Oxidative Stress as a Critical Factor in Nonalcoholic Fatty Liver Disease Pathogenesis

Plant-derived bioactive peptides and protein hydrolysates for managing MAFLD: A systematic review of in vivo effects

Metabolic dysfunction-associated fatty liver disease (MAFLD) represents a growing health concern worldwide. Among the pursuit of therapeutic interventions, interest in natural bioactive compounds has intensified because of their potential hepatoprotective effects. This systematic review aims to evaluate the impact of plant-derived hydrolysates and peptides on MAFLD through the current literatures, encompassing their mechanisms of action. Key outcomes evaluated included changes in liver enzymes, liver lipid content, inflammation markers, and histopathological improvements. Preliminary findings suggest a potential beneficial effect of plant-derived hydrolysates and peptides on the improvement of MAFLD-related parameters, with mechanisms implicating antioxidant, anti-inflammatory, and lipid-lowering properties. This review highlights emerging evidence supporting the potential therapeutic role of plant-derived hydrolysates and peptides in the management of MAFLD. However, more well-designed clinical trials with larger sample sizes and longer durations are warranted to elucidate their efficacy, optimal dose, and long-term safety.

The association between dietary intake of branched-chain amino acids and the odds of nonalcoholic fatty liver disease among overweight and obese children and adolescents

Objectives

Dietary supplementation with branched-chain amino acids (BCAAs), including leucine, isoleucine, and valine, has shown potential benefits for the metabolic profile. However, emerging population-based studies suggest that BCAAs may mediate pathways related to cardiometabolic risk factors, possibly due to their involvement in the dysregulation of insulin metabolic pathways. This study aimed to investigate the association between BCAAs intake and the odds of nonalcoholic fatty liver disease (NAFLD) in children and adolescents with overweight and obesity.

Methods

This cross-sectional study encompassed individuals aged 6 to 18 years with WHO body mass index (BMI)-for-age z-score ≥ 1. NAFLD diagnosis was done using an ultrasonography scan of the liver and gastroenterologist confirmation. Dietary BCAAs intake was assessed using a validated 147-item food frequency questionnaire. Logistic regression models, adjusted for potential confounders, were used to estimate the odds ratios (OR) and 95% confidence interval (CI) of NAFLD across quartiles of BCAAs intake.

Results

A total of 505 (52.9% boys) with mean ± SD age and BMI-for-age-Z-score of 10.0 ± 2.3 and 2.70 ± 1.01, respectively, were enrolled. After adjusting for potential confounders, participants in the highest quartile of total dietary BCAAs (OR: 1.87;95%CI:1.06-3.28) and leucine (OR: 1.84;95%CI:1.03-3.29) intake had greater odds of developing NAFLD compared with those in the lowest quartile. There was no significant association between dietary valine and isoleucine intake and the odds of NAFLD.

Conclusions

The study findings suggest that increased dietary intake of BCAAs, particularly leucine, may have detrimental effects on the development of NAFLD.

Prenatal melatonin reprograms liver injury in male pups caused by maternal exposure to a high-fat diet and microplastics

Prenatal exposure to a high-fat diet (HFD) or microplastics can impact liver fat accumulation in offspring. This study investigates the protective effects of prenatal melatonin on liver injury in male pups resulting from maternal exposure to a HFD and microplastics. Pregnant Sprague-Dawley rats were fed either an HFD or a normal chow diet, with some groups exposed to microplastics alone or in combination with melatonin. Male pups were evaluated on postnatal day 7. Results indicated that pups in the HFD-microplastics group (HFD-Mi) exhibited increased liver lipid accumulation (observed in histological staining), apoptosis (elevated cleaved caspase 3, phospho-AKT, and TUNEL staining), inflammation (higher IL- 6 and TNF-α), and oxidative stress (elevated malondialdehyde). Conversely, melatonin treatment (HFD-Mi + M) significantly reduced these effects, including lipid accumulation, apoptosis, and inflammation, while enhancing antioxidant enzyme glutathione peroxidase activity and improving lipid metabolism (reduced SREBP- 1 expression). These findings suggest that prenatal melatonin mitigates liver injury caused by maternal HFD and microplastics through its anti-inflammatory, antioxidative, and lipid-regulating properties, underscoring its potential hepatoprotective role.

Dietary manganese intake is positively associated with metabolic dysfunction-associated steatotic liver disease: a multicohort study

BACKGROUND AND AIMS

Manganese (Mn) is an essential nutrient that plays a crucial role in maintaining normal physiological functions of the human body. However, overexposure to Mn often leads to adverse health outcomes and contributes to the development of a variety of diseases. Several studies have explored the relationship between dietary Mn and metabolic dysfunction-associated steatotic liver disease (MASLD) risk. Two UK Biobank (UKB)-based studies suggested that Mn, as a key nutrient, may be associated with a reduced risk of MASLD. Another study found an association between the dietary antioxidant index and the onset of non-alcoholic fatty liver disease (NAFLD), highlighting the importance of nutritional factors (including Mn) in liver health. However, the relationship between dietary Mn intake and MASLD in the Chinese population remains unexplored, and further research is needed to elucidate its underlying mechanisms.

METHODS

This prospective multi-cohort study had 1,137 adults from the Guangzhou Nutrition and Health Study (GNHS) cohort and 17,649 people from the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) cohort. We measured dietary intake using a validated and standardized food frequency questionnaire. Annual abdominal ultrasound was used to diagnose new-onset MASLD. We used multivariable Cox regression models to assess the relationship between dietary Mn intake and the risk of MASLD.

RESULTS

In the TCLSIH cohort, 3640 MASLD cases were observed with a follow-up time of 60,190 person-years. After taking into account possible confounding factors, the multivariable HRs (95% CIs) for MASLD across the quartiles of dietary Mn intake in males were 1.00 (reference), 1.08 (0.96-1.21), 1.12 (0.99-1.26), and 1.16 (1.02-1.31), with a P for trend = 0.02; for females, the HRs (95% CIs) for MASLD across the quartiles of dietary Mn intake were 1.00, 1.11 (0.95-1.31), 1.08 (0.91-1.28), and 0.97 (0.81-1.16), with a P for trend = 0.58. After adjustment for proteins, lipids, and carbohydrates, the HRs (95% CIs) for MASLD across the quartiles of dietary Mn intake in males were 1.00 (reference), 1.11 (0.97-1.26), 1.14 (1.00-1.31), and 1.16 (1.00-1.34), with a P for trend = 0.045. For females, the HRs (95% CIs) for MASLD across the quartiles of dietary Mn intake were 1.00 (reference), 1.08 (0.91-1.30), 1.06 (0.88-1.27), and 0.93 (0.76-1.13), with a P for trend = 0.39. In the GNHS cohort, 624 MASLD cases were observed with a follow-up time of 6454 person-years. After adjusting for relevant confounders, the HRs (95% CIs) for males comparing T3 versus T1 of dietary Mn intake were 1.04 (0.65-1.60); the HRs (95% CIs) for females comparing T3 versus T1 of dietary Mn intake were 1.00 (0.78-1.29).

CONCLUSION

In males, higher dietary Mn intake is associated with a higher incidence of MASLD.

Paricalcitol, an active vitamin D analog, mitigates dexamethasone-induced hepatic injury: Role of autophagy, pyroptosis, and PERK/Nrf2/HO-1 signaling pathway

Drug-induced toxicity is considered a crucial clinical affair, as some adverse effects could be severe or life threatening. Drugs may have adverse effects by altering biological pathways that aren't always involved in the drug's reaction. From this perspective, the purpose of the current study was to assess the impacts of paricalcitol, a synthetic, active, and selective vitamin D receptor activator, on dexamethasone-induced liver injury, and discover the probable implicated signaling pathways as well. Male Wistar rats were treated with paricalcitol at a dose of 0.2 μg/kg, daily, i.p for 12 days and injected with 8 mg/kg dexamethasone i.p daily over the last 6 days. Administration of paricalcitol improved liver function markers, lipid profile, reduced histopathologic changes in hepatic sections, and restored normal oxidative status. Moreover, paricalcitol markedly decreased hepatic collagen deposition as confirmed by Masson's trichrome staining. Paricalcitol effectively inhibited endoplasmic reticulum stress through decreasing expression of tissue PERK and Chop, increasing hepatic Nrf2, and HO-1 activity. Besides, paricalcitol decreased levels of NLRP3 and IL-1β as well as decreased expression of active caspase-1 p20, GSDMD-N-terminal indicating suppression of NLRP3/caspase-1/GSDMD pyroptosis pathway. Paricalcitol can protect against dexamethasone-induced liver injury showing a promising therapeutic value in drug-induced liver injuries.

Paraoxonase-like APMAP maintains endoplasmic-reticulum-associated lipid and lipoprotein homeostasis

Oxidative stress perturbs lipid homeostasis and contributes to metabolic diseases. Though ignored when compared with mitochondrial oxidation, the endoplasmic reticulum (ER) generates reactive oxygen species requiring antioxidant quality control. Using multi-organismal profiling featuring Drosophila, zebrafish, and mammalian hepatocytes, here we characterize the paraoxonase-like C20orf3/adipocyte plasma-membrane-associated protein (APMAP) as an ER-localized antioxidant that suppresses ER lipid oxidation to safeguard ER function. APMAP-depleted cells exhibit defective ER morphology, ER stress, and lipid peroxidation dependent on ER-oxidoreductase 1α (ERO1A), as well as sensitivity to ferroptosis and defects in ApoB-lipoprotein homeostasis. Similarly, organismal APMAP depletion in Drosophila and zebrafish perturbs ApoB-lipoprotein homeostasis. Strikingly, APMAP loss is rescued with chemical antioxidant N-acetyl-cysteine (NAC). Lipidomics identifies that APMAP loss elevates phospholipid peroxidation and boosts ceramides-signatures of lipid stress. Collectively, we propose that APMAP is an ER-localized antioxidant that promotes lipid and lipoprotein homeostasis in the ER network.

