Dietary anthocyanins as nutritional therapy for nonalcoholic fatty liver disease. Oxid Med Cell Longev. 2013;2013:145421. [PMID: 24282628 PMCID: PMC3824564 DOI: 10.1155/2013/145421]

Siphonaxanthin, a Carotenoid From Green Algae, Inhibits Lipogenesis in Hepatocytes via the Suppression of Liver X Receptor α Activity

Nonalcoholic fatty liver disease (NAFLD) has shown an increasing morbidity in recent years. Here, we demonstrated that siphonaxanthin (SPX), a rare marine carotenoid, exhibits a strong inhibitory effect on aggravated hepatic lipogenesis in vitro and would be a promising candidate in the prevention and alleviation of NAFLD in the future. In this study, we conducted a preliminary assessment of the effect of SPX on hepatic lipogenesis by using the HepG2 cell line, derived from human liver cancer, as a model of the liver. SPX significantly suppressed the excess accumulation of triacylglycerol induced by liver X receptor α (LXRα) agonist by downregulating a nuclear transcription factor named sterol regulatory element-binding protein-1c and a set of related genes. Moreover, fatty acid translocase (CD36) and fatty acid-binding protein-1, which regulates fatty acid uptake, also exhibited significant decrease in transcriptional levels. Furthermore, we found that SPX blocked LXRα activation and would be a promising candidate for antagonist of LXRα.

Niga-ichigoside F1 ameliorates high-fat diet-induced hepatic steatosis in male mice by Nrf2 activation

Niga-ichigoside F1 ameliorated high-fat diet-induced hepatic steatosis by increasing Nrf2 nuclear translocation to regulate lipid metabolism genes expression in livers of C57BL/6J mice.

Medicinal plants and bioactive natural compounds in the treatment of non-alcoholic fatty liver disease: A clinical review

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver diseases, and is closely related to metabolic syndrome and its related conditions, diabetes mellitus and dyslipidemia. On the other hand, NAFLD as a multisystem disease increases the risk of several chronic diseases include type 2 diabetes mellitus, cardiovascular disease (CVD), and chronic kidney disease. The main objective was to review the efficacy of bioactive natural compounds assessed by clinical trials. Search literature using four databases (PubMed, EBSCO, Web of Science, and Ovid Medline) to review publications that focused on the impact of bioactive natural compounds in NAFLD treatment. Due to the lack of effective pharmacological treatments available for NAFLD, lifestyle modifications such as following a healthy diet, vigorous physical activity, and weight reduction remain the first line of treatment for NAFLD. However, due to the poor adherence to this type of treatment, especially for long-term weight loss diets some of which may have harmful effects on the liver, finding novel therapeutic agents for NAFLD treatment and/or preventing NAFLD progression has garnered significant interest. Although the therapeutic agents of NAFLD treatment have been reviewed previously, to date, no summary has been conducted of clinical trials examining the effects of herbal compounds on NAFLD-related biomarkers. This review highlights the beneficial role of herbal bioactives and medicinal plants in NAFLD treatment, particularly as complementary to a healthy lifestyle. All natural products described in this review seem to have some benefits to improve oxidative stress, cellular inflammation and insulin-resistance, which always remain as the "primum movens" of NAFLD pathogenesis.

Dietary Anthocyanins against Obesity and Inflammation

Chronic low-grade inflammation plays a pivotal role in the pathogenesis of obesity, due to its associated chronic diseases such as type II diabetes, cardiovascular diseases, pulmonary diseases and cancer. Thus, targeting inflammation is an attractive strategy to counter the burden of obesity-induced health problems. Recently, food-derived bioactive compounds have been spotlighted as a regulator against various chronic diseases due to their low toxicity, as opposed to drugs that induce severe side effects. Here we describe the beneficial effects of dietary anthocyanins on obesity-induced metabolic disorders and inflammation. Red cabbage microgreen, blueberry, blackcurrant, mulberry, cherry, black elderberry, black soybean, chokeberry and jaboticaba peel contain a variety of anthocyanins including cyanidins, delphinidins, malvidins, pelargonidins, peonidins and petunidins, and have been reported to alter both metabolic markers and inflammatory markers in cells, animals, and humans. This review discusses the interplay between inflammation and obesity, and their subsequent regulation via the use of dietary anthocyanins, suggesting an alternative dietary strategy to ameliorate obesity and obesity associated chronic diseases.

