mGluR5 signaling to produce 2-AG, which induces CB1R-mediated alcoholic steatosis.

Experimental Applications of in situ Liver Perfusion Machinery for the Study of Liver Disease.

The liver is involved in a wide range of activities in vertebrates and some other animals, including metabolism, protein synthesis, detoxification, and the immune system. Until now, various methods have been devised to study liver diseases; however, each method has its own limitations. In situ liver perfusion machinery, originally developed in rats, has been successfully adapted to mice, enabling the study of liver diseases. Here we describe the protocol, which is a simple but widely applicable method for investigating the liver diseases. The liver is perfused in situ by cannulation of the portal vein and suprahepatic inferior vena cava (IVC), with antegrade closed circuit circulation completed by clamping the infrahepatic IVC. In situ liver perfusion can be utilized to evaluate immune cell migration and function, hemodynamics and related cellular reactions in each type of hepatic cells, and the metabolism of toxic or other compounds by changing the composition of the circulating media. In situ liver perfusion method maintains liver function and cell viability for up to 2 h. This study also describes an optional protocol using density-gradient centrifugation for the separation of different types of hepatic cells, allowing the determination of changes in each cell type. In summary, this method of in situ liver perfusion will be useful for studying liver diseases as a complement to other established methods.

CX3CR1 differentiates F4/80low monocytes into pro-inflammatory F4/80high macrophages in the liver.

The expression of chemokine receptor CX3CR1 is related to migration and signaling in cells of the monocyte-macrophage lineage. The precise roles of CX3CR1 in the liver have been investigated but not clearly elucidated. Here, we investigated the roles of CX3CR1 in hepatic macrophages and liver injury. Hepatic and splenic CX3CR1lowF4/80low monocytes and CX3CR1lowCD16- monocytes were differentiated into CX3CR1highF4/80high or CX3CR1highCD16+ macrophages by co-culture with endothelial cells. Moreover, CX3CL1 deficiency in human umbilical vein endothelial cells (HUVECs) attenuated the expression of interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), whereas recombinant CX3CL1 treatment reversed this expression in co-cultured monocytes. Upon treatment with clodronate liposome, hepatic F4/80high macrophages were successfully depleted at day 2 and recovered similarly in CX3CR1+/GFP and CX3CR1GFP/GFP mice at week 4, suggesting a CX3CR1-independent replacement. However, F4/80high macrophages of CX3CR1+/GFP showed a stronger pro-inflammatory phenotype than CX3CR1GFP/GFP mice. In clodronate-treated chimeric CX3CR1+/GFP and CX3CR1GFP/GFP mice, CX3CR1+F4/80high macrophages showed higher expression of IL-1ß and TNF-α than CX3CR1-F4/80high macrophages. In alcoholic liver injury, despite the similar frequency of hepatic F4/80high macrophages, CX3CR1GFP/GFP mice showed reduced liver injury, hepatic fat accumulation, and inflammatory responses than CX3CR1+/GFP mice. Thus, CX3CR1 could be a novel therapeutic target for pro-inflammatory macrophage-mediated liver injury.

Fermented Moringa oleifera Decreases Hepatic Adiposity and Ameliorates Glucose Intolerance in High-Fat Diet-Induced Obese Mice.

Metabolic diseases, such as glucose intolerance and nonalcoholic fatty-liver disease (NAFLD), are primary risk factors for life-threatening conditions such as diabetes, heart attack, stroke, and hepatic cancer. Extracts from the tropical tree Moringa oleifera show antidiabetic, antioxidant, anti-inflammatory, and anticancer effects. Fermentation can further improve the safety and nutritional value of certain foods. We investigated the efficacy of fermented M. oleifera extract (FM) against high-fat diet (HFD)-induced glucose intolerance and hepatic lipid accumulation and investigated the underlying mechanisms by analyzing expression of proteins and genes involved in glucose and lipid regulation. C57BL/6 mice were fed with normal chow diet (ND) or HFD supplemented with distilled water (DW, control), nonfermented M. oleifera extract (NFM), or FM for 10 weeks. Although body weights were similar among HFD-fed treatment groups, liver weight was decreased, and glucose tolerance test (GTT) results improved in the FM group compared with DW and NFM groups. Hepatic lipid accumulation was also lower in the FM group, and expressions of genes involved in liver lipid metabolism were upregulated. In addition, HFD-induced endoplasmic reticulum (ER) stress, oxidative stress, and lipotoxicity in quadriceps muscles were decreased by FM. Finally, proinflammatory cytokine mRNA expression was decreased by FM in the liver, epididymal adipose tissue, and quadriceps of HFD-fed mice. FMs may decrease glucose intolerance and NAFLD under HFD-induced obesity by decreasing ER stress, oxidative stress, and inflammation.