Hidden in the Fat: Unpacking the Metabolic Tango Between Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Syndrome

Metabolic syndrome (MetS) and metabolic dysfunction-associated steatotic liver disease (MASLD) are closely related, with rapidly increasing prevalence globally, driving significant public health concerns. Both conditions share common pathophysiological mechanisms such as insulin resistance (IR), adipose tissue dysfunction, oxidative stress, and gut microbiota dysbiosis, which contribute to their co-occurrence and progression. While the clinical implications of this overlap, including increased cardiovascular, renal, and hepatic risk, are well recognized, current diagnostic and therapeutic approaches remain insufficient due to the clinical and individuals' heterogeneity and complexity of these diseases. This review aims to provide an in-depth exploration of the molecular mechanisms linking MetS and MASLD, identify critical gaps in our understanding, and highlight existing challenges in early detection and treatment. Despite advancements in biomarkers and therapeutic interventions, the need for a comprehensive, integrated approach remains. The review also discusses emerging therapies targeting specific pathways, the potential of precision medicine, and the growing role of artificial intelligence in enhancing research and clinical management. Future research is urgently needed to combine multi-omics data, precision medicine, and novel biomarkers to better understand the complex interactions between MetS and MASLD. Collaborative, multidisciplinary efforts are essential to develop more effective diagnostic tools and therapies to address these diseases on a global scale.

Hepatoprotective effects of polysaccharide from Morchella esculenta are associated with activation of the AMPK/Sirt1 signaling pathway in mice with NAFLD

The functional food application of edible fungus polysaccharides has been widely studied based on their variety of potential pharmacological activities. However, the hepatoprotective effects and mechanisms of Morchella esculenta polysaccharide against nonalcoholic fatty liver disease (NAFLD) remain unknown. A high-fat diet (HFD) fed C57BL/6 J mice for 8 weeks was employed to establish NAFLD with simple steatosis, methionine choline deficiency (MCD) diet for 4 weeks induced hepatic steatohepatitis and fibrosis. The M. esculenta polysaccharide (MCP) or saline was administered intragastrically. MCP markedly reduced hepatic and serum triglyceride (TG) and cholesterol contents in HFD-fed mice. Moreover, treatment with MCP ameliorated nonalcoholic steatohepatitis (NASH) progression in MCD-fed mice, as evidenced by ameliorated hepatic steatosis, inflammatory response, and fibrosis. Mechanistically, MCP suppressed the expression of lipogenic genes and inflammatory cytokines and upregulated peroxisome proliferator-activated receptor (PPAR)-α expression to induce fatty acid β-oxidation. These beneficial effects were attributed to activating the AMP-activated kinase (AMPK)/Sirtuin 1 (Sirt1) signaling pathway. Therefore, we provided evidence that MCP might be an effective dietary supplement to ameliorate NAFLD.

Pseudonatural Flavonols as Novel Copper Ionophores for NAFLD Intervention via Synergistic Copper Delivery and Flavonoid Activity

Copper plays crucial roles in fundamental life processes, including proliferation, metabolism, and survival. Copper deficiency is associated with multiple diseases, such as nonalcoholic fatty liver disease (NAFLD) and Wilson's disease. Therapeutic programs targeting copper supply are prospectively employed for disease intervention. Herein, we developed biofriendly copper ionophores (HQFs) by constructing pseudonatural flavonols, which possess flavonoid bioactivity and enhanced copper transport properties. In cell models and mice, we found that HQF-mediated copper delivery synergistically, safely, and efficiently intervened in the development of fatty liver. Mechanistically, NAFLD remission involves fatty acid metabolism, anti-inflammatory processes, and pentose phosphate pathway (PPP) enhancement. Our work is the first to propose the utilization of synergistic copper loading and flavonoid activity for NAFLD intervention, which may inform the clinical management of liver disease.

Mitochondrial targeted therapies in MAFLD

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a clinical-pathological syndrome primarily characterized by excessive accumulation of fat in hepatocytes, independent of alcohol consumption and other well-established hepatotoxic agents. Mitochondrial dysfunction is widely acknowledged as a pivotal factor in the pathogenesis of various diseases, including cardiovascular diseases, cancer, neurodegenerative disorders, and metabolic diseases such as obesity and obesity-associated MAFLD. Mitochondria are dynamic cellular organelles capable of modifying their functions and structures to accommodate the metabolic demands of cells. In the context of MAFLD, the excess production of reactive oxygen species induces oxidative stress, leading to mitochondrial dysfunction, which subsequently promotes metabolic disorders, fat accumulation, and the infiltration of inflammatory cells in liver and adipose tissue. This review aims to systematically analyze the role of mitochondria-targeted therapies in MAFLD, evaluate current therapeutic strategies, and explore future directions in this rapidly evolving field. We specifically focus on the molecular mechanisms underlying mitochondrial dysfunction, emerging therapeutic approaches, and their clinical implications. This is of significant importance for the development of new therapeutic approaches for these metabolic disorders.

Diet, oxidative stress and MAFLD: a mini review

Globally, metabolic dysfunction-associated fatty liver disease (MAFLD), also known as non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD), is a common chronic liver disease. The progression of MAFLD leads to a vicious cycle in which oxidative stress results from the disease that is augmenting de-novo lipid levels and increases steatosis. Most non-enzymatic antioxidants are present in food. Therefore, the present review summarizes the findings of studies on food-derived antioxidants and presents an oxidative stress-related regulatory network in MAFLD, offering new ideas for MAFLD prevention and treatment.

Assessing clenbuterol's modulation of metabolic and inflammatory pathways in Nile tilapia (Oreochromas niloticous) fed high fat diet

This study was performed to reveal the metabolic effects and molecular mechanisms that govern the dietary incorporation of clenbuterol on growth performance, haemato-biochemical changes, histological alteration, and gene expression regulating glucose and lipid metabolism in normal and high-fat diets fed in Nile tilapia (Oreochromis niloticus). Six experimental diets were formulated, incorporating different concentrations of clenbuterol. The 1st three groups were supplemented with a diet comprising 6% fat, with clenbuterol of 0, 5, and 10 g/kg diet was designated as F6 clenb0, F6clenb5, and F6clenb10, respectively. The other treatment groups were fed a diet of 12% fat, with clenbuterol 0, 5, and 10 g/kg diet, respectively termed F12 clenb0, F12 clenb5, and F12 clenb10. The results revealed that compared to the control group, HFD exhibited a marked reduction in FBW, BWG, PER, and body protein percent but significantly increased the FCR, IPF, liver fat percent, and body ash percent with altered hematological parameters, raised serum biomarkers of hepatic and renal injury. HFD signally raised mRNA expression of pro-inflammatory cytokines, and declined nrf2 and antioxidative function-related genes. Also increased mRNA expression of lipogenic genes as FAS and SREBP-1c and gluconeogenic genes as pepck and g6pc while downregulated, pparα, cpt1, acox1. Nevertheless, clenbuterol supplementation significantly reversed the aforementioned findings induced by HFD. Clenbuterol inclusion significantly improves growth performance and antioxidant defenses by modulating nrf2 signaling and reducing inflammatory response, reduces fatty acid synthesis, and enhances mitochondrial β-oxidation not only functioning as a lipid regulator and effectively alleviating fat accumulation in the liver but playing an essential role in the control of glucose metabolism by reducing hepatic glucose production in high-fat diet-fed Nile tilapias well.

The effects of kefir drink on liver aminotransferases and metabolic indicators in patients with nonalcoholic fatty liver disease: a randomized controlled trial

BACKGROUND AND AIM

Probiotics play an important role in the control and treatment of non-alcoholic fatty liver disease (NAFLD). Kefir drink is a fermented beverage and has indicated some beneficial health effects. The aim of this study was to evaluate the effects of kefir drink on liver aminotransferases, anthropometric indices, glycemic index, lipid profile, blood pressure (BP), high sensitivity C-reactive protein, and malondialdehyde in patients with NAFLD.

METHODS

In an 8-week randomized clinical trial, 80 patients with NAFLD were randomized into two groups of 40. After a 2-week run-in period, the groups received a dietary plan and dietary plan plus a cup of kefir drink twice a day (500 cc/d), respectively. Also, demographic, anthropometric, laboratory, BP, dietary intake, and physical activity assessments were analyzed before and after the intervention.

RESULTS

At last, seventy-two participants completed the study. No significant difference in changes in BP, anthropometric indices, and laboratory data (P > 0.05) except HDL-C (P = 0.02) and fat-free mass (P < 0.001) was observed between the two study groups.

CONCLUSION

Based on the results, Drinking 500 cc/d kefir beverage had no significant effect on liver aminotransferases and metabolic indicators, except for HDL-C and fat-free mass in patients with NAFLD.

TRIAL REGISTRATION

IRCT20170916036204N6 (2018/08/03).

Effects of Cynara scolymus L. Bract Extract on Lipid Metabolism Disorders Through Modulation of HMG-CoA Reductase, Apo A-1, PCSK-9, p-AMPK, SREBP-2, and CYP2E1 Expression

Background/Objectives: Hyperlipidemia is a major contributor to metabolic complications and tissue damage, leading to conditions such as liver steatosis, atherosclerosis, and obesity. This study aimed to investigate the effects of aqueous artichoke bract extract (AE) on lipid metabolism, liver antioxidative defense, and liver steatosis in mice fed a high-fat, high-sucrose diet while elucidating the underlying mechanisms. Methods: An 8-week study used hyperlipidemic mice treated with AE at daily doses of 100 and 200 mg/kg bw, compared to fenofibrate. Plasma, liver, fecal, and biliary lipids, as well as blood glucose, were analyzed enzymatically. The liver antioxidative defense was assessed by measuring reduced glutathione, malondialdehyde (MDA), and antioxidant enzyme activities, while liver steatosis was evaluated through transaminase and alkaline phosphatase activities and histological monitoring of lipid droplets. Polyphenol profiling and quantification were performed using HPLC-DAD, and potential mechanisms were predicted by molecular docking and confirmed in HepG2 cells. Results: At 200 mg/kg, AE significantly improved plasma lipid profiles by reducing total cholesterol, triglycerides, and LDL-cholesterol while increasing HDL-cholesterol. It facilitated cholesterol reduction in the liver and its excretion, indicating activation of reverse cholesterol transport, which led to reduced body weight and liver steatosis. AE lowered MDA levels and enhanced antioxidant enzyme activities. AE was found to be safe (LD50 > 5000 mg/kg) and modulated gene expression in HepG2 cells. Conclusions: Based on our results, the artichoke bract extract could be considered a natural resource of bioactive compounds to treat hyperlipidemia and related cardiometabolic diseases.

