Inflammation as a potential link between nonalcoholic fatty liver disease and insulin resistance

Therapeutic Targets and Approaches to Manage Inflammation of NAFLD

Non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), are the leading causes of chronic liver disease globally. They are driven by complex mechanisms where inflammation plays a pivotal role in disease progression. Current therapies, including lifestyle changes and pharmacological agents, are limited in efficacy, particularly in addressing the advanced stages of the disease. Emerging approaches targeting inflammation, metabolic dysfunction, and fibrosis offer promising new directions, though challenges such as treatment complexity and heterogeneity persist. This review concludes the main therapeutic targets and approaches to manage inflammation currently and emphasizes the critical need for future drug development and combination therapy for NAFLD/NASH management.

PBMC transcriptome reveals an early metabolic risk profile in young rats with metabolically obese, normal-weight phenotype

Metabolically obese, normal-weight (MONW) phenotype is characterized by visceral adiposity and obesity-related complications despite the absence of excess body weight. Early identification of this phenotype is crucial to establish preventive strategies. We aim to validate the utility of peripheral blood mononuclear cells (PBMC) transcriptome to detect metabolic risk related to the MONW phenotype at early life stages (young adulthood). Male Wistar rats were pair-fed either standard (NW group) or a high-fat diet (MONW group) after weaning, until 3.5 months. Global gene expression was examined by microarray in PBMC, and specific genes of interest by RT-qPCR in PBMC and liver. Results were validated in adult 6-month-old MONW rats. Young MONW animals had similar weight to controls (NW group) but greater adiposity, including liver fat content, and insulin resistance signs. PBMC transcriptome distinguished clearly MONW from NW rats. Neurological pathways were affected in line with impaired cognition in these animals. Most top-regulated genes were related to inflammation, including the top-up and down-regulated genes, Hpgds and Slfn4. Expression of fatty liver-related genes like Mkrn1 and Nampt was also affected in PBMC of the young MONW group mirroring liver alteration. Slfn4 and Mkrn1 appeared as especially relevant biomarkers with altered expression also in PBMC of adult 6-month-old MONW rats. In conclusion, PBMC transcriptomic analysis emerges as a tool for identifying early biomarkers of obesity-related metabolic risk in young and apparently healthy (lean) subjects, pointing towards increased inflammation, liver fat deposition, and cognitive alterations.

Lack of Efficacy of Pomegranate Supplementation on Insulin Resistance and Sensitivity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The objective of this study is to assess the impact of pomegranate supplements on insulin resistance (IR) and insulin sensitivity through a systematic review and meta-analysis of randomized controlled trials (RCTs). Additionally, we aim to analyze the differences in efficacy among various pomegranate extracts and the sensitivity of different diseases to pomegranate supplementation. We conducted searches in PubMed, Embase, Web of Science, and Cochrane Library up to October 30, 2023, for relevant studies published in English. The treatment group required the intake of pomegranate extract for a minimum of 4 weeks, with no restrictions on the extract type. The control group received a placebo or a treatment excluding pomegranate extract. The primary outcome was homeostatic model assessment for insulin resistance (HOMA-IR) and fasting insulin (FI), and the secondary outcome was quantitative insulin sensitivity check index (QUICKI). RoB 2 was used to assess the risk of bias in the original studies. We pre-specified subgroup analyses based on types of intervention, intervention duration, health condition, and intervention dose. Sensitivity analysis was conducted to validate result stability, utilizing Begg's test and Egger's test for publication bias. Data synthesis and analysis were performed using Stata 15.1 software. This study included a total of 15 RCTs with 673 participants conducted in 7 countries. Risk of bias results indicated an overall low risk of bias of the articles. Participants included healthy individuals, overweight and obese individuals, non-alcoholic fatty liver disease (NAFLD) patients, type 2 diabetes (T2DM) patients, polycystic ovary syndrome (PCOS) patients, metabolic syndrome (MS) patients, and individuals with hyperlipidemia. Pomegranate extract variations included pomegranate juice (PJ), pomegranate seed oil (PSO) capsule, pomegranate/pomegranate peel (PP) extract capsule, and pomegranate peel-added bread. The control groups primarily received placebo treatments with varying dosage and frequency. No adverse reactions were reported in any of the studies. The summary results showed that compared to the control groups, pomegranate extract had no significant impact on improving HOMA-IR levels in participants (WMD = -0.03, 95%CI: -0.37 to 0.31, and p = 0.851) and FI (WMD = -0.03, 95%CI: -0.42 to 0.36, and p = 0.862). Additionally, there was no significant advantage of pomegranate extract on QUICKI changes in T2DM and PCOS patients (WMD = 0.00, 95%CI: 0.00 to 0.01, and p = 0.002). Subgroup analysis results indicated that pomegranate extract could improve HOMA-IR levels in PCOS patients (WMD = -0.42, 95%CI: -0.54 to -0.29, and p < 0.001) and FI levels in T2DM, PCOS, and NAFLD patients. Our results indicate that pomegranate extract only improves HOMA-IR and FI levels in PCOS patients and FI levels in T2DM and NAFLD patients. No significant difference has been found for HOMA-IR, FI, or QUICKI in other metabolic diseases. The current evidence suggests that we should interpret the value of pomegranate extract in regulating IR and sensitivity cautiously. In the future, there is a need for more rigorously designed RCTs to specifically evaluate the impact of pomegranate supplementation on insulin sensitivity in patients with NAFLD, PCOS, and T2DM.

Excess dietary sugar and its impact on periodontal inflammation: a narrative review

INTRODUCTION

Sugar is omnipresent in the current food environment and sugar consumption has drastically risen over the past century. Extensive evidence highlights the negative health consequences of consuming excess dietary sugars, leading the World Health Organization (WHO) and the American Heart Association (AHA) to devise guidelines to restrict sugar intake. According to the WHO's Global Oral Health Status Report of 2022, oral diseases and severe periodontitis are a massive public health problem, and dietary sugars are a modifiable risk factor.

METHODS

We conducted a literature review using key databases to summarise the health effects of excessive sugar consumption and their potential role in periodontal inflammation.

RESULTS AND CONCLUSION

Available evidence suggests that excess dietary fructose and sucrose can cause low-grade systemic inflammation; and induce dysbiosis in both gut and the oral microbiota. Also, dietary sugar is potentially addictive and hypercaloric and its overconsumption can lead to obesity, metabolic syndrome, and other risk factors for periodontal inflammation. Hence, an unbalanced diet with excess dietary sugars holds the potential to initiate and aggravate periodontal inflammation. In the modern food environment that enables and facilitates a high-sugar diet, adopting a diverse diet and restricting sugar intake according to WHO and AHA guidelines seem beneficial to systemic and periodontal health. Since clinical evidence is limited, future research should study the effectiveness of dietary interventions that control sugar consumption in preventing and managing the global public health problem of periodontal inflammation.

Rabeprazole mitigates obesity-induced chronic inflammation and insulin resistance associated with increased M2-type macrophage polarization

Macrophage polarization is closely associated with obesity-induced chronic inflammation and insulin resistance. Proton pump inhibitor Rabeprazole has long been used to treat gastritis and gastric ulcers. However, whether Rabeprazole plays a role in macrophage polarization during obesity is unknown. Here, we show that Rabeprazole suppresses M1-type macrophage-mediated inflammation, leads to increased M2-type macrophages and alters the polarization status from M1 to M2 in vitro. Mechanistically, Rabe-regulated macrophage polarization is associated with inhibition of NF-κB and activation of STAT6 signaling pathways. Furthermore, Rabeprazole induces M2-type adipose tissue macrophages and alleviates chronic inflammation, improving glucose tolerance and insulin sensitivity in high-fat diet-fed mice. In addition, Rabeprazole increases CD206+ M2-type liver macrophages and relieves liver inflammation, alleviating liver injury and lipid accumulation. Thus, our findings show that Rabeprazole effectively regulates macrophage polarization and controls obesity-associated chronic inflammation and insulin resistance, thus providing a potential therapeutic strategy against obesity-associated metabolic diseases.

Resveratrol attenuates against high-fat-diet-promoted non-alcoholic fatty liver disease in rats mainly by targeting the miR-34a/SIRT1 axis

This study evaluated if miR-34a/SIRT1 signalling mediates the anti-hepatosteatotic effect of resveratrol (RSV) in high-fat-diet (HFD)-fed rats. Rats were divided into seven groups (n = 6/each) as control, control + miR-34a agomir negative control, HFD, HFD + miR-34a, HFD + RSV, HFD + RSV + Ex-527 (a SIRT1 inhibitor), and HFD + RSV + miR-34a agomir. After 8 weeks, RSV suppressed dyslipidemia, lowered fasting glucose and insulin levels, improved insulin sensitivity, and prevented hepatic lipid accumulation. These effects were associated with hepatic downregulation of SREBP1 and SREBP2, upregulation of PPARα, and acetylation of Nrf2 (activation) and NF-κβ p65 (inhibition). Also, RSV reduced the transcription of miR-34a and increased the nuclear localisation of SIRT1 in the livers, muscles, and adipose tissues of HFD-fed rats. All these effects were prevented by EX-527 and miR-34a agmir. In conclusion, RSV prevents HFD-induced insulin resistance and hepatic steatosis by suppressing miR-34a-induced activation of SIRT1.

Extracellular Vesicles and Their Correlation with Inflammatory Factors in an Experimental Model of Steatotic Liver Disease Associated with Metabolic Dysfunction

Background/Aims: Extracellular vesicles (EVs) are promising as a biomarker of metabolic dysfunction associated steatotic liver disease (MASLD). The objective is to study EVs and their involvement in MASLD concerning the disease's pathogenesis and progression characteristics. Methods: Male adult Sprague Dawley rats were randomly assigned into two experimental models of MASLD: MASLD-16 and MASLD-28, animals received a choline-deficient high-fat diet (CHFD) and Control-16 and Control-28, animals received a standard diet (SD) for 16 and 28 weeks, respectively. Biological samples from these animal models were used, as well as previously registered variables. EVs from hepatic tissue were characterized using confocal microscopy. EVs were isolated through differential ultracentrifugation from serum and characterized using NanoSight. The data from the EVs were correlated with biochemical, molecular, and histopathological parameters. Results: Liver EVs were identified through the flotillin-1 protein. EVs were isolated from the serum of all groups. There was a decrease of EVs concentration in MASLD-28 in comparison with Control-28 (P < 0.001) and a significant increase in EVs concentration in Control-28 compared with Control-16 (P < 0.001). There was a strong correlation between serum EVs concentration with hepatic gene expression of interleukin (Il)6 (r2 = 0.685, P < 0.05), Il1b (r2 = 0.697, P < 0.05) and tumor necrosis factor-alpha (Tnfa; r2 = 0.636, P < 0.05) in MASLD-16. Moreover, there was a strong correlation between serum EVs size and Il10 in MASLD-28 (r2 = 0.762, P < 0.05). Conclusion: The concentration and size of EVs correlated with inflammatory markers, suggesting their involvement in the systemic circulation, cellular communication, and development and progression of MASLD, demonstrating that EVs have the potential to serve as noninvasive biomarkers for MASLD diagnosis and prognosis.

Lactiplantibacillus plantarum ZDY2013 Inhibits the Development of Non-Alcoholic Fatty Liver Disease by Regulating the Intestinal Microbiota and Modulating the PI3K/Akt Pathway

Non-alcoholic fatty liver disease (NAFLD) is a common chronic hepatic condition whose impact on human health is increasingly significant. The imbalance of the gut microbiome, linked to insulin resistance, heightened intestinal permeability, and pro-inflammatory reactions, may be the linchpin in the development of NAFLD. In our research, the impact of Lactiplantibacillus plantarum ZDY2013 administration for 12 weeks on gut microbiota dysbiosis induced by a high-fat, high-fructose, high-cholesterol (FHHC) diet in male C57BL/6n mice was investigated. Research results presented that the intervention of L. plantarum ZDY2013 in mice fed with the FHHC diet could restore their liver function and regulate oxidative stress. Compared to mice in the model group, the intervention of L. plantarum ZDY2013 significantly regulated the gut microbiota, inhibited the LPS/NF-κB pathway, and led to a lower level of colonic inflammation in the mice administered with L. plantarum ZDY2013. It also improved insulin resistance to regulate the PI3K/Akt pathway and lipid metabolism, thereby resulting in reduced fat accumulation in the liver. The above results suggest that the intervention of L. plantarum ZDY2013 can hinder the progression of diet-induced NAFLD by reducing inflammation to regulate the PI3K/Akt pathway and regulating gut microbiota disturbance.

Evaluation of hepatoprotective and antidiarrheal activities of the hydromethanol crude extract and solvent fractions of Schinus molle L. (Anacardiaceae) leaf and fruit in mice

Background

Liver disease is any disease that negatively affects the normal function of the liver, and it is a major health problem that challenges not only healthcare professionals, but also the pharmaceutical industry and drug regulatory agencies. Similarly, diarrhea is the second leading cause of death among children under five globally next to pneumonia. The available synthetic drugs for the treatment of liver disorders and diarrhoea have limited safety and efficacy.

Objective

To evaluate the in vivo hepatoprotective and antidiarrheal activities of hydroalcoholic leaf and fruit extracts of Schinus molle L. (Anacardiaceae) in mice.

Methods

Hepatoprotective activity of the extracts was evaluated by using CCl4 induced hepatotoxicity in mice model. In this model, mice were divided into groups and treated as follows. The normal control and toxicant control groups were treated with the vehicle used for reconstitution, the positive control was treated with the standard drug (silymarin), and the test groups were treated with different doses of plant extracts daily in the morning for seven days. Additionally, all groups except the normal control were treated with CCl4 (2 mg/kg, IP) on the 4th day of treatment, 30 min post-dose. On the 7th day, blood was collected from each mouse via a cardiac puncture. The collected blood was centrifuged, and serum levels of ALT, AST, and ALP were determined using an automated chemistry analyser. Data were analysed using one-way analysis of variance (ANOVA) followed by Tukey's post-hoc test.The antidiarrheal activity of the extract was investigated using castor oil-induced diarrhoea, enteropooling, and small intestine transit. The test groups received various doses (100, 200, and 400 mg/kg) of the extract, whereas the positive control received loperamide (3 mg/kg), and the negative control received the vehicle (distilled water, 10 ml/kg).

Result

Hepatoprotective activity: The leaf and fruit crude extracts showed significant improvement in the body weight and liver weight of mice compared to the untreated toxicant control. Additionally, treatment with hydromethanol leaf and fruit extracts caused a significant (P < 0.05) improvement in liver biomarkers compared to the toxicant control. Similarly, the n-butanol and chloroform fractions of the fruit extract caused a significant reduction (P < 0.01) in serum AST, ALT, ALP and Bilirubin levels and a significant (P < 0.001) increase in total protein compared to the toxicant control. However, none of the three solvent fractions (n-butanol, chloroform, and aqueous) of the fruit extract significantly affected (P > 0.05) the level of albumin compared with the toxicant control.Antidiarrheal activity: In the castor oil-induced diarrheal model, the 80 % methanol extract delayed the onset of defaecation and significantly reduced the number and weight of faeces at all tested doses compared to the negative control. In the enteropooling test, 80 ME significantly (P < 0.001) reduced the weight and volume of intestinal fluid at all tested doses compared with the negative control. Results from the charcoal meal test revealed that the extracts produced a significant anti-motility effect at all tested doses compared with the negative control.

Conclusion

This study confirmed the hepatoprotective and antidiarrheal activities of hydroalcoholic extracts. The highest test dose produced the maximum hepatoprotective and antidiarrheal activities in all models.

Recent Progresses on Pathophysiology, Diagnosis, Therapeutic Modalities, and Management of Non-alcoholic Fatty Liver Disorder

Abstract:

Non-alcoholic fatty liver disease (NAFLD) is currently the utmost common chronic liver disorder that happens through all age groups and is identified to occur in 14%-30% of the general population, demonstrating a critical and grossing clinical issue because of the growing incidence of obesity and overweight. From the histological aspect, it looks like alcoholic liver damage, but it happens in patients who avoid remarkable alcohol usage. NAFLD comprises a broad spectrum, ranging from benign hepatocellular steatosis to inflammatory nonalcoholic steatohepatitis (NASH), different levels of fibrosis, and cirrhosis. Patients with NASH are more susceptible to more rapid progression to cirrhosis and hepatocellular carcinoma. There is no single factor that drives proceeding from simple steatosis to NASH. However, a combination of multi parameters such as genetic background, gut microflora, intake of high fat/ fructose dietary contents or methionine/choline-deficient diet, and consequently accumulated hepatocellular lipids mainly including triglycerides and also other bio-analytes, such as free fatty acids, cholesterol, and phospholipids display a crucial role in disease promotion. NAFLD is related to overweight and insulin resistance (IR) and is regarded as the hepatic presentation of the metabolic syndrome, an amalgamation of medical statuses such as hyperlipidemia, hypertension, type 2 diabetes, and visceral obesity. Despite the increasing prevalence of this disease, which imposes a remarkable clinical burden, most affected patients remain undiagnosed in a timely manner, largely related to the asymptomatic entity of NAFLD patients and the unavailability of accurate and efficient noninvasive diagnostic tests. However, liver biopsy is considered a gold standard for NAFLD diagnosis, but due to being expensive and invasiveness is inappropriate for periodic disease screening. Some noninvasive monitoring approaches have been established recently for NAFLD assessment. In addition to the problem of correct disease course prediction, no effective therapeutic modalities are approved for disease treatment. Imaging techniques can commonly validate the screening and discrimination of NAFLD; nevertheless, staging the disease needs a liver biopsy. The present therapeutic approaches depend on weight loss, sports activities, and dietary modifications, although different insulin-sensitizing drugs, antioxidants, and therapeutic agents seem hopeful. This review aims to focus on the current knowledge concerning epidemiology, pathogenesis, and different biochemical experiments and imaging modalities applied to diagnose the different grades of NAFLD and its management, as well as new data about pharmacological therapies for this disorder.

Association between cataract and fatty liver diseases from a nationwide cross-sectional study in South Korea

This study examined the link between fatty liver disease (FLD) and cataracts, as previous research has suggested that FLD may contribute to metabolic syndrome, systemic inflammation, and potentially cataracts. We studied a nationwide cross-sectional cohort of the Fifth Korean National Health and Nutrition Examination Survey 2010-2011. FLD was defined as nonalcoholic FLD (NAFLD) and metabolic dysfunction-associated FLD (MAFLD). Multinomial logistic regression was utilized to investigate the relationship between cataracts and FLD after adjustment for potential confounders. Participants with cataracts had higher liver fibrosis scores, including the NAFLD fibrosis score (NFS; P < 0.001), fibrosis-4 index (FIB4; P < 0.001), and fatty liver index (FLI; P = 0.001). NAFLD was not associated with a higher odds ratio (OR) for cataracts in the fully adjusted model (OR = 1.23, P = 0.058). MAFLD was significantly associated with a higher OR (OR = 1.34, P = 0.006). After adjusting for all factors, the severity of FLD was linked to an increased risk of cataracts, with significant linear trends (P values for linear trends of NFS, FIB4, and FLI < 0.05). After adjusting for well-known cataract risk factors, MAFLD was significantly associated with cataracts. Our analysis suggests that FLD may serve as an independent risk factor for cataracts.

A review of experimental and clinical studies on the therapeutic effects of pomegranate (Punica granatum) on non-alcoholic fatty liver disease: Focus on oxidative stress and inflammation

Non-alcoholic fatty liver disease (NAFLD) is frequently linked to metabolic disorders and is prevalent in obese and diabetic patients. The pathophysiology of NAFLD involves multiple factors, including insulin resistance (IR), oxidative stress (OS), inflammation, and genetic predisposition. Recently, there has been an emphasis on the use of herbal remedies with many people around the world resorting to phytonutrients or nutraceuticals for treatment of numerous health challenges in various national healthcare settings. Pomegranate (Punica granatum) parts, such as juice, peel, seed and flower, have high polyphenol content and is well known for its antioxidant capabilities. Pomegranate polyphenols, such as hydrolyzable tannins, anthocyanins, and flavonoids, have high antioxidant capabilities that can help lower the OS and inflammation associated with NAFLD. The study aimed to investigate whether pomegranate parts could attenuate OS, inflammation, and other risk factors associated with NAFLD, and ultimately prevent the development of the disease. The findings of this study revealed that: 1. pomegranate juice contains hypoglycemic qualities that can assist manage blood sugar levels, which is vital for avoiding and treating NAFLD. 2. Polyphenols from pomegranate flowers increase paraoxonase 1 (PON1) mRNA and protein levels in the liver, which can help protect liver enzymes and prevent NAFLD. 3. Punicalagin (PU) is one of the major ellagitannins found in pomegranate, and PU-enriched pomegranate extract (PE) has been shown to inhibit HFD-induced hyperlipidemia and hepatic lipid deposition in rats. 4. Pomegranate fruit consumption, which is high in antioxidants, can decrease the activity of AST and ALT (markers of liver damage), lower TNF-α (a marker of inflammation), and improve overall antioxidant capacity in NAFLD patients. Overall, the polyphenols in pomegranate extracts have antioxidant, anti-inflammatory, hypoglycemic, and protective effects on liver enzymes, which can help prevent and manage NAFLD effects on liver enzymes, which can help prevent and manage NAFLD.

Digital Twin-Enabled Personalized Nutrition Improves Metabolic Dysfunction-Associated Fatty Liver Disease in Type 2 Diabetes: Results of a 1-Year Randomized Controlled Study

OBJECTIVE

Postprandial hyperglycemia drives insulin resistance and inflammation, leading to metabolic dysfunction-associated fatty liver disease (MAFLD). Prediction of postprandial glycemic responses by digital twin (DT) technology can fashion a personalized nutrition, activity, and sleep to treat type 2 diabetes (T2D) and MAFLD. This study examines the effects of DT-enabled personalized nutrition, activity, and sleep on glycemic status, surrogate markers of MAFLD, and magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) in patients with T2D.

METHODS

In an open-label randomized trial (2:1), 319 people with T2D were eligible to intervention (DT) or standard care (SC). DT patients followed personalized meal plans with foods suggested by artificial intelligence with least predicted postprandial glycemic response. The primary end point was to compare change in hemoglobin A1c (HbA1c) and medicine reduction between the DT and SC groups. Key secondary end points included remission to compare liver function test scores and visceral adiposity using MRI.

RESULTS

HbA1C was significantly better for DT than for SC (-2.9 [1.8] vs -0.3 [1.2]; P < .001) at 1 year with 72.7% remission of T2D. In patients with abnormal baseline values, significant improvements were seen in DT vs SC patients from baseline to 1 year in nonalcoholic fatty liver disease liver fat score (mean [SD]; -2.5 [2.0] vs -0.1 [1.5]; P < .001) and nonalcoholic fatty liver disease fibrosis score (-1.20 [0.9] vs -0.1 [1.0]; P < .001), respectively. Improvements are seen with DT compared with SC in other liver fat, fibrosis score, and %liver fat by MRI-PDFF.

CONCLUSION

At 1 year, DT-enabled personalized treatment significantly improved hyperglycemia and surrogate markers of MAFLD and MRI-PDFF.

UBE2M-mediated neddylation of TRIM21 regulates obesity-induced inflammation and metabolic disorders

Inflammation is closely associated with obesity and related metabolic disorders. However, its origin during obesity is largely unknown. Here, we report that ubiquitin-conjugating enzyme E2M (UBE2M) is critical to obesity-related inflammation induced by macrophages. In mice with UBE2M-deficient macrophages, obesity, insulin resistance, and hepatic steatosis induced by a high-fat diet are greatly alleviated, an effect related to the decreased proinflammatory activity of macrophages due to reduced IL-1β production. Mechanistically, UBE2M deficiency inhibits the neddylation of E3 ubiquitin ligase TRIM21 on K129/134, leading to reduced recruitment and ubiquitination-mediated degradation of E3 ubiquitin ligase VHL. Subsequently, VHL reduces HIF-1α-induced IL-1β production by degrading HIF-1α. Targeting macrophage TRIM21 with Trim21 antisense oligonucleotide-loaded red blood cell extracellular vesicles effectively inhibits obesity-induced inflammation and related metabolic disorders. Thus, our results demonstrate that macrophage UBE2M is essential for obesity-induced inflammation and that TRIM21 is a proof-of-concept target for treating obesity and associated metabolic diseases.

Role of Oxidative Stress and Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become a widely studied subject due to its increasing prevalence and links to diseases such as type 2 diabetes and obesity. It has severe complications, including nonalcoholic steatohepatitis, cirrhosis, hepatocellular carcinoma, and portal hypertension that can lead to liver transplantation in some cases. To better prevent and treat this pathology, it is important to understand its underlying physiology. Here, we identify two main factors that play a crucial role in the pathophysiology of NAFLD: oxidative stress and the key role of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). We discuss the pathophysiology linking these factors to NAFLD pathophysiology.

Steroid Use and Risk of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease: Systematic Review and Meta-analysis

GOALS

We sought to evaluate the association of steroids with nonalcoholic fatty liver disease (NAFLD) among patients with inflammatory bowel disease (IBD).

BACKGROUND

Patients with IBD are at increased risk of NAFLD. Steroids may have a role in the pathogenesis of NAFLD.

STUDY

We searched MEDLINE (through PubMed) and Embase for studies from inception to July 2021. We included published interventional and observational studies of adults 18 years or older with ulcerative colitis or Crohn's disease. We reported odds ratios, 95% confidence intervals, and generated forest plots. A random effects model generated a summary effect estimate. Publication bias was assessed by funnel plot and Egger's test. Study quality was examined using modified Newcastle-Ottawa scale (NOS) and Agency for Healthcare Research and Quality (AHRQ).

RESULTS

A total of 12 observational studies with 3497 participants were included. NAFLD was identified in 1017 (29.1%) patients. The pooled odds ratio for the development of NAFLD in steroid users versus non-users was 0.87 (95% confidence interval: 0.72-1.04). There was no significant heterogeneity between studies ( I ²=0.00%, P =0.13). No publication bias was detected by funnel plot or Egger's test ( P =0.24). Findings were consistent among subgroup analyses stratified by study quality.

CONCLUSION

In this meta-analysis, steroids were not associated with NAFLD in patients with IBD. Steroids may not need to be withheld from patients with IBD for the purposes of preventing NAFLD. Additional prospective studies that systematically document steroid exposure and important confounders among patients with IBD are warranted.

Progesterone Has No Impact on the Beneficial Effects of Estradiol Treatment in High-Fat-Fed Ovariectomized Mice

In recent decades, clinical and experimental studies have revealed that estradiol contributes enormously to glycemic homeostasis. However, the same consensus does not exist in women during menopause who undergo replacement with progesterone or conjugated estradiol and progesterone. Since most hormone replacement treatments in menopausal women are performed with estradiol (E2) and progesterone (P4) combined, this work aimed to investigate the effects of progesterone on energy metabolism and insulin resistance in an experimental model of menopause (ovariectomized female mice-OVX mice) fed a high-fat diet (HFD). OVX mice were treated with E2 or P4 (or both combined). OVX mice treated with E2 alone or combined with P4 displayed reduced body weight after six weeks of HFD feeding compared to OVX mice and OVX mice treated with P4 alone. These data were associated with improved glucose tolerance and insulin sensitivity in OVX mice treated with E2 (alone or combined with P4) compared to OVX and P4-treated mice. Additionally, E2 treatment (alone or combined with P4) reduced both hepatic and muscle triglyceride content compared with OVX control mice and OVX + P4 mice. There were no differences between groups regarding hepatic enzymes in plasma and inflammatory markers. Therefore, our results revealed that progesterone replacement alone does not seem to influence glucose homeostasis and ectopic lipid accumulation in OVX mice. These results will help expand knowledge about hormone replacement in postmenopausal women associated with metabolic syndrome and non-alcoholic fatty liver disease.

Anthocyanins ameliorate obesity-associated metainflammation: Preclinical and clinical evidence

The growing rates of obesity worldwide call for intervention strategies to help control the pathophysiological consequences of weight gain. The use of natural foods and bioactive compounds has been suggested as such a strategy because of their recognized antioxidant and anti-inflammatory properties. For example, polyphenols, especially anthocyanins, are candidates for managing obesity and its related metabolic disorders. Obesity is well known for the presence of metainflammation, which has been labeled as an inflammatory activation that leads to a variety of metabolic disorders, usually related to increased oxidative stress. Considering this, anthocyanins may be promising natural compounds able to modulate several intracellular mechanisms, mitigating oxidative stress and metainflammation. A wide variety of foods and extracts rich in anthocyanins have become the focus of research in the field of obesity. Here, we bring together the current knowledge regarding the use of anthocyanins as an intervention tested in vitro, in vivo, and in clinical trials to modulate metainflammation. Most recent research applies a wide variety of extracts and natural sources of anthocyanins, in diverse experimental models, which represents a limitation of the research field. However, the literature is sufficiently consistent to establish that the in-depth molecular analysis of gut microbiota, insulin signaling, TLR4-triggered inflammation, and oxidative stress pathways reveals their modulation by anthocyanins. These targets are interconnected at the cellular level and interact with one another, leading to obesity-associated metainflammation. Thus, the positive findings with anthocyanins observed in preclinical models might directly relate to the positive outcomes in clinical studies. In summary and based on the entirety of the relevant literature, anthocyanins can mitigate obesity-related perturbations in gut microbiota, insulin resistance, oxidative stress and inflammation and therefore may contribute as a therapeutic tool in people living with obesity.

IL-6-GP130 signaling protects human hepatocytes against lipid droplet accumulation in humanized liver models

Liver steatosis is an increasing health issue with few therapeutic options, partly because of a paucity of experimental models. In humanized liver rodent models, abnormal lipid accumulation in transplanted human hepatocytes occurs spontaneously. Here, we demonstrate that this abnormality is associated with compromised interleukin-6 (IL-6)-glycoprotein 130 (GP130) signaling in human hepatocytes because of incompatibility between host rodent IL-6 and human IL-6 receptor (IL-6R) on donor hepatocytes. Restoration of hepatic IL-6-GP130 signaling, through ectopic expression of rodent IL-6R, constitutive activation of GP130 in human hepatocytes, or humanization of an Il6 allele in recipient mice, substantially reduced hepatosteatosis. Notably, providing human Kupffer cells via hematopoietic stem cell engraftment in humanized liver mice also corrected the abnormality. Our observations suggest an important role of IL-6-GP130 pathway in regulating lipid accumulation in hepatocytes and not only provide a method to improve humanized liver models but also suggest therapeutic potential for manipulating GP130 signaling in human liver steatosis.

Time-of-day defines NAD+ efficacy to treat diet-induced metabolic disease by synchronizing the hepatic clock in mice

The circadian clock is an endogenous time-tracking system that anticipates daily environmental changes. Misalignment of the clock can cause obesity, which is accompanied by reduced levels of the clock-controlled, rhythmic metabolite NAD⁺. Increasing NAD⁺ is becoming a therapy for metabolic dysfunction; however, the impact of daily NAD⁺ fluctuations remains unknown. Here, we demonstrate that time-of-day determines the efficacy of NAD⁺ treatment for diet-induced metabolic disease in mice. Increasing NAD⁺ prior to the active phase in obese male mice ameliorated metabolic markers including body weight, glucose and insulin tolerance, hepatic inflammation and nutrient sensing pathways. However, raising NAD⁺ immediately before the rest phase selectively compromised these responses. Remarkably, timed NAD⁺ adjusted circadian oscillations of the liver clock until completely inverting its oscillatory phase when increased just before the rest period, resulting in misaligned molecular and behavioral rhythms in male and female mice. Our findings unveil the time-of-day dependence of NAD⁺-based therapies and support a chronobiology-based approach.

Recent evaluation about inflammatory mechanisms in nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is common chronic metabolic liver disorder which is associated with fat accumulation in the liver. It causes a wide range of pathological effects such as insulin resistance, obesity, hypertension, diabetes, non-alcoholic steatohepatitis (NASH) and cirrhosis, cardiovascular diseases. The molecular mechanisms that cause the initiation and progression of NAFLD remain fully unclear. Inflammation is regarded as a significant mechanism which could result in cell death and tissue injury. Accumulation of leukocytes and hepatic inflammation are important contributors in NAFLD. Excessive inflammatory response can deteriorate the tissue injury in NAFLD. Thus, inhibition of inflammation improves NAFLD by reducing intrahepatic fat content, increasing β-oxidation of fatty acids, inducing hepato-protective autophagy, overexpressing peroxisome proliferator-activated receptor- γ (PPAR-γ), as well as attenuating hepatocyte apoptosis and increasing insulin sensitivity. Therefore, understanding the molecules and signaling pathways suggests us valuable information about NAFLD progression. This review aimed to evaluate the inflammation in NAFLD and the molecular mechanism on NAFLD.

In Vitro Probiotic Properties of Bifidobacterium animalis subsp. lactis SF and Its Alleviating Effect on Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease with many influencing factors. With the increasing role of the gut–liver axis in various liver diseases, research on the prevention and treatment of NAFLD with probiotics is increasing. In the present study, a Bifidobacterium animalis subsp. strain, B. lactis SF, was isolated from the feces of healthy infants and characterized by sequencing of the 16S rDNA. A systematic probiotic evaluation was carried out, and a diet-induced mouse model was constructed to study the effect and mechanism of B. lactis SF on diet-induced NAFLD. Results show that B. lactis SF has excellent gastrointestinal fluid tolerance and intestinal colonization, and strong antibacterial and antioxidant capabilities. In vivo, B. lactis SF modulated intestinal flora, restored the intestinal barrier, and inhibited LPS entrance into the portal circulation, which subsequently inhibited the TLR4/NF-κB and modulated the PI3K-Akt/AMPK signaling pathway, attenuated the inflammatory response, and reduced lipid accumulation. In addition, B. lactis SF attenuated oxidative stress and further alleviated autophagy, resulting in an ameliorative effect on NAFLD. Therefore, our study provides a new dietary method for the treatment of NAFLD.

The capsaicinoid nonivamide suppresses the inflammatory response and attenuates the progression of steatosis in a NAFLD-rat model

Nonalcoholic fatty liver disease (NAFLD) is relatively associated with comorbidities in obesity and metabolic inflammation. Low-grade inflammation following the high-fat diet (HFD)-induced NAFLD can promote the development of nonalcoholic steatohepatitis (NASH) through particularly liver-resident immune cell recruitment and hepatic nuclear factor kappa B (NF-κB) pathway. Therefore, inflammatory intervention may contribute to NASH reduction. Pelargonic acid vanillylamide (PAVA) or nonivamide is one of the pungent capsaicinoids of Capsicum species and has been found in chili peppers. Our previous study demonstrated that PAVA improved hepatic function, decreased oxidative stress and reduced apoptotic cell death but the insight role of PAVA on NAFLD is still unclear. Thus, this study aimed to investigate the underlying anti-inflammatory mechanism of PAVA in an NAFLD-rat model. Male Sprague Dawley rats were fed with normal diet or HFD for 16 weeks. Then high-fat rats were given vehicle or PAVA (1 mg/kg/day) for another 4 weeks. We found that PAVA alleviated hepatic inflammation associated with the reducing toll-like receptor 4/NF-κB pathway, showing significantly lower recruitment of cluster of differentiation 44. PAVA also maintained activity of insulin signaling pathway, and attenuated NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome formation. NAFLD progresses to NASH through transforming growth factor (TGF-β1), and also recovery to simple stage followed by PAVA suppresses pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, interleukin-6, and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway. Therefore, our findings suggest that PAVA provides a novel therapeutic approach for NAFLD and slows the progression to NASH.

The interactions between inflammation and insulin resistance: molecular mechanisms in insulin-producing and insulin-dependent tissues

In the modern world the prevalence of obesity and type 2 diabetes mellitus (T2DM) significantly increases. In this light the risks of obesity-associated complications also grow up. The crucial linkage between obesity and its metabolic and cardiovascular complications is inflammatory process. The mechanism of this linkage is similar in pancreas and insulin-dependent tissues both on cells, cell-to-cell communication and signaling pathway levels: the catalysts are different lipids (cholesterol, free fatty acids, triglycerides), which are able to activate Toll-like receptors of innate immunity and inflammation. Nextly, IKK- and JNK-dependent cascades activate the secretion of inflammatory cytokines TNFa, IL-1b, IL-6 and others, which act by paracrine and autocrine manner and support inflammation both in local and systemic levels. Thus, insulin-producing and insulin-dependent tissues, which are involved in T2DM pathogenesis, through the inflammatory process integrate in pathogenic and self-maintaining cycle, which leads to the suppression of insulin secretion, pancreatic β-cell failure and the development of insulin-dependent tissues insulin resistance.

Verapamil-loaded supramolecular hydrogel patch attenuates metabolic dysfunction-associated fatty liver disease via restoration of autophagic clearance of aggregated proteins and inhibition of NLRP3

BACKGROUND

Obesity, a serious threat to public health, is linked to chronic metabolic complications including insulin resistance, type-2 diabetes, and metabolic dysfunction-associated fatty liver disease (MAFLD). Current obesity medications are challenged by poor effectiveness, poor patient compliance, and potential side effects. Verapamil is an inhibitor of L-type calcium channels, FDA-approved for the treatment of hypertension. We previously investigated the effect of verapamil on modulating autophagy to treat obesity-associated lipotoxicity. This study aims to develop a verapamil transdermal patch and to evaluate its anti-obesity effects.

METHODS

Verapamil is loaded in biomimetic vascular bundle-like carboxymethyl pullulan-based supramolecular hydrogel patches cross-linked with citric acid and glycerol linkages (CLCMP). The investigation was then carried out to determine the therapeutic effect of verapamil-loaded CLCMP (Vera@CLCMP) on diet-induced obese mice.

RESULTS

Vera@CLCMP hydrogel patches with hierarchically organized and anisotropic pore structures not only improved verapamil bioavailability without modifying its chemical structure but also enhanced verapamil release through the stratum corneum barrier. Vera@CLCMP patches exhibit low toxicity and high effectiveness at delivering verapamil into the systemic circulation through the dermis in a sustained manner. Specifically, transdermal administration of this patch into diet-induced obese mice drastically improved glucose tolerance and insulin sensitivity and alleviated metabolic derangements associated with MAFLD. Furthermore, we uncovered a distinct molecular mechanism underlying the anti-obesity effects associated with the hepatic NLR family pyrin domain-containing 3 (NLRP3) inflammasome and autophagic clearance by the vera@CLCMP hydrogel patches.

CONCLUSION

The current study provides promising drug delivery platforms for long-term family treatment of chronic diseases, including obesity and metabolic dysfunctions.

IS FECAL CALPROTECTIN DETERMINATION USEFUL FOR PATIENTS WITH METABOLIC ASSOCIATED FATTY LIVER DISEASE?

OBJECTIVE

Aim: To investigate the possible relationship between fecal calprotectin (FC) level and ultrasound indicators of steatosis and fibrosis wich defined by attenuation coefficient (AC) and liver stiffness (LS) from two-dimensional (2D) shear-wave elastography (SWE) in patients with metabolically associated fatty liver disease (MAFLD).

PATIENTS AND METHODS

Materials and Methods: The study included 110 persons with MAFLD; mean age 51.3±4.8 years, 65 (59.1%) men. There were used laboratory, sonography and statistical methods.

RESULTS

Results: Stage S1 of steatosis was diagnosed in 42 (38.2%), S2 - in 56 (50.9%), S3 - only in 12 (10.9%) MAFLD patients. The carbohydrate metabolism disorders were found in 62 (56.4%); 38 (34.5%) patients among them suffered from type 2 diabetes. The lipid metabolism disorders were diagnosed in the vast majority of patients included in this study. The minimal excess of fecal calprotectin (FC) was detected in 72 MAFLD patients (65.5%), the moderate increase of FC was found in 12 persons, the FC more than 10-fold excess of the norm was observed in only 8 MAFLD patients. FC levels were significantly elevated in MAFLD patients with a S2-S3 compared to those with a S1 (75.8 [42.9-112.1] vs. 46.3 [28.2-65.4], p<0.01).

CONCLUSION

Conclusions: Fecal calprotectin levels are significantly elevated in patients with MAFLD. Future studies are warranted to establish the definitive role and clinical utility of FC as a potential biomarker of probably liver steatosis as well as other diseases associated with methabolic syndrome and its complications.

A diet-independent zebrafish model for NAFLD recapitulates patient lipid profiles and offers a system for small molecule screening

Non-alcoholic Fatty Liver Disease (NAFLD) or pathological hepatic lipid overload, is considered to affect obese individuals. However, NAFLD in lean individuals is prevalent, especially in South Asian population. The pathophysiology of lean NAFLD is not well understood and most animal models of NAFLD use the high-fat diet paradigm. To bridge this gap, we have developed a diet-independent model of NAFLD in zebrafish. We have previously shown that chronic systemic inflammation causes metabolic changes in the liver leading to hepatic fat accumulation in an IL6 overexpressing (IL6-OE) zebrafish model. In the present study, we compared the hepatic lipid composition of adult IL6-OE zebrafish to the controls and found an accumulation of saturated triacylglycerols and a reduction in the unsaturated triacylglycerol species reminiscent of NAFLD patients. Zebrafish is an ideal system for chemical genetic screens. We tested whether the hepatic lipid accumulation in the IL6-OE is responsive to chemical treatment. We found that PPAR-gamma agonist Rosiglitazone, known to reduce lipid overload in the high-fat diet models of NAFLD, could ameliorate the fatty liver phenotype of the IL6-OE fish. Rosiglitazone treatment reduced the accumulation of saturated lipids and showed a concomitant increase in unsaturated TAG species in our inflammation-induced NAFLD model. Our observations suggest that the IL6-OE model can be effective for small molecule screening to identify compounds that can reverse hepatic lipid accumulation, especially relevant to lean NAFLD.

Insulin resistance phenotype is associated with vascular risk phenotype at the end of the second decade of life: a population-based study

We hypothesize that early events of diabetes and cardiovascular disease continuums would be ongoing and associated in adolescents. We investigated the association between the Insulin Resistance Phenotype and the Vascular Risk Phenotype at the end of the second decade of life and indirect pathways from social vulnerability, alcohol consumption, and body fat mass. It is a population-based study in the RPS cohort of 18-19 years (n = 2,515), São Luís, Brazil. The theoretical model analyzed the association between Insulin Resistance Phenotype and Vascular Risk Phenotype by sex, using structural equation modeling (SEM). The Insulin Resistance Phenotype was a latent variable deduced from the correlations of Triglyceride to HDL ratio, Triglyceride Glycemic index, and VLDL; the Vascular Risk Phenotype was deduced from Systolic Blood Pressure, Diastolic Blood Pressure, and Pulse Wave Velocity. The Insulin Resistance Phenotype was directly associated with the Vascular Risk Phenotype in males (standardized coefficient SC = 0.183; p < 0.001) and females (SC = 0.152; p < 0.001). The Insulin Resistance Phenotype was an indirect pathway in the association of alcohol consumption and higher values of fat mass index with the Vascular Risk Phenotype. VLDL presented the highest factor loading, appearing as a marker of insulin resistance linked to cardiovascular risk in young people. Lower values of socioeconomic status, harmful use of alcohol, and high body fat values were also associated with higher values of the two phenotypes. The association of the Insulin Resistance Phenotype with the Vascular Risk Phenotype suggests common pathophysiological mechanisms present in early events in the continuums of diabetes and cardiovascular disease in adolescence.

Plasma Calprotectin Levels Associate with Suspected Metabolic-Associated Fatty Liver Disease and All-Cause Mortality in the General Population

Metabolic-associated fatty liver disease (MAFLD) is characterized by hepatic steatosis, metabolic dysregulation, and neutrophilic inflammation. In this study, we hypothesized that systemic levels of plasma calprotectin, as a biomarker of neutrophilic inflammation, may be associated with suspected MAFLD. Plasma calprotectin levels were measured in subjects (n = 5446) participating in the Prevention of Renal and Vascular ENd-stage Disease (PREVEND) cohort study. Suspected MAFLD was defined by the fatty liver index (FLI ≥ 60) and hepatic steatosis index (HSI ≥ 36) as proxies. Plasma calprotectin levels were significantly higher in subjects with FLI ≥ 60 (0.57 [IQR: 0.42−0.79] mg/L, n = 1592) (p < 0.001) compared to subjects with FLI < 60 (0.46 [0.34−0.65] mg/L, n = 3854). Multivariable logistic regression analyses revealed that plasma calprotectin levels were significantly associated with suspected MAFLD (FLI ≥ 60), even after adjustment for potential confounding factors, including current smoking, alcohol consumption, hypertension, diabetes, cardiovascular diseases, insulin resistance (HOMA-IR), hs-CRP, eGFR, and total cholesterol levels (OR 1.19 [95% CI: 1.06−1.33], p = 0.003). Interaction analyses revealed significant effect modifications for the association between plasma calprotectin and suspected MAFLD by BMI (p < 0.001) and hypertension (p = 0.003), with the strongest associations in subjects with normal BMI and without hypertension. Prospectively, plasma calprotectin levels were significantly associated with all-cause mortality after adjustment for potential confounding factors, particularly in subjects without suspected MAFLD (FLI < 60) (hazard ratio (HR) per doubling: 1.34 (1.05−1.72), p < 0.05). In conclusion, higher plasma calprotectin levels are associated with suspected MAFLD and with the risk of all-cause mortality, the latter especially in subjects without suspected MAFLD.

Transcription factor EB inhibits non-alcoholic fatty liver disease through fibroblast growth factor 21

We sought to explore the potential role of transcription factor EB (TFEB) in the pathogenesis of the non-alcoholic fatty liver disease (NAFLD). An NAFLD mouse model was established by high-fat diet induction, and then "gain of function" and "loss of function" experiments were performed to determine the potential protective effects of TFEB on NAFLD using TFEB knockdown and TFEB-overexpressed mice. The mediating effect of FGF21 was verified by injection of recombinant mouse fibroblast growth factor 21 (rmFGF21) and knockout of FGF21, and the regulatory effect of TFEB on FGF21 was examined. Mechanistic target of rapamycin (mTOR), ribosomal S6 kinase, TFEB, and FGF21 are involved in the NAFLD process. Overexpression of TFEB in NAFLD mice could reverse lipid deposition and metabolic changes in NAFLD mice. RmFGF21 can reverse the aggravation of NAFLD by TFEB knockdown. Increased expression of TFEB alleviates NAFLD, possibly through upregulation of FGF21 expression by targeting the FGF21 promoter. This study may lay a basis for identifying new drug targets for NAFLD treatment. KEY MESSAGES: Transcription factor EB (TFEB) is involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), and fibroblast growth factor 21 (FGF21) exerts a significantly positive effect on NAFLD. In the current study, we found that starvation led to an increase in liver lipids, which was reversed by re-feeding. Phosphorylated mTOR, ribosomal S6 kinase, TFEB, and FGF21 are involved in the above process. The increased expression of TFEB in NAFLD mice by tail vein injection of Ad-TFEB could reverse lipid deposition and metabolic changes in NAFLD mice. TFEB upregulated FGF21 expression by targeting the promoter of FGF21. This study adds to our understanding of the potential role of TFEB on the progression of NAFLD. This study may lay a basis for identifying new drug target of NAFLD treatment.

The effects of berberine supplementation on cardiovascular risk factors in adults: A systematic review and dose-response meta-analysis

Cardiovascular disease (CVD) is a major concern today. Herbal medicine is one helping way to control CVD risks. One conclusive of herbal medicine is Berberine (BBR) and converse about it still exists, to clarify this issue, this meta-analysis was performed. PubMed/Medline, Scopus, and Web of Science were searched for RCTs in adults on the effect of BBR supplementation on CVD risk factors up to July 2022. The pooled results showed BBR significantly reduced triglyceride (WMD = -23.70 mg/dl; 95%CI -30.16, -17.25; P < 0.001), total cholesterol (WMD = -20.64 mg/dl; 95%CI -23.65, -17.63; P < 0.001), low-density lipoprotein WMD = -9.63 mg/dl; 95%CI, -13.87, -5.39; P < 0.001), fasting blood glucose (FBG) (WMD = -7.74 mg/dl; 95%CI -10.79, -4.70; P < 0.001), insulin (WMD = -3.27 mg/dl; 95%CI -4.46,-2.07; P < 0.001), HbA1c (WMD = -0.45%; 95%CI -0.68, -0.23; P < 0.001), HOMA-IR (WMD = -1.04; 95%CI -1.55, -0.52; P < 0.001), systolic blood pressure (WMD = -5.46 mmHg; 95%CI -8.17, -2.76; P < 0.001), weight (WMD = -0.84; 95%CI -1.34,-0.34; P < 0.001), body mass index (WMD = -0.25 kg/m2; 95%CI -0.46, -0.04; P = 0.020), while increased high-density lipoprotein (HDL) (WMD = 1.37 mg/dl; 95%CI 0.41,2.23; P = 0.005). The optimal dose of BBR was 1 g/day for TG, TC, and weight, 1.8 g/day for insulin and HOMA-IR, and 5 g/day for HDL. FBG's most efficient time frame was 40 weeks from the beginning of supplementation, whereas DBP and waist circumference was 50 weeks. In conclusion, the lipid profile, FBG balance, obesity parameters, and SBP were improved with BBR supplementation.

Systematic review registration

CRD42022347004.

The ketogenic diet prevents steatosis and insulin resistance by reducing lipogenesis, diacylglycerol accummulation, and PKC activity in male rat liver

KEY POINTS

The accumulation of diacylglycerol (DAG), ceramides and inflammation are key factors that cause insulin resistance and nonalcoholic fatty liver (NAFLD). This study provides evidence that a ketogenic diet (KD) rich in fat and devoid of carbohydrate reduced DAG content and preserved insulin signalling in the liver. The KD shifted metabolism away from lipogenesis by enhancing genes involved in mitochondrial biogenesis and fatty acid oxidations in the liver. The KD also promoted the production of beneficial very long-chain ceramides instead of potentially harmful long-chain ceramides. Through multiple mechanisms, the KD exerted anti-steatogenic and insulin-sensitizing effects in the liver, which supports the use of this dietary intervention to treat NAFLD.

ABSTRACT

Obesity-associated insulin resistance plays a major role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). The accumulation of diacylglycerol (DAG), ceramides and inflammation are key factors that cause NAFLD. In recent years, the ketogenic diet (KD) has emerged as an effective non-pharmacological intervention for the treatment of NAFLD and other obesity-related metabolic disorders. What remains undetermined is how the KD affects DAG and ceramides content and insulin sensitivity in the liver. Thus, this research was designed to assess these variables, as well as glucose and fat metabolism and markers of inflammation in livers of rats exposed for 8 weeks to one of the following diets: standard chow (SC), obesogenic high-fat, sucrose-enriched diet (HFS), or a KD. Despite having a higher fat content than the HFS diet, the KD did not cause steatosis and preserved hepatic insulin signalling. The KD reduced DAG content and protein kinase C epsilon (PKCε) activity, but markedly increased liver ceramides content. However, whereas the KD increased ceramide synthase 2 (CerS2) expression, it suppressed CerS6 expression, an effect that promoted the production of beneficial very long-chain ceramides instead of harmful long-chain ceramides. The KD also enhanced the liver expression of key genes involved in mitochondrial biogenesis and fatty acid oxidation (Pgc-1α and Fgf21), suppressed inflammatory genes (Tnfα, Nf-kb, Tlr4, and Il6), and shifted substrate away from de-novo lipogenesis. Thus, through multiple mechanisms the KD exerted anti-steatogenic and insulin-sensitizing effects in the liver, which supports the use of this dietary intervention to treat NAFLD. Abstract figure legend This article is protected by copyright. All rights reserved.

Spirulina reduces diet-induced obesity through downregulation of lipogenic genes expression in Psammomys obesus

The present study evaluates the protective effect of spirulina against diet-induced obesity and metabolic disorders in Psammomys obesus, an animal model of metabolic syndrome. Psammomys obesus lives on a low-energy diet, in order to remain healthy. However, under a standard laboratory chow diet (SLCD), this animal exhibits insulin resistance, which occurs as a result of obesity. Psammomys obesus was maintained on SLCD, in order to evaluate the effect of spirulina on obesity development with a particular focus on glucose and lipid metabolism, as well as the mRNA expression of some pro-inflammatory cytokines. After 12 weeks of treatment with spirulina, there was a significant reduction in body weight gain, plasma glucose, insulin and triglyceride levels. There was also a significant reduction in the mRNA expression of genes involved in lipogenesis and inflammation. Spirulina improved insulin sensitivity, glucose and lipid metabolism. These findings highlight the positive effect of spirulina on weight maintenance.

Trends in insulin resistance: insights into mechanisms and therapeutic strategy

The centenary of insulin discovery represents an important opportunity to transform diabetes from a fatal diagnosis into a medically manageable chronic condition. Insulin is a key peptide hormone and mediates the systemic glucose metabolism in different tissues. Insulin resistance (IR) is a disordered biological response for insulin stimulation through the disruption of different molecular pathways in target tissues. Acquired conditions and genetic factors have been implicated in IR. Recent genetic and biochemical studies suggest that the dysregulated metabolic mediators released by adipose tissue including adipokines, cytokines, chemokines, excess lipids and toxic lipid metabolites promote IR in other tissues. IR is associated with several groups of abnormal syndromes that include obesity, diabetes, metabolic dysfunction-associated fatty liver disease (MAFLD), cardiovascular disease, polycystic ovary syndrome (PCOS), and other abnormalities. Although no medication is specifically approved to treat IR, we summarized the lifestyle changes and pharmacological medications that have been used as efficient intervention to improve insulin sensitivity. Ultimately, the systematic discussion of complex mechanism will help to identify potential new targets and treat the closely associated metabolic syndrome of IR.

Celecoxib attenuates hepatosteatosis by impairing de novo lipogenesis via Akt-dependent lipogenic pathway

Mounting evidence indicates that hepatic de novo lipogenesis is a common abnormality in non-alcoholic fatty liver disease (NAFLD) patients. We investigated whether a selective COX-2 inhibitor, celecoxib, alleviates hepatic steatosis by targeting an Akt-driven lipogenic pathway. We estimated the efficacy of celecoxib in a novel Akt-driven NAFLD mouse model established via hydrodynamic transfection of activated forms of AKT and in fructose-fed NAFLD mice that exhibited increased insulin-independent hepatic lipogenesis. AKT-transfected and insulin-stimulated human hepatoma cells were used for the in vitro experiments. Haematoxylin and eosin staining, immunohistochemistry and immunoblotting were performed for mechanistic studies. The results revealed that celecoxib ameliorated hepatic steatosis in the AKT-triggered NAFLD mice. Mechanistically, celecoxib effectively suppressed AKT/mTORC1 signalling and its downstream lipogenic cascade in the Akt-driven NAFLD mice and in vitro. Furthermore, celecoxib had limited efficacy in alleviating hepatic lipid accumulation and showed no influence on lipogenic proteins associated with hepatic lipogenesis in fructose-administered mice. This study suggests that celecoxib may be favourable for the treatment of NAFLD, especially in the subset with Akt-triggered hepatic lipogenesis.

NADPH Oxidases Connecting Fatty Liver Disease, Insulin Resistance and Type 2 Diabetes: Current Knowledge and Therapeutic Outlook

Nonalcoholic fatty liver disease (NAFLD), characterized by ectopic fat accumulation in hepatocytes, is closely linked to insulin resistance and is the most frequent complication of type 2 diabetes mellitus (T2DM). One of the features connecting NAFLD, insulin resistance and T2DM is cellular oxidative stress. Oxidative stress refers to a redox imbalance due to an inequity between the capacity of production and the elimination of reactive oxygen species (ROS). One of the major cellular ROS sources is NADPH oxidase enzymes (NOX-es). In physiological conditions, NOX-es produce ROS purposefully in a timely and spatially regulated manner and are crucial regulators of various cellular events linked to metabolism, receptor signal transmission, proliferation and apoptosis. In contrast, dysregulated NOX-derived ROS production is related to the onset of diverse pathologies. This review provides a synopsis of current knowledge concerning NOX enzymes as connective elements between NAFLD, insulin resistance and T2DM and weighs their potential relevance as pharmacological targets to alleviate fatty liver disease.

Using adipose-derived mesenchymal stem cells to fight the metabolic complications of obesity: Where do we stand?

Obesity is a critical risk factor for the development of metabolic diseases, and its prevalence is increasing worldwide. Stem cell-based therapies have become a promising tool for therapeutic intervention. Among them are adipose-derived mesenchymal stem cells (ADMSCs), secreting numerous bioactive molecules, like growth factors, cytokines, and chemokines. Their unique features, including immunosuppressive and immunomodulatory properties, make them an ideal candidates for clinical applications. Numerous experimental studies have shown that ADMSCs can improve pancreatic islet cell viability and function, ameliorate hyperglycemia, improve insulin sensitivity, restore liver function, counteract dyslipidemia, lower pro-inflammatory cytokines, and reduce oxidative stress in the animal models. These results prompted scientists to use ADMSCs clinically. However, up to date, there have been few clinical studies or ongoing trails using ADMSCs to treat metabolic disorders such as type 2 diabetes mellitus (T2DM) or liver cirrhosis. Most human studies have implemented autologous ADMSCs with minimal risk of cellular rejection. Because the functionality of ADMSCs is significantly reduced in subjects with obesity and/or metabolic syndrome, their efficacy is questioned. ADMSCs transplantation may offer a potential therapeutic approach for the treatment of metabolic complications of obesity, but randomized controlled trials are required to establish their safety and efficacy in humans prior to routine clinical use.

Mesenchymal Stromal/Stem Cells and Their Extracellular Vesicles Application in Acute and Chronic Inflammatory Liver Diseases: Emphasizing on the Anti-Fibrotic and Immunomodulatory Mechanisms

Various factors, including viral and bacterial infections, autoimmune responses, diabetes, drugs, alcohol abuse, and fat deposition, can damage liver tissue and impair its function. These factors affect the liver tissue and lead to acute and chronic liver damage, and if left untreated, can eventually lead to cirrhosis, fibrosis, and liver carcinoma. The main treatment for these disorders is liver transplantation. Still, given the few tissue donors, problems with tissue rejection, immunosuppression caused by medications taken while receiving tissue, and the high cost of transplantation, liver transplantation have been limited. Therefore, finding alternative treatments that do not have the mentioned problems is significant. Cell therapy is one of the treatments that has received a lot of attention today. Hepatocytes and mesenchymal stromal/stem cells (MSCs) are used in many patients to treat liver-related diseases. In the meantime, the use of mesenchymal stem cells has been studied more than other cells due to their favourable characteristics and has reduced the need for liver transplantation. These cells increase the regeneration and repair of liver tissue through various mechanisms, including migration to the site of liver injury, differentiation into liver cells, production of extracellular vesicles (EVs), secretion of various growth factors, and regulation of the immune system. Notably, cell therapy is not entirely excellent and has problems such as cell rejection, undesirable differentiation, accumulation in unwanted locations, and potential tumorigenesis. Therefore, the application of MSCs derived EVs, including exosomes, can help treat liver disease and prevent its progression. Exosomes can prevent apoptosis and induce proliferation by transferring different cargos to the target cell. In addition, these vesicles have been shown to transport hepatocyte growth factor (HGF) and can promote the hepatocytes'(one of the most important cells in the liver parenchyma) growths.

Ginsenoside Rg2 Ameliorating CDAHFD-Induced Hepatic Fibrosis by Regulating AKT/mTOR-Mediated Autophagy

Ginsenoside Rg2 (G-Rg2) in the rhizome of Panax ginseng can modify lipid accumulation, oxidative stress, and apoptosis in the liver induced by a high-fat diet. This research adds to this by assessing the potential antifibrosis effect of G-Rg2 (including possible mechanisms). G-Rg2 significantly improved pathological changes in liver tissue induced by a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD), it inhibited serum transaminase, plasma lipopolysaccharide, and liver hydroxyproline levels; it inhibited TGF-β1, α-SMA, and COL1A1 expression, it activated the AKT/mTOR signal pathway, and it inhibited liver expression of autophagy-related proteins. The in vitro experiments showed that G-Rg2 also restored the autophagy flux impairment induced by oleic acid and inhibited TGF-β1 expression by promoting p62 degradation in hepatocytes. In hepatic stellate (HSC-T6) cells, G-Rg2 reversed lipopolysaccharide-induced activation through the AKT/mTOR signaling pathway, inhibiting autophagy. Thus, G-Rg2 ameliorates CDAHFD-induced liver fibrosis and lipopolysaccharide-induced HSC-T6 cell activation by inhibiting AKT/mTOR-mediated autophagy.

Dietary and Lifestyle Inflammation Scores Are Inversely Associated with Metabolic-Associated Fatty Liver Disease among Iranian Adults: A Nested Case-Control Study

BACKGROUND

Diet and lifestyle may affect risk for metabolic-associated fatty liver disease (MAFLD) by chronically elevating systemic inflammation.

OBJECTIVES

In this study we investigated the separate and joint associations of dietary and lifestyle inflammation scores (DIS and LIS, respectively) with MAFLD risk.

METHODS

For this nested case-control study we identified and recruited 968 patients with MAFLD (defined as having a fatty liver index ≥60 plus ≥1 of the following conditions: overweight or obese, type II diabetes mellitus, evidence of metabolic dysregulation) and 964 controls from among 35-70-y-old men and women in the baseline phase of the Sabzevar Persian Cohort Study. We collected demographic, lifestyle, anthropometric, biochemical, and dietary intake information (via a validated FFQ) from which we calculated a circulating inflammation biomarker-weighted, predominantly whole foods and beverages-based, 19-component DIS and a 3-component LIS. We estimated DIS- and LIS-MAFLD associations using multivariable unconditional logistic regression. We also calculated equal-weight DIS and LIS to capture all potential mechanisms (inflammation plus other mechanisms) for associations of diet and lifestyle with MAFLD risk.

RESULTS

Among those in the highest relative to the lowest DIS and LIS tertiles, the multivariable-adjusted ORs and their 95% CIs were OR: 1.84; 95% CI: 1.61, 2.07; Ptrend < 0.001, and OR: 1.96; 95% CI: 1.69, 2.21; Ptrend < 0.001, respectively. For those in the highest relative to the lowest joint DIS and LIS tertile, the values were OR: 2.56; 95% CI: 2.19, 2.93; Pinteraction < 0.001. The findings were similar by sex. The third tertile values for the equal-weight DIS- and LIS-MAFLD associations were OR: 1.87; 95% CI: 1.41, 2.34; and OR: 2.16; 95% CI: 1.85, 2.46, respectively.

CONCLUSIONS

Our results suggest that higher balances of pro- relative to anti-inflammatory dietary and lifestyle exposures, separately and especially jointly, may be associated with higher MAFLD risk among adults. Also, inflammation may be the primary mechanism through which diet affects MAFLD risk.

Non-alcoholic fatty liver disease in type 1 diabetes: Prevalence and pathophysiology

Non-alcoholic fatty liver disease (NAFLD) is the most frequent chronic liver disease in the general population with a global prevalence of 25%. It is often associated with metabolic syndrome and type 2 diabetes, as insulin resistance and hyperinsulinemia are known to be favoring factors. Recent studies have described growing incidence of NAFLD in type 1 diabetes (T1D) as well. Although increasing prevalence of metabolic syndrome in these patients seems to explain part of this increase in NAFLD, other underlying mechanisms may participate in the emergence of NAFLD. Notably, some genetic factors are more associated with fatty liver disease, but their prevalence in T1D has not been evaluated. Moreover, oxidative stress, poor glucose control and long-lasting hyperglycemia, as well as exogenous insulin administration play an important role in intrahepatic fat homeostasis. The main differential diagnosis of NAFLD in T1D is glycogenic hepatopathy, which needs to be considered mostly in T1D patients with poor glycemic control. This article aims to review the prevalence and pathophysiology of NAFLD in T1D and open perspectives for clinicians taking care of T1D patients with potential hepatopathy.

α-Lactalbumin peptide Asp-Gln-Trp alleviates hepatic insulin resistance and modulates gut microbiota dysbiosis in high-fat diet-induced NAFLD mice

α-Lactalbumin peptide Asp-Gln-Trp (DQW) alleviates hepatic insulin resistance via activating the IRS1/PI3K/AKT pathway and modulates gut microbiota dysbiosis in high-fat diet-induced NAFLD mice.

Chlorogenic acid improves glucose tolerance, lipid metabolism, inflammation and microbiota composition in diabetic db/db mice

INTRODUCTION

Chronic and acute chlorogenic acid (CGA) can improve glucose tolerance (GT) and insulin sensitivity (IS). However, whether acute administration of CGA has beneficial effects on hepatic lipid metabolism and cecal microbiota composition remains unclear.

METHODS

In the current study, diabetic db/db mice were administered CGA or metformin, and db/m mice were used as controls to explore the effects of CGA on hepatic lipid metabolism, including fatty acid oxidation and transportation and triglyceride (TG) lipolysis and synthesis. Moreover, alterations in the inflammatory response and oxidative stress in the liver and gut microbe composition were evaluated.

RESULTS

The results showed that CGA decreased body weight and improved glucose tolerance and insulin resistance, and these effects were similar to those of metformin. CGA decreased hepatic lipid content by increasing the expression of CPT1a (carnitine palmitoyltransferase 1a), ACOX1 (Acyl-CoA oxidase 1), ATGL (adipose triglyceride lipase), and HSL (hormone-sensitive lipase) and decreasing that of MGAT1 (monoacylglycerol O-acyltransferase 1), DGAT1 (diacylglycerol O-acyltransferase), DGAT2, CD36, and FATP4 (fatty acid transport protein 4). Additionally, CGA restored the expression of inflammatory genes, including TNF-α (tumor necrosis factor-alpha), IL-1β (interleukin-1beta), IL-6, and IL-10, and genes encoding antioxidant enzymes, including SOD1 (superoxide dismutases 1), SOD2 (superoxide dismutases 2), and GPX1 (glutathione peroxidase 1). Furthermore, CGA improved the bacterial alpha and beta diversity in the cecum. Moreover, CGA recovered the abundance of the phylum Bacteroidetes and the genera Lactobacillus, Blautia, and Enterococcus.

DISCUSSION

CGA can improve the antidiabetic effects, and microbes may critically mediate these beneficial effects.

Anti-inflammatory diet consumption reduced fatty liver indices

The aim of this study was to assess the association between dietary inflammatory index (DII) and non-invasive markers of liver status in adults. This cross-sectional study was performed on 8520 adults, recruited in Ravansar Non-Communicable Diseases (RaNCD) cohort study, western Iran. The DII score was calculated based on participants’ dietary intakes obtained from Food Frequency Questionnaire (FFQ). Fatty Liver Index (FLI) score was calculated by anthropometric measurements and some non-invasive markers of liver status. Linear regression models were applied to estimate the associations and adjust the possible confounding factors. A greater DII score was significantly associated with higher energy intake, body mass index (BMI), body fat mass (BFM), blood pressure, and FLI (P < 0.001). Participants with the highest DII score had a significantly higher consumption saturated fat, trans fat and red meat than those in the lowest quartile (P < 0.001). After adjustments of age and sex, participants in the highest quartile of the DII score had a greater risk of FLI (β: 0.742, 95% CI: 0.254, 0.601). More pro-inflammatory diet in participants was associated with a higher FLI. The DII score was positively associated with non-invasive liver markers. Thus, having an anti-inflammatory diet can help balance liver enzymes, reduce obesity, and decrease fatty liver.

Carminic acid mitigates fructose-triggered hepatic steatosis by inhibition of oxidative stress and inflammatory reaction

Excessive fructose (Fru) consumption has been reported to favor nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanism is still elusive, lacking effective therapeutic strategies. Carminic acid (CA), a glucosylated anthraquinone found in scale insects like Dactylopius coccus, exerts anti-tumor and anti-oxidant activities. Nevertheless, its regulatory role in Fru-induced NAFLD is still obscure. Here, the effects of CA on NAFLD in Fru-challenged mice and the underlying molecular mechanisms were explored. We found that Fru intake significantly led to insulin resistance and dyslipidemia in liver of mice, which were considerably attenuated by CA treatment through repressing endoplasmic reticulum (ER) stress. Additionally, inflammatory response induced by Fru was also attenuated by CA via the blockage of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs) and tumor necrosis factor α/TNF-α receptor (TNF-α/TNFRs) signaling pathways. Moreover, Fru-provoked oxidative stress in liver tissues was remarkably attenuated by CA mainly through improving the activation of nuclear factor erythroid 2-related factor 2 (Nrf-2). These anti-dyslipidemias, anti-inflammatory and anti-oxidant activities regulated by CA were confirmed in the isolated primary hepatocytes with Fru stimulation. Importantly, the in vitro experiments demonstrated that Fru-induced lipid accumulation was closely associated with inflammatory response and reactive oxygen species (ROS) production regulated by TNF-α and Nrf-2 signaling pathways, respectively. In conclusion, these results demonstrated that CA could be considered as a potential therapeutic strategy to attenuate metabolic disorder and NAFLD in Fru-challenged mice mainly through suppressing inflammatory response and oxidative stress.