Impact of the Co-Administration of N-3 Fatty Acids and Olive Oil Components in Preclinical Nonalcoholic Fatty Liver Disease Models: A Mechanistic View

Di-2-ethylhexyl phthalate disrupts hepatic lipid metabolism in obese mice by activating the LXR/SREBP-1c and PPAR-α signaling pathways

Di-2-ethylhexyl phthalate (DEHP), a widely utilized plasticizer, has been described as a potential obesogen based on in vivo disruption of hepatic lipid homeostasis and in vitro promotion of lipid accumulation. However, limited literature exists regarding the specific ramifications of DEHP exposure on obese individuals, and the precise mechanisms underlying the adverse effects of DEHP exposure remain unclear. This study aimed to assess the impact of DEHP on hepatic lipid metabolism in obese mice by comparing them to normal mice. Following a 10-week DEHP exposure period, the obese mice exhibited higher blood lipid levels, more severe hepatic steatosis, and more infiltrations of inflammatory cells in liver tissue than normal mice. Interestingly, the body weight of the mice exhibited no significant alteration. In addition, transcriptomic analyses revealed that both lipogenesis and fatty acid oxidation contributed to hepatic lipid metabolism dysregulation following DEHP exposure. More specifically, alterations in the transcription of genes associated with hepatic lipid metabolism were linked to the different responses to DEHP exposure observed in normal and obese mice. Additionally, the outcomes of in vitro experiments validated the in vivo findings and demonstrated that DEHP exposure could modify hepatic lipid metabolism in normal mice by activating the LXR/SREBP-1c signaling pathway to promote lipogenesis. At the same time, DEHP exposure led to inhibition of the Camkkβ/AMPK pathway to suppress β-fatty acid oxidation. Conversely, in obese mice, DEHP exposure was found to be associated with the stimulation of both lipogenesis and fatty acid oxidation via activation of the LXR/SREBP-1c and PPAR-α signaling pathways, respectively. The findings presented in this study first elucidate the contrasting mechanisms underlying DEHP-induced liver damage in obese and normal mice, thereby offering valuable insights into the pathogenesis of DEHP-induced liver damage in individuals with obesity.

4-octyl itaconate protects against oxidative stress-induced liver injury by activating the Nrf2/Sirt3 pathway through AKT and ERK1/2 phosphorylation

4-octyl itaconate (4-OI) is a cell-permeable itaconate derivative with anti-inflammatory and antioxidant properties. However, its therapeutic potential for oxidative stress-induced liver injury remains unknown. This study investigated the hepatoprotective effects and mechanisms of 4-OI against oxidative damage in in vitro and in vivo models. 4-OI attenuated H2O2-induced cytotoxicity, oxidative stress, and mitochondrial dysfunction in L02 and HepG2 cells. Untargeted metabolomics profiling and pathway analysis identified the PI3K/AKT/mTOR and MAPK pathways as key regulators of 4-OI's protective effects. Specifically, 4-OI induced phosphorylation of AKT and ERK1/2, leading to activation of the Nrf2 signaling pathway. Nrf2 upregulated expression of the mitochondrial deacetylase Sirt3, which subsequently alleviated H2O2-induced cell injury. In mice, 4-OI reduced acetaminophen (APAP)-induced liver injury as evidenced by attenuated hepatocellular necrosis and decreased serum liver enzymes. It also elevated hepatic expression of Nrf2, Sirt3, p-AKT and p-ERK1/2. Inhibition of AKT, ERK1/2 or Nrf2 blocked the protective effects of 4-OI in vitro, suggesting its antioxidant activity is mediated by activating the Nrf2/Sirt3 pathway via AKT and ERK1/2 phosphorylation. In summary, 4-OI exerted antioxidant and hepatoprotective effects by activating the Nrf2/Sirt3 signaling pathway through AKT and ERK1/2 phosphorylation, which were elucidated using in vitro and in vivo oxidative stress models. This provides novel insights into the mechanisms of 4-OI against oxidative stress-related liver diseases.

Protein concentrations and activities of fatty acid desaturase and elongase enzymes in liver, brain, testicle, and kidney from mice: Substrate dependency

The synthesis rates of n-3 and n-6 polyunsaturated fatty acids (PUFAs) in rodents and humans are not agreed upon and depend on substrate availability independently of the capacity for synthesis. Therefore, we aimed to assess the activities of the enzymes for n-3 and n-6 PUFA synthesis pathways in liver, brain, testicle, kidney, heart, and lung, in relation to their protein concentration levels. Eight-week-old Balb/c mice (n = 8) were fed a standard chow diet (6.2% fat, 18.6% protein, and 44.2% carbohydrates) until 14 weeks of age, anesthetized with isoflurane and tissue samples were collected (previously perfused) and stored at -80°C. The protein concentration of the enzymes (Δ-6D, Δ-5D, Elovl2, and Elovl5) were assessed by ELISA kits; their activities were assayed using specific PUFA precursors and measuring the respective PUFA products as fatty acid methyl esters by gas chromatographic analysis. The liver had the highest capacity for PUFA biosynthesis, with limited activity in the brain, testicles, and kidney, while we failed to detect activity in the heart and lung. The protein concentration and activity of the enzymes were significantly correlated. Furthermore, Δ-6D, Δ-5D, and Elovl2 have a higher affinity for n-3 PUFA precursors compared to n-6 PUFA. The capacity for PUFA synthesis in mice mainly resides in the liver, with enzymes having preference for n-3 PUFAs.

Dietary and Nutritional Interventions in Nonalcoholic Fatty Liver Disease in Pediatrics

Nonalcoholic fatty liver disease (NAFLD) is pediatrics' most common chronic liver disease. The incidence is high in children and adolescents with obesity, which is associated with an increased risk of disease progression. Currently, there is no effective drug therapy in pediatrics; therefore, lifestyle interventions remain the first line of treatment. This review aims to present an updated compilation of the scientific evidence for treating this pathology, including lifestyle modifications, such as exercise and dietary changes, highlighting specific nutritional strategies. The bibliographic review was carried out in different databases, including studies within the pediatric population where dietary and/or nutritional interventions were used to treat NAFLD. Main interventions include diets low in carbohydrates, free sugars, fructose, and lipids, in addition to healthy eating patterns and possible nutritional interventions with n-3 polyunsaturated fatty acids (EPA and DHA), amino acids (cysteine, L-carnitine), cysteamine, vitamins, and probiotics (one strain or multi-strain). Lifestyle changes remain the main recommendation for children with NAFLD. Nevertheless, more studies are required to elucidate the effectiveness of specific nutrients and bioactive compounds in this population.

Higher consumption of animal organ meat is associated with a lower prevalence of nonalcoholic steatohepatitis

Background

Animal organ meat (offal) is a food with high nutrient density that is popular in different parts of the world, but its relationship with nonalcoholic steatohepatitis (NASH) is unclear. We aimed to examine whether daily animal organ meat consumption is associated with the presence of NASH in individuals with nonalcoholic fatty liver disease (NAFLD).

Methods

A total of 136 Chinese adults with biopsy-proven NAFLD were included. Definite NASH was defined as NAFLD activity score ≥4 and at least one point for steatosis, ballooning, and lobular inflammation. Daily animal organ meat consumption was estimated using a self-administered validated food frequency questionnaire. Logistic regression analysis was performed to assess the association between animal organ meat intake and liver disease severity.

Results

The 136 participants (80.9% men) of the study had a mean ± standard deviation (SD) age of 39.0±12.5 years and body mass index of 27.4±3.6 kg/m2. Prevalence of definite NASH was 65.4%. Daily median organ meat consumption was 1.30 g/1,000 kcal. Animal organ meat consumption was inversely associated with the presence of NASH even after adjustment of demographics, lifestyle variables, metabolic and dietary factors, as well as liver fibrosis stage; adjusted-odds ratios (95% confidence intervals) for NASH were 0.15 (0.03, 0.69) for the highest tertile and 0.18 (0.05, 0.70) for the medium tertile, compared to the lowest (reference) tertile of animal organ meat intake (P value for trend =0.024).

Conclusions

Our results suggest for the first time that higher animal organ meat consumption is associated with a lower prevalence of NASH in Chinese individuals with biopsy-proven NAFLD.

Extra-virgin olive oil ameliorates high-fat diet-induced seminal and testicular disorders by modulating the cholesterol pathway

BACKGROUND

Rabbits are sensitive to dietary cholesterol and rapidly develop hypercholesterolemia, leading to prominent subfertility. Sterol regulatory element-binding protein isoform 2 drives the intracellular cholesterol pathway in many tissues, including the testicles. Its abnormal regulation could be the mainly responsible for the failure of suppressing cholesterol synthesis in a cholesterol-enriched environment, ultimately leading to testicular and seminal alterations. However, extra-virgin olive oil consumption has beneficial properties that promote lowering of cholesterol levels, including the recovery of seminal parameters altered under a high-fat diet.

OBJECTIVES

Our goal was to investigate the effects of high-fat diet supplementation with extra-virgin olive oil at the molecular level on rabbit testes, by analyzing sterol regulatory element-binding protein isoform 2 protein and its corresponding downstream effectors.

MATERIALS AND METHODS

During 12 months, male rabbits were fed a control diet, high-fat diet, or 6-month high-fat diet followed by 6-month high-fat diet plus extra-virgin olive oil. Serum lipids, testosterone levels, bodyweight, and seminal parameters were tested. The mRNA and protein levels of sterol regulatory element-binding protein isoform 2, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, and low-density lipoprotein receptor were determined by semi-quantitative polymerase chain reaction and Western blotting techniques. The expression pattern of sterol regulatory element-binding protein isoform 2 protein in the rabbit testicles was studied by indirect immunofluorescence. In addition, testicular cholesterol was detected and quantified by filipin staining and gas chromatography.

RESULTS

The data showed that the addition of extra-virgin olive oil to high-fat diet reduced testicular cholesterol levels and recovered the expression of sterol regulatory element-binding protein isoform 2, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, and low-density lipoprotein receptor initially altered by the high-fat diet.

DISCUSSION AND CONCLUSIONS

The combination of high-fat diet with extra-virgin olive oil encourages testicular recovery by modifying the expression of the enzymes related to intracellular cholesterol management.

Plasma Fatty Acid Composition, Oxidative and Inflammatory Status, and Adherence to the Mediterranean Diet of Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a complex and increasingly prevalent cardiometabolic disorder worldwide. As of today, NAFLD is a pathology without specific pharmacological treatment, with the Mediterranean diet (MedDiet) being the most widely used approach for its management. The objective of this study is to assess the effects of adherence to the Mediterranean diet on fatty acid plasma levels, as well as on the oxidative and inflammatory status of NAFLD patients. A total of 100 adult patients (40-60 years old) diagnosed with NAFLD and from the Balearic Islands, Spain, were classified into three groups according to their adherence to the MedDiet. Consumption was assessed using a validated 143-item semiquantitative Food Frequency Questionnaire. Food items (g/day) were categorised according to their processing using the NOVA system. Anthropometrics, blood pressure, aminotransferases, Dietary Inflammatory Index (DII), inflammatory biomarkers, and fatty acid levels were measured in the plasma of NAFLD patients. High adherence to the MedDiet is associated to a highly plant-based diet, low ultra-processed food (UPF) consumption, low intake of dietary lipids, low intake of animal fats, high intake of monounsaturated fatty acid (MUFA; mainly palmitoleic acid), low intake of saturated fatty acids (SFAs; practically all dietary SFAs), low intake of trans-fatty acids, high intake of omega-3 fatty acids (mainly eicosapentaenoic acid), a higher n-6:n-3 in ratio, low intake of omega-6 fatty acids, and a low level of interleukin-6 (IL-6). High adherence to the MedDiet is related to a better fatty acid profile in the plasma, fewer SFAs and more MUFA and polyunsaturated fatty acids (PUFAs), a plasma biochemical profile, better proinflammatory status, and decreased ultra-processed food consumption of NAFLD patients.

Potential Clinical Applications of Pro-Resolving Lipids Mediators from Docosahexaenoic Acid

Docosahexaenoic acid (C22:6n-3, DHA) is the precursor of specialized pro-resolving lipid mediators (SPMs), such as resolvin, protectin, and maresin families which have been considered therapeutic bioactive compounds for human health. Growing evidence indicates that DHA and SPMs are beneficial strategies in the amelioration, regulation, and duration of inflammatory processes through different biological actions. The present review discusses the reported therapeutic benefits of SPMs on various diseases and their potential clinical applications.

Therapeutic Potentials of Reducing Liver Fat in Non-Alcoholic Fatty Liver Disease: Close Association with Type 2 Diabetes

Nonalcoholic fatty liver disease (NAFLD), the most widespread chronic liver disease worldwide, confers a significant burden on health systems and leads to increased mortality and morbidity through several extrahepatic complications. NAFLD comprises a broad spectrum of liver-related disorders, including steatosis, cirrhosis, and hepatocellular carcinoma. It affects almost 30% of adults in the general population and up to 70% of people with type 2 diabetes (T2DM), sharing common pathogenetic pathways with the latter. In addition, NAFLD is closely related to obesity, which acts in synergy with other predisposing conditions, including alcohol consumption, provoking progressive and insidious liver damage. Among the most potent risk factors for accelerating the progression of NAFLD to fibrosis or cirrhosis, diabetes stands out. Despite the rapid rise in NAFLD rates, identifying the optimal treatment remains a challenge. Interestingly, NAFLD amelioration or remission appears to be associated with a lower risk of T2DM, indicating that liver-centric therapies could reduce the risk of developing T2DM and vice versa. Consequently, assessing NAFLD requires a multidisciplinary approach to identify and manage this multisystemic clinical entity early. With the continuously emerging new evidence, innovative therapeutic strategies are being developed for the treatment of NAFLD, prioritizing a combination of lifestyle changes and glucose-lowering medications. Based on recent evidence, this review scrutinizes all practical and sustainable interventions to achieve a resolution of NAFLD through a multimodal approach.

Efficacy of Submicron Dispersible Free Phytosterols on Non-Alcoholic Fatty Liver Disease: A Pilot Study

BACKGROUND

No pharmacological treatment is yet approved for non-alcoholic fatty liver disease (NAFLD). Plant sterols have shown healthy properties beyond lowering LDL-cholesterol, including lowering triglycerides and lipoprotein plasma levels. Despite pre-clinical data suggesting their involvement in liver fat control, no clinical study has yet been successful.

AIMS

Testing a sub-micron, free, phytosterol dispersion efficacy on NAFLD.

METHODS

A prospective, uncontrolled pilot study was carried out on 26 patients with ≥17.4% liver steatosis quantified by magnetic resonance imaging. Subjects consumed daily a sub-micron dispersion providing 2 g of phytosterols. Liver fat, plasma lipids, lipoproteins, liver enzymes, glycemia, insulinemia, phytosterols, liposoluble vitamins and C-reactive protein were assessed at baseline and after one year of treatment.

RESULTS

Liver steatosis relative change was -19%, and 27% of patients reduced liver fat by more than 30%. Statistically and clinically significant improvements in plasma triglycerides, HDL-C, VLDL and HDL particle number and C-reactive protein were obtained, despite the rise of aspartate aminotransferase, glycemia and insulinemia. Though phytosterol plasma levels were raised by >30%, no adverse effects were presented, and even vitamin D increased by 23%.

CONCLUSIONS

Our results are the first evidence in humans of the efficacy of submicron dispersible phytosterols for the treatment of liver steatosis, dyslipidemia and inflammatory status in NAFLD.

Effects of Fish Oil, Lipid Mediators, Derived from Docosahexaenoic Acid, and Their Co-Treatment against Lipid Metabolism Dysfunction and Inflammation in HFD Mice and HepG2 Cells

Although fish oil (FO) and lipid mediators (LM) derived from polyunsaturated fatty acids can prevent obesity, their combined effects and cellular metabolism remain unclear. Therefore, this study aimed to examine the potential protective and metabolic effects of FO in combination with LM (a mixture of 17S-monohydroxy docosahexaenoic acid, resolvin D5, and protectin DX [3:47:50], derived from docosahexaenoic acid (DHA)) on palmitic acid (PA)-induced HepG2 cells and high-fat- diet (HFD)-induced C57BL/6J mice after 9-week treatment. Lipid metabolism disorders and inflammation induced by HFD and PA were substantially reduced after FO and LM treatment. Further, FO and LM treatments reduced lipid accumulation by increasing fatty acid oxidation via peroxisome proliferator-activated receptor α and carnitine-palmitoyl transferase 1 as well as by decreasing fatty acid synthesis via sterol regulatory element-binding protein-1c and fatty acid synthase. Finally, FO and LM treatment reduced inflammation by blocking the NF-κB signaling pathway. Importantly, the combination of FO and LM exhibited more robust efficacy against nonalcoholic fatty liver disease, suggesting that FO supplemented with LM is a beneficial dietary strategy for treating this disease.

Serum metabolic effects of corn oligopeptides with 7-day supplementation on early post-surgery primary liver cancer patients: a double-blind randomized controlled trial

BACKGROUND

Liver cancer as the main leading cancer has caused heavy burdens globally. The prognosis of liver cancer is closely related with postoperative nutrition support. Corn oligopeptides (COPs) are protein hydrolysates produced by enzymatic treatments, which have shown potential bioactivities, such as inhibiting angiotensin I-converting enzyme, resisting lipid peroxidation and anti-oxidant. However, the correlation between COPs and liver cancer patients is still unknown and the potential mechanism of COPs on liver cancer is unclear as well. The aim of this study was to assess effects of 7-day intervention of COPs after surgery on liver function and serum metabolic profiles of liver cancer patients.

METHODS

Patients were assigned into COPs intervention group (n=50) and control group (n=91) for 7 days. Investigations were scheduled at 1st day and 7th day after liver resection surgery respectively, mainly including anthropometric, biochemical indexes and liquid chromatography-mass spectrometry (LC/MS) analysis.

RESULTS

Seven-day supplementation of COPs on early post-surgery liver cancer patients down-regulated levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin and up-regulated prothrombin time activity and prealbumin levels. LC/MS analysis revealed metabolic signatures including regulation of 16 metabolites, which was closely related with two metabolic pathways (nicotinate and nicotinamide metabolism, fatty acid metabolism).

CONCLUSIONS

COPs supplementation has displayed the potentials on alleviating the injury of liver function and it may be due to regulation of fatty acid metabolism, nicotinate and nicotinamide metabolism, lipid peroxidation and anti-inflammatory action. More researches are warranted in future to confirm the exact mechanisms.

Combination Treatment with Hydroxytyrosol and Vitamin E Improves NAFLD-Related Fibrosis

Non-alcoholic fatty liver disease (NAFLD)-related liver fibrosis results in the encapsulation of injured liver parenchyma by a collagenous scar mainly imputable to hepatic stellate cells’ activation. Approved pharmacological treatments against NAFLD-related fibrosis are still lacking, but natural compounds such as hydroxytyrosol (HXT) and vitamin E (VitE), are emerging as promising therapeutic opportunities. In this study, the potential anti-fibrotic effect of HXT + VitE combination therapy was investigated in vitro and in vivo. In particular, tumor growth factor (TGF)-β-activated LX-2 cells as an in vitro model, and carbon tetrachloride plus a Western diet as a mice model were employed. The effect of HXT + VitE on fibrosis was also investigated in children with biopsy-proven NAFLD. Our results demonstrated that HXT + VitE caused a reduction of proliferation, migration, contractility, and expression of pro-fibrogenic genes in TGF-β-activated LX-2 cells. HXT + VitE treatment also antagonized TGF-β-dependent upregulation of pro-oxidant NOX2 by interfering with nuclear translocation/activation of SMAD2/3 transcription factors. The mouse model of NAFLD-related fibrosis treated with HXT + VitE showed a marked reduction of fibrosis pattern by histology and gene expression. Accordingly, in children with NAFLD, HXT + VitE treatment caused a decrease of circulating levels of PIIINP and NOX2 that was supported over time. Our study suggests that HXT + VitE supplementation may improve NAFLD-related fibrosis.

Progress in Nonalcoholic Fatty Liver Disease: SIRT Family Regulates Mitochondrial Biogenesis

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, insulin resistance, mitochondrial dysfunction, inflammation, and oxidative stress. As a group of NAD+-dependent III deacetylases, the sirtuin (SIRT1-7) family plays a very important role in regulating mitochondrial biogenesis and participates in the progress of NAFLD. SIRT family members are distributed in the nucleus, cytoplasm, and mitochondria; regulate hepatic fatty acid oxidation metabolism through different metabolic pathways and mechanisms; and participate in the regulation of mitochondrial energy metabolism. SIRT1 may improve NAFLD by regulating ROS, PGC-1α, SREBP-1c, FoxO1/3, STAT3, and AMPK to restore mitochondrial function and reduce steatosis of the liver. Other SIRT family members also play a role in regulating mitochondrial biogenesis, fatty acid oxidative metabolism, inflammation, and insulin resistance. Therefore, this paper comprehensively introduces the role of SIRT family in regulating mitochondrial biogenesis in the liver in NAFLD, aiming to further explain the importance of SIRT family in regulating mitochondrial function in the occurrence and development of NAFLD, and to provide ideas for the research and development of targeted drugs. Relatively speaking, the role of some SIRT family members in NAFLD is still insufficiently clear, and further research is needed.

Ferulic Acid Prevents Nonalcoholic Fatty Liver Disease by Promoting Fatty Acid Oxidation and Energy Expenditure in C57BL/6 Mice Fed a High-Fat Diet

There is a consensus that ferulic acid (FA), the most prominent phenolic acid in whole grains, displays a protective effect in non-alcoholic fatty liver disease (NAFLD), though its underlying mechanism not fully elucidated. This study aimed to investigate the protective effect of FA on high-fat diet (HFD)-induced NAFLD in mice and its potential mechanism. C57BL/6 mice were divided into the control diet (CON) group, the HFD group, and the treatment (HFD+FA) group, fed with an HFD and FA (100 mg/kg/day) by oral gavage for 12 weeks. Hematoxylin and eosin (H&E) staining and Oil Red O staining were used to evaluate liver tissue pathological changes and lipid accumulation respectively. It was demonstrated that FA supplementation prevented HFD-induced NAFLD, which was evidenced by the decreased accumulation of lipid and hepatic steatosis in the HFD+FA group. Specifically, FA supplementation decreased hepatic triacylglycerol (TG) content by 33.5% (p < 0.01). Metabolic cage studies reveal that FA-treated mice have elevated energy expenditure by 11.5% during dark phases. Mechanistically, FA treatment increases the expression of rate-limiting enzymes of fatty acid oxidation and ketone body biosynthesis CPT1A, ACOX1 and HMGCS2, which are the peroxisome proliferator-activated receptors α (PPARα) targets in liver. In conclusion, FA could effectively prevent HFD-induced NAFLD possibly by activating PPARα to increase energy expenditure and decrease the accumulation of triacylglycerol in the liver.

White meat proteins were more conducive to hepatic antioxidative status than soybean and red meat proteins

Intake of protein-rich foods might induce oxidative stress in organs. This study investigated the impacts of protein sources including casein, soybean, fish, chicken, pork, and beef proteins on hepatic oxidation and antioxidation status in rats. It was shown that meat proteins produced higher reactive oxygen species in livers (from 64,868 to 87,153 F/mgpro) than casein (54,045 F/mgpro) and soybean protein (48,361 F/mgpro, p < .05). Pork and soybean proteins induced higher hepatic oxidative stress than fish, chicken and beef proteins by increasing malondialdehyde production (>16%, p < .05). White meat (fish and chicken) proteins promoted hepatic superoxide dismutase activity and total antioxidant capacity compared to soybean and red meat (pork and beef) proteins (p < .05). Compared to red meat proteins, white meat proteins increased hepatic expressions of thioredoxin and glutaredoxin. Rats fed red meat proteins showed hepatic steatosis with small vacuoles. Therefore, white meat proteins were more conducive to hepatic antioxidative status than soybean and red meat proteins. PRACTICAL APPLICATIONS: Intake of protein-rich foods may induce oxidative stress response at both cell and organ levels. The objective of this study was to investigate the impacts of different protein sources including casein, soybean, fish, chicken, pork, and beef proteins on oxidation and antioxidation status in rat livers. It was shown that meat proteins induced higher production of reactive oxygen species than casein and soybean protein. However, white meat proteins showed higher antioxidant capacity than soybean and red meat proteins by increasing hepatic superoxide dismutase activity and total antioxidant capacity. Therefore, compared to soybean and red meat proteins, white meat proteins lowered hepatic oxidative stress by reducing malondialdehyde production. This study suggested that intake of moderate white meat proteins was more conducive to hepatic antioxidative status than intake of soybean and red meat proteins. This study would promote the understanding of healthy effects of different protein sources.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components—such as oleic acid, hydroxytyrosol, and oleuropein—in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

Salvianolic acid B inhibits the progression of liver fibrosis in rats via modulation of the Hedgehog signaling pathway

Salvianolic acid B (Sal B) has previously reported anti-hepatic fibrosis effects, though it is not clear if it can inhibit hepatic fibrosis by regulating the hedgehog (Hh) signaling pathway. The aim of the present study was to explore the roles and mechanism of Sal B in preventing and treating liver fibrosis in rats. The study also aimed to determine the role of the Hh signaling pathway in this process. A rat model of liver fibrosis was induced through the subcutaneous injection of 50% carbon tetrachloride, followed by treatment with Sal B. After gavage, blood was collected to detect serum markers of liver injury. The degree of liver fibrosis and tissue damage was assessed using histopathological analysis. Western blotting and reverse transcription-quantitative PCR were used to detect the expression levels of TGF-β1 and Hh signaling pathway-related genes, including Sonic hedgehog (Shh) protein, membrane protein receptor protein patched homolog 1 (Ptch1), membrane protein receptor Smoothened (Smo) and transcription factor glioma-associated oncogene homolog 1 (Gli1). Serum alanine aminotransferase, aspartate aminotransferase and total bilirubin levels were decreased, whilst levels of albumin were increased in rats with liver fibrosis that were treated with Sal B (P<0.05). Additionally, significant increases in TGF-β1, Shh, Ptch1, Smo, Gli1 and α-smooth muscle actin expression levels were observed in the liver tissues of rats with hepatic fibrosis (P<0.05). However, Sal B treatment significantly reduced the expression levels of these proteins (P<0.05). In conclusion, the results of the present study suggested that the Hh signaling pathway may be activated during the process of rat liver fibrosis. Thus, Sal B may exert its anti-hepatic fibrosis effects, at least in part, by inhibiting the activation of the Hh signaling pathway.

Changes in secoiridoids content and chemical characteristics of cultivated and wild Algerian olive oil, in term of fruit maturation

Wild varieties in nature are known to be better adapted to climate change and more resistant to arid conditions common in some regions of the world. Oil samples of two cultivated varieties, Chemlal and Lemli, and one sylvestris variety were collected at four different harvesting periods in the semi-arid region of Bouira, Algeria. The aim of this study was to determine the influence of the genetic and maturity factors on the quality indices (acidity, peroxides value, and the parameters K232, K270), fatty acids profile, phenolic composition, and antioxidant activity of monovarietal olive oils. The study showed that early harvest dates of the fruits produced oils richer in pigments and phenolic compounds, with high antioxidant activity registered in both wild and cultivated varieties. Moreover, all oil samples showed high values of secoiridoids exceeding 60–90% of total biophenols, with higher values found in oleaster oils, which are correlated with high resistance to oxidation attacks. UHPLC-DAD and UHPLC-HRMS analyses showed that the secoiridoids composition is dominated by a profile rich in several isomers of oleuropein and ligstroside aglycons, which in turn represent more than 60% of the total secoiridoids in olive and Oleaster oils. Furthermore, chemometric analysis on the data allowed a better appreciation of the sensitivity of the virgin olive oil composition to the changes in genetic and ripening factors. According to the principal component analysis, phenolic and fatty acid profiles were the most important components contributing to the discrimination between olive oil samples.

Phloretin attenuation of hepatic steatosis via an improvement of mitochondrial dysfunction by activating AMPK-dependent signaling pathways in C57BL/6J mice and HepG2 cells

Phloretin, a dihydrochalcone, widely exists in the fruits of apple trees and crabapple trees (Malus prunifolia) with multiple biological activities. Presently, we studied the function of phloretin on the attenuation of hepatic steatosis and further explored the underlying mechanisms both in vitro and in vivo. Male C57BL/6J mice were fed a normal diet or high fat diet (HFD) with or without phloretin (100 mg kg^-1) for 12 weeks. HepG2 cells were induced by 200 μM palmitic acid (PA) and co-incubated with phloretin (50 μM) for 24 h. The results showed that phloretin treatment significantly decreased the accumulation of lipids in the liver of the HFD-fed C57BL/6J mice and PA-induced HepG2 cells. Also, phloretin effectively ameliorated hepatic steatosis via promoting fatty acid β-oxidation (FAO). This biological activity of phloretin was closely related to its capacity to improve mitochondrial dysfunction, including the promotion of mitochondrial biosynthesis and inhibition of mitochondrial swelling through the AMPK-dependent SIRT1/PGC-1α and SIRT3/CypD signaling pathways, respectively. These results demonstrate that phloretin effectively improves mitochondrial function and ameliorates HFD-induced hepatic steatosis through an AMPK-dependent signaling pathway.

Mechanism of subchronic vinyl chloride exposure combined with a high-fat diet on hepatic steatosis

Vinyl chloride (VC) is a common industrial organic chlorine and environmental pollutant. In recent years, the dietary structure of residents especially Chinese has gradually shifted to western dietary patterns. VC aggravates dietary fatty acid-induced hepatic steatosis, but its mechanism is still unclear. And if the risk factors for steatosis persist, more severe diseases such as fibrosis and cirrhosis will occur. Therefore, we studied the effects and mechanisms of VC (160 and 800 mg/m³ ) and its metabolite (chloroacetaldehyde, 2.25, 4.5, and 9 μM) on hepatic steatosis of high-fat diet (HFD)-fed mice and palmitic acid (PA, 100 μM) treated HepG2 cells. Liver and serum biochemical indicators and pathological staining of the liver showed that the hepatic steatosis of VC combined with HFD groups was more severe than that of single-exposure groups (HFD group, low-dose VC group, and high-dose VC group). Moreover, VC enhanced HFD-induced oxidative stress (OS) and endoplasmic reticulum stress (ERS) and further upregulated the expression of sterol regulatory element-binding protein 1 (SREBP-1) and FAS. Besides, antioxidants and ERS inhibitors reduced the steatosis of HepG2 cells induced by VC metabolites and PA. These results suggest that VC exposure can enhance the degree of hepatic steatosis in HFD-fed mice. VC combined with HFD led to OS and ERS and upregulated the expression of de novo lipogenesis-related proteins, which may be related to the occurrence of hepatic steatosis. And the increased expression of CYP2E1 induced by VC combined with HFD may be the cause of OS.

Sex Differences in Nonalcoholic Fatty Liver Disease: Estrogen Influence on the Liver-Adipose Tissue Crosstalk

Significance: Nonalcoholic fatty liver disease (NAFLD) is a hepatic and systemic disorder with a complex multifactorial pathogenesis. Owing to the rising incidence of obesity and diabetes mellitus, the prevalence of NAFLD and its impact on global health care are expected to increase in the future. Differences in NAFLD exist between males and females, and among females depending on their reproductive status. Clinical and preclinical data show that females in the fertile age are more protected against NAFLD, and studies in postmenopausal women and ovariectomized animal models support a protective role for estrogens. Recent Advances: An efficient crosstalk between the liver and adipose tissue is necessary to regulate lipid and glucose metabolism, protecting the liver from steatosis and insulin resistance contributing to NALFD. New advances in the knowledge of sexual dimorphism in liver and adipose tissue are providing interesting clues about the sex differences in NAFLD pathogenesis that could inspire new therapeutic strategies. Critical Issues: Sex hormones influence key master regulators of lipid metabolism and oxidative stress in liver and adipose tissue. All these sex-biased metabolic adjustments shape the crosstalk between liver and adipose tissue, contributing to the higher protection of females to NAFLD. Future Directions: The development of novel drugs based on the protective action of estrogens, but without its feminizing or undesired side effects, might provide new therapeutic strategies for the management of NAFLD. Antioxid. Redox Signal. 35, 753-774.

A novel supplement with yeast β-glucan, prebiotic, minerals and Silybum marianum synergistically modulates metabolic and inflammatory pathways and improves steatosis in obese mice

OBJECTIVE

To evaluate the synergic effects of a novel oral supplement formulation, containing prebiotics, yeast β-glucans, minerals and silymarin (Silybum marianum), on lipid and glycidic metabolism, inflammatory and mitochondrial proteins of the liver, in control and high-fat diet-induced obese mice.

METHODS

After an acclimation period, 32 male C57BL/6 mice were divided into the following groups: nonfat diet (NFD) vehicle, NFD supplemented, high-fat diet (HFD) vehicle and HFD supplemented. The vehicle and experimental formulation were administered orally by gavage once a day during the last four weeks of the diet (28 consecutive days). We then evaluated energy homeostasis, inflammation, and mitochondrial protein expression in these groups of mice.

RESULTS

After four weeks of supplementation, study groups experienced reduced glycemia, dyslipidemia, fat, and hepatic fibrosis levels. Additionally, proliferator-activated receptor-α, AMP-activated protein kinase-1α, peroxisome proliferator-activated receptor γ co-activator-1α, and mitochondrial transcription factor A expression levels were augmented; however, levels of inhibitor of nuclear factor-κB kinase subunit α and p65 nuclear factor-κB expression, and oxidative markers were reduced. Notably, the cortisol/C-reactive protein ratio, a well-characterized marker of the hypothalamic-pituitary-adrenal axis immune interface status, was found to be modulated by the supplement.

CONCLUSION

We discovered that the novel supplement was able to modify different antioxidant, metabolic and inflammatory pathways, improving the energy homeostasis and inflammatory status, and consequently alleviated hepatic steatosis.

Maternal DHA Supplementation during Pregnancy and Lactation in the Rat Protects the Offspring against High-Calorie Diet-Induced Hepatic Steatosis

Maternal supplementation during pregnancy with docosahexaenoic acid (DHA) is internationally recommended to avoid postpartum maternal depression in the mother and improve cognitive and neurological outcomes in the offspring. This study was aimed at determining whether this nutritional intervention, in the rat, protects the offspring against the development of obesity and its associated metabolic disorders. Pregnant Wistar rats received an extract of fish oil enriched in DHA or saline (SAL) as placebo by mouth from the beginning of gestation to the end of lactation. At weaning, pups were fed standard chow or a free-choice, high-fat, high-sugar (fc-HFHS) diet. Compared to animals fed standard chow, rats exposed to the fc-HFHS diet exhibited increased body weight, liver weight, body fat and leptin in serum independently of saline or DHA maternal supplementation. Nevertheless, maternal DHA supplementation prevented both the glucose intolerance and the rise in serum insulin resulting from consumption of the fc-HFHS diet. In addition, animals from the DHA-fc-HFHS diet group showed decreased hepatic triglyceride accumulation compared to SAL-fc-HFHS rats. The beneficial effects on glucose homeostasis declined with age in male rats. Yet, the preventive action against hepatic steatosis was still present in 6-month-old animals of both sexes and was associated with decreased hepatic expression of lipogenic genes. The results of the present work show that maternal DHA supplementation during pregnancy programs a healthy phenotype into the offspring that was protective against the deleterious effects of an obesogenic diet.

Omega-3 fatty acid blood levels are inversely associated with cardiometabolic risk factors in HFpEF patients: the Aldo-DHF randomized controlled trial

Objectives

To evaluate associations of omega-3 fatty acid (O3-FA) blood levels with cardiometabolic risk markers, functional capacity and cardiac function/morphology in patients with heart failure with preserved ejection fraction (HFpEF).

Background

O3-FA have been linked to reduced risk for HF and associated phenotypic traits in experimental/clinical studies.

Methods

This is a cross-sectional analysis of data from the Aldo-DHF-RCT. From 422 patients, the omega-3-index (O3I = EPA + DHA) was analyzed at baseline in n = 404 using the HS-Omega-3-Index^® methodology. Patient characteristics were; 67 ± 8 years, 53% female, NYHA II/III (87/13%), ejection fraction ≥ 50%, E/e′ 7.1 ± 1.5; median NT-proBNP 158 ng/L (IQR 82–298). Pearson’s correlation coefficient and multiple linear regression analyses, using sex and age as covariates, were used to describe associations of the O3I with metabolic phenotype, functional capacity, echocardiographic markers for LVDF, and neurohumoral activation at baseline/12 months.

Results

The O3I was below (< 8%), within (8–11%), and higher (> 11%) than the target range in 374 (93%), 29 (7%), and 1 (0.2%) patients, respectively. Mean O3I was 5.7 ± 1.7%. The O3I was inversely associated with HbA1c (r = − 0.139, p = 0.006), triglycerides-to-HDL-C ratio (r = − 0.12, p = 0.017), triglycerides (r = − 0.117, p = 0.02), non-HDL-C (r = − 0.101, p = 0.044), body-mass-index (r = − 0.149, p = 0.003), waist circumference (r = − 0.121, p = 0.015), waist-to-height ratio (r = − 0.141, p = 0.005), and positively associated with submaximal aerobic capacity (r = 0.113, p = 0.023) and LVEF (r = 0.211, p < 0.001) at baseline. Higher O3I at baseline was predictive of submaximal aerobic capacity (β = 15.614, p < 0,001), maximal aerobic capacity (β = 0.399, p = 0.005) and LVEF (β = 0.698, p = 0.007) at 12 months.

Conclusions

Higher O3I was associated with a more favorable cardiometabolic risk profile and predictive of higher submaximal/maximal aerobic capacity and lower BMI/truncal adiposity in HFpEF patients.

Graphic abstract

Omega-3 fatty acid blood levels are inversely associated with cardiometabolic risk factors in HFpEF patients. Higher O3I was associated with a more favorable cardiometabolic risk profile and aerobic capacity (left) but did not correlate with echocardiographic markers for left ventricular diastolic function or neurohumoral activation (right). An O3I-driven intervention trial might be warranted to answer the question whether O3-FA in therapeutic doses (with the target O3I 8–11%) impact on echocardiographic markers for left ventricular diastolic function and neurohumoral activation in patients with HFpEF. This figure contains modified images from Servier Medical Art (https://smart.servier.com) licensed by a Creative Commons Attribution 3.0 Unported License.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01925-9.

Lactobacillus acidophilus and vitamin C attenuate ethanol-induced intestinal and liver injury in mice

Ethanol exposure frequently induces intestinal and liver injury, dysbiosis of the gut microbiota and vitamin C (VC) deficiency. Gut microbiota-targeted therapy is emerging as an important adjuvant method for protecting the body against ethanol-induced injury, particularly probiotics containing Lactobacillus acidophilus (LA). However, the feasibility and efficiency of using synbiotics containing LA and VC against ethanol-induced injury remained largely undetermined. To examine the advantages of LA+VC, their effect was evaluated in an ethanol-fed mouse model. The results suggested that LA+VC restored gut microbiota homeostasis and reinstated the immune balance of colonic T-regulatory cells (CD4⁺CD45⁺forkhead box p3⁺). In addition, intestinal barrier disorders were improved via upregulating tight junction proteins (claudin-2, zona occludens-1 and occludin) and mucus secretion, which prevented the translocation of lipopolysaccharide into circulatory systems and subsequently reduced the expression of Toll-like receptor 4 in liver tissues. In this context, LA+VC treatment reduced the inflammatory response in the liver, which was likely responsible for the improved liver function in ethanol-challenged mice. Collectively, these results indicated that LA+VC treatment significantly protected the intestine and liver from ethanol damage by enhancing intestinal barrier function and reducing systemic inflammation. The present study paved the way for further exploration of synbiotics based on Lactobacillus species and VC.

The metabolic dysfunction of white adipose tissue induced in mice by a high-fat diet is abrogated by co-administration of docosahexaenoic acid and hydroxytyrosol

BACKGROUND

Nutritional interventions are promising tools for the prevention of obesity. The n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) docosahexaenoic acid (DHA) modulates immune and metabolic responses while the antioxidant hydroxytyrosol (HT) prevents oxidative stress (OS) in white adipose tissue (WAT).

OBJECTIVE

The DHA plus HT combined protocol prevents WAT alterations induced by a high-fat diet in mice. Main related mechanisms.

METHODS

Male C57BL/6J mice were fed a control diet (CD; 10% fat, 20% protein, and 70% carbohydrates) or a high fat diet (HFD) (60% fat, 20% protein, and 20% carbohydrates) for 12 weeks, without and with supplementation of DHA (50 mg kg-1 day-1), HT (5 mg kg-1 day-1) or both. Measurements of WAT metabolism include morphological parameters, DHA content in phospholipids (gas chromatography), lipogenesis, OS and inflammation markers, mitochondrial activity and gene expression of transcription factors SREBP-1c, PPAR-γ, NF-κB (p65) and Nrf2 (quantitative polymerase chain reaction and enzyme-linked immunosorbent assay).

RESULTS

The combined DHA and HT intervention attenuated obesity development, suppressing the HFD-induced inflammatory and lipogenic signals, increasing antioxidant defenses, and maintaining the phospholipid LCPUFA n-3 content and mitochondrial function in WAT. At the systemic level, the combined intervention also improved the regulation of glucose and adipokine homeostasis.

CONCLUSION

The combined DHA and HT protocol appears to be an important nutritional strategy for the treatment of metabolic diseases, with abrogation of obesity-driven metabolic inflammation and recovery of a small-healthy adipocyte phenotype.

DHA-enriched phosphatidylserine ameliorates non-alcoholic fatty liver disease and intestinal dysbacteriosis in mice induced by a high-fat diet

Docosahexaenoic acid-enriched phosphatidylserine (DHA-PS) has attracted increasing attention because of its unique health benefits. In this study, DHA-PS was biosynthesized from DHA-enriched phosphatidylcholine (DHA-PC), which was extracted from herring roe, Clupea harengus. The ameliorating effect of DHA-PS on high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) was investigated using a mouse model. The DHA-PS treatment ameliorated NAFLD and effectively decreased the serum total cholesterol, triglyceride, non-esterified fatty acid, and low-density lipoprotein cholesterol levels and considerably increased the serum high-density lipoprotein cholesterol levels. Moreover, the DHA-PS treatment reduced the levels of liver-function enzymes and pro-inflammatory cytokines and also the oxidative stress indices. Furthermore, DHA-PS increased the diversity and richness of the beneficial intestinal microorganisms, suggesting its potential as a dietary supplement and functional food to combat HFD-induced NAFLD.

Beneficial effects of natural compounds on experimental liver ischemia-reperfusion injury

Liver ischemia-reperfusion injury (IRI) is a phenomenon inherent to hepatic surgery that severely compromises the organ functionality, whose underlying mechanisms involve cellular and molecular interrelated processes leading to the development of an excessive inflammatory response. Liver resident cells and those recruited in response to injury generate pro-inflammatory signals such as reactive oxygen species, cytokines, chemokines, proteases and lipid mediators that contribute to hepatocellular necrosis and apoptosis. Besides, dying hepatocytes release damage-associated molecular patterns that actívate inflammasomes to further stimulate inflammatory responses leading to massive cell death. Since liver IRI is a complication of hepatic surgery in man, extensive preclinical studies have assessed potential protective strategies, including the supplementation with natural compounds, with the objective to downregulate nuclear factor-κB functioning, the main effector of inflammatory responses. This can be accomplished by either the activation of peroxisome proliferator-activated receptor-α, G protein-coupled receptor 120 or antioxidant signaling pathways, the synthesis of specific pro-resolving mediators, downregulation of Toll-like receptor 4 activity or additional contributory mechanisms that are beginning to be understood. The latter aspect is a crucial issue to be accomplished in preclinical studies, in order to establish adequate conditions for the supplementation with natural products before major liver surgeries in man involving warm IR, such as hepatic trauma or resection of large intrahepatic tumors.

Açaí (Euterpe oleracea Martius) supplementation improves oxidative stress biomarkers in liver tissue of dams fed a high-fat diet and increases antioxidant enzymes' gene expression in offspring

Lipids excess from an uterine environment can increase free radicals production of and thus induce oxidative status imbalance, a key factor for progression of non-alcoholic fatty liver disease (NAFLD) in offspring. Food antioxidant components in maternal diet may play an important role in preventing offspring metabolic disorders. The objective of the study was to evaluate the effects of açaí pulp supplementation on maternal high-fat diet, by assessing activity and expression of antioxidant enzymes and biomarkers of oxidative stress in the liver. Female Fisher rats were divided into four groups and fed a control diet (C), a high-fat diet (HF), a control diet supplemented with açaí (CA) and a high-fat diet supplemented with açaí (HFA) before mating, during gestation and lactation. The effects of açaí supplementation on oxidative stress biomarkers and antioxidant enzymes expression were evaluated in dams and male offspring after weaning. HFA diet increased body weight in dams, however reduced absolute and relative liver weight. There was a reduction in liver biomarkers of oxidative stress, malondialdehyde and carbonyl protein, as well as in catalase, glutathione peroxidase and superoxide dismutase activity. In offspring, HFA diet reduced liver weight and increased Gpx1, Gpx4 and Sod1 mRNA expression. These results suggest that açaí is able to restore redox status, preventing oxidative damage in dams by a direct mechanism and to promote beneficial effects on expression of antioxidant defences related genes in offspring.

The new coumarin compound Bis 3 ameliorates cognitive disorder and suppresses brain-intestine-liver systematic oxidative stress in high-fat diet mice

High-fat diet (HFD)-induced systemic oxidative damage is critical to the pathological process of obesity and is associated with energy metabolism and cognitive disorders. In our previous research, the coumarin derivative Bis 3 was shown to improve neurological disorders as a potent free radical scavenger. In this study, a 12-week high-fat diet model was established, and mice were randomly divided into 3 groups: standard diet, high-fat diet, and high-fat diet with Bis 3 treatment. Our results demonstrated that Bis 3 attenuated body weight gain and inhibited the development of insulin resistance in high-fat diet-fed mice. Bis 3 protected against high fat-induced intestinal barrier integrity damage and lipid content disorder. HFD-induced hepatocyte lipid metabolism disorder and hepatocyte damage were also alleviated by Bis 3. Moreover, the results of cognitive tests indicated that Bis 3 attenuated high fat-induced cerebral dysfunction, such as cognitive disorders. Importantly, Bis 3 simultaneously ameliorated oxidative stress in the digestive and central nervous systems. These findings suggest that Bis 3 protects against systematic oxidative stress in HFD-induced obese mice, balancing insulin resistance, lipid metabolic disorders, and cognitive disorders through its antioxidative effects, indicating that Bis 3, a novel free radical scavenger, might represent a new therapeutic strategy for high fat-induced chronic systemic redox imbalance.

Elucidation of SIRT-1/PGC-1α-associated mitochondrial dysfunction and autophagy in nonalcoholic fatty liver disease

Background

Nonalcoholic fatty liver disease (NAFLD) can lead to chronic liver diseases associated with mitochondrial damages. However, the exact mechanisms involved in the etiology of the disease are not clear.

Methods

To gain new insights, the changes affecting sirtuin 1 (SIRT-1) during liver fat accumulation was investigated in a NAFLD mouse model. In addition, the in vitro research investigated the regulation operated by SIRT-1 on mitochondrial structures, biogenesis, functions, and autophagy.

Results

In mice NAFLD, high-fat-diet (HFD) increased body weight gain, upregulated serum total cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, blood glucose, insulin levels, and liver malondialdehyde, and decreased liver superoxide dismutase activity. In liver, the levels of SIRT-1 and peroxisome proliferator-activated receptor-gamma coactivator -1α (PGC-1α) decreased. The expression of peroxisome proliferator-activated receptor-α and Beclin-1 proteins was also reduced, while p62/SQSTM1 expression increased. These results demonstrated SIRT-1 impairment in mouse NAFLD. In a well-established NAFLD cell model, exposure of the HepG2 hepatocyte cell line to oleic acid (OA) for 48 h caused viability reduction, apoptosis, lipid accumulation, and reactive oxygen species production. Disturbance of SIRT-1 expression affected mitochondria. Pre-treatment with Tenovin-6, a SIRT-1 inhibitor, aggravated the effect of OA on hepG2, while this effect was reversed by CAY10602, a SIRT-1 activator. Further investigation demonstrated that SIRT-1 activity was involved in mitochondrial biogenesis through PGC-1α and participated to the balance of autophagy regulatory proteins.

Conclusion

In conclusion, in high-fat conditions, SIRT-1 regulates multiple cellular properties by influencing on mitochondrial physiology and lipid autophagy via the PGC-1α pathway. The SIRT-1/PGC-1α pathway could be targeted to develop new NAFLD therapeutic strategies.

LDL/HDL cholesterol ratio is associated with new-onset NAFLD in Chinese non-obese people with normal lipids: a 5-year longitudinal cohort study

Background

Low-density lipoprotein to high density lipoprotein (LDL/HDL) cholesterol ratio has been reported to predict the risk of many metabolic diseases. However, the association between the LDL/HDL cholesterol ratio and nonalcoholic fatty liver disease (NAFLD) has not been established.

Methods

A longitudinal cohort design was adopted in this study; 9767 non-obese subjects without NAFLD were included and analyzed. The subjects were grouped according to the quintile of LDL/HDL cholesterol ratio. The cumulative incidence of NAFLD and the independent effect of the LDL/HDL cholesterol ratio on NAFLD during 5 years of follow-up were calculated using the Kaplan-Meier method and Cox proportional-hazards regression model.

Results

During the 5-year follow-up period, 841 subjects were diagnosed with new-onset NAFLD, and the 1-, 2-, 3-, 4-, and 5-year cumulative incidence rates of NAFLD were 1.16, 4.65, 8.33, 12.43, and 25.14%, respectively. In the multivariable-adjusted Cox proportional-hazards regression model, the LDL/HDL cholesterol ratio was significantly associated with the risk for NAFLD (HR: 1.66, 95% CI: 1.38–1.99, P trend< 0.001), especially among young people (HR: 3.96, 95% CI: 1.50–10.46, P interaction< 0.05). Additionally, receiver operating characteristic curve analysis showed that the LDL/HDL cholesterol ratio was better than HDL cholesterol and LDL cholesterol in predicting new-onset NAFLD.

Conclusions

LDL/HDL cholesterol ratio is an independent predictor of NAFLD in Chinese non-obese people with normal lipids, and its predictive value is higher than that of other lipoproteins. In clinical practice, the LDL/HDL cholesterol ratio can be used to identify people at high risk of NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01457-1.

Overconsumption of Omega-6 Polyunsaturated Fatty Acids (PUFAs) versus Deficiency of Omega-3 PUFAs in Modern-Day Diets: The Disturbing Factor for Their "Balanced Antagonistic Metabolic Functions" in the Human Body

Polyunsaturated fatty acids (PUFAs) contain ≥2 double-bond desaturations within the acyl chain. Omega-3 (n-3) and Omega-6 (n-6) PUFAs are the two known important families in human health and nutrition. In both Omega families, many forms of PUFAs exist: α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) from the n-3 family and linoleic acid (LA), dihomo-γ-linolenic acid (DGLA), and arachidonic acid (AA) from the n-6 family are the important PUFAs for human health. Omega-3 and Omega-6 PUFAs are competitively metabolized by the same set of desaturation, elongation, and oxygenase enzymes. The lipid mediators produced from their oxidative metabolism perform opposing (antagonistic) functions in the human body. Except for DGLA, n-6 PUFA-derived lipid mediators enhance inflammation, platelet aggregation, and vasoconstriction, while those of n-3 inhibit inflammation and platelet aggregation and enhance vasodilation. Overconsumption of n-6 PUFAs with low intake of n-3 PUFAs is highly associated with the pathogenesis of many modern diet-related chronic diseases. The volume of n-6 PUFAs is largely exceeding the volume of n-3PUFAs. The current n-6/n-3 ratio is 20-50/1. Due to higher ratios of n-6/n-3 in modern diets, larger quantities of LA- and AA-derived lipid mediators are produced, becoming the main causes of the formation of thrombus and atheroma, the allergic and inflammatory disorders, and the proliferation of cells, as well as the hyperactive endocannabinoid system. Therefore, in order to reduce all of these risks which are due to overconsumption of n-6 PUFAs, individuals are required to take both PUFAs in the highly recommended n-6/n-3 ratio which is 4-5/1.

Hydrogen gas alleviates acute alcohol-induced liver injury by inhibiting JNK activation

Binge alcohol drinking is fast becoming a global health concern, with the liver among the first organ involved and the one afflicted with the greatest degree of injury. Oxidative stress, alterations in hepatic metabolism, immunity and inflammation have all been reported to contribute to the development of alcoholic liver disease (ALD). Hydrogen gas (H₂) serves a key role in the modulation of hepatic redox, immune and inflammatory homeostasis. However, the effects of treatment using intraperitoneal injection of H₂ on ALD remain unexplored. Therefore, the aim of the present study was to investigate the effects and underlying mechanism of intraperitoneal injection of H₂ on acute alcohol-induced liver injury in a mouse model. H₂ was administered by daily intraperitoneal injections (1.0 ml/100 g) for 4 days. On day 4, the mice received H₂ after fasting for 5.5 h. After 30 min, the mice were administered with 33% (v/v) ethanol at a cumulative dose of 4.5 g/kg body weight by four equally divided gavages at 20-min intervals. Blood and liver tissues were collected at 16 h after the first ethanol gavage. Subsequently, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride and total cholesterol (TC) levels were analyzed using an Automatic Clinical Analyzer. Hepatic JNK activity and GAPDH levels were examined by western blotting. It was observed that acute ethanol gavage induced liver injury, as indicated by significantly increased serum ALT and AST levels, which were effectively decreased by H₂ at 16 h after the first ethanol gavage. In addition, H₂ treatment reduced serum TC levels in the Alcohol+H₂ group when compared with those in Alcohol group. Mechanistically, H₂ attenuated hepatic JNK phosphorylation induced by acute ethanol gavage. Therefore, the results of the present study demonstrated that treatment with exogenous H₂ by intraperitoneal injection may alleviate acute alcohol-induced liver injury by inhibiting hepatic JNK activation, which may represent a novel therapeutic strategy for ALD.

Treatments for NAFLD: State of Art

Non-alcoholic fatty liver disease (NAFLD) is to date the most common chronic liver disease in clinical practice and, consequently, a major health problem worldwide. It affects approximately 30% of adults in the general population and up to 70% of patients with type 2 diabetes (T2DM). Despite the current knowledge of the epidemiology, pathogenesis, and natural history of NAFLD, no specific pharmacological therapies are until now approved for this disease and, consequently, general strategies have been proposed to manage it. They include: (a) lifestyle change in order to promote weight loss by diet and physical activity, (b) control of the main cardiometabolic risk factors, (c) correction of all modifiable risk factors leading the development and progression of advanced forms of NAFLD, and (d) prevention of hepatic and extra-hepatic complications. In the last decade, several potential agents have been widely investigated for the treatment of NAFLD and its advanced forms—shedding some light but casting a few shadows. They include some glucose-lowering drugs (such as pioglitazone, glucagon-like peptide-1 (GLP-1) receptor agonists, sodium-glucose co-transporter-2 (SGLT-2) inhibitors), antioxidants (such as vitamin E), statins or other lipid lowering agents, bile and non-bile acid farnesoid X activated receptor (FXR) agonists, and others. This narrative review discusses in detail the different available approaches with the potential to prevent and treat NAFLD and its advanced forms.

Sinapic acid ameliorates D-galactosamine/lipopolysaccharide-induced fulminant hepatitis in rats: Role of nuclear factor erythroid-related factor 2/heme oxygenase-1 pathways

BACKGROUND

Sinapic acid (SA) has been shown to have various pharmacological properties such as antioxidant, antifibrotic, anti-inflammatory, and anticancer activities. Its mechanism of action is dependent upon its ability to curb free radical production and protect against oxidative stress-induced tissue injuries.

AIM

To study the hepatoprotective effects of SA against lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver failure (ALF) in rats.

METHODS

Experimental ALF was induced with an intraperitoneal (i.p.) administration of 8 μg LPS and 800 mg/kg D-GalN in normal saline. SA was administered orally once daily starting 7 d before LPS/D-GalN treatment.

RESULTS

Data showed that SA ameliorates acute liver dysfunction, decreases serum levels of alanine transaminase (ALT), and aspartate aminotransferase (AST), as well as malondialdehyde (MDA) and NO levels in ALF model rats. However, pretreatment with SA (20 mg/kg and 40 mg/kg) reduced nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and levels of inflammatory cytokines (tumor necrosis factor-α and interleukin 6). Also, SA increased the activity of the nuclear factor erythroid-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway.

CONCLUSION

In conclusion, SA offers significant protection against LPS/D-GalN-induced ALF in rats by upregulating Nrf2/HO-1 and downregulating NF-κB.

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.

Oxidative Stress in NAFLD: Role of Nutrients and Food Contaminants

Non-alcoholic fatty liver disease (NAFLD) is often the hepatic expression of metabolic syndrome and its comorbidities that comprise, among others, obesity and insulin-resistance. NAFLD involves a large spectrum of clinical conditions. These range from steatosis, a benign liver disorder characterized by the accumulation of fat in hepatocytes, to non-alcoholic steatohepatitis (NASH), which is characterized by inflammation, hepatocyte damage, and liver fibrosis. NASH can further progress to cirrhosis and hepatocellular carcinoma. The etiology of NAFLD involves both genetic and environmental factors, including an unhealthy lifestyle. Of note, unhealthy eating is clearly associated with NAFLD development and progression to NASH. Both macronutrients (sugars, lipids, proteins) and micronutrients (vitamins, phytoingredients, antioxidants) affect NAFLD pathogenesis. Furthermore, some evidence indicates disruption of metabolic homeostasis by food contaminants, some of which are risk factor candidates in NAFLD. At the molecular level, several models have been proposed for the pathogenesis of NAFLD. Most importantly, oxidative stress and mitochondrial damage have been reported to be causative in NAFLD initiation and progression. The aim of this review is to provide an overview of the contribution of nutrients and food contaminants, especially pesticides, to oxidative stress and how they may influence NAFLD pathogenesis.

Lipidomics and Anti-Inflammation Activity of Brown Algae, Lobophora sp., in Vietnam

Lobophora sp., belonging to brown macro algae phylum, is found in coral reefs. In this study, the fatty acid composition, lipid classes, polar lipid molecular forms, and bioactivities of this algae have been determined. It follows that five classes including polar lipid (Pol), sterol (ST), free fatty acids (FFA), triacylglycerol (TAG), and hydrocarbon and wax (HW), 23 fatty acids containing 5 PUFAs (ALA, GLA, AA, EPA, and DHA) and 157 molecular types of polar lipid group containing 48 phospholipid molecular forms belonging to 4 subclasses (PI (11), PC (14), PG (22), PA (1)), 45 glycolipid molecular forms classified into 3 subclasses of MGDG (8), DGDG (1), SQDG (36), and 64 betaine lipid molecular forms belonging to 2 subclasses (DGTA (37), DGTS (27)) have been identified for the first time from this algae. Furthermore, both polar lipid (PL) and unpolar lipid (UPL) show the NO inhibition activities with values of IC50 ranging from 52.10 to 66.21 µg/mL. Thus, lipid of this brown algae could promise to be a potential source for application in food, cosmetic, and pharmaceutic industry.

The related mechanism of complete Freund's adjuvant-induced chronic inflammation pain based on metabolomics analysis

Chronic inflammation pain is a debilitating disease, and its mechanism still remains poorly understood. This study attempted to illuminate the metabolic mechanism of chronic inflammation pain induced by complete Freund’s adjuvant (CFA) injection, especially at spinal level. The chronic inflammation pain model was established by CFA administration. Behavioral testing including mechanical allodynia and thermal hyperalgesia was performed. Meanwhile, a liquid chromatography–mass spectrometry‐based metabolomics approach was applied to analyze potential metabolic biomarkers. The orthogonal partial least squares discrimination analysis mode was employed for determining metabolic changes, and a western blot was performed to detect the protein expression change. The results showed that 27 metabolites showed obviously abnormal expression and seven metabolic pathways were significantly enriched, comprising aminoacyl‐tRNA biosynthesis, arginine and proline metabolism, histidine metabolism, purine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, glutathione metabolism, and phenylalanine metabolism. Meanwhile, the results showed that the expression of arginase I and nitric oxide levels were elevated in the CFA group compared with the control group, while the argininosuccinate synthetase and argininosuccinatelyase proteins were not significantly different between the groups. These findings demonstrate that metabolic changes of the spinal cord may be implicated in neurotransmitter release and pain conductivity following CFA administration.

Protective Role of Probiotic Supplements in Hepatic Steatosis: A Rat Model Study

Background

Treating nonalcoholic fatty liver disease (NAFLD) is considered one of the public health priorities in the past decade. So far, probiotics have represented promising results in controlling the signs and symptoms of NAFLD. However, attempts to find the ideal probiotic strain are still ongoing. The present study is designed to find the best strain amongst suitable probiotic strains according to their ability to ameliorate histopathological and oxidative stress biomarkers in hepatic steatosis-induced rats.

Methods

Initially, four probiotics species, including Lactobacillus (L.) acidophilus, L. casei, L. reuteri, and Bacillus coagulans, were cultured and prepared as a lyophilized powder for animals. The experiment lasted for fifty days. Initially, hepatic steatosis was induced by excessive ingestion of D-fructose in rats for eight weeks, followed by eight weeks of administering probiotics and D-fructose concurrently. Forty-two six-week-old male rats were alienated to different groups and were supplemented with different probiotics (1∗10⁹ CFU in 500 mL drinking water). After eight weeks, blood and liver samples were taken for further evaluation, and plasma and oxidative stress markers corresponding to liver injuries were examined.

Results

Administration of probiotics over eight weeks reversed hepatic and blood triglyceride concentration and blood glucose levels. Also, probiotics significantly suppressed markers of oxidative stress in the liver tissue.

Conclusions

Although some of the single probiotic formulations were able to mitigate oxidative stress markers, mixtures of probiotics significantly ameliorated more symptoms in the NAFLD animals. This enhanced effect might be due to probiotics' cumulative potential to maintain oxidative stress and deliver improved lipid profiles, liver function markers, and inflammatory markers.

Nicotinamide and ascorbic acid nanoparticles against the hepatic insult induced in rats by high fat high fructose diet: A comparative study

AIMS

Non-alcoholic fatty liver disease (NAFLD) caused by consumption of high levels of fat and sugars (HFHS) in diet is considered one of the most dangerous medical complications among children and adolescents. Nicotinamide is among the promising candidates in ameliorating HFHS diet-induced NAFLD, but its use is limited by the possibility of prompting hepatotoxicity in high doses. Ascorbic acid is another promising candidate, however its use as a hepatoprotective agent is limited by its chemical instability. Therefore, the aim of the study was to overcome their delivery limitations and enhance their hepatoprotective activity by loading into nanoparticles.

KEY FINDINGS

In the present study, upon incorporating nicotinamide or ascorbic acid in chitosan nanoparticles, they ameliorated the insulin-resistant status induced in rats by a high-fat-high-fructose (HFHF) diet. Both formulae decreased serum level of ALT and AST, as well as liver tissue total cholesterol, triglycerides and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels. They also decreased oxidative and nitrosative stresses along with a significant increase in the hepatocellular energy. The biochemical findings were further confirmed by histopathological examination. Finally from the obtained data it could be concluded that chitosan nicotinamide nanoparticles at a dose level (10 mg/kg, p.o.) demonstrated beneficial pharmacological effect with safer toxicity profile than chitosan ascorbic acid nanoparticles.

SIGNIFICANCE

Nicotinamide chitosan nanoparticles could be recommended as daily supplement in the recovery from NAFLD.

Protective Effects of Eicosapentaenoic Acid Plus Hydroxytyrosol Supplementation Against White Adipose Tissue Abnormalities in Mice Fed a High-Fat Diet

Objective: Obesity induced by high-fat diet (HFD) elicits white adipose tissue dysfunction. In this study, we have hypothesized that the metabolic modulator eicosapentaenoic acid (EPA) combined with the antioxidant hydroxytyrosol (HT) attenuates HFD-induced white adipose tissue (WAT) alterations. Methods: C57BL/6J mice were administered with a HFD (60% fat, 20% protein, 20% carbohydrates) or control diet (CD; 10% fat, 20% protein, 70% carbohydrates), with or without EPA (50 mg/kg/day), HT (5 mg/kg/day), or both for 12 weeks. Determinations in WAT include morphological parameters, EPA and docosahexaenoic acid content in phospholipids (gas chromatography), lipogenesis, oxidative stress (OS) and inflammation markers, and gene expression and activities of transcription factors, such as sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma (PPAR-γ), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) (p65 subunit) and nuclear factor erythroid 2-related factor 2 (Nrf2) (quantitative polymerase chain reaction and enzyme linked immunosorbent assay). Results: HFD led to WAT hypertrophy in relation to PPAR-γ downregulation. WAT metabolic dysfunction was characterized by upregulation of lipogenic SREBP-1c system, mitochondrial energy metabolism depression, loss of the antioxidant Nrf2 signaling with OS enhancement, n-3 long-chain polyunsaturated fatty acids depletion and activation of the pro-inflammatory NF-κB system. EPA and HT co-supplementation diminished HFD-dependent effects additively, reaching values close or similar to controls. Conclusion: Data presented strengthen the importance of combined protocols such as EPA plus HT to attenuate metabolic-inflammatory states triggered by obesity.

Potential metabolism determinants and drug-drug interactions of a natural flavanone bavachinin

Bavachinin, a natural bioactive flavanone, is reported to have many pharmacological proprieties, especially anti-osteoporosis activity. Here we aim to determine the roles of cytochrome P450s (CYP), UDP-glucuronosyltransferases (UGT), and efflux transporters in metabolism and drug–drug interactions (DDI) of bavachinin. Phase I metabolism and glucuronidation were performed by human liver microsomes (HLM) and human intestine microsomes (HIM). Reaction phenotyping was used to identify the main CYPs and UGTs. Gene silencing methods were employed to investigate the roles of breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs) in HeLa1A1 cells. Inhibition mechanisms towards CYPs and UGTs were explored through kinetic modeling. Three phase I metabolites (M1–M3) and one glucuronide (G1) were detected after incubation of bavachinin with HLM and HIM. The intrinsic clearance (CL_int) values of M1 and G1 by HLM were 89.4 and 270.2 μL min⁻¹ mg⁻¹, respectively, while those of M3 and G1 by HIM were 25.8 and 247.1 μL min⁻¹ mg⁻¹, respectively. CYP1A1, 1A2, 1B1, 2C8, 2C19, and UGT1A1, 1A8 participated more in bavachinin metabolism. The metabolism showed marked species difference. BCRP and MRP4 were identified as the main contributors. Bavachinin displayed potent inhibitory effects against several CYP and UGT isozymes (K_i = 0.28–2.53 μM). Bavachinin was subjected to undergo metabolism and disposition by CYPs, UGTs, BCRP, MRP4, and was also a potent non-selective inhibitor against several CYPs and UGTs.

Metabolism, efflux transport and drug–drug interactions of bavachinin.

Exchanging dietary fat source with extra virgin olive oil does not prevent progression of diet-induced non-alcoholic fatty liver disease and insulin resistance

Dietary fat is discussed to be critical in the development of non-alcoholic fatty liver disease. Here, we assess the effect of exchanging dietary fat source from butterfat to extra virgin olive oil on the progression of an already existing diet-induced non-alcoholic fatty liver disease in mice. Female C57BL/6J mice were fed a liquid butterfat-, fructose- and cholesterol-rich diet (BFC, 25E% from butterfat) or control diet (C, 12%E from soybean oil) for 13 weeks. In week 9, fat sources of some BFC- and C-fed mice were switched either to 25E% or 12E% olive oil (OFC and CO). Glucose and insulin tolerance tests were performed, and markers of liver damage and glucose metabolism were assessed. After 6 weeks of feeding, BFC-fed mice had developed marked signs of insulin resistance, which progressed to week 12 being not affected by the exchange of fat sources. Liver damage was similar between BFC- and OFC-fed mice. Markers of lipid metabolism and lipid peroxidation in liver and of insulin signaling in liver and muscle were also similarly altered in BFC- and OFC-fed mice. Taken together, our data suggest that exchanging butterfat with extra virgin olive oil has no effect on the progression of non-alcoholic fatty liver disease and glucose tolerance in mice.