Copper status and its relation to abdominal obesity indices and liver function in non-alcoholic fatty liver disease: a case-control study

OBJECTIVE

This study investigated copper (Cu) status in relation to abdominal obesity indices and liver function in patients with non-alcoholic fatty liver disease (NAFLD). This case-control study was carried out on 80 overweight/obese patients with NAFLD and 80 apparently healthy age, sex, and body mass index (BMI)-matched controls. A validated and reliable 168-item semi-quantitative food frequency questionnaire was completed for each subject and fasting serum levels of liver aminotransferases, ferritin, Cu and ceruloplasmin were assessed.

RESULTS

Mean intakes of energy and carbophydrate were significantly lower in patients with NAFLD than the control group while mean protein intake was highre (p < 0.05). Although mean Cu intake was greater in cases than controls, low dietary intake of Cu was found in 7.5% and 32.5% of the cases and controls, respectively. Apart from serum levels of liver aminotransferases (p < 0.001) and ferritin (p = 0.010), no significant differences were found in serum levels of Cu and ceruloplasmin. Serum and dietary Cu were positively correlated with obesity indices and serum ceruloplasmin was correlated with waist to height ratio and ferritin only in cases (p < 0.05). Low Cu intake (< 0.95 mg/day) was more likely to increase the odds of NAFLD (p for trend = 0.002), after adjusting for potential confounders.

Rice Straw-Derived Biochar Mitigates Microcystin-LR-Induced Hepatic Histopathological Injury and Oxidative Damage in Male Zebrafish via the Nrf2 Signaling Pathway

Microcystin-leucine arginine (MC-LR) poses a serious threat to aquatic animals during cyanobacterial blooms. Recently, biochar (BC), derived from rice straw, has emerged as a potent adsorbent for eliminating hazardous contaminants from water. To assess the joint hepatotoxic effects of environmentally relevant concentrations of MC-LR and BC on fish, male adult zebrafish (Danio rerio) were sub-chronically co-exposed to varying concentrations of MC-LR (0, 1, 5, and 25 μg/L) and BC (0 and 100 μg/L) in a fully factorial experiment. After 30 days exposure, our findings suggested that the existence of BC significantly decreased MC-LR bioavailability in liver. Furthermore, histopathological analysis revealed that BC mitigated MC-LR-induced hepatic lesions, which were characterized by mild damage, such as vacuolization, pyknotic nuclei, and swollen mitochondria. Compared to the groups exposed solely to MC-LR, decreased malondialdehyde (MDA) and increased catalase (CAT) and superoxide dismutase (SOD) were noticed in the mixture groups. Concurrently, significant changes in the mRNA expression levels of Nrf2 pathway genes (cat, sod1, gstr, keap1a, nrf2a, and gclc) further proved that BC reduces the oxidative damage induced by MC-LR. These findings demonstrate that BC decreases MC-LR bioavailability in the liver, thereby alleviating MC-LR-induced hepatotoxicity through the Nrf2 signaling pathway in zebrafish. Our results also imply that BC could serve as a potentially environmentally friendly material for mitigating the detrimental effects of MC-LR on fish.

Subchronic Exposure to Low-Level Lanthanum, Cerium, and Yttrium Mixtures Altered Cell Cycle and Increased Oxidative Stress Pathways in Human LO-2 Hepatocytes but Did Not Cause Malignant Transformation

Human exposures to rare earth elements are increasing with expanded use in aerospace, precision instruments, and new energy batteries, materials, and fertilizers. Individually these elements have low toxicity, although few investigations have examined the health effects of longer-term mixture exposures. We used the LO-2 cell line to examine the effects of graded exposures to lanthanum, cerium, and yttrium (LCY) mixtures at 1-, 100-, and 1000-fold their human background levels (0.31 μg/L La, 0.25 μg/L Ce, and 0.12 μg/L Y) on cell cycle, oxidative stress, and nuclear factor erythroid-2-related factor (NRF2) pathway biomarkers, assessing responses every 10 passages up to 100 passages. Cell migration, concanavalin A, malignant transformation, and tumorigenesis in nude mice were also examined. Mixed LCY exposures activated oxidative stress and the NRF2 pathway by the 30th passage and increased the proportion of cells in the S phase and cell cycle-specific biomarkers by the 40th passage. LCY exposures did not cause malignant transformation of hepatocytes or induced tumorigenesis in nude mice but enhanced cell proliferation, migration, and agglutination. Importantly, LCY mixtures with longer-term exposure activated the NRF2 pathway and altered the hepatocyte cell cycle at doses far below those used in previous toxicological studies. The consequences of LCY mixtures for public health merit further study.

Bidirectional associations among gallstone disease, non-alcoholic fatty liver disease, kidney stone disease

BACKGROUND

A body of evidence has suggested bidirectional relationships among gallstone disease (GSD), non-alcoholic fatty liver disease (NAFLD), and kidney stone disease (KSD). However, the results are inconsistent, and studies on this topic in China are relatively few. Our goal is to explore the bidirectional associations among these three diseases through a multicenter study, systematic review, and meta-analysis.

AIM

To explore the bidirectional associations among these three diseases through a multicenter study, systematic review, and meta-analysis. The results may help to investigate the etiology of these diseases and shed light on the individualized prevention of these three diseases.

METHODS

Subjects who participated in physical examinations in Beijing, Tianjin, Chongqing in China were recruited. Multivariable logistic regression was employed to explore the bidirectional relationships among GSD, KSD, and NAFLD. Systematic review and meta-analysis were initiated to confirm the epidemiologic evidence from previous observational studies. Furthermore, trial sequential analysis (TSA) was conducted to evaluate whether the evidence was sufficient and conclusive.

RESULTS

Significant bidirectional associations were detected among the three diseases, independent of potential confounding factors. The pooled results of the systematic review and meta-analysis also corroborated the aforementioned results. The combined evidence from the multicenter study and meta-analysis was significant [pooled odds ratio (OR) = 1.42, 95%CI: 1.16-1.75, KSD → GSD; pooled OR = 1.48, 95%CI: 1.31-1.67, GSD → KSD; pooled OR = 1.31, 95%CI: 1.17-1.47, GSD → NAFLD; pooled OR = 1.37, 95%CI: 1.26-1.50, NAFLD → GSD; pooled OR = 1.28, 95%CI: 1.08-1.51, NAFLD → KSD; pooled OR = 1.21, 95%CI: 1.16-1.25, KSD → NAFLD]. TSA indicated that the evidence was sufficient and conclusive.

CONCLUSION

The present study presents relatively sufficient evidence for the positive bidirectional associations among GSD, KSD, and NAFLD. The results may provide clues for investigating the etiology of these three diseases and offer a guideline for identifying high-risk patients.

Association Between Serum Uric Acid to Creatinine Ratio and Metabolic-Associated Fatty Liver Disease in Southeast China (TyG-BMI as a Potential Mediator)

Purpose

Serum uric acid to creatinine ratio (SUA/Cr) has been associated with an increased risk of metabolic syndrome; however, limited evidence exists regarding the relationship between SUA/Cr and metabolic-associated fatty liver disease (MAFLD). This study aims to investigate the association between SUA/Cr, TyG-BMI (triglyceride glucose-body mass index), and MAFLD in Chinese adults.

Patients and Methods

The data were obtained from a health examination conducted at Nanping First Hospital. Spearman correlation analysis was employed to assess the association between SUA/Cr or TyG-BMI and various risk factors pertinent to MAFLD. A multivariate logistic regression model was utilized to investigate the relationship between SUA/Cr or TyG-BMI and MAFLD. Additionally, restricted cubic splines (RCS) and receiver operating characteristic (ROC) curve analyses were applied to explore the relationship between SUA/Cr and MAFLD. Mediation models were constructed to figure out the mediating role of TyG-BMI in the association between SUA/Cr and MAFLD.

Results

Spearman correlation analysis showed a significant association between SUA/Cr and multiple risk factors for MAFLD (such as BMI, SBP, DBP, TG, TC, ALT, AST, GGT, FPG, and HDL). Furthermore, SUA/Cr had a positive correlation with TyG-BMI (P<0.05). The logistic model demonstrated that elevated levels of SUA/Cr were significantly associated with an increased risk of MAFLD, even after adjusting for confounding factors (odds ratio [OR]: 1.390; 95% confidence interval [CI]: 1.255-1.538). The RCS curves revealed a consistent and monotonic increase in the relationship between SUA/Cr levels and the occurrence of MAFLD. Moreover, SUA/Cr exhibited moderate discriminatory ability in identifying individuals with MAFLD (AUC: 0.669). Mediation analysis indicated that approximately 52.05% of the positive association between SUA/Cr and MAFLD was mediated by TyG-BMI.

Conclusion

Our findings suggest a substantial association between elevated levels of SUA/Cr and an increased risk of MAFLD in the Chinese adult population, with TyG-BMI mediating this correlation.

Nicotine aggravates high-fat diet-induced non-alcoholic fatty liver disease in mice via inhibition of CISD3

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease globally. Growing data suggests that smoking plays an important role in the evolution of NAFLD. CDGSH iron sulfur domain 3 (CISD3) regulates critical biological activities. However, its role in nicotine-associated NAFLD and its underlying mechanisms have not been elucidated. Mice were given a high-fat diet for 10 weeks to induce the development of NAFLD. The results revealed that in mice with NAFLD, nicotine treatment resulted in reduced CISD3 expression, leading to mitochondrial dysfunction and impaired β-oxidation. Notably, exacerbation of hepatic steatosis and inflammatory injury was observed. Furthermore, Cisd3-knockout exacerbated lipid accumulation, aggravating oxidative stress and apoptosis. In conclusion, these results contribute to our knowledge of the function of CISD3 in nicotine-associated NAFLD, revealing the possibility of using CISD3 as a potential molecular target for treating NAFLD.

Evaluating the potential impact of sodium-glucose cotransporter-2 inhibitor "canagliflozin" on the hepatic damage triggered by hypertension in rats

Hypertension (HTN) is a prevalent chronic disease. HTN and liver disease association is extensively noted. Thus, finding a medication that can alleviate HTN and its accompanying liver insult would be promising. This study investigated the potential impacts of canagliflozin "sodium-glucose cotransporter-2 inhibitor" on the liver of the Nω-nitro-L-arginine methyl ester (L-NAME)-induced HTN rat model. Twenty-four adult male rats were divided into four groups; negative control group, canagliflozin group, L-NAME group: 50 mg/kg of L-NAME was injected daily for 5 weeks and L-NAME + canagliflozin group: 1 week after L-NAME injection both L-NAME + canagliflozin (40 mg/kg) were given concomitantly daily for further 4 weeks. Liver functions, serum lipid profile, hepatic oxidative/nitrative stress biomarkers, gene expression of lipogenic enzymes, B-cell lymphoma 2 (Bcl2), and DNA fragmentation, were measured. Besides, hepatic histology and immunohistochemistry of nuclear factor kappa B (NF-κB) and endothelial nitric oxide synthase (eNOS) were assessed. Canagliflozin improved hepatic lipogenesis via the downregulation of fatty acid synthase (FAS) and transcriptional regulatory element binding protein 1c (SREBP1c) genes leading to an improved serum lipid profile. Further, canagliflozin modified the eNOS/inducible nitric oxide synthase (iNOS) pathway and decreased the NF-κB immunoreactivity besides restoring the oxidants-antioxidants balance; increased reduced glutathione concomitant with declined malondialdehyde. This improvement of the liver was mirrored by the significant restoration of liver architecture and confirmed by the preserved liver DNA content and upregulation of the antiapoptotic Bcl2 mRNA level and attenuation of the alanine transaminase, aspartate aminotransferase. In conclusion, canagliflozin is a promising anti-hypertensive and hepatic-supportive medication. RESEARCH HIGHLIGHTS: Canagliflozin's antioxidant, anti-inflammatory, anti-lipogenic, and antiapoptotic characteristics mitigate remote liver compromise caused by hypertension. Canagliflozin can be exploited as a hepatoprotective and antihypertensive medication.

Lycorine ameliorates liver steatosis, oxidative stress, ferroptosis and intestinal homeostasis imbalance in MASLD mice

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease worldwide and few drugs are available for its treatment. Lycorine has effective anti-inflammatory and lipid-lowering effects, but the impact on MASLD is not fully understood. In this study, we intend to test the intervention effect of lycorine on MASLD.

METHODS

A MASLD mouse model was constructed on a high-fat diet for 16 weeks, and low, medium, and high doses of lycorine were given by gavage for the last 4 weeks. Detecting indicators related to liver steatosis, oxidative stress, and ferroptosis. In vivo and in vitro experiments co-validate potential targets identified by network pharmacology, molecular docking and western blot for lycorine intervention in MASLD liver. A combination of pathology, western blot, qRT-PCR, and 16 S rRNA sequencing verified adipose tissue and intestinal alterations.

RESULTS

Lycorine ameliorated hepatic steatosis, oxidative stress and ferroptosis in MASLD mice by inhibiting the expression of phosphorylated EGFR, inhibiting the PI3K/AKT signaling pathway. We also observed a dose-dependent effect of lycorine to improve some of the indicators of MASLD. In vitro, knockdown of EGFR significantly attenuated palmitic acid-induced hepatocyte steatosis. In addition, lycorine promoted WAT browning for thermogenesis and energy consumption, affected the composition of intestinal flora, improved the intestinal barrier, and reduced intestinal inflammation.

CONCLUSIONS

EGFR was the target of lycorine intervention in MASLD. Lycorine ameliorated hepatic steatosis, oxidative stress and ferroptosis by affecting the EGFR/PI3K/AKT signaling pathway in MASLD mice. Furthermore, lycorine promoted WAT browning and ameliorated intestinal homeostatic imbalance. The above effects may also have dose-dependent effects.

Branched-chain amino acids alleviate NAFLD via inhibiting de novo lipogenesis and activating fatty acid β-oxidation in laying hens

The adverse metabolic impacts of branched-chain amino acids (BCAA) have been elucidated are mediated by isoleucine and valine. Dietary restriction of isoleucine promotes metabolic health and increases lifespan. However, a high protein diet enriched in BCAA is presently the most useful therapeutic strategy for nonalcoholic fatty liver disease (NAFLD), yet, its underlying mechanism remains largely unknown. Fatty liver hemorrhagic syndrome (FLHS), a specialized laying hen NAFLD model, can spontaneously develop fatty liver and hepatic steatosis under a high-energy and high-protein dietary background that the pathogenesis of FLHS is similar to human NAFLD. The mechanism underlying dietary BCAA control of NAFLD development in laying hens remains unclear. Herein, we demonstrate that dietary supplementation with 67 % High BCAA has unique mitigative impacts on NAFLD in laying hens. A High BCAA diet alleviates NAFLD, by inhibiting the tryptophan-ILA-AHR axis and MAPK9-mediated de novo lipogenesis (DNL), promoting ketogenesis and energy metabolism, and activating PPAR-RXR and pexophagy to promote fatty acid β-oxidation. Furthermore, we uncover that High BCAA strongly activates ubiquitin-proteasome autophagy via downregulating UFMylation to trigger MAPK9-mediated DNL, fatty acid elongation and lipid droplet formation-related proteins ubiquitination degradation, activating PPAR-RXR and pexophagy mediated fatty acid β-oxidation and lipolysis. Together, our data highlight moderating intake of high BCAA by inhibiting the AHR/MAPK9 are promising new strategies in NAFLD and FLHS treatment.

Lack of Nr2e1 expression in hepatocytes impaired cell survival and aggravated palmitate-induced oxidative stress

PURPOSE

Nuclear receptor subfamily 2 group E member 1 (Nr2e1) has been regarded as an essential regulator in neural stem cells. However, its function is still not clear in hepatocytes. This study aimed to clarify the effects of Nr2e1-deficiency in hepatocytes in lipotoxic conditions.

MATERIALS/METHODS

Nr2e1-knockdown AML12 ​cells were generated by lentiviral vector transfection. The influences of Nr2e1-deficiency on hepatocyte survival were determined by cell cycle progression and cell apoptosis rate using flow cytometry. Real-time quantitative PCR and Western blot were used to examine the genes and protein expression related to apoptosis, lipid metabolism, and oxidative stress. Meanwhile, RNA sequencing was adopted in liver samples from Nr2e1-knockout (Nr2e1-KO) mice.

RESULTS

Nr2e1 expression was observed with a significant decrease in AML12 ​cells after palmitic acid-stimulation. Knockdown of Nr2e1 in AML12 ​cells resulted in increased sensitivity to lipotoxicity, evidenced by a partial G0/G1 cell-cycle arrest and higher rates of cell apoptosis. Moreover, Nr2e1-knockdown AML12 ​cells presented increased gene expressions relative to lipid synthesis but decreased levels of β-oxidation related genes. Lack of Nr2e1 augmented palmitate-induced oxidative stress in hepatocytes. In vivo, differential genes in Nr2e1-KO mice liver were enriched in pathways associated with liver regeneration and cell proliferation.

CONCLUSIONS

This study indicated that hepatocytes lacking Nr2e1 were more susceptible to lipotoxic-mediated damage. Nr2e1 may serve as a potential target for the development of novel therapies for lipotoxicity-induced liver injury.

Salvianolic acid A attenuates non-alcoholic fatty liver disease by regulating the AMPK-IGFBP1 pathway

Non-alcoholic fatty liver disease (NAFLD) affects approximately a quarter of the population and, to date, there is no approved drug therapy for this condition. Individuals with type 2 diabetes mellitus (T2DM) are at a significantly elevated risk of developing NAFLD, underscoring the urgency of identifying effective NAFLD treatments for T2DM patients. Salvianolic acid A (SAA) is a naturally occurring phenolic acid that is an important component of the water-soluble constituents isolated from the roots of Salvia miltiorrhiza Bunge. SAA has been demonstrated to possess anti-inflammatory and antioxidant stress properties. Nevertheless, its potential in ameliorating diabetes-associated NAFLD has not yet been fully elucidated. In this study, diabetic ApoE-/- mice were employed to establish a NAFLD model via a Western diet. Following this, they were treated with different doses of SAA (10 mg/kg, 20 mg/kg) via gavage. The study demonstrated a marked improvement in liver injury, lipid accumulation, inflammation, and the pro-fibrotic phenotype after the administration of SAA. Additionally, RNA-seq analysis indicated that the primary pathway by which SAA alleviates diabetes-induced NAFLD involves the cascade pathways of lipid metabolism. Furthermore, SAA was found to be effective in the inhibition of lipid accumulation, mitochondrial dysfunction and ferroptosis. A functional enrichment analysis of RNA-seq data revealed that SAA treatment modulates the AMPK pathway and IGFBP-1. Further experimental results demonstrated that SAA is capable of inhibiting lipid accumulation through the activation of the AMPK pathway and IGFBP-1.

Silymarin inhibits the lipogenic pathway and reduces worsening of non-alcoholic fatty liver disease (NAFLD) in mice

CONTEXT

The role of silymarin in hepatic lipid dysfunction and its possible mechanisms of action were investigated.

OBJECTIVE

To evaluate the effects of silymarin on hepatic and metabolic profiles in mice fed with 30% fructose for 8 weeks.

METHODS

We evaluated the antioxidant profile of silymarin; mice consumed 30% fructose and were treated with silymarin (120 mg/kg/day or 240 mg/kg/day). We performed biochemical, redox status, and histopathological assays. RT-qPCR was performed to detect ACC-1, ACC-2, FAS, and CS expression, and western blotting to detect PGC-1α levels.

RESULTS

Silymarin contains high levels of phenolic compounds and flavonoids and exhibited significant antioxidant capacity in vitro. In vivo, the fructose-fed groups showed increased levels of AST, ALT, SOD/CAT, TBARS, hepatic TG, and cholesterol, as well as hypertriglyceridaemia, hypercholesterolaemia, and increased ACC-1 and FAS. Silymarin treatment reduced these parameters and increased mRNA levels and activity of hepatic citrate synthase.

CONCLUSIONS

These results suggest that silymarin reduces worsening of NAFLD.

PIM1 alleviated liver oxidative stress and NAFLD by regulating the NRF2/HO-1/NQO1 pathway

AIMS

Non-alcoholic fatty liver disease (NAFLD) has risen as a significant global public health issue, for which vertical sleeve gastrectomy (VSG) has become an effective treatment method. The study sought to elucidate the processes through which PIM1 mitigates the advancement of NAFLD. The Pro-viral integration site for Moloney murine leukemia virus 1 (PIM1) functions as a serine/threonine kinase. Bioinformatics analysis revealed that reduced PIM1 expression in NAFLD.

METHODS

To further prove the role of PIM1 in NAFLD, an in-depth in vivo experiment was performed, in which male C57BL/6 mice were randomly grouped to receive a normal or high-fat diet for 24 weeks. They were operated or delivered the loaded adeno-associated virus which the PIM1 was overexpressed (AAV-PIM1). In an in vitro experiment, AML12 cells were treated with palmitic acid to induce hepatic steatosis.

KEY FINDINGS

The results revealed that the VSG surgery and virus delivery of mice alleviated oxidative stress, and apoptosis in vivo. For AML12 cells, the levels of oxidative stress, apoptosis, and lipid metabolism were reduced via PIM1 upregulation. Moreover, ML385 treatment resulted in the downregulation of the NRF2/HO-1/NQO1 signaling cascade, indicating that PIM1 mitigates NAFLD by targeting this pathway.

SIGNIFICANCE

PIM1 alleviated mice liver oxidative stress and NAFLD induced by high-fat diet by regulating the NRF2/HO-1/NQO1 signaling Pathway.

Regulation of Keap1-Nrf2 signaling in health and diseases

Nuclear factor erythroid 2-related factor 2 (Nrf2) functions as a central regulator in modulating the activities of diverse antioxidant enzymes, maintaining cellular redox balance, and responding to oxidative stress (OS). Kelch-like ECH-associated protein 1 (Keap1) serves as a principal negative modulator in controlling the expression of detoxification and antioxidant genes. It is widely accepted that OS plays a pivotal role in the pathogenesis of various diseases. When OS occurs, leading to inflammatory infiltration of neutrophils, increased secretion of proteases, and the generation of large quantities of reactive oxygen radicals (ROS). These ROS can oxidize or disrupt DNA, lipids, and proteins either directly or indirectly. They also cause gene mutations, lipid peroxidation, and protein denaturation, all of which can result in disease. The Keap1-Nrf2 signaling pathway regulates the balance between oxidants and antioxidants in vivo, maintains the stability of the intracellular environment, and promotes cell growth and repair. However, the antioxidant properties of the Keap1-Nrf2 signaling pathway are reduced in disease. This review overviews the mechanisms of OS generation, the biological properties of Keap1-Nrf2, and the regulatory role of its pathway in health and disease, to explore therapeutic strategies for the Keap1-Nrf2 signaling pathway in different diseases.

Sophorae tonkinensis radix polysaccharide attenuates acetaminophen-induced liver injury by regulating the miR-140-5p-related antioxidant mechanism

STRP1, a polysaccharide active ingredient isolated from the traditional Chinese medicine Sophorae tonkinensis radix, has demonstrated a protective effect against acetaminophen (APAP)-induced liver injury (AILI). The underlying molecular mechanism was investigated in this study. Here, an acute liver damage mouse model was generated by APAP (400 mg/kg) and used to identify the protective effect of STRP1 (200 mg/kg) on mouse livers. In vitro cell experiments were used to further verify the related signaling pathways. Initially, in our study, STRP1 treatment reduced APAP-induced liver injury by decreasing aminotransferase activity and cell apoptosis and increasing cell proliferation. Furthermore, STRP1 treatment significantly increased Nrf2 expression and alleviated oxidative stress caused by reactive oxygen species in AILI. Based on bioinformatics and experimental studies, miR-140-5p was identified and found to be reduced by STRP1, increasing Nrf2 expression. Additionally, Nrf2 played an important role in the protective impact of STRP1-suppressed miR-140-5p expression. Generally, these results showed that STRP1-mediated suppression of miR-140-5p expression mitigates AILI by activating the Nrf2-mediated Nrf2-Keap1 pathway. This study revealed that STRP1 might be a potential treatment agent for AILI.

Dietary Chitosan Attenuates High-Fat Diet-Induced Oxidative Stress, Apoptosis, and Inflammation in Nile Tilapia (Oreochromis niloticus) through Regulation of Nrf2/Kaep1 and Bcl-2/Bax Pathways

Fatty liver injury is a prevalent condition in most farmed fish, yet the molecular mechanisms underpinning this pathology remain largely elusive. A comprehensive feeding trial spanning eight weeks was conducted to discern the potential of dietary chitosan in mitigating the deleterious effects of a high-fat diet (HFD) while concurrently exploring the underlying mechanism. Growth performance, haemato-biochemical capacity, antioxidant capacity, apoptotic/anti-apoptotic gene expression, inflammatory gene expression, and histopathological changes in the liver, kidney, and intestine were meticulously assessed in Nile tilapia. Six experimental diets were formulated with varying concentrations of chitosan. The first three groups were administered a diet comprising 6% fat with chitosan concentrations of 0%, 5%, and 10% and were designated as F6Ch0, F6Ch5, and F6Ch10, respectively. Conversely, the fourth, fifth, and sixth groups were fed a diet containing 12% fat with chitosan concentrations of 0%, 5%, and 10%, respectively, for 60 days and were termed F12Ch0, F12Ch5, and F12Ch10. The results showed that fish fed an HFD demonstrated enhanced growth rates and a significant accumulation of fat in the perivisceral tissue, accompanied by markedly elevated serum hepatic injury biomarkers and serum lipid levels, along with upregulation of pro-apoptotic and inflammatory markers. In stark contrast, the expression levels of nrf2, sod, gpx, and bcl-2 were notably decreased when compared with the control normal fat group. These observations were accompanied by marked diffuse hepatic steatosis, diffuse tubular damage, and shortened intestinal villi. Intriguingly, chitosan supplementation effectively mitigated the aforementioned findings and alleviated intestinal injury by upregulating the expression of tight junction-related genes. It could be concluded that dietary chitosan alleviates the adverse impacts of an HFD on the liver, kidney, and intestine by modulating the impaired antioxidant defense system, inflammation, and apoptosis through the variation in nrf2 and cox2 signaling pathways.

Lauric acid attenuates hepato-metabolic complications and molecular alterations in high-fat diet-induced nonalcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) has emerged as a major chronic liver illness characterized by increase of lipid content in the liver. This study investigated the role of lauric acid to treat NAFLD in male adult Sprague Dawley rats. In this study, to induce NAFLD in the rats, a high-fat diet (HFD) was administered for eight consecutive weeks. Lauric acid groups received lauric acid (250 and 500 mg/kg; orally), concurrently with HFD for eight consecutive weeks. Lauric acid could ameliorate the serum levels of TG, TC, ALT, AST, blood glucose, and insulin. Moreover, lauric acid significantly elevated the levels of SOD, GSH, catalase, and IL-10. Additionally, it lowered the hepatic levels of MDA, ROS, MPO, 4-HNE, interleukin (IL)-1β, and tumor necrosis factor (TNF-α). Furthermore, lauric acid significantly up-regulated the hepatic expression of IRS1, AMPK, PI3K, and SIRT1 genes. In parallel, lauric acid could improve the histopathological picture of the liver and reduce the liver apoptosis via decreasing the expression of annexin V (Anx V). Finally, our data proposed that lauric acid could be an effective candidate for the NAFLD treatment.

Pterostilbene alleviates cafeteria diet-induced obesity and underlying depression in adolescent male Swiss albino mice and affects insulin resistance, inflammation, HPA axis dysfunction and SIRT1 mediated leptin-ghrelin signaling

Cafeteria diet (CD) model for in-vivo studies mimics the western diet having imbalanced nutritional value, high caloric-density and palatability. Uncontrolled eating leads to the development of childhood obesity, poor self-esteem and depression due to its effects on brain development. Herbal supplements are novel inclusion in the management of obesity and mental well-being. Pterostilbene (PTE) found in blueberries and Pterocarpus marsupium heartwood, is known to prevent obesity in invivo models. Adolescent Swiss albino male mice were fed on CD for 70 days and the development of obesity was assessed by gain in body weight, abdominal circumference. Forced swim and tail suspension test confirmed depression in CD fed mice. Obesity induced depressed (OID) mice were treated with PTE (10, 20, 40 mg/kg), standard antiobesity drug cetilistat (10 mg/kg), antidepressant fluoxetine (10 mg/kg) for 28 days. Post treatment, PTE-treated mice showed reduction in BW and depression-like behavior analysed using paradigms such as sucrose preference, open field, marble burying, and resident intruder test in comparison to the CD group. Insulin resistance, lipid profile, antioxidant enzyme, inflammatory cytokines (NF-κB, IL-6, TNF α) and cortisol levels were mitigated by PTE. It also restored normal cellular architecture of the brain and adipose tissue and increased the Silent mating type information regulation 2 homolog1 (SIRT1), leptin and ghrelin receptors gene expression in the brain. Thus, it can be concluded that PTE might have inhibited OID like behavior in mice via inhibition of IR, modulating neuroinflammation and hypothalamic-pituitary-adrenal axis dysfunction and upregulating SIRT1 mediated leptin-ghrelin signaling.

Supplementation of Micro- and Macronutrients-A Role of Nutritional Status in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a condition in which the pathological cumulation of fat with coexisting inflammation and damage of hepatic cells leads to progressive dysfunctions of the liver. Except for the commonly well-known major causes of NAFLD such as obesity, dyslipidemia, insulin resistance, or diabetes, an unbalanced diet and imbalanced nutritional status should also be taken into consideration. In this narrative review, we summarized the current knowledge regarding the micro- and macronutrient status of patients suffering from NAFLD considering various diets and supplementation of chosen supplements. We aimed to summarize the knowledge indicating which nutritional impairments may be associated with the onset and progression of NAFLD at the same time evaluating the potential therapy targets that could facilitate the healing process. Except for the above-mentioned objectives, one of the most important aspects of this review was to highlight the possible strategies for taking care of NAFLD patients taking into account the challenges and opportunities associated with the micronutrient status of the patients. The current research indicates that a supplementation of chosen vitamins (e.g., vitamin A, B complex, C, or D) as well as chosen elements such as zinc may alleviate the symptoms of NAFLD. However, there is still a lack of sufficient data regarding healthy ranges of dosages; thus, further research is of high importance in this matter.

Microcystin-LR and polystyrene microplastics jointly lead to hepatic histopathological damage and antioxidant dysfunction in male zebrafish

The co-occurrence of cyanobacterial blooms and nano-microplastic pollution in the water is becoming an emerging risk. To assess the combined hepatotoxicity of microcystin-LR (MC-LR) and polystyrene microplastics (PSMPs) on zebrafish (Danio rerio), male adult zebrafish were exposed to single MC-LR (0, 1, 5, 25 μg/L) and a mixture of MC-LR and PSMPs (100 μg/L). After 60 d exposure, the results indicated that PSMPs significantly increased the MC-LR bioaccumulation in the livers in contrast to the single 25 μg/L MC-LR treatment group. Moreover, the severity of hepatic pathological lesions was aggravated in the MC-LR + PSMPs treatment groups, which were mainly characterized by cellular vacuolar degeneration, swollen hepatocytes, and pyknotic nucleus. The ultrastructural changes also proved that PSMPs combined with MC-LR could enhance the swollen mitochondria and dilated endoplasmic reticulum. The biochemical results, including increased malondialdehyde (MDA) and decreased glutathione (GSH), indicated that PSMPs intensified the MC-LR-induced oxidative damage in the combined treatment groups. Concurrently, alterations of sod1 and keap1a mRNA levels also confirmed that PSMPs together with MC-LR jointly lead to enhanced oxidative injury. Our findings demonstrated that PSMPs enhanced the MC-LR bioavailability by acting as a vector and exacerbating the hepatic injuries and antioxidant dysfunction in zebrafish.

O-GlcNAcylation mediates H2O2-induced apoptosis through regulation of STAT3 and FOXO1

The O-linked-β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is a critical post-translational modification that couples the external stimuli to intracellular signal transduction networks. However, the critical protein targets of O-GlcNAcylation in oxidative stress-induced apoptosis remain to be elucidated. Here, we show that treatment with H2O2 inhibited O-GlcNAcylation, impaired cell viability, increased the cleaved caspase 3 and accelerated apoptosis of neuroblastoma N2a cells. The O-GlcNAc transferase (OGT) inhibitor OSMI-1 or the O-GlcNAcase (OGA) inhibitor Thiamet-G enhanced or inhibited H2O2-induced apoptosis, respectively. The total and phosphorylated protein levels, as well as the promoter activities of signal transducer and activator of transcription factor 3 (STAT3) and Forkhead box protein O 1 (FOXO1) were suppressed by OSMI-1. In contrast, overexpressing OGT or treating with Thiamet-G increased the total protein levels of STAT3 and FOXO1. Overexpression of STAT3 or FOXO1 abolished OSMI-1-induced apoptosis. Whereas the anti-apoptotic effect of OGT and Thiamet-G in H2O2-treated cells was abolished by either downregulating the expression or activity of endogenous STAT3 or FOXO1. These results suggest that STAT3 or FOXO1 are the potential targets of O-GlcNAcylation involved in the H2O2-induced apoptosis of N2a cells.

Ameliorative effects of aqueous extract from rosemary on oxidative stress and inflammation pathways caused by a high-fat diet in C57BL/6 mice

Rosemary is an herb exhibits biological properties, attenuates inflammation, oxidative stress, and improves lipid profile. Here, we evaluated the effects of rosemary aqueous extract (RE) on mice fed with a high-fat diet (HFD). Male C57BL/6 mice were administered a control diet or HFD for 10 weeks. The treated groups received RE in the diet at different concentrations: 25, 250, and 500 mg/100 g. After 10 weeks, serum concentrations of glucose, lipid, insulin, leptin, adiponectin, and cytokines were evaluated and the oxygen radical absorbance capacity was determined. Histological analysis was performed to determine the concentrations of triacylglycerides (TG), total cholesterol, cytokines, and antioxidant enzymes as well as the expression of genes involved in lipid metabolism, oxidative stress, and inflammation. The dietary RE ameliorated HFD-induced weight gain, adipose tissue weight, glucose intolerance, and insulin, leptin, and free fatty acid levels. Reduction in hepatic TG deposition was observed. The levels of inflammatory cytokines decreased, and the expression of genes involved in lipid metabolism increased. RE mitigated oxidative stress and reduced the production of reactive oxygen species in HepG2 and 3T3-L1 cells. Therefore, RE is a potential therapeutic agent for the prevention of inflammation and oxidative stress outcomes associated with obesity.

Probiotic yogurt regulates gut microbiota homeostasis and alleviates hepatic steatosis and liver injury induced by high-fat diet in golden hamsters

This study aimed to investigate the beneficial effects of probiotic yogurt on lipid metabolism and gut microbiota in metabolic-related fatty liver disease (MAFLD) golden hamsters fed on a high-fat diet (HFD). The results demonstrated that probiotic yogurt significantly reversed the adverse effects caused by HFD, such as body and liver weight gain, liver steatosis and damage, sterol deposition, and oxidative stress after 8 weeks of intervention. qRT-PCR analysis showed that golden hamsters fed HFD had upregulated genes related to adipogenesis, increased free fatty acid infiltration, and downregulated genes related to lipolysis and very low-density lipoprotein secretion. Probiotic yogurt supplements significantly inhibited HFD-induced changes in the expression of lipid metabolism-related genes. Furthermore, 16S rRNA gene sequencing of the intestinal content microbiota suggested that probiotic yogurt changed the diversity and composition of the gut microbiota in HFD-fed hamsters. Probiotic yogurt decreased the ratio of the phyla Firmicutes/Bacteroidetes, the relative abundance of the LPS-producing genus Desulfovibrio, and bacteria involved in lipid metabolism, whereas it increased the relative abundance of short-chain fatty acids producing bacteria in HFD-fed hamsters. Predictive functional analysis of the microbial community showed that probiotic yogurt-modified genes involved in LPS biosynthesis and lipid metabolism. In summary, these findings support the possibility that probiotic yogurt significantly improves HFD-induced metabolic disorders through modulating intestinal microflora and lipid metabolism and effectively regulating the occurrence and development of MAFLD. Therefore, probiotic yogurt supplementation may serve as an effective nutrition strategy for the treatment of patients with MAFLD clinically.

Does Resveratrol Improve Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)?

Metabolic dysfunction-associated steatotic liver disease (MASLD) is influenced by a variety of factors, including environmental and genetic factors. The most significant outcome is the alteration of free fatty acid and triglyceride metabolism. Lipotoxicity, impaired autophagy, chronic inflammation, and oxidative stress, as well as coexisting insulin resistance, obesity, and changes in the composition of gut microbiota, are also considered crucial factors in the pathogenesis of MASLD. Resveratrol is a polyphenolic compound that belongs to the stilbene subgroup. This review summarises the available information on the therapeutic effects of resveratrol against MASLD. Resveratrol has demonstrated promising antisteatotic, antioxidant, and anti-inflammatory activities in liver cells in in vitro and animal studies. Resveratrol has been associated with inhibiting the NF-κB pathway, activating the SIRT-1 and AMPK pathways, normalizing the intestinal microbiome, and alleviating intestinal inflammation. However, clinical studies have yielded inconclusive results regarding the efficacy of resveratrol in alleviating hepatic steatosis or reducing any of the parameters found in MASLD in human patients. The lack of homogeneity between studies, low bioavailability of resveratrol, and population variability when compared to animal models could be the reasons for this.

Bis(2-ethylhexyl)-tetrabromophthalate Poses a Higher Exposure Risk and Induces Gender-Specific Metabolic Disruptions in Zebrafish Liver

Bis(2-ethylhexyl)-tetrabromophthalate (TBPH), a typical novel brominated flame retardant, has been ubiquitously identified in various environmental and biotic media. Consequently, there is an urgent need for precise risk assessment based on a comprehensive understanding of internal exposure and the corresponding toxic effects on specific tissues. In this study, we first investigated the toxicokinetic characteristics of TBPH in different tissues using the classical pseudo-first-order toxicokinetic model. We found that TBPH was prone to accumulate in the liver rather than in the gonad, brain, and muscle of both female and male zebrafish, highlighting a higher internal exposure risk for the liver. Furthermore, long-term exposure to TBPH at environmentally relevant concentrations led to increased visceral fat accumulation, signaling potential abnormal liver function. Hepatic transcriptome analysis predominantly implicated glycolipid metabolism pathways. However, alterations in the profile of associated genes and biochemical indicators revealed gender-specific responses following TBPH exposure. Besides, histopathological observations as well as the inflammatory response in the liver confirmed the development of nonalcoholic fatty liver disease, particularly in male zebrafish. Altogether, our findings highlight a higher internal exposure risk for the liver, enhancing our understanding of the gender-specific metabolic-disrupting potential associated with TBPH exposure.

Glutamine prevents high-fat diet-induced hepatic lipid accumulation in mice by modulating lipolysis and oxidative stress

Metabolic-associated fatty liver disease (MAFLD) is related to metabolic dysfunction and is characterized by excess fat storage in the liver. Several studies have indicated that glutamine could be closely associated with lipid metabolism disturbances because of its important role in intermediary metabolism. However, the effect of glutamine supplementation on MAFLD progression remains unclear. Here, we used a high-fat diet (HFD)-induced MAFLD C57BL/6 mouse model, and glutamine was supplied in the drinking water at different time points for MAFLD prevention and reversal studies. A MAFLD prevention study was performed by feeding mice an HFD concomitant with 4% glutamine treatment for 24 weeks, whereas the MAFLD reversal study was performed based on 4% glutamine treatment for 13 weeks after feeding mice an HFD for 10 weeks. In the prevention study, glutamine treatment ameliorated serum lipid storage, hepatic lipid injury, and oxidative stress in HFD-induced obese mice, although glutamine supplementation did not affect body weight, glucose homeostasis, energy expenditure, and mitochondrial function. In the MAFLD reversal study, there were no noticeable changes in the basic physiological phenotype and hepatic lipid metabolism. In summary, glutamine might prevent, but not reverse, HFD-induced MAFLD in mice, suggesting that a cautious attitude is required regarding its use for MAFLD treatment.

Integrative analysis identifies oxidative stress biomarkers in non-alcoholic fatty liver disease via machine learning and weighted gene co-expression network analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease globally, with the potential to progress to non-alcoholic steatohepatitis (NASH), cirrhosis, and even hepatocellular carcinoma. Given the absence of effective treatments to halt its progression, novel molecular approaches to the NAFLD diagnosis and treatment are of paramount importance.

Methods

Firstly, we downloaded oxidative stress-related genes from the GeneCards database and retrieved NAFLD-related datasets from the GEO database. Using the Limma R package and WGCNA, we identified differentially expressed genes closely associated with NAFLD. In our study, we identified 31 intersection genes by analyzing the intersection among oxidative stress-related genes, NAFLD-related genes, and genes closely associated with NAFLD as identified through Weighted Gene Co-expression Network Analysis (WGCNA). In a study of 31 intersection genes between NAFLD and Oxidative Stress (OS), we identified three hub genes using three machine learning algorithms: Least Absolute Shrinkage and Selection Operator (LASSO) regression, Support Vector Machine - Recursive Feature Elimination (SVM-RFE), and RandomForest. Subsequently, a nomogram was utilized to predict the incidence of NAFLD. The CIBERSORT algorithm was employed for immune infiltration analysis, single sample Gene Set Enrichment Analysis (ssGSEA) for functional enrichment analysis, and Protein-Protein Interaction (PPI) networks to explore the relationships between the three hub genes and other intersecting genes of NAFLD and OS. The distribution of these three hub genes across six cell clusters was determined using single-cell RNA sequencing. Finally, utilizing relevant data from the Attie Lab Diabetes Database, and liver tissues from NASH mouse model, Western Blot (WB) and Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) assays were conducted, this further validated the significant roles of CDKN1B and TFAM in NAFLD.

Results

In the course of this research, we identified 31 genes with a strong association with oxidative stress in NAFLD. Subsequent machine learning analysis and external validation pinpointed two genes: CDKN1B and TFAM, as demonstrating the closest correlation to oxidative stress in NAFLD.

Conclusion

This investigation found two hub genes that hold potential as novel targets for the diagnosis and treatment of NAFLD, thereby offering innovative perspectives for its clinical management.

Endotoxin Inflammatory Action on Cells by Dysregulated-Immunological-Barrier-Linked ROS-Apoptosis Mechanisms in Gut-Liver Axis

Our study highlighted the immune changes by pro-inflammatory biomarkers in the gut-liver-axis-linked ROS-cell death mechanisms in chronic and acute inflammations when gut cells are exposed to endotoxins in patients with hepatic cirrhosis or steatosis. In duodenal tissue samples, gut immune barrier dysfunction was analyzed by pro-inflammatory biomarker expressions, oxidative stress, and cell death by flow cytometry methods. A significant innate and adaptative immune system reaction was observed as result of persistent endotoxin action in gut cells in chronic inflammation tissue samples recovered from hepatic cirrhosis with the A-B child stage. Instead, in patients with C child stage of HC, the endotoxin tolerance was installed in cells, characterized by T lymphocyte silent activation and increased Th1 cytokines expression. Interesting mechanisms of ROS-cell death were observed in chronic and acute inflammation samples when gut cells were exposed to endotoxins and immune changes in the gut-liver axis. Late apoptosis represents the chronic response to injury induction by the gut immune barrier dysfunction, oxidative stress, and liver-dysregulated barrier. Meanwhile, necrosis represents an acute and severe reply to endotoxin action on gut cells when the immune system reacts to pro-inflammatory Th1 and Th2 cytokines releasing, offering protection against PAMPs/DAMPs by monocytes and T lymphocyte activation. Flow cytometric analysis of pro-inflammatory biomarkers linked to oxidative stress-cell death mechanisms shown in our study recommends laboratory techniques in diagnostic fields.

Topical rhubarb charcoal-crosslinked chitosan/silk fibroin sponge scaffold for the repair of diabetic ulcers improves hepatic lipid deposition in db/db mice via the AMPK signalling pathway

BACKGROUND

Type 2 diabetes mellitus (T2DM) is closely linked to metabolic syndrome, characterised by insulin resistance, hyperglycaemia, abnormal lipid metabolism, and chronic inflammation. Diabetic ulcers (DUs) comprise consequential complications that arise as a result of T2DM. To investigate, db/db mice were used for the disease model. The findings demonstrated that a scaffold made from a combination of rhubarb charcoal-crosslinked chitosan and silk fibroin, designated as RCS/SF, was able to improve the healing process of diabetic wounds in db/db mice. However, previous studies have primarily concentrated on investigating the impacts of the RSC/SF scaffold on wound healing only, while its influence on the entire body has not been fully elucidated.

MATERIAL AND METHODS

The silk fibroin/chitosan sponge scaffold containing rhubarb charcoal was fabricated in the present study using a freeze-drying approach. Subsequently, an incision with a diameter of 8 mm was made on the dorsal skin of the mice, and the RCS/SF scaffold was applied directly to the wound for 14 days. Subsequently, the impact of RCS/SF scaffold therapy on hepatic lipid metabolism was assessed through analysis of serum and liver biochemistry, histopathology, quantitative real-time PCR (qRT-PCR), immunohistochemistry, and Western blotting.

RESULTS

The use of the RCS/SF scaffold led to an enhancement in the conditions associated with serum glucolipid metabolism in db/db mice. An assessment of hepatic histopathology further confirmed this enhancement. Additionally, the qRT-PCR analysis revealed that treatment with RCS/SF scaffold resulted in the downregulation of genes associated with fatty acid synthesis, fatty acid uptake, triglyceride (TG) synthesis, gluconeogenesis, and inflammatory factors. Moreover, the beneficial effect of the RCS/SF scaffold on oxidative stress was shown by assessing antioxidant enzymes and lipid peroxidation. Additionally, the network pharmacology analysis verified that the adenosine monophosphate-activated protein kinase (AMPK) signalling pathway had a vital function in mitigating non-alcoholic fatty liver disease (NAFLD) by utilizing R. officinale. The measurement of AMPK, sterol regulatory element binding protein 1 (SREBP1), fatty acid synthase (FASN), and acetyl CoA carboxylase (ACC) gene and protein expression provided support for this discovery. Furthermore, the molecular docking investigations revealed a robust affinity between the active components of rhubarb and the downstream targets of AMPK (SREBP1 and FASN).

CONCLUSION

By regulating the AMPK signalling pathway, the RCS/SF scaffold applied topically effectively mitigated hepatic lipid accumulation, decreased inflammation, and attenuated oxidative stress. The present study, therefore, emphasises the crucial role of the topical RCS/SF scaffold in regulating hepatic lipid metabolism, thereby confirming the concept of "external and internal reshaping".

Oxidative stress in metabolic dysfunction-associated steatotic liver disease (MASLD): How does the animal model resemble human disease?

Despite decades of research, the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) is still not completely understood. Based on the evidence from preclinical models, one of the factors proposed as a main driver of disease development is oxidative stress. This study aimed to search for the resemblance between the profiles of oxidative stress and antioxidant defense in the animal model of MASLD and the group of MASLD patients. C57BL/6J mice were fed with the Western diet for up to 24 weeks and served as the animal model of MASLD. The antioxidant profile of mice hepatic tissue was determined by liquid chromatography-MS3 spectrometry (LC-MS/MS). The human cohort consisted of 20 patients, who underwent bariatric surgery, and 6 controls. Based on histological analysis, 4 bariatric patients did not have liver steatosis and as such were also classified as controls. Total antioxidant activity was measured in sera and liver biopsy samples. The hepatic levels of antioxidant enzymes and oxidative damage were determined by Western Blot. The levels of antioxidant enzymes were significantly altered in the hepatic tissue of mice with MASLD. In contrast, there were no significant changes in the antioxidant profile of hepatic tissue of MASLD patients, except for the decreased level of carbonylated proteins. Decreased protein carbonylation together with significant correlations between the thioredoxin system and parameters describing metabolic health suggest alterations in the thiol-redox signaling. Altogether, these data show that even though the phenotype of mice closely resembles human MASLD, the animal-to-human translation of cellular and molecular processes such as oxidative stress may be more challenging.

Exploring the Multifaceted Landscape of MASLD: A Comprehensive Synthesis of Recent Studies, from Pathophysiology to Organoids and Beyond

Non-alcoholic fatty liver disease (NAFLD) is a widespread contributor to chronic liver disease globally. A recent consensus on renaming liver disease was established, and metabolic dysfunction-associated steatotic liver disease, MASLD, was chosen as the replacement for NAFLD. The disease's range extends from the less severe MASLD, previously known as non-alcoholic fatty liver (NAFL), to the more intense metabolic dysfunction-associated steatohepatitis (MASH), previously known as non-alcoholic steatohepatitis (NASH), characterized by inflammation and apoptosis. This research project endeavors to comprehensively synthesize the most recent studies on MASLD, encompassing a wide spectrum of topics such as pathophysiology, risk factors, dietary influences, lifestyle management, genetics, epigenetics, therapeutic approaches, and the prospective trajectory of MASLD, particularly exploring its connection with organoids.

Sestrin2 maintains hepatic immune homeostasis and redox balance partially via inhibiting RIPK3-mediated necroptosis in metabolic dysfunction-associated steatohepatitis

BACKGROUND & AIMS

Necroptosis, a novel type of programmed cell death, is intricately associated with inflammatory response. Currently, most studies focus on the activation of necroptosis, while the mechanisms underlying the negative regulation of necroptosis remain poorly understood.

METHODS

The effects of sestrin2 (SESN2) overexpression or knockdown on the regulation of necroptosis were assessed in the TNFα/Smac-mimetic/Z-VAD-FMK (T/S/Z)-induced necroptosis model and palmitic acid (PA)-induced lipotoxicity model. Western-blot, co-Immunoprecipitation, Glutathione S-transferase pull-down, and confocal assays were employed to explore the regulatory mechanisms including protein-protein interactions and post-translational modification. Furthermore, we used GSK'872, a specific inhibitor of receptor-interacting serine/threonine-protein kinase (RIPK) 3, to evaluate the relationship between SESN2-related alterations and RIPK3-mediated necroptosis in T/S/Z-induced necroptosis model, PA-induced lipotoxicity model, and high-fat high-cholesterol diet (HFHCD)-induced non-alcoholic steatohepatitis model.

RESULTS

Our findings revealed that SESN2 was upregulated under conditions that induce necroptosis and functioned as a negative regulator of necroptosis. High levels of SESN2 could equipped hepatocytes with the ability to defend against necroptotic inflammation and oxidative stress. Mechanistically, SESN2 interacted with RIPK3 and tuned down necroptosis by inhibiting the phosphorylation of RIPK3, promoting the ubiquitination of RIPK3, and preventing the formation of the RIPK1/RIPK3 necrosome. The depletion of SESN2 resulted in excessive necroptosis, accompanied by increased fat accumulation, inflammation, and oxidative stress in the experimental steatohepatitis model. Blocking necroptosis by GSK'872 reduced the liberation of pro-inflammatory cytokines and reactive oxygen species generation, but not hepatocyte fat deposition, in both PA-treated SESN2 knockout cells and HFHCD-fed SESN2 knockout mice, suggesting that the activation of RIPK3-mediated necroptosis may partially account for the hyperinflammation and excessive oxidative stress induced by SESN2 deficiency.

CONCLUSION

Our results suggested that SESN2 inhibited RIPK3-mediated necroptosis; this regulation is an important for the immune homeostasis and the redox balance in the liver.

Hydroalcoholic extract from Sechium edule (Jacq.) S.w. root reverses oleic acid-induced steatosis and insulin resistance in vitro

Steatosis is characterized by fat accumulation and insulin resistance (IR) in hepatocytes, which triggers a pro-oxidant, pro-inflammatory environment that may eventually lead to cirrhosis or liver carcinoma. This work was aimed to assess the effect of Sechium edule root hydroalcoholic extract (rSe-HA) (rich in cinnamic and coumaric acid, among other phenolic compounds) on triglyceride esterification, lipid degradation, AMPK expression, and the phosphorylation of insulin receptor in a Ser312 residue, as well as on the redox status, malondialdehyde (MDA) production, and the production of proinflammatory cytokines in an in vitro model of steatosis induced by oleic acid, to help develop a phytomedicine that could reverse this pathology. rSe-HA reduced triglyceride levels in hepatocyte lysates, increased lipolysis by activating AMPK at Thr172, and improved the redox status, as evidenced by the concentration of glycerol and formazan, respectively. It also prevented insulin resistance (IR), as measured by glucose consumption and the phosphorylation of the insulin receptor at Ser312. It also prevented TNFα and IL6 production and decreased the levels of MDA and nitric oxide (ON). Our results indicate that rSe-HA reversed steatosis and controlled the proinflammatory and prooxidant environment in oleic acid-induced dysfunctional HepG2 hepatocytes, supporting its potential use to control this disorder.

Paraoxonase-like APMAP maintains endoplasmic reticulum-associated lipid and lipoprotein homeostasis

Oxidative stress perturbs lipid homeostasis and contributes to metabolic diseases. Though ignored compared to mitochondrial oxidation, the endoplasmic reticulum (ER) generates reactive oxygen species requiring antioxidant quality control. Using multi-organismal profiling featuring Drosophila, zebrafish, and mammalian cells, here we characterize the paraoxonase-like APMAP as an ER-localized protein that promotes redox and lipid homeostasis and lipoprotein maturation. APMAP-depleted mammalian cells exhibit defective ER morphology, elevated ER and oxidative stress, lipid droplet accumulation, and perturbed ApoB-lipoprotein homeostasis. Critically, APMAP loss is rescued with chemical antioxidant NAC. Organismal APMAP depletion in Drosophila perturbs fat and lipoprotein homeostasis, and zebrafish display increased vascular ApoB-containing lipoproteins, particles that are atherogenic in mammals. Lipidomics reveals altered polyunsaturated phospholipids and increased ceramides upon APMAP loss, which perturbs ApoB-lipoprotein maturation. These ApoB-associated defects are rescued by inhibiting ceramide synthesis. Collectively, we propose APMAP is an ER-localized antioxidant that promotes lipid and lipoprotein homeostasis.

Nisin lantibiotic prevents NAFLD liver steatosis and mitochondrial oxidative stress following periodontal disease by abrogating oral, gut and liver dysbiosis

Oral microbiome dysbiosis mediates chronic periodontal disease, gut microbial dysbiosis, and mucosal barrier disfunction that leads to steatohepatitis via the enterohepatic circulation. Improving this dysbiosis towards health may improve liver disease. Treatment with antibiotics and probiotics have been used to modulate the microbial, immunological, and clinical landscape of periodontal disease with some success. The aim of the present investigation was to evaluate the potential for nisin, an antimicrobial peptide produced by Lactococcus lactis, to counteract the periodontitis-associated gut dysbiosis and to modulate the glycolipid-metabolism and inflammation in the liver. Periodontal pathogens, namely Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum, were administrated topically onto the oral cavity to establish polymicrobial periodontal disease in mice. In the context of disease, nisin treatment significantly shifted the microbiome towards a new composition, commensurate with health while preventing the harmful inflammation in the small intestine concomitant with decreased villi structural integrity, and heightened hepatic exposure to bacteria and lipid and malondialdehyde accumulation in the liver. Validation with RNA Seq analyses, confirmed the significant infection-related alteration of several genes involved in mitochondrial dysregulation, oxidative phosphorylation, and metal/iron binding and their restitution following nisin treatment. In support of these in vivo findings indicating that periodontopathogens induce gastrointestinal and liver distant organ lesions, human autopsy specimens demonstrated a correlation between tooth loss and severity of liver disease. Nisin's ability to shift the gut and liver microbiome towards a new state commensurate with health while mitigating enteritis, represents a novel approach to treating NAFLD-steatohepatitis-associated periodontal disease.

Shenge Formula attenuates high-fat diet-induced obesity and fatty liver via inhibiting ACOX1

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide. Shenge Formula (SGF) is a traditional Chinese medicine that has been used in the clinical treatment of NAFLD, and its therapeutic potential in patients and NAFLD animal models has been demonstrated in numerous studies. However, its underlying mechanism for treating NAFLD remains unclear.

PURPOSE

The aim of this study was to investigate the mechanism of SGF in the treatment of NAFLD using the proteomics strategy.

METHODS

Ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to determine the main components of SGF. A mouse model of nonalcoholic fatty liver disease was constructed by feeding mice with a high-fat diet for 16 weeks. SGF was administered for an additional 8 weeks, and metformin was used as a positive control. Liver sections were subjected to histopathological assessments. LC-MS/MS was used for the label-free quantitative proteomic analysis of liver tissues. Candidate proteins and pathways were validated both in vivo and in vitro through qRT-PCR, western blot, and immunohistochemistry. The functions of the validated pathways were further investigated using the inhibition strategy.

RESULTS

Thirty-nine ingredients were identified in SGF extracts, which were considered to be key compounds in the treatment of NAFLD. SGF administration attenuated obesity and fatty liver by reducing the body weight and liver weight in HFD-fed mice. It also relieved HFD-induced insulin resistance. More importantly, hepatic steatosis was significantly attenuated by SGF administration both in vivo and in vitro. Proteomic profiling of mouse liver tissues identified 184 differential expressed proteins (DEPs) associated with SGF treatment. Bioinformatic analysis of DEPs revealed that regulating the lipid metabolism and energy consumption process of hepatocytes was the main role of SGF in NAFLD treatment. This also indicated that ACOX1 might be the potential target of SGF, which was subsequently verified both in vitro and in vivo. The results demonstrated that SGF inhibited ACOX1 activity, thereby activating PPARα and upregulating CPT1A expression. Increased CPT1A expression promoted mitochondrial β-oxidation, leading to reduced lipid accumulation in hepatocytes.

CONCLUSIONS

Overall, our findings confirmed the protective effect of SGF against NAFLD and revealed the underlying molecular mechanism of regulating lipid metabolism.