Radish (Raphanus sativus) and Diabetes

For more than three decades, various in vitro and in vivo studies have linked radishes with diabetes, though this link has not been discussed. This review systematically addresses and summarizes the effect of radishes on diabetes. We searched the Web of Science, PubMed, and EMBASE databases for English language articles from June 1987 through May 2017 using the key words "radish" and "diabetes," and the references from particular reports were also considered if relevant. In summary, radish has been identified as having antidiabetic effects, making it favorable for those with diabetic conditions. This may be due to its ability to enhance the antioxidant defense mechanism and reduce the accumulation of free radicals, affect hormonal-induced glucose hemostasis, promote glucose uptake and energy metabolism, and reduce glucose absorption in the intestine. However, this summary requires further confirmation in research in vivo studies and clinical trials.

Aronia melanocarpa Extract Ameliorates Hepatic Lipid Metabolism through PPARγ2 Downregulation

Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Studies have demonstrated that anthocyanin-rich foods may improve hyperlipidemia and ameliorate hepatic steatosis. Here, effects of Aronia melanocarpa (AM), known to be rich of anthocyanins, on hepatic lipid metabolism and adipogenic genes were determined. AM was treated to C57BL/6N mice fed with high fat diet (HFD) or to FL83B cells treated with free fatty acid (FFA). Changes in levels of lipids, enzymes and hormones were observed, and expressions of adipogenic genes involved in hepatic lipid metabolism were detected by PCR, Western blotting and luciferase assay. In mice, AM significantly reduced the body and liver weight, lipid accumulation in the liver, and levels of biochemical markers such as fatty acid synthase, hepatic triglyceride and leptin. Serum transaminases, indicators for hepatocyte injury, were also suppressed, while superoxide dismutase activity and liver antioxidant capacity were significantly increased. In FL83B cells, AM significantly reduced FFA-induced lipid droplet accumulation. Protein synthesis of an adipogenic transcription factor, peroxisome proliferator-activated receptor γ2 (PPARγ2) was inhibited in vivo. Furthermore, transcriptional activity of PPARγ2 was down-regulated in vitro, and mRNA expression of PPARγ2 and its downstream target genes, adipocyte protein 2 and lipoprotein lipase were down-regulated by AM both in vitro and in vivo. These results show beneficial effects of AM against hepatic lipid accumulation through the inhibition of PPARγ2 expression along with improvements in body weight, liver functions, lipid profiles and antioxidant capacity suggesting the potential therapeutic efficacy of AM on NAFLD.

Anthocyanins in chokeberry and purple maize attenuate diet-induced metabolic syndrome in rats

OBJECTIVE

Increased consumption of fruits and vegetables as functional foods leads to the reduction of signs of metabolic syndrome. The aim of this study was to measure and compare cardiovascular, liver, and metabolic parameters following chronic administration of the same dose of anthocyanins either from chokeberry (CB) or purple maize (PM) in rats with diet-induced metabolic syndrome.

METHODS

Male Wistar rats were fed a maize starch (C) or high-carbohydrate, high-fat diet (H) and divided into six groups for 16 wk. The rats were fed C, C with CB or PM for the last 8 wk (CCB or CPM), H, H with CB or PM for the last 8 wk (HCB or HPM); CB and PM rats received ∼8 mg anthocyanins/kg daily. The rats were monitored for changes in blood pressure, cardiovascular and hepatic structure and function, glucose tolerance, and adipose tissue mass.

RESULTS

HCB and HPM rats showed reduced visceral adiposity index, total body fat mass, and systolic blood pressure; improved glucose tolerance, liver, and cardiovascular structure and function; decreased plasma triacylglycerols and total cholesterol compared with H rats. Inflammatory cell infiltration was reduced in heart and liver.

CONCLUSION

CB and PM interventions gave similar responses, suggesting that anthocyanins are the bioactive molecules in the attenuation or reversal of metabolic syndrome by prevention of inflammation-induced damage.

Chardonnay Grape Seed Flour Ameliorates Hepatic Steatosis and Insulin Resistance via Altered Hepatic Gene Expression for Oxidative Stress, Inflammation, and Lipid and Ceramide Synthesis in Diet-Induced Obese Mice

To identify differentially expressed hepatic genes contributing to the improvement of high-fat (HF) diet-induced hepatic steatosis and insulin resistance following supplementation of partially defatted flavonoid-rich Chardonnay grape seed flour (ChrSd), diet-induced obese (DIO) mice were fed HF diets containing either ChrSd or microcrystalline cellulose (MCC, control) for 5 weeks. The 2-h insulin area under the curve was significantly lowered by ChrSd, indicating that ChrSd improved insulin sensitivity. ChrSd intake also significantly reduced body weight gain, liver and adipose tissue weight, hepatic lipid content, and plasma low-density lