Attenuation of High-Fat Diet-Induced Rat Liver Oxidative Stress and Steatosis by Combined Hydroxytyrosol- (HT-) Eicosapentaenoic Acid Supplementation Mainly Relies on HT

Effects of endogenous DHA milk and exogenous DHA milk on oxidative stress and cognition in SAMP8 mice

In this study, Senescence Accelerated Mice (SAMP8) were supplemented with exogenous DHA milk, endogenous DHA milk, normal milk, or 0.9 % saline solution. Enzyme-linked immunosorbent assay (ELISA), gas chromatography (GC), ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI MS/MS), and Morris water maze were used to characterize the effects of diet on oxidative stress and cognition in SAMP8 mice. Supplementation endogenous DHA milk or exogenous DHA milk can enhance the antioxidant capacity of mice organs. Endogenous DHA milk increased the superoxide dismutase (SOD) activity of mice brain and serum than normal milk and 0.9 % saline solution (P ≤ 0.05), as well as increased SOD activity of mice liver and glutathione peroxidase (GSH-Px) activity of mice brain than normal milk (P ≤ 0.05). Exogenous DHA milk increased SOD activity of mice brain than normal milk and 0.9 % saline solution, as well as increased SOD activity of mice serum than 0.9 % saline solution (P ≤ 0.05). Several polar lipid relative content, such as 18:0/18:2 PS, 17:0 Ceramide, and 20:4 LPC in mice brain was affected by dietary supplementation with DHA-containing milk. Lipid oxidation metabolites in mice brain were not affected by DHA-containing milk. Endogenous DHA milk increased the number of platform location crossing times of mice in the Morris water maze test, compared with Exogenous DHA milk, normal milk, and 0.9 % saline solution (P ≤ 0.05).

Relevant Aspects of Combined Protocols for Prevention of N(M)AFLD and Other Non-Communicable Diseases

Obesity is a global health issue characterized by the excessive fat accumulation, leading to an increased risk of chronic noncommunicable diseases (NCDs), including metabolic dysfunction-associated fatty liver disease (MAFLD), which can progress from simple steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved pharmacological protocols for prevention/treatment of MAFLD, and due the complexity lying beneath these mechanisms, monotherapies are unlikely to be efficacious. This review article analyzes the possibility that NCDs can be prevented or attenuated by the combination of bioactive substances, as they could promote higher response rates, maximum reaction results, additive or synergistic effects due to compounds having similar or different mechanisms of action and/or refraining possible side effects, related to the use of lower doses and exposures times than monotherapies. Accordingly, prevention of mouse MAFLD is observed with the combination of the omega-3 docosahexaenoic acid with the antioxidant hydroxytyrosol, whereas attenuation of mild cognitive impairment is attained by folic acid plus cobalamin in elderly patients. The existence of several drawbacks underlying published monotherapies or combined trials, opens space for adequate and stricter experimental and clinical tryouts to achieve meaningful outcomes with human applicability.

Madhuca longifolia-hydro-ethanolic-fraction reverses mitochondrial dysfunction and modulates selective GLUT expression in diabetic mice fed with high fat diet

BACKGROUND

Metabolic disorder is characterized as chronic low-grade inflammation which elevates the systemic inflammatory markers. The proposed hypothesis behind this includes occurrence of hypoxia due to intake of high fat diet leading to oxidative stress and mitochondrial dysfunction.

AIM

In the present work our aim was to elucidate the possible mechanism of action of hydroethanolic fraction of M. longifolia leaves against the metabolic disorder.

METHOD AND RESULTS

In the present investigation, effect of Madhuca longifolia hydroethanolic fraction (MLHEF) on HFD induced obesity and diabetes through mitochondrial action and selective GLUT expression has been studied. In present work, it was observed that HFD (50% of diet) on chronic administration aggravates the metabolic problems by causing reduced imbalanced oxidative stress, ATP production, and altered selective GLUT protein expression. Long term HFD administration reduced (p < 0.001) the SOD, CAT level significantly along with elevated liver function marker AST and ALT. MLHEF administration diminishes this oxidative stress. HFD administration also causes decreased ATP/ADP ratio owing to suppressed mitochondrial function and elevating LDH level. This oxidative imbalance further leads to dysregulated GLUT expression in hepatocytes, skeletal muscles and white adipose tissue. HFD leads to significant (p < 0.001) upregulation in GLUT 1 and 3 expression while significant (p < 0.001) downregulation in GLUT 2 and 4 expressions in WAT, liver and skeletal muscles. Administration of MLHEF significantly (p < 0.001) reduced the LDH level and also reduces the mitochondrial dysfunction.

CONCLUSION

Imbalances in GLUT levels were significantly reversed in order to maintain GLUT expression in tissues on the administration of MLHEF.

Enhancement of biochemical and genomic pathways through lycopene-loaded nano-liposomes: Alleviating insulin resistance, hepatic steatosis, and autophagy in obese rats with non-alcoholic fatty liver disease: Involvement of SMO, GLI-1, and PTCH-1 genes

Non-alcoholic fatty liver (NAFL) is a prevalent hepatic disorder of global significance that can give rise to severe complications. This research endeavor delves into the potential of nano-liposomal formulated Lycopene (Lip-Lyco) in averting the development of obesity and insulin resistance, both of which are major underlying factors contributing to NAFL. The investigation further scrutinizes the impact of Lip-Lyco on intricate cellular pathways within the liver tissue of rats induced with NAFL, specifically focusing on the progression of steatosis and fibrosis. To establish an obesity-NAFL model, twenty rats were subjected to a high-fat diet (HFD) for a duration of twelve weeks, after which they received an oral treatment of Lip-Lyco (10mg/kg) for an additional eight weeks. Another group of sixteen non-obese rats were subjected to treatment with or without Lip-Lyco, serving as a control for comparison. Results: The rats on a hypercaloric diet had high body mass index (BMI) and insulin resistance, reflected in disturbed serum adipokines and lipid profiles. Oxidative stress, inflammation, and apoptosis were evident in hepatic tissue, and the autophagic process in hepatocytes was inhibited. Additionally, the hedgehog pathway was activated in the liver tissue of NAFL group. Lip-Lyco was found to counteract all these aspects of NAFL pathogenesis. Lip-Lyco exhibited antioxidant, anti-inflammatory, hypoglycemic, antiapoptotic, autophagy-inducing, and Hedgehog signaling inhibitory effects. This study concludes that Lip-Lyco, a natural compound, has promising therapeutic potential in combating NAFLdisease. However, more experimental and clinical studies are required to confirm the effectiveness of lycopene in treating NAFLdisease.

Bergamot leaf extract treats cardiorenal metabolic syndrome and associated pathophysiological factors in rats fed with a high sugar fat diet

Bergamot citrus (Citrus bergamia Risso et Poiteau), have been used as a strategy to prevent or treat comorbidities associated with metabolic syndrome parameters, such as cardiorenal metabolic syndrome (CRMS). The aim was to test the effect of bergamot leaf extract on CRMS and associated pathophysiological factors in rats fed with a high sugar-fat diet. Animals were divided into two experimental groups with control diet (Control, n = 30) and high sugar-fat diet (HSF, n = 30) for 20 weeks. Once CRMS was detected, animals were redivided to begin the treatment with Bergamot Leaf Extract (BLE) by gavage (50 mg/kg) for 10 weeks: control diet + placebo (Control, n = 09), control diet + BLE (Control + BLE, n = 09), HSF diet + placebo (HSF, n = 09), HSF + BLE (n = 09). Evaluation included nutritional, metabolic and hormonal analysis; and renal and cardiac parameters. HSF groups presented obesity, dyslipidemia, hypertension, hyperglycemia, hyperinsulinemia, insulin resistance. BLE showed protection against effects on hypertriglyceridemia, insulin resistance, renal damage, and structural and functional alterations of the heart. Conclusion: Bergamot leaf extract shows potential as a therapeutic to treat CRMS in animals fed with a high sugar-fat diet.

Overexpression of NAG-1/GDF15 prevents hepatic steatosis through inhibiting oxidative stress-mediated dsDNA release and AIM2 inflammasome activation

Mitochondrial dysfunction and oxidative stress-mediated inflammasome activation play critical roles in the pathogenesis of the non-alcoholic fatty liver disease (NAFLD). Non-steroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1), or growth differentiation factor-15 (GDF15), is associated with many biological processes and diseases, including NAFLD. However, the role of NAG-1/GDF15 in regulating oxidative stress and whether this process is associated with absent in melanoma 2 (AIM2) inflammasome activation in NAFLD are unknown. In this study, we revealed that NAG-1/GDF15 is significantly downregulated in liver tissues of patients with steatosis compared to normal livers using the Gene Expression Omnibus (GEO) database, and in free fatty acids (FFA, oleic acid/palmitic acid, 2:1)-induced HepG2 and Huh-7 cellular steatosis models. Overexpression of NAG-1/GDF15 in transgenic (Tg) mice significantly alleviated HFD-induced obesity and hepatic steatosis, improved lipid homeostasis, enhanced fatty acid β-oxidation and lipolysis, inhibited fatty acid synthesis and uptake, and inhibited AIM2 inflammasome activation and the secretion of IL-18 and IL-1β, as compared to their wild-type (WT) littermates without reducing food intake. Furthermore, NAG-1/GDF15 overexpression attenuated FFA-induced triglyceride (TG) accumulation, lipid metabolism deregulation, and AIM2 inflammasome activation in hepatic steatotic cells, while knockdown of NAG-1/GDF15 demonstrated opposite effects. Moreover, NAG-1/GDF15 overexpression inhibited HFD- and FFA-induced oxidative stress and mitochondrial damage which in turn reduced double-strand DNA (dsDNA) release into the cytosol, while NAG-1/GDF15 siRNA showed opposite effects. The reduced ROS production and dsDNA release may be responsible for attenuated AIM2 activation by NAG-1/GDF15 upon fatty acid overload. In conclusion, our results provide evidence that other than regulating lipid homeostasis, NAG-1/GDF15 protects against hepatic steatosis through a novel mechanism via suppressing oxidative stress, mitochondrial damage, dsDNA release, and AIM2 inflammasome activation.

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NAG-1/GDF15 is downregulated in human steatotic liver and FFA-induced liver cells.

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NAG-1/GDF15 inhibits hepatic steatosis and improves lipid homeostasis.

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AIM2 inflammasome is activated in steatosis models and is inhibited by NAG-1/GDF15.

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NAG-1/GDF15 reduces oxidative stress and mitochondrial damage in steatosis models.

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NAG-1/GDF15 inhibits mitochondrial dsDNA release and thus inhibits AIM2 activation.

The Effects of High Fat Diet on the Liver of the White Rat Model Obesity

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease with the manifestation of over-accumulation of fat in the liver. AIM: The purpose of this study was to assess the degree of occurrence of steatosis in rats induced by a standard diet, a high-fat diet, and a modified high-fat diet. METHODS: This study used 18 white rats of the Wistar strain, divided into three groups, and fed for 9 weeks. Before feeding, all rats were measured their body weight, abdominal circumference, and body length. We measured body weight every week, while body length and waist circumference were measured every 2 weeks. After 9 weeks of diet, all rats were subjected to injection of Ketamine and examined for metabolic markers and histopathological examination of liver organs. RESULT: There was an increase in body weight of rats in the three groups with the average percentage increase in body weight in the three groups of rats before and after being fed a diet for 9 weeks found in Group 1 29.19% 1 (187−264.40 g), Group 2 by 19.12% (219.33−275 g), and Group 3 24.53% (213.33−275 g). Steatosis in Group 1 was 57.50% of hepatocytes containing macrovesicular fat droplets and called Grade 2 (moderate). In contrast, with a high-fat diet, steatosis occurred around 93.33%−95% of hepatocytes containing macrovesicular fat droplets and called steatosis Grade 3 (severe). CONCLUSION: The percentage of hepatocytes that had steatosis in obese rats induced by a high-fat diet was more significant than in obese models induced by a standard diet.

Anti-obesity effects of the n-butanol fraction of the methanolic leaf extract of Artemisia campestris from Tunisian pharmacopeia in male Wistar rats

OBJECTIVES

This study aimed to investigate the effect of the n-butanol fraction of the methanol leaf extract of Artemisia campestris (BFAC), growing wild in the arid zone of Tunisia, on induced obesity in male Wistar rats.

METHODS

The total phenolic content and antioxidant capacity of the BFAC were estimated. The main phenolic composition of the BFAC was determined using the high-performance chromatography system coupled with a diode array detector technics. Five groups of rats received either a standard diet (SD group), a high-fat diet (HFD group), or an HFD supplemented with oral administration of BFAC for eight weeks.

RESULTS

The BFAC showed higher phenolic content and antioxidant potential than the total leaf methanol extract. Chlorogenic acid, rutin, and dicaffeoylquinic acids were identified in the BFAC. HFD increased body and relative liver weights, as well as serum and hepatic levels of triglycerides and total cholesterol, compared to SD. HFD generated significant oxidative stress in the liver by increasing lipid peroxidation and reducing glutathione-S-transferase, catalase, and glutathione peroxidase activities, compared to SD. These HFD-altered parameters were restored to normal values by oral treatment with the BFAC.

CONCLUSIONS

These findings give first evidence about the antiobesity efficacy of A. campestris. Such a study would enhance existing information and promote the use of this species.

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.

Perspectives in liver redox imbalance: Toxicological and pharmacological aspects underlying iron overloading, nonalcoholic fatty liver disease, and thyroid hormone action

Oxidative stress is an imbalance between oxidants and antioxidants in favor of the oxidants, leading to a disruption of redox signaling and control, and/or molecular damage altering cellular functions. This redox imbalance may trigger different responses depending on the antioxidant potential of a given cell, the level of reactive oxygen/nitrogen species (ROS/RNS) attained and the time of exposure, with protective effects being induced at low ROS/RNS levels in acute or short-term conditions, and harmful effects after high ROS/RNS exposure in prolonged situations. Relevant conditions underlying liver redox imbalance include iron overload associated with ROS production via Fenton chemistry and the magnitude of the iron labile pool achieved, with low iron exposure inducing protective effects related to nuclear factor-κB, signal transducer and activation of transcription 3, and nuclear factor erythroid-related factor 2 (Nrf2) activation and upregulation of ferritin, hepcidin, acute-phase response and antioxidant components, whereas high iron exposure causes drastic oxidation of biomolecules, mitochondrial dysfunction, and cell death due to necrosis, apoptosis and/or ferroptosis. Redox imbalance in nonalcoholic fatty liver disease (NAFLD) is related to polyunsaturated fatty acid depletion, lipogenic factor sterol regulatory element-binding protein-1c upregulation, fatty acid oxidation-dependent peroxisome proliferator-activated receptor-α downregulation, low antioxidant factor Nrf2 and insulin resistance, a phenomenon that is exacerbated in nonalcoholic steatohepatitis triggering an inflammatory response. Thyroid hormone (T₃ ) administration determines liver preconditioning against ischemia-reperfusion injury due to the redox activation of several transcription factors, AMP-activated protein kinase, unfolded protein response and autophagy. High grade liver redox imbalance occurring in severe iron overload is adequately handled by iron chelation, however, that underlying NAFLD/NASH is currently under study in several Phase II and Phase III trials.

Hepatopreventive properties of hydroxytyrosol and mannitol-rich extracts obtained from exhausted olive pomace using green extraction methods

Hydroxytyrosol and mannitol rich extracts from exhausted olive pomace were obtained by green extraction methodologies. Supplementation of these extracts alleviated CCl4-induced hepatic damage and protected DNA.

Hepatoprotective Effect of Bee Bread in Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) Rats: Impact on Oxidative Stress and Inflammation

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a pathological accumulation of hepatic lipid closely linked with many metabolic disorders, oxidative stress and inflammation. We aimed to evaluate the hepatoprotective effect of bee bread on oxidative stress and inflammatory parameters in MAFLD rats. Twenty-eight male Sprague-Dawley rats were assigned into four groups (n = 7/group): normal control (NC), high-fat diet (HFD), bee bread (HFD + Bb, HFD + 0.5 g/kg/day bee bread) and orlistat (HFD + Or, HFD + 10 mg/kg/day orlistat) groups. After 12 weeks, the HFD group demonstrated significantly higher body weight gain, serum levels of lipids (TG, TC, LDL), liver enzymes (AST, ALT, ALP) and adiponectin, liver lipids (TG, TC) and insulin resistance (HOMA-IR). Furthermore, the HFD group showed significantly decreased antioxidant enzyme activities (GPx, GST, GR, SOD, CAT) and GSH level, and increased liver oxidative stress (TBARS, NO), translocation of Nrf2 to the nucleus, Keap1 expression and inflammation (TNF-α, NF-κβ, MCP-1) together with histopathological alterations (steatosis, hepatocyte hypertrophy, inflammatory cell infiltration, collagen deposition), which indicated the presence of non-alcoholic steatohepatitis (NASH) and fibrosis. Bee bread significantly attenuated all these changes exerted by HFD feeding. In conclusion, our results suggest that bee bread might have antioxidant, anti-inflammatory, anti-steatotic and anti-fibrotic effects that are beneficial in protecting liver progression towards NASH and fibrosis.

Olive Tree Derivatives and Hydroxytyrosol: Their Potential Effects on Human Health and Its Use as Functional Ingredient in Meat

Olive (Olea europaea) is one of the most extensive crops in the Mediterranean countries, and an important source of extra distinctive compounds that has been widely tested due to its known health benefits. Olive derivatives, such as extra virgin olive oil (EVOO) and olive leaves are rich in antioxidant compounds such as hydroxytyrosol (HXT) and oleuropein and oleic acid, as main monounsaturated fatty acid. Because of HXT molecular structure, its regular consumption reports important beneficial properties such as anti-inflammatory, antimicrobial, antioxidant, and anticancer. As a matter of fact, its antioxidant and antimicrobial effects made this compound a good preservative agent against meat deterioration and spoilage, capable of replacing some synthetic additives whose continued and regular consumption may negatively affect the human health. On the contrary side, this extract has an unpleasant odor and flavor, so a synthetic source of HXT could also be used to improve the sensory quality of the meat products. In this sense, this review exposes the health benefits provided by the consumption of EVOO and HXT, and the newest research about its application on meat, together new trends about its use as functional ingredient in meat and meat products.

Bio protectors’ effect on the composition of some amino acids under alcohol-induced oxidative stress

The studies, which may reveal some elements of regulation between the metabolic processes of proteins (at the level of translation and changes in the amino acid spectrum) as well as catabolism and anabolism of carbohydrates under conditions of pathological deviations of the functioning of the animal organism, are promising, and the search for protective substances of a different nature is necessary. The aim is to study and analyze a bio protectors’ effect on the composition of some amino acids under alcohol-induced oxidative stress. During the experimental period, changes in the body weight of rats confirm the depressant effect of alcohol on the dynamics of weight gain of animals during their growth and development, and the positive protective effect of betaine and additives (protein+minerals). The increased activity of alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase in the blood serum of rats in experimental groups of animals with the absence of protectors’ substances in the diet indicates a deviation in the functional capacity of the liver. The determined indices of the content of creatinine and urea were increased significantly that points out on possible pathological deviation of the kidney. Under alcohol substances, changes of such biochemical indexes value as lactate dehydrogenase, superoxide dismutase, and catalase, and the content of malonic dialdehyde indicate oxidative stress. In the case of bio protectors’ presence, values of biochemical parameters become to ones in the animals of control groups. It was observed, that betaine has a higher potential for the correction of the above pathological abnormalities than protein-containing additives with minerals in the form of chelate, but the last is perspective for further study and their use as a raw material for the development of more complex bio protectors

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.

Quantitative Profiling of Oxylipin Reveals the Mechanism of Pien-Tze-Huang on Alcoholic Liver Disease

Alcoholic liver disease (ALD) is a liver disease caused by long-term alcohol consumption. ROS-mediated oxidative stress is the leading cause of ALD. Pien-Tze-Huang (PZH), a traditional formula, is famous in China. This study was designed to evaluate the effects and explore the potential mechanisms of PZH in ALD. Forty mice were randomly divided into five groups: control group (normal diet + vehicle), model group (ethanol diet + vehicle), PZH-L group (ethanol diet + PZH (0.125 g/kg)), PZH-M group (ethanol diet + PZH (0.25 g/kg)), and PZH-H group (ethanol diet + PZH (0.5 g/kg)). The mice were sacrificed, and their liver and blood samples were preserved. Liver steatosis, triglyceride (TG), total cholesterol, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels were assayed. Malondialdehyde (MDA), glutathione peroxidase (GSH-PX), and total superoxide dismutase were identified using commercial kits. Oxylipins were profiled, and the data were analyzed. The AMPK/ACC/CPT1A pathway was identified using real-time polymerase chain reaction and western blotting. The PZH-H intervention significantly alleviated hepatic steatosis and injury and reduced the levels of liver TG and serum ALT and AST. In addition, MDA levels were markedly reduced, and GSH-PX activity significantly increased after PZH-H intervention. Finally, PZH-H increased the levels of 17-HETE, 15-HEPE, 9-HOTrE, 13-HOTrE, and 5,6-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid, and reduced PGE2 levels. PZH-H intervention also promoted the phosphorylation of AMPK and ACC, and the expression of CPT1A. In conclusion, PZH reduced oxidative stress and alleviated hepatic steatosis and injury. The mechanism was correlated with the oxylipin metabolites/AMPK/ACC/CPT1A axis.

Pelargonidin ameliorates CCl4-induced liver fibrosis by suppressing the ROS-NLRP3-IL-1β axis via activating the Nrf2 pathway

Liver fibrosis is a histological change that often occurs due to hepatic stellate cell (HSC) activation and excessive formation of an extracellular matrix in the liver. Pelargonidin (PEL) is a natural anthocyanidin existing in blueberries, berries, strawberries, and red radishes and has been demonstrated to possess health beneficial effects. Herein, we investigated the effect of PEL on liver fibrosis induced by CCl4 and hepatic stellate cells induced by transforming growth factor-β (TGF-β). We found that PEL administration prevented liver injury and liver fibrosis induced by CCl4 in a dose-dependent manner. Further data revealed that PEL increased liver nuclear factor E2-related factor 2 (Nrf2) and reduced liver oxidative stress and the expression levels of NLRP3, caspase-1 and IL-1β. In TGF-β-challenged HSCs (LX-2 cells), PEL effectively inhibited the LX-2 cell activation. In addition, the anti-fibrosis effects of PEL in LX-2 cells were abolished by Nrf2 knockdown. In summary, our study demonstrated that PEL ameliorated CCl4-induced liver fibrosis and HSC activation induced by TGF-β. The possible molecular mechanisms of PEL in liver fibrosis may be attributed to its suppression of ROS-NLRP3-IL-1β signaling by Nrf2 activation.

Excesive consumption of unsaturated fatty acids leads to oxidative and inflammatory instability in Wistar rats

Lifestyle modifications such as increase in high-fat food consumption importantly increases the risks for cardiovascular disease. The principal objective of this study is to analyze effects of different high fat diet (HFD) sources on haemodynamic parameters, lipid and oxidative profile, myeloperoxidase activity, and markers of inflammation (IL-6/pentraxin-3). HFD containing 20% of fat, provided by lard (saturated) or soybean oil (unsaturated), as well as control diet were administering to three groups (L, SO and C). Food efficiency ratio and plasma lipids were significantly elevated in both HFD groups. However, only SO group showed an increase in systolic arterial pressure, oxidative stress index, myeloperoxidase activity, liver lipids as well as markers of inflammation: IL-6 and pentraxin-3 (PTX3). In summary, these results indicate inflammogenic potential of excessive soybean oil consumption in triggering liver damage.

Contrasting Effects of Fasting on Liver-Adipose Axis in Alcohol-Associated and Non-alcoholic Fatty Liver

Background: Fatty liver, a major health problem worldwide, is the earliest pathological change in the progression of alcohol-associated (AFL) and non-alcoholic fatty liver disease (NAFL). Though the causes of AFL and NAFL differ, both share similar histological and some common pathophysiological characteristics. In this study, we sought to examine mechanisms responsible for lipid dynamics in liver and adipose tissue in the setting of AFL and NAFL in response to 48 h of fasting. Methods: Male rats were fed Lieber-DeCarli liquid control or alcohol-containing diet (AFL model), chow or high-fat pellet diet (NAFL model). After 6-8 weeks of feeding, half of the rats from each group were fasted for 48 h while the other half remained on their respective diets. Following sacrifice, blood, adipose, and the liver were collected for analysis. Results: Though rats fed AFL and NAFL diets both showed fatty liver, the physiological mechanisms involved in the development of each was different. Here, we show that increased hepatic de novo fatty acid synthesis, increased uptake of adipose-derived free fatty acids, and impaired triglyceride breakdown contribute to the development of AFL. In the case of NAFL, however, increased dietary fatty acid uptake is the major contributor to hepatic steatosis. Likewise, the response to starvation in the two fatty liver disease models also varied. While there was a decrease in hepatic steatosis after fasting in ethanol-fed rats, the control, chow and high-fat diet-fed rats showed higher levels of hepatic steatosis than pair-fed counterparts. This diverse response was a result of increased adipose lipolysis in all experimental groups except fasted ethanol-fed rats. Conclusion: Even though AFL and NAFL are nearly histologically indistinguishable, the physiological mechanisms that cause hepatic fat accumulation are different as are their responses to starvation.

Effects of Long-Term DHA Supplementation and Physical Exercise on Non-Alcoholic Fatty Liver Development in Obese Aged Female Mice

Obesity and aging are associated to non-alcoholic fatty liver disease (NAFLD) development. Here, we investigate whether long-term feeding with a docosahexaenoic acid (DHA)-enriched diet and aerobic exercise, alone or in combination, are effective in ameliorating NAFLD in aged obese mice. Two-month-old female C57BL/6J mice received control or high fat diet (HFD) for 4 months. Then, the diet-induced obese (DIO) mice were distributed into four groups: DIO, DIO + DHA (15% dietary lipids replaced by a DHA-rich concentrate), DIO + EX (treadmill running), and DIO + DHA + EX up to 18 months. The DHA-rich diet reduced liver steatosis in DIO mice, decreasing lipogenic genes (Dgat2, Scd1, Srebp1c), and upregulated lipid catabolism genes (Hsl/Acox) expression. A similar pattern was observed in the DIO + EX group. The combination of DHA + exercise potentiated an increase in Cpt1a and Ppara genes, and AMPK activation, key regulators of fatty acid oxidation. Exercise, alone or in combination with DHA, significantly reversed the induction of proinflammatory genes (Mcp1, Il6, Tnfα, Tlr4) in DIO mice. DHA supplementation was effective in preventing the alterations induced by the HFD in endoplasmic reticulum stress-related genes (Ern1/Xbp1) and autophagy markers (LC3II/I ratio, p62, Atg7). In summary, long-term DHA supplementation and/or exercise could be helpful to delay NAFLD progression during aging in obesity.

The pivotal role of heme Oxygenase-1 in reversing the pathophysiology and systemic complications of NAFLD

The pathogenesis and molecular pathways involved in non-alcoholic fatty liver disease (NAFLD) are reviewed, as well as what is known about mitochondrial dysfunction that leads to heart disease and the progression to steatohepatitis and hepatic fibrosis. We focused our discussion on the role of the antioxidant gene heme oxygenase-1 (HO-1) and its nuclear coactivator, peroxisome proliferator-activated receptor-gamma coactivator (PGC1-α) in the regulation of mitochondrial biogenesis and function and potential therapeutic benefit for cardiac disease, NAFLD as well as the pharmacological effect they have on the chronic inflammatory state of obesity. The result is increased mitochondrial function and the conversion of white adipocyte tissue to beige adipose tissue ("browning of white adipose tissue") that leads to an improvement in signaling pathways and overall liver function. Improved mitochondrial biogenesis and function is essential to preventing the progression of hepatic steatosis to NASH and cirrhosis as well as preventing cardiovascular complications.

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.

Biochemical and histopathological assessment of liver in a rat model of metabolic syndrome induced by high-carbohydrate high-fat diet

This study aimed to evaluate the oxidative stress status, antioxidants capacity, and presence of nonalcoholic fatty liver disease (NAFLD) in an animal model of MetS induced by high-carbohydrate high-fat (HCHF) diet. Male Wistar rats were randomized into two groups, assigned for two different types of diet (standard rat pellet or HCHF diet) for 20 weeks. Liver was excised, weighed, and subjected to lipid peroxidation, nitric oxide (NO·) production, antioxidants activity, and histological assessment. The HCHF rats had higher lipid peroxidation and NO· level but lower enzymatic and nonenzymatic antioxidant levels than the normal animals. Histological evaluation revealed higher lobular inflammation, hepatocellular ballooning, NAFLD activity score, and lipid accumulation in the liver of HCHF group. In conclusion, the HCHF diet causes an increase in oxidative stress, depletion of antioxidants capacity, NAFLD, and liver injury. The induction of oxidative stress may be partially responsible for the development of NAFLD in MetS. PRACTICAL APPLICATIONS: The prevalence of MetS is estimated to increase rapidly with the escalating levels of obesity, diabetes, hypertension, and dyslipidemia. A suitable animal model of MetS that best mimicked the human disease state with known underlying mechanisms responsible for the pathogenesis of MetS is indispensable to search for potential adjunct therapies and drug targets. Thus, our current study elucidated the involvement of oxidative stress in linking MetS and NAFLD which might resemble the pathogenesis of MetS among Southeast Asian population.

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.

Quercetin and hydroxytyrosol as modulators of hepatic steatosis: A NAFLD-on-a-chip study

Organs-on-chip (OoCs) are catching on as a promising and valuable alternative to animal models, in line with the 3Rs initiative. OoCs enable the creation of three-dimensional (3D) tissue microenvironments with physiological and pathological relevance at unparalleled precision and complexity, offering new opportunities to model human diseases and to test the potential therapeutic effect of drugs, while overcoming the limited predictive accuracy of conventional 2D culture systems. Here, we present a liver-on-a-chip model to investigate the effects of two naturally occurring polyphenols, namely quercetin and hydroxytyrosol, on nonalcoholic fatty liver disease (NAFLD) using a high-content analysis readout methodology. NAFLD is currently the most common form of chronic liver disease; however, its complex pathogenesis is still far from being elucidated, and no definitive treatment has been established so far. In our experiments, we observed that both polyphenols seem to restrain the progression of the free fatty acid-induced hepatocellular steatosis, showing a cytoprotective effect due to their antioxidant and lipid-lowering properties. In conclusion, the findings of the present work could guide novel strategies to contrast the onset and progression of NAFLD.

Suppression of high-fat diet-induced obesity-associated liver mitochondrial dysfunction by docosahexaenoic acid and hydroxytyrosol co-administration

OBJECTIVE

Obesity-induced by high-fat diet (HFD) is associated with liver steatosis, oxidative stress and mitochondrial dysfunction, which can be eluded by the co-administration of the lipid metabolism modulator docosahexaenoic acid (DHA) and the antioxidant hydroxytyrosol (HT).

METHODS

C57BL/6J mice fed a HFD were orally administered either with vehicle, DHA, HT or DHA+HT for 12 weeks. We measured parameters related to insulin resistance, serum lipid levels, liver fatty acid (FA) content and steatosis score, concomitantly with those associated with mitochondrial energy functions modulated by the transcriptional coactivator PGC-1a.

RESULTS

HFD induced insulin resistance, liver steatosis with n-3 FA depletion, and loss of mitochondrial respiratory functions with diminished NAD⁺/NADH ratio and ATP levels compared with CD, with the parallel decrease in the expression of the components of the PGC-1α cascade, namely, PPAR-α, FGF21 and AMPK, effects that were not observed in mice subjected to DHA and HT co-administration.

CONCLUSIONS

Data presented indicate that the combination of DHA and HT prevents the development of liver steatosis and the associated mitochondrial dysfunction induced by HFD, thus strengthening the significance of this protocol as a therapeutic strategy avoiding disease evolution into more irreversible forms characterised by the absence of adequate pharmacological therapy in human obesity.

Potential Effects of Antioxidant and Serum Cholesterol-Lowering Effects ofGynura bicolorWater Extracts in Syrian Hamster

Gynura bicolor(Roxb. and Willd.) DC (G. bicolor) is a dietary vegetable in the Far East. The aims of the present study were to investigate the antioxidant effects of theG. bicolorwater extract (GBWE) and its ability to regulate the blood lipid and lipoprotein profiles. In this study, the pigment composition and antioxidant ability of the GBWE were analyzed. Syrian hamsters were fed a high-fat diet (HFD) and the GBWE for 12 weeks, and the blood lipid levels, lipoprotein profiles, and cholesterol metabolism-related enzyme levels were then examined. The results showed that the GBWE exhibited excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and ferrous-ion-chelating ability. The hepatic glutathione levels in the hamsters were increased after the administration of low (0.4 g/kg BW, GBWE-L) or high (0.8 g/kg BW, GBWE-H) levels of the GBWE. The GBWE-H-treated hamsters exhibited significantly decreased serum levels of total cholesterols (TC) and low-density lipoprotein-cholesterol (LDL-C) and significantly increased levels of lectin-cholesterol acetyltransferase (LCAT). These results showed that GBWE-H can reduce the total cholesterol and LDL-C levels in HFD-fed hamsters, and this reduction might be involved in the regulation of LCAT expression.

Polysaccharides from Dicliptera chinensis ameliorate liver disturbance by regulating TLR-4/NF-κB and AMPK/Nrf2 signalling pathways

The purpose of this study was to alleviate liver disturbance by applying polysaccharides from Dicliptera chinensis (DCP) to act on the adenosine monophosphate-activated protein kinase/ nuclear factor erythroid 2-related factor 2 (AMPK/ Nrf2) oxidative stress pathway and the Toll-like receptor 4 (TLR-4)/ nuclear factor kappa-B (NF-κB) inflammatory pathway and to establish an in vivo liver disturbance model using male C57BL/6J and TLR-4 knockout (^-/- ) mice. For this, we evaluated the expression levels of SREBP-1 and Nrf2 after silencing the expression of AMPK using siRNA technology. Our results show that with regard to the TLR-4/ NF-κB inflammatory pathway, DCP inhibits TLR-4, up-regulates the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), reduces the expression of phospho(p)-NF-κB and leads to the reduction of downstream inflammatory factors, such as tumour necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β, thereby inhibiting the inflammatory response. Regarding the AMPK/ Nrf2 oxidative stress pathway, DCP up-regulates the expression of p-AMPK and Nrf2, in addition to regulating glucose and lipid metabolism, oxidative stress and ameliorating liver disturbance symptoms. In summary, our study shows that DCP alleviates liver disturbances by inhibiting mechanisms used during liver inflammation and oxidative stress depression, which provides a new strategy for the clinical treatment of liver disturbance.

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

Nonalcoholic fatty liver disease (NAFLD) is present in approximately 25% of the population worldwide. It is characterized by the accumulation of triacylglycerol in the liver, which can progress to steatohepatitis with different degrees of fibrosis, stages that lack approved pharmacological therapies and represent an indication for liver transplantation with consistently increasing frequency. In view that hepatic steatosis is a reversible condition, effective strategies preventing disease progression were addressed using combinations of natural products in the preclinical high-fat diet (HFD) protocol (60% of fat for 12 weeks). Among them, eicosapentaenoic acid (C20:5n-3, EPA) and docosahexaenoic acid (C22:5n-3, DHA), DHA and extra virgin olive oil (EVOO), or EPA plus hydroxytyrosol (HT) attained 66% to 83% diminution in HFD-induced steatosis, with the concomitant inhibition of the proinflammatory state associated with steatosis. These supplementations trigger different molecular mechanisms that modify antioxidant, antisteatotic, and anti-inflammatory responses, and in the case of DHA and HT co-administration, prevent NAFLD. It is concluded that future studies in NAFLD patients using combined supplementations such as DHA plus HT are warranted to prevent liver steatosis, thus avoiding its progression into more unmanageable stages of the disease.

N-Carbamylglutamate and l-arginine supplementation improve hepatic antioxidant status in intrauterine growth-retarded suckling lambs

The influence of dietary supplementation of l-arginine (Arg) or N-carbamylglutamate (NCG) on the hepatic antioxidant status in intrauterine-growth-retarded (IUGR) suckling lambs remains unclear. The current work aimed to investigate the regulatory mechanisms whereby dietary Arg or NCG alter hepatic antioxidant status in suckling lambs suffering from IUGR. Forty-eight newborn Hu lambs of normal birth weight (CON) and IUGR were allocated randomly into four groups of 12 animals each: CON (4.25 ± 0.14 kg), IUGR (3.01 ± 0.12 kg), IUGR + 1% Arg (2.99 ± 0.13 kg), or IUGR + 0.1% NCG (3.03 ± 0.11 kg). All lambs were raised for a period of 21 days from 7 to 28 days after birth. Compared with the IUGR suckling animals, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and reduced glutathione (GSH) content were greater (P < 0.05), and protein carbonyl and malondialdehyde (MDA) levels were reduced (P < 0.05) in the livers of both IUGR + 1% Arg and 0.1% NCG suckling animals. Relative to IUGR suckling lambs, supplementing with Arg or NCG markedly reduced (P < 0.05) reactive oxygen species (ROS) levels, apoptosis, and necrosis in liver. Relative to IUGR suckling lambs, protein and mRNA expression of GSH-Px1, SOD2, catalase (CAT), heme oxygenase-1 (HO-1), inducible nitric oxide (NO) synthase (iNOS), and epithelial NO synthase (eNOS) increased in IUGR animals receiving Arg or NCG (P < 0.05). Both Arg and NCG can protect neonates from IUGR-induced hepatic oxidative damage through promoting the expression of antioxidative enzymes (including SOD, CAT, and GSH-Px), phase II metabolizing enzymes, and activation of the NO pathway.

The influence of dietary supplementation of l-arginine (Arg) or N-carbamylglutamate (NCG) on the hepatic antioxidant status in intrauterine-growth-retarded (IUGR) suckling lambs remains unclear.

Urolithins Attenuate Multiple Symptoms of Obesity in Rats Fed on a High-Fat Diet

BACKGROUND

Urolithins are gut microbiota-derived polyphenol metabolites, produced following the consumption of pomegranate, berries, and nuts. Recent studies have shown the potentials of these metabolites on reducing triglycerides accumulation in cultured hepatocytes and adipocytes. In this study, we investigated the ability of both urolithin A (Uro-A) and urolithin B (Uro-B) to attenuate obesity and associated symptoms in a high-fat diet-induced obesity model in rats.

METHODS

Twenty-four male Wistar rats were randomly assigned to four groups. Group 1 was fed on a normal diet while groups 2, 3, and 4 were fed on a high-fat diet for 10 weeks. After this, groups 3 and 4 were treated with 2.5mg/kg body weight of Uro-A and Uro-B intraperitoneally, respectively. Body weight, serum lipid profile, hepatic antioxidant activity, hepatic lipid accumulation, fecal lipid content, and the expressions of genes involved in lipogenesis and hepatic ER stress were quantified.

RESULTS

Indeed, a high-fat diet resulted in increased body weight, visceral adipose tissue mass, and oxidative stress in rats. However, treatment with both Uro-A and Uro-B decreased body weight and visceral adipose tissue mass. These metabolites restored hepatic antioxidant capacity and decreased lipid accumulation in addition to an increase in fecal fat excretion. Moreover, both Uro-A and Uro-B treatment downregulated the expression of LXRα and SREBP1c; involved in de novo lipogenesis while upregulating PPARα expression for increased fatty acid oxidation. Furthermore, Uro-A and Uro-B decreased the expression of PERK and IRE1α; which are involved in hepatic ER stress. Taken together, our results showed the potentials of Uro-A and Uro-B in mitigating obesity symptoms and they could thus provide promising roles in the future as functional anti-obesity candidates.

Docosahexaenoic acid and hydroxytyrosol co-administration fully prevents liver steatosis and related parameters in mice subjected to high-fat diet: A molecular approach

Attenuation of high-fat diet (HFD)-induced liver steatosis is accomplished by different nutritional interventions. Considering that the n-3 PUFA docosahexaenoic acid (DHA) modulates lipid metabolism and the antioxidant hydroxytyrosol (HT) diminishes oxidative stress underlying fatty liver, it is hypothesized that HFD-induced steatosis is suppressed by DHA and HT co-administration. Male C57BL/6J mice were fed a control diet (CD; 10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks, without and with supplementation of DHA (50 mg/kg/day), HT (5 mg/kg/day) or both. The combined DHA + HT protocol fully prevented liver steatosis and the concomitant pro-inflammatory state induced by HFD, with suppression of lipogenic and oxidative stress signaling, recovery of fatty acid oxidation capacity and enhancement in resolvin availability affording higher inflammation resolution capability. Abrogation of HFD-induced hepatic steatosis by DHA and HT co-administration represents a crucial therapeutic strategy eluding disease progression into stages lacking efficacious handling at present time.

Indole-3-Acetic Acid Alleviates Nonalcoholic Fatty Liver Disease in Mice via Attenuation of Hepatic Lipogenesis, and Oxidative and Inflammatory Stress

Recent evidences have linked indole-3-acetic acid (IAA), a gut microbiota-derived metabolite from dietary tryptophan, with the resistance to liver diseases. However, data supporting IAA-mediated protection against nonalcoholic fatty liver disease (NAFLD) from an in vivo study is lacking. In this study, we assessed the role of IAA in attenuating high-fat diet (HFD)-induced NAFLD in male C57BL/6 mice. Administration of IAA (50 mg/kg body weight) by intraperitoneal injection was found to alleviate HFD-induced elevation in fasting blood glucose and homeostasis model assessment of insulin resistance (HOMA-IR) index as well as plasma total cholesterol, low-density lipoprotein cholesterol (LDL-C), and glutamic-pyruvic transaminase (GPT) activity. Histological examination further presented the protective effect of IAA on liver damage induced by HFD feeding. HFD-induced an increase in liver total triglycerides and cholesterol, together with the upregulation of genes related to lipogenesis including sterol regulatory element binding-protein 1 (Srebf1), steraroyl coenzyme decarboxylase 1 (Scd1), peroxisome proliferator-activated receptor gamma (PPARγ), acetyl-CoA carboxylase 1 (Acaca), and glycerol-3-phosphate acyltransferase, mitochondrial (Gpam), which were mitigated by IAA treatment. The results of reactive oxygen species (ROS) and malonaldehyde (MDA) level along with superoxide dismutase (SOD) activity and glutathione (GSH) content in liver tissue evidenced the protection of IAA against HFD-induced oxidative stress. Additionally, IAA attenuated the inflammatory response of liver in mice exposed to HFD as shown by the reduction in the F4/80-positive macrophage infiltration and the expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α). In conclusion, our findings uncover that IAA alleviates HFD-induced hepatotoxicity in mice, which proves to be associated with the amelioration in insulin resistance, lipid metabolism, and oxidative and inflammatory stress.

High-fat diet induces mouse liver steatosis with a concomitant decline in energy metabolism: attenuation by eicosapentaenoic acid (EPA) or hydroxytyrosol (HT) supplementation and the additive effects upon EPA and HT co-administration

High-fat-diet (HFD) feeding is associated with liver oxidative stress (OS), n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) depletion, hepatic steatosis and mitochondrial dysfunction. Our hypothesis is that the HFD-induced liver injury can be attenuated by the combined supplementation of n-3 LCPUFA eicosapentaenoic acid (EPA) and the antioxidant hydroxytyrosol (HT). The C57BL/6J mice were administered an HFD (60% fat, 20% protein, 20% carbohydrates) or control diet (CD; 10% fat, 20% protein, 70% carbohydrates), with or without EPA (50 mg kg-1 day-1), HT (5 mg kg-1 day-1), or EPA + HT (50 and 5 mg kg-1 day-1, respectively) for 12 weeks. We measured the body and liver weights and dietary and energy intakes along with liver histology, FA composition, steatosis score and associated transcription factors, mitochondrial functions and metabolic factors related to energy sensing through the AMP-activated protein kinase (AMPK) and PPAR-γ coactivator-1α (PGC-1α) cascade. It was found that the HFD significantly induced liver steatosis, with a 66% depletion of n-3 LCPUFAs and a 100% increase in n-6/n-3 LCPUFA ratio as compared to the case of CD (p < 0.05). These changes were concomitant with (i) a 95% higher lipogenic and 70% lower FA oxidation signaling, (ii) a 40% diminution in mitochondrial respiratory capacity and (iii) a 56% lower ATP content. HFD-induced liver steatosis was also associated with (iv) a depressed mRNA expression of AMPK-PGC-1α signaling components, nuclear respiratory factor-2 (NRF-2) and β-ATP synthase. These HFD effects were significantly attenuated by the combined EPA + HT supplementation in an additive manner. These results suggested that EPA and HT co-administration partly prevented HFD-induced liver steatosis, thus strengthening the importance of combined interventions in hepatoprotection in non-alcoholic fatty liver disease.

The Nutraceutical Value of Olive Oil and Its Bioactive Constituents on the Cardiovascular System. Focusing on Main Strategies to Slow Down Its Quality Decay during Production and Storage

Cardiovascular diseases represent the principal cause of morbidity and mortality worldwide. It is well-known that oxidative stress and inflammatory processes are strongly implicated in their pathogenesis; therefore, anti-oxidant and anti-inflammatory agents can represent effective tools. In recent years a large number of scientific reports have pointed out the nutraceutical and nutritional value of extra virgin olive oils (EVOO), strongholds of the Mediterranean diet, endowed with a high nutritional quality and defined as functional foods. In regard to EVOO, it is a food composed of a major saponifiable fraction, represented by oleic acid, and a minor unsaponifiable fraction, including a high number of vitamins, polyphenols, and squalene. Several reports suggest that the beneficial effects of EVOO are linked to the minor components, but recently, further studies have shed light on the health effects of the fatty fraction and the other constituents of the unsaponifiable fraction. In the first part of this review, an analysis of the clinical and preclinical evidence of the cardiovascular beneficial effects of each constituent is carried out. The second part of this review is dedicated to the main operating conditions during production and/or storage that can directly influence the shelf life of olive oil in terms of both nutraceutical properties and sensory quality.

Atorvastatin Induces Hepatotoxicity in Diabetic Rats via Oxidative Stress, Inflammation, and Anti-Apoptotic Pathway

Background

Patients with diabetes mellitus (DM) commonly receive statins to suppress vulnerability to adverse cardiovascular events. It has been clinically proven that hepatotoxicity is one of the most severe adverse effects of statins.

Material/Methods

We constructed diabetic rat models by feeding rats with high-fat food and by injection of low-dose STZ. Rats were randomized into 2 groups: a DM group (n=10) and a control (CON) group (n=5). CON rats received a normal diet, whereas DM rats ate high-fat food. Rats in the DM group underwent intraperitoneal STZ (35 mg/kg) injection following 6-week diet restriction. On the seventh day following STZ or blank injection, rats with FBG concentration over 11.1 mM were regarded as successfully established models and were used for further research.

Results

We showed that severe liver injury occurred in diabetic rats treated with 20 mg/kg atorvastatin, as evidenced by attenuation of liver enzyme activities, elevation of bilirubin levels, and alterations in the hepatic architecture, including hepatocyte death by necrosis, lymphocyte infiltration, and fibrosis. We also found that atorvastatin increased the secretion of pro-inflammatory factors such as L-1, TNF, IL-6, and IL-18 by enhancing activation of the NF-B signal pathway in the livers of diabetic rats. Atorvastatin elevated the levels of ROS and reduced the antioxidant enzyme (SOD and CAT) activities. Atorvastatin also increased the expression of anti-apoptotic protein BCL2 and decreased the expression of pro-apoptotic protein BAX in the livers of diabetic rats.

Conclusion

Atorvastatin exerts potentially hepatotoxic effects on diabetic rats by modulating oxidative/antioxidative status, pro-inflammatory cytokine production, and apoptosis inhibition.

Hydroxytyrosol, Tyrosol and Derivatives and Their Potential Effects on Human Health

The Mediterranean diet and olive oil as its quintessential part are almost synonymous with a healthy way of eating and living nowadays. This kind of diet has been highly appreciated and is widely recognized for being associated with many favorable effects, such as reduced incidence of different chronic diseases and prolonged longevity. Although olive oil polyphenols present a minor fraction in the composition of olive oil, they seem to be of great importance when it comes to the health benefits, and interest in their biological and potential therapeutic effects is huge. There is a growing body of in vitro and in vivo studies, as well as intervention-based clinical trials, revealing new aspects of already known and many new, previously unknown activities and health effects of these compounds. This review summarizes recent findings regarding biological activities, metabolism and bioavailability of the major olive oil phenolic compounds—hydroxytyrosol, tyrosol, oleuropein, oleocanthal and oleacein—the most important being their antiatherogenic, cardioprotective, anticancer, neuroprotective and endocrine effects. The evidence presented in the review concludes that these phenolic compounds have great pharmacological potential, however, further studies are still required.

Combined docosahexaenoic acid and thyroid hormone supplementation as a protocol supporting energy supply to precondition and afford protection against metabolic stress situations

Liver preconditioning (PC) refers to the development of an enhanced tolerance to injuring stimuli. For example, the protection from ischemia-reperfusion (IR) in the liver that is obtained by previous maneuvers triggering beneficial molecular and functional changes. Recently, we have assessed the PC effects of thyroid hormone (T_3; single dose of 0.1 mg/kg) and n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs; daily doses of 450 mg/kg for 7 days) that abrogate IR injury to the liver. This feature is also achieved by a combined T₃ and the n-3 LCPUFA docosahexaenoic acid (DHA) using a reduced period of supplementation of the FA (daily doses of 300 mg/kg for 3 days) and half of the T₃ dosage (0.05 mg/kg). T₃ -dependent protective mechanisms include (i) the reactive oxygen species (ROS)-dependent activation of transcription factors nuclear factor-κB (NF-κB), AP-1, signal transducer and activator of transcription 3, and nuclear factor erythroid-2-related factor 2 (Nrf2) upregulating the expression of protective proteins. (ii) ROS-induced endoplasmic reticulum stress affording proper protein folding. (iii) The autophagy response to produce FAs for oxidation and ATP supply and amino acids for protein synthesis. (iv) Downregulation of inflammasome nucleotide-bonding oligomerization domain leucine-rich repeat containing family pyrin containing 3 and interleukin-1β expression to prevent inflammation. N-3 LCPUFAs induce antioxidant responses due to Nrf2 upregulation, with inflammation resolution being related to production of oxidation products and NF-κB downregulation. Energy supply to achieve liver PC is met by the combined DHA plus T₃ protocol through upregulation of AMPK coupled to peroxisome proliferator-activated receptor-γ coactivator 1α signaling. In conclusion, DHA plus T₃ coadministration favors hepatic bioenergetics and lipid homeostasis that is of crucial importance in acute and clinical conditions such as IR, which may be extended to long-term or chronic situations including steatosis in obesity and diabetes. © 2019 IUBMB Life, 71(9):1211-1220, 2019.

Olive Oil Effects on Colorectal Cancer

Colorectal cancer is the fourth cause of cancer-related death worldwide. A Mediterranean diet showed protective action against colorectal cancer due to the intake of different substances. Olive oil is a fundamental component of the Mediterranean diet. Olive oil is rich in high-value health compounds (such as monounsaturated free fatty acids, squalene, phytosterols, and phenols). Phenolic compounds exert favourable effects on free radicals, inflammation, gut microbiota, and carcinogenesis. The interaction between gut microbiota and olive oil consumption could modulate colonic microbial composition or activity, with a possible role in cancer prevention. Gut microbiota is able to degrade some substances found in olive oil, producing active metabolites with chemopreventive action. Further clinical research is needed to clarify the beneficial effects of olive oil and its components. A better knowledge of the compounds found in olive oil could lead to the development of nutritional supplements or chemotherapeutic agents with a potential in the prevention and treatment of colorectal cancer.