The effect of omega-3 unsaturated fatty acids on non-alcoholic fatty liver disease: A systematic review and meta-analysis of RCTs

Current and experimental pharmacotherapy for the management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, with its incidence increasing in parallel with the global prevalence of obesity and type 2 diabetes mellitus. Despite our steadily increasing knowledge of its pathogenesis, there is as yet no available pharmacotherapy specifically tailored for NAFLD. To define the appropriate management, it is important to clarify the context in which the disease appears. In the case of concurrent metabolic comorbidities, NAFLD patients are treated by targeting these comorbidities, such as diabetes and obesity. Thus, GLP-1 analogs, PPAR, and SGLT2 inhibitors have recently become central to the treatment of NAFLD. In parallel, randomized trials are being conducted to explore new agents targeting known pathways involved in NAFLD progression. However, there is an imperative need to intensify the effort to design new, safe drugs with biopsy-proven efficacy. Of note, the main target of the pharmacotherapy should be directed to the regression of fibrotic NASH, as this histologic stage has been correlated with increased overall as well as liver-related morbidity and mortality. Herein we discuss the drugs currently at the forefront of NAFLD treatment.

3,5-Dimethyl-2,4,6-trimethoxychalcone Lessens Obesity and MAFLD in Leptin-Deficient ob/ob Mice

Chalcones constitute an important group of natural compounds abundant in fruits and comestible plants. They are a subject of increasing interest because of their biological activities, including anti-diabetic and anti-obesity effects. The simple chalcone structural scaffold can be modified at multiple sites with different chemical moieties. Here, we generated an artificial chalcone, i.e., 3,5-dimethyl-2,4,6-trimethoxychalcone (TriMetChalc), derived from 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC). DMC is a major compound of Cleistocalyx operculatus, a plant widely used in Asia for its anti-hyperglycemic activity. Using ob/ob mice as an obesity model, we report that, after 3 weeks of per os administration, TriMetChalc modified food intake through the specific activation of brain structures dedicated to the regulation of energy balance. TriMetChalc also decreased weight gain, glucose intolerance, and hepatic steatosis. Moreover, through extensive liver lipidomic analysis, we identified TriMetChalc-induced modifications that could contribute to improving the liver status of the animals. Hence, TriMetChalc is a chalcone derivative capable of reducing food intake and the addition of glucose intolerance and hepatic steatosis in a mouse model of obesity. In light of these results, we believe that TriMetChalc action deserves to be more deeply evaluated over longer treatment periods and/or in combination with other chalcones with protective effects on the liver.

Effectiveness of Omega-3 Polyunsaturated Fatty Acids in Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Non-alcoholic fatty liver disease (NAFLD) is a prevalent liver disorder characterized by excessive hepatic fat accumulation without alcohol intake. It can progress to non-alcoholic steatohepatitis, increasing the risk of cirrhosis and liver failure. This study aims to evaluate the efficacy of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in treating NAFLD. A systematic review and meta-analysis was conducted including studies published from January 2018 to June 2023. Databases searched included PubMed, Embase, Cochrane Library, and ClinicalTrials.gov. Inclusion criteria comprised randomized controlled trials and cohort studies involving human subjects or animal models with NAFLD. Data were extracted and analyzed to assess the impact of omega-3 PUFAs on liver fat, hepatic enzymes, and serum lipid profiles using RevMan 5.4. A total of 15 studies met the inclusion criteria. Omega-3 supplementation significantly decreased alanine aminotransferase (ALT) (mean difference = -2.12, 95% confidence interval (CI) = -3.36, -0.87) and aspartate aminotransferase (AST) (mean difference = -1.50, 95% CI = -2.59, -0.42). Gamma-glutamyl transferase levels showed a trend toward reduction (mean difference = -0.82, 95% CI = -1.66, 0.02). Serum lipid profiles improved significantly with reductions in triglycerides, low-density lipoprotein, and total cholesterol along with significant reductions in AST, ALT, and alkaline phosphatase in animal models. Omega-3 PUFAs appear to offer beneficial effects on liver enzymes, serum lipid profiles, and anthropometric indices in NAFLD patients. While their impact on liver fat content remains uncertain, omega-3 supplementation could serve as a valuable adjunct treatment for enhancing metabolic profiles and liver function in NAFLD patients.

Planetary Health Diet Compared to Dutch Dietary Guidelines: Nutritional Content and Adequacy

In 2019, the EAT-Lancet Commission proposed a Planetary Health Diet (PHD) to address challenges toward sustainable and healthy diets. However, its suitability within the Dutch context and a comparison with the Dutch Dietary Guidelines (DDG) needs investigation. Our study aimed to compare the PHD with DDG in terms of food groups, servings, nutritional content, and adequacy in adults. We modeled two theoretical diets, the PHD (PHD-NL) and another based on the DDG (DDG-NL), using the Dutch National Food Consumption Survey (FCS-2016) and Dutch Food Composition Database to calculate the nutritional content and compared it with the Dutch Dietary Reference Values (DRVs). The PHD included higher quantities of vegetables, fish, legumes, and nuts, while the DDG suggested more significant amounts of cereals, tubers, starchy vegetables, dairy, and red meat. We observed differences in macronutrient distribution; while both diets lacked sufficient vitamin D, calcium content was lower in the PHD-NL. The PHD-NL had higher levels of fiber, vegetable protein, unsaturated fats, and non-heme iron, while vitamins B2, B6, B12, and calcium were lower than the DDG-NL diet. The PHD-NL has nutritional adequacy in the Dutch context, except for vitamin D and calcium, although it is essential to be cautious with iron because of the bioavailability of non-heme iron in plant-based diets. These findings have implications for the adoption of a sustainable diet according to nutritional requirements, population health status, and sociocultural context, as well as compliance with specific dietary behaviors of populations.

A systematic review and meta-analysis of randomized controlled trials to evaluate plant-based omega-3 polyunsaturated fatty acids in nonalcoholic fatty liver disease patient biomarkers and parameters

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is prevalent in 25-30% of British and European populations, representing a potential global public health crisis. Marine omega-3 (n-3) polyunsaturated fatty acids offer well-evidenced benefits to NAFLD biomarkers; however, the effect of plant-based n-3 has not been evaluated with a systematic review and meta-analysis.

OBJECTIVE

The review aimed to systematically evaluate the effect of plant-based n-3 supplementation on NAFLD surrogate biomarkers and parameters.

DATA SOURCES

Medline (EBSCO), PubMed, CINAHL (EBSCO), Cochrane Central Register of Controlled Trials, the International Clinical Trials Registry Platform, and Google Scholar databases were searched to identify randomized controlled trials published between January 1970 and March 2022 evaluating the impact of plant-based n-3 interventions on diagnosed NAFLD. The review followed the PRISMA checklist and is PROSPERO registered (CRD42021251980).

DATA EXTRACTION

A random-effects model and generic inverse variance methods synthesized quantitative data, followed by a leave-one-out method for sensitivity analysis. We identified 986 articles; after the application of selection criteria, six studies remained with 362 patients with NAFLD.

RESULTS

The meta-analysis showed that plant-based n-3 fatty acid supplementation significantly reduced alanine aminotransferase (ALT) (mean difference: 8.04 IU/L; 95% confidence interval: 14.70, 1.38; I2 = 48.61%) and plasma/serum triglycerides (44.51 mg/dL; 95% confidence interval: -76.93, -12.08; I2 = 69.93%), alongside body-composition markers in patients with NAFLD (P < 0.05).

CONCLUSION

Plant-based n-3 fatty acid supplementation improves ALT enzyme biomarkers, triglycerides, body mass index, waist circumference, and weight loss when combined with lifestyle interventions to increase physical activity and a calorie-controlled diet. Further research is needed to identify the most effective plant-based n-3 sources in larger numbers of patients with NAFLD over longer study durations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021251980.

Effects of Breeds on the Content of Functional Nutrition in Eggs

The purpose of this study was to compare the differences in the content of functional nutrients in eggs, performance parameters, and egg quality parameters of different chicken breeds. In Trial 1, 150 41-week-old hens of each breed, including the Dwarf Layer, White Leghorn, Silky fowl, Beijing-you chicken, and Shouguang chicken, were randomly assigned to the control (CON) and 2.5% flaxseed oil (FSO) groups to compare the difference in n-3 polyunsaturated fatty acid (PUFA) content in eggs. The contents of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total n-3 PUFA in eggs were increased (p < 0.05) in the FSO groups. The ALA (4.28%), DHA (2.03%), and total n-3 PUFA (6.46%) contents in eggs of Dwarf Layer were the highest among the five breeds (p < 0.05). To further verify if other functional nutrients also have such differences, 600 24-week-old White Leghorn and Dwarf Layer were allocated to four groups: CON, FSO, 0.02% selenium-enriched yeast (SEY), and 0.20% marigold flower extract (MFE), in Trial 2. The content of functional nutrients in eggs was significantly increased (p < 0.05) after feeding these additions. After feeding FSO, the eggs of the Dwarf Layer had a higher n-3 PUFA content than the White Leghorn (p < 0.05). However, no significant differences were found in selenium and lutein content in different breeds. Performance and egg quality were not negatively impacted by FSO, SEY, or MFE.

Eugenia sonderiana O. Berg leaves: Phytochemical characterization, evaluation of in vitro and in vivo antidiabetic effects, and structure-activity correlation

Several medicinal plants have drawn the attention of researchers by its phytochemical composition regarding their potential for treating chronic complications of diabetes mellitus. In this context, plants of the Myrtaceae family popularly used in Brazil for the treatment of diabetes mellitus, including Eugenia sonderiana, have shown beneficial effects due to the presence of phenolic compounds and saponins in their chemical constitution. Thus, the present work aimed to perform the phytochemical characterization of the hydroethanolic extract of E. sonderiana leaves using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS), along with in vitro and in vivo studies of antidiabetic activity. The chemical characterization revealed the presence of phenolic compounds, flavonoids, neolignans, tannins, and saponins. In addition, the extract exhibited minimum inhibitory concentrations of alpha-amylase and alpha-glycosidase higher than the acarbose in the in vitro tests. Also, the in vivo tests revealed a slight increase in body mass in diabetic rats, as well as a significant decrease in water and feed consumption provided by the extract. Regarding serum biochemical parameters, the extract showed significant activity in decreasing the levels of glucose, hepatic enzymes, and triglycerides, in addition to maintaining HDL cholesterol levels within normal ranges, protecting the cell membranes against oxidative damage. Thus, the extract of E. sonderiana leaves was considered promising pharmaceutical ingredient in the production of a phytotherapy medication.

Dietary fatty acids and risk of non-alcoholic steatohepatitis: A national study in the United States

Background

Non-alcoholic steatohepatitis (NASH), the early invertible stage of non-alcoholic fatty liver disease, has become a public health challenge due to the great burden and lack of effective treatment. Dietary nutrients are one of the modifiable factors to prevent and slow down disease progression. However, evidence linking dietary fatty acids intake and risk of NASH is lacking.

Objectives

This study aimed to examine the association between dietary total saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), their subtypes, the ratio of unsaturated (UFAs) to SFAs, and the risk of NASH among a nationwide population in the United States.

Methods

This cross-sectional study was conducted among 4,161 adults in the national health and nutrition examination survey in 2017-2018 cycle. Moreover, NASH was defined by transient elastography. Dietary fatty acids were assessed using a validated 24-h food recall method. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results

A total of 2,089 (50.2%) participants with NASH were identified. Compared with participants in the bottom tercile of dietary intakes of total PUFAs, those in the highest tercile had lower risk of NASH, with an adjusted OR of 0.67 (95% CI: 0.46-0.97). Similar associations were found between the subtype of PUFA 18:3 and NASH, while the fully adjusted OR in the highest tercile was 0.67 (95% CI: 0.47-0.96). Interactions of dietary PUFAs and body mass index (BMI) could be found influencing NASH risk. Stronger associations of dietary total PUFAs intakes with NASH risk were found in obese participants (OR, 95% CI: 0.41, 0.22-0.75) than in the non-obese participants (OR, 95% CI: 1.00, 0.70-1.43; p-interaction = 0.006). Similar effects on risk of NASH were also observed between BMI and dietary intakes of PUFA 18:3. However, no significant associations were observed between NASH risk and dietary total SFAs, MUFAs, their subtypes as well as the ratio of UFAs to SFAs.

Conclusion

Dietary intakes of total PUFAs, as well as its subtype of PUFA 18:3, were inversely associated with risk of NASH. The further large prospective studies need to be conducted to confirm the findings of this study.

Effect of Probiotics on Liver Enzymes in Patients With Non-alcoholic Fatty Liver Disease: An Umbrella of Systematic Review and Meta-Analysis

Non-alcoholic fatty liver disease (NAFLD) has become prevalent in recent decades, especially in developed countries; yet the approaches for preventing and treating NAFLD are not clear. This study aimed to summarize meta-analyses of randomized controlled trials that examined the effects of probiotics on NAFLD. We systematically searched PubMed, Scopus, Embase, Web of Science, and Cochrane Central Library databases up to August 2021. All Meta-analysis studies assessing the effect of probiotics on liver function tests [alanine aminotransferase (ALT), aspartate aminotransferase (AST), and Gamma-glutamyl transferase (GGT)] were included. Meta-analysis was conducted using a random-effects model. Sensitivity and subgroup analyses were also performed. The umbrella study covered ten eligible studies involving 5,162 individuals. Beneficial effects of probiotics supplementation were revealed on ALT (ES = −10.54 IU/L; 95% CI: −12.70, −8.39; p < 0.001; I² = 60.9%, p = 0.006), AST (ES = −10.19 IU/L, 95%CI: −13.08, −7.29, p < 0.001; I² = 79.8%, p < 0.001), and GGT (ES = −5.88 IU/L, 95% CI: −7.09, −4.67, p = 0.009; I² = 0.0%, p = 0.591) levels. Probiotics have ameliorating effects on ALT, AST, and GGT levels in patients with NAFLD. Overall, Probiotics could be recommended as an adjuvant therapeutic method for the management of NAFLD.

Lifestyle as well as metabolic syndrome and non-alcoholic fatty liver disease: an umbrella review of evidence from observational studies and randomized controlled trials

BACKGROUND & AIMS

Recent epidemiological studies have indicated that NAFLD is pathologically associated with a sedentary lifestyle, unhealthy dietary habits and metabolic syndrome. An umbrella review of meta-analyses was performed to summarize the quality of evidence regarding the epidemiologic associations between lifestyle, metabolic syndrome, and non-alcoholic fatty liver disease (NAFLD) in regards to risk and treatment.

METHODS

We searched PubMed, Web of Science and Embase Database from inception until June 1, 2021. Meta-analyses of observational studies and randomized controlled trials (RCTs) examining the associations of lifestyle as well as metabolic syndrome with NAFLD risk or treatment were screened. We assessed meta-analyses of observational studies based on random-effect summary effect sizes and their P values, 95% prediction intervals, heterogeneity, and small-study effects. For meta-analyses of RCTs, outcomes with a random-effect P < 0.005 and a high-GRADE assessment were classified as strong evidence.

RESULTS

A total of 37 publications were included in this review: twenty-two publications reporting 41 meta-analyses of observational studies (37 unique outcomes) and 15 publications reporting 81 meta-analyses of RCTs (63 unique outcomes) met the inclusion criteria. Methodological quality was high for 97% of the included meta-analyses. Quality of evidence was rated high only for the association of sugar-sweetened soda consumption with increased NAFLD risk in meta-analyses of observational studies. Only 3 therapeutic interventions (green tea improving ALT, TG, TC and LDL, omega-3 PUFAs improving HOMR-IR and plasma glucose, and exercise improving RT and ALT) from meta -analyses of RCTs with suggestive (change to high/low/etc) levels of evidence were identified.

CONCLUSION

Despite many meta-analyses exploring the associations of lifestyle as well as metabolic syndrome with the risk or treatment of NAFLD, robust clinical RCTs are needed to further investigate the associations between lifestyle modifications and incidence of NAFLD or therapeutic effects on disease progression.

Maternal consumption of ɷ3 attenuates metabolic disruption elicited by saturated fatty acids-enriched diet in offspring rats

BACKGROUND AND AIMS

High-fat diet (HFD) intake during gestation and lactation has been associated with an increased risk of developing cardiometabolic disorders in adult offspring. We investigated whether metabolic alterations resulting from the maternal consumption of HFD are prevented by the addition of omega-3 (ɷ3) in the diet.

METHODS AND RESULTS

Wistar rat dams were fed a control (C: 19% of lipids and ɷ6:ɷ3 = 12), HF (HF: 33% lipids and ɷ6:ɷ3 = 21), or HF enriched with ɷ3 (HFω3: 33% lipids and ɷ6:ɷ3 = 9) diet during gestation and lactation, and their offspring food consumption, murinometric measurements, serum levels of metabolic markers, insulin and pyruvate sensitivity tests were evaluated. The maternal HFD increased body weight at birth, dyslipidemia, and elevated fasting glucose levels in the HF group. The enrichment of ɷ3 in the maternal HFD led to lower birth weight and improved lipid, glycemic, and transaminase biochemical profile of the HFω3 group until the beginning of adulthood. However, at later adulthood of the offspring, there was no improvement in these biochemical parameters.

CONCLUSION

Our findings show the maternal consumption of high-fat ɷ3-rich diet is able to attenuate or prevent metabolic disruption elicited by HFD in offspring until 90 days old, but not in the long term, as observed at 300 days old of the offspring.

Synthesis of encapsulated fish oil using whey protein isolate to prevent the oxidative damage and cytotoxicity of titanium dioxide nanoparticles in rats

Fish oil exhibited several beneficial effects on human health; however, its applications face several challenges such as its effects on the organoleptic properties of food and its susceptibility to oxidation. Titanium dioxide NPs (TiO₂-NPs) are utilized widely in pharmaceutical and food applications although there are some reports about their oxidative damage to living organisms. The current work was undertaken to identify fatty acids content in mullet fish oil, encapsulation, and characterization of the oil, and to assess the protective efficiency of the encapsulated mullet fish oil (EMFO) against the oxidative damage and genotoxicity of TiO₂-NPs in rats. Sixty female Sprague-Dawley rats were distributed to 6 groups and treated for 21 days included the control group; TiO₂-NPs-treated group (50 mg/kg b.w); the groups treated with EMFO (50 or 100 mg/kg b.w) and the groups received TiO₂-NPs plus EMFO at the low or high dose. Samples of blood, liver, and kidney were taken for different assays and histological studies. The GC-FID analysis showed that a total of 14 different fatty acids were found in Mullet fish oil included 41.4% polyunsaturated fatty acids (PUFAs), 31.1% monounsaturated fatty acids (MUFAs), and 25.1% saturated fatty acids (SFAs). The structure of EMFO was spherical with an average diameter of 234.5 nm and a zeta potential of -6.24 mV and was stable up to 10 days at 25 °C with EE of 81.08%. The PV of EMFO was decreased at 5 days then increased at 15 days; however, TBARS was increased throughout the storage time over 15 days. The biological evaluation showed that TiO₂-NPs disturb the hepato-nephro functions, lipid profile, inflammatory cytokines, oxidative stress markers, antioxidant enzymes activity, and their corresponding gene expression along with severe pathological alterations in both hepatic and renal tissue. Co-administration of EMFO induced a strong antioxidant role, and the high level could normalize the majority of the parameters tested and the histological picture of the hepatic and renal tissues. These results pointed out that the encapsulation technology enhances the protective role of EMFO against oxidative stress and genotoxicity of TiO₂-NPs through the prevention of ω-3 PUFAs oxidation and controlling their release.

The effects of canola and olive oils consumption compared to sunflower oil, on lipid profile and hepatic steatosis in women with polycystic ovarian syndrome: a randomized controlled trial

BACKGROUND

Polycystic Ovarian Syndrome (PCOS) is one of the most common endocrinopathies and metabolic disorders in women during their reproductive years. It is often associated with dyslipidemia and other risk factors of cardiovascular diseases (CVD). This study was aimed to evaluate dietary intervention effects with canola and olive oils compared to sunflower oil on lipid profile and fatty liver severity among women with PCOS.

METHOD

This study was a 10-week intervention including 72 women with PCOS. Patients were randomly assigned to three groups for receiving 25 g/day canola, olive, or sunflower oils for 10 weeks. The primary and secondary outcomes were to assess changes in lipid profile and in fatty liver severity, respectively.

RESULT

At the end of the study, 72 patients with a mean age of 29.31 were analysed. Canola oil consumption resulted in a significant reduction in serum levels of TG (P = 0.002) and TC/HDL (P = 0.021), LDL/HDL (P = 0.047), and TG/HDL (P = 0.001) ratios, however, there was no significant reduction in lipid profile following olive oil consumption. Canola (P < 0.001) and olive oils (P = 0.005) could significantly reduce the fatty liver grade. Moreover, HOMA-IR in both canola (P < 0.001) and olive (P = 0.004) groups was significantly decreased.

CONCLUSION

In total, compared to olive and sunflower oils, significant improvements in lipid profile, liver function, and HOMA-IR were observed following canola oil consumption in women with PCOS.

TRIAL REGISTRATION

IR.MUI.

RESEARCH

REC.1397.315. Registered 30 JUNE 2019 - Retrospectively registered, https://www.irct.ir/trial/38684.

Fructose, Omega 3 Fatty Acids, and Vitamin E: Involvement in Pediatric Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is currently the most common form of liver disease in both adults and children, becoming the leading cause for liver transplant in many countries. Its prevalence has increased considerably in recent years, mainly due to the explosive increase in pediatric obesity rates. NAFLD is strongly associated with central obesity, diabetes, dyslipidemia and insulin resistance, and it has been considered as the hepatic manifestation of the metabolic syndrome. Its complex pathophysiology involves a series of metabolic, inflammatory and oxidative stress processes, among others. Given the sharp increase in the prevalence of NAFLD and the lack of an appropriate pharmacological approach, it is crucial to consider the prevention/management of the disease based on lifestyle modifications such as the adoption of a healthy nutrition pattern. Herein, we review the literature and discuss the role of three key nutrients involved in pediatric NAFLD: fructose and its participation in metabolism, Omega-3 fatty acids and its anti-inflammatory effects and vitamin E and its action on oxidative stress.

Effects of dietary macronutrients on liver fat content in adults: a systematic review and meta-analysis of randomized controlled trials

Dietary macronutrient composition may affect hepatic liver content and its associated diseases, but the results from human intervention trials have been equivocal or underpowered. We aimed to assess the effects of dietary macronutrient composition on liver fat content by conducting a systematic review and meta-analysis of randomized controlled trials in adults. Four databases (PubMed, Embase, Web of Science, and COCHRANE Library) were systematically searched for trials with isocaloric diets evaluating the effect of dietary macronutrient composition (energy percentages of fat, carbohydrates, and protein, and their specific types) on liver fat content as assessed by magnetic resonance techniques, computed tomography or liver biopsy. Data on change in liver fat content were pooled by random or fixed-effects meta-analyses and expressed as standardized mean difference (SMD). We included 26 randomized controlled trials providing data for 32 comparisons on dietary macronutrient composition. Replacing dietary fat with carbohydrates did not result in changes in liver fat (12 comparisons, SMD 0.01 (95% CI -0.36; 0.37)). Unsaturated fat as compared with saturated fat reduced liver fat content (4 comparisons, SMD -0.80 (95% CI -1.09; -0.51)). Replacing carbohydrates with protein reduced liver fat content (5 comparisons, SMD -0.33 (95% CI -0.54; -0.12)). Our meta-analyses showed that replacing carbohydrates with total fat on liver fat content was not effective, while replacing carbohydrates with proteins and saturated fat with unsaturated fat was. More well-performed and well-described studies on the effect of types of carbohydrates and proteins on liver fat content are needed, especially studies comparing proteins with fats.

Effects of Omega-3 Polyunsaturated Fatty Acid Supplementation on Non-Alcoholic Fatty Liver: A Systematic Review and Meta-Analysis

(1) Aim: Non-alcoholic fatty liver disease (NAFLD) is a prevalent disease worldwide. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) bear anti-inflammatory action and can ameliorate hyperlipidemia. We wish to appraise the effects of n-3 PUFAs supplement on NAFLD. (2) Methods: We searched CENTRAL, Embase, and MEDLINE on 29 March 2020 for randomized control trials (RCTs) on the effects of n-3 PUFAs supplementation in treating NAFLD. The Cochrane Collaboration's tool was used to assess the risk of bias of included RCTs. (3) Results: We included 22 RCTs with 1366 participants. The risk of bias of included RCTs was generally low or unclear. n-3 PUFAs supplementation significantly reduced liver fat compared with placebo (pooled risk ratio 1.52; 95% confidence interval (CI) 1.09 to 2.13). n-3 PUFAs supplementation also significantly improved the levels of triglyceride, total cholesterol, high-density lipoprotein, and body-mass index, with pooled mean difference and 95% CI being -28.57 (-40.81 to -16.33), -7.82 (-14.86 to -0.79), 3.55 (1.38 to 5.73), and -0.46 (-0.84 to -0.08), respectively. (4) Conclusions: The current evidence supports the effects of n-3 PUFAs supplementation in improving fatty liver. n-3 PUFAs supplementation may also improve blood lipid levels and obesity.

The Evaluation of Effective Drugs for the Treatment of Non-Alcoholic Fatty Liver Disease: A Systematic Review and Network Meta-Analysis

Purpose: Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis are two forms of fatty liver disease with benign and malignant nature, respectively. These two conditions can cause an increased risk of liver cirrhosis and hepatocellular carcinoma. Given the importance and high prevalence of NAFLD, it is necessary to investigate the results of different studies in related scope to provide a clarity guarantee of effectiveness. Therefore, this systematic review and meta-analysis aim to study the efficacy of various medications used in the treatment of NAFLD. Methods: A systematic search of medical databases identified 1963 articles. After exclusion of duplicated articles and those which did not meet our inclusion criteria, eta-analysis was performed on 84 articles. Serum levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) were set as primary outcomes and body mass index (BMI), hepatic steatosis, and NAFLD activity score (NAS) were determined as secondary outcomes. Results: Based on the P-score of the therapeutic effects on the non-alcoholic steatohepatitis (NASH), we observed the highest efficacy for atorvastatin, tryptophan, orlistat, omega-3 and obeticholic acid for reduction of ALT, AST, BMI, steatosis and NAS respectively. Conclusion: This meta-analysis showed that atorvastatin. life-style modification, weight loss, and BMI reduction had a remarkable effect on NAFLD-patients by decreasing aminotransferases.

Oxidative Stress and Non-Alcoholic Fatty Liver Disease: Effects of Omega-3 Fatty Acid Supplementation

Aging is a complex phenomenon characterized by the progressive loss of tissue and organ function. The oxidative-stress theory of aging postulates that age-associated functional losses are due to the accumulation of ROS-induced damage. Liver function impairment and non-alcoholic fatty liver disease (NAFLD) are common among the elderly. NAFLD can progress to non-alcoholic steatohepatitis (NASH) and evolve to hepatic cirrhosis or hepatic carcinoma. Oxidative stress, lipotoxicity, and inflammation play a key role in the progression of NAFLD. A growing body of evidence supports the therapeutic potential of omega-3 polyunsaturated fatty acids (n-3 PUFA), mainly docosahaexenoic (DHA) and eicosapentaenoic acid (EPA), on metabolic diseases based on their antioxidant and anti-inflammatory properties. Here, we performed a systematic review of clinical trials analyzing the efficacy of n-3 PUFA on both systemic oxidative stress and on NAFLD/NASH features in adults. As a matter of fact, it remains controversial whether n-3 PUFA are effective to counteract oxidative stress. On the other hand, data suggest that n-3 PUFA supplementation may be effective in the early stages of NAFLD, but not in patients with more severe NAFLD or NASH. Future perspectives and relevant aspects that should be considered when planning new randomized controlled trials are also discussed.

Omega-3 fatty acids and nonalcoholic fatty liver disease in adults and children: where do we stand?

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic fatty liver disease worldwide. The incidence of NAFLD parallels the prevalence of obesity. Moreover, NAFLD can progress to nonalcoholic steatohepatitis (NASH), cirrhosis and primary hepatocellular cancer (HCC). As such, NAFLD has become a major public health concern. We discuss recent clinical trials and meta-analyses evaluating the efficacy of C20-22 ω3 polyunsaturated fatty acids (PUFA) to attenuate preexisting NAFLD in adults and children.

RECENT FINDINGS

Humans with NAFLD and NASH; and preclinical mouse models of NASH, have a high abundance of hepatic saturated (SFA) and monounsaturated (MUFA) fat, but a low abundance of hepatic C20-22 ω3 PUFA. This change in hepatic fat type and abundance is associated with hepatic lipotoxicity, inflammation, oxidative stress and fibrosis. Recent meta-analyses and clinical trials evaluated the capacity of C20-22 ω3 PUFA dietary supplementation to improve health outcomes in adults and children with preexisting NAFLD. Diets supplemented with docosahexaenoic acid (DHA, 22 : 6,ω3) alone or with eicosapentaenoic acid (EPA, 20 : 5,ω3) are tolerated and effective at lowering liver fat in NAFLD patients. However, outcomes are mixed with respect to C20-22 ω3 PUFA attenuation of more severe NAFLD markers, such as hepatic injury, inflammation and fibrosis.

SUMMARY

These studies suggest that dietary supplementation with C20-22 ω3 PUFA should be considered as a viable and effective option to lower liver fat in obese adults and children with NAFLD.

Potential Therapeutic Benefits of Herbs and Supplements in Patients with NAFLD

Our aim is to review the efficacy of various herbs and supplements as a possible therapeutic option in the treatment and/or prevention of nonalcoholic fatty liver disease (NAFLD). We performed a systematic review of medical literature using the PubMed Database by searching the chemical names of many common herbs and supplements with “AND (NAFLD or NASH)”. Studies and medical literature that discussed the roles and usage of herbs and supplements in NAFLD and nonalcoholic steatohepatitis (NASH) from inception until 20 June 2018 were reviewed. Many studies have claimed that the use of various herbs and supplements may improve disease endpoints and outcomes related to NAFLD and/or NASH. Improvement in liver function tests were noted. Amelioration or reduction of lobular inflammation, hepatic steatosis, and fibrosis were also noted. However, well-designed studies demonstrating improved clinical outcomes are lacking. Furthermore, experts remain concerned about the lack of regulation of herbs/supplements and the need for further research on potential adverse effects and herb–drug interactions. In conclusion, preliminary data on several herbs have demonstrated promising antioxidant, anti-inflammatory, anti-apoptotic, and anti-adipogenic properties that may help curtail the progression of NAFLD/NASH. Clinical trials testing the safety and efficacy must be completed before widespread use can be recommended.

GPCRs in NLRP3 Inflammasome Activation, Regulation, and Therapeutics

The NLRP3 inflammasome is an intracellular multimeric protein complex which plays an important role in the pathogenesis of various human inflammatory diseases, such as diabetes, Alzheimer's disease and atherosclerosis. Recently, various G protein-coupled receptors (GPCRs) have been reported to be involved in the activation and regulation of the NLRP3 inflammasome by sensing multiple ions, metabolites, and neurotransmitters, suggesting GPCR signaling is an important regulator for NLRP3 inflammasome. Here, we will review how various GPCRs promote or inhibit NLRP3 inflammasome activation and discuss the implications of GPCRs as drug targets for the therapy of NLRP3-driven diseases.

Effect of dietary omega-3 fatty acid supplementation on frailty-related phenotypes in older adults: a systematic review and meta-analysis protocol

INTRODUCTION

The beneficial effect of dietary omega-3 supplementation in younger adults or older people with acute or chronic disease is established. Knowledge is now needed about the effect in medically stable older people. The objective of this study is to examine and assess the evidence for a role of dietary omega-3 polyunsaturated fatty acid (PUFA) supplementation in older adults on (1) muscle mass and muscle strength, (2) inflammatory biomarkers and (3) physical activity.

METHODS AND ANALYSIS

A systematic review and data synthesis will be conducted of randomised controlled trials in older people not recruited for any given disease diagnosis. Placebo-controlled studies reporting interventions involving dietary supplementation of omega-3 PUFAs, eicosapentaenoic acid and docosahexaenoic acid will be included. Outcomes must include changes from baseline to last available follow-up for one or more of the following: muscle mass, inflammatory biomarkers, physical activity, walking speed, weight change, hand grip strength or muscle strength. Once the search strategy has been carried out, two independent researchers will assess relevant papers for eligibility. Articles up until 31 December 2017 in any language will be included. We will provide a narrative synthesis of the findings from the included studies. Studies will be grouped for meta-analysis according to the outcome(s) provided. Where studies have used the same type of intervention, with the same outcome measure, we will pool the results using a random effects meta-analysis, with standardised mean differences for continuous outcomes and risk ratios for binary outcomes, and calculate 95% CI and two-sided p values for each outcome.

ETHICS AND DISSEMINATION

No research ethics approval is required for this systematic review as no confidential patient data will be used. The results of this systematic review will be disseminated through publication in an open-access peer-reviewed journal and through conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42017080240.

Fish Oil Supplementation Alleviates the Altered Lipid Homeostasis in Blood, Liver, and Adipose Tissues in High-Fat Diet-Fed Rats

This study investigated the effects of dietary supplementation of fish oil on the signals of lipid metabolism involved in hepatic cholesterol and triglyceride influx and excretion in high-fat diet (HFD)-fed rats. Fish oil (FO) repressed body (HFD, 533 ± 18.2 g; HFD+FO, 488 ± 28.0 g, p < 0.05) and liver weights (HFD, 5.7 ± 0.6 g/100 g of body weight; HFD+FO, 4.8 ± 0.4 g/100 g of body weight, p < 0.05) in HFD-fed rats. Fish oil could also improve HFD-induced imbalance of lipid metabolism in blood, liver, and adipose tissues including the significant decreases in plasma and liver total cholesterol (TC) (plasma-HFD, 113 ± 33.6 mg/dL; HFD+FO, 50.0 ± 5.95 mg/dL, p < 0.05; liver-HFD, 102 ± 13.0 mg/g liver; [corrected] HFD+FO, 86.6 ± 7.81 mg/g liver, [corrected] p < 0.05), blood, liver, and adipose triglyceride (TG) (blood-HFD, 52.5 ± 20.4 mg/dL; HFD+FO, 29.8 ± 4.30 mg/dL, p < 0.05; liver-HFD, 56.2 ± 10.0 mg/g liver; [corrected] HFD+FO, 30.3 ± 5.28 mg/g liver, [corrected] p < 0.05; adipose-HFD, 614 ± 73.2 mg/g liver, [corrected] HFD+FO, 409 ± 334 mg/g of adipose tissue, [corrected] p < 0.05), and low density (HFD, 79.8 ± 40.9 mg/dL; HFD+FO, 16.6 ± 5.47 mg/dL, p < 0.05) and very-low-density (HFD, 49.7 ± 33.3 mg/dL; HFD+FO, 10.4 ± 3.45 mg/dL, p < 0.05) lipoprotein and the significant increases in fecal TC (HFD, 12.2 ± 0.67 mg/g feces; [corrected] HFD+FO, 16.3 ± 2.04 mg/g feces, [corrected] < 0.05) and TG (HFD, 2.09 ± 0.10 mg/g feces; [corrected] HFD+FO, 2.38 ± 0.22 mg/g feces, [corrected] p < 0.05) and lipoprotein lipase activity of adipose tissues (HFD, 16.6 ± 3.64 μM p-nitrophenol; HFD+FO, 24.5 ± 4.19 μM p-nitrophenol, p < 0.05). Moreover, fish oil significantly activated the protein expressions of hepatic lipid metabolism regulators (AMPKα and PPARα) and significantly regulated the lipid-transport-related signaling molecules (ApoE, MTTP, ApoB, Angptl4, ApoCIII, ACOX1, and SREBPF1) in blood or liver of HFD-fed rats. These results suggest that fish oil supplementation improves HFD-induced imbalance of lipid homeostasis in blood, liver, and adipose tissues in rats.

Omega-3 Fatty Acids and Fatty Liver Disease in Children

Nonalcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease in Industrialized Countries in adults and children. It is estimated that NAFLD will become the main indication for liver transplantation in the next decade. NAFLD is also considered the hepatic feature of metabolic syndrome and therefore it is generally associated to the risk of developing some metabolic complications, with negative impact on patient's survival. Today, no pharmacological treatment has been identified for NAFLD, and behavioral approach, based on diet and regular physical exercise, represent the current recommended treatment, even if with disappointing results. For these reasons, several pharmacological trials have been conducted, in order to identify possible alternative therapy direct against pathogenetic targets of NAFLD. Several data have suggested the potential beneficial role of omega-3 fatty acids in NAFLD and its related metabolic disarray. In this chapter, we try to elucidate the molecular and clinical available evidence for the omega-3 supplementation in pediatric NAFLD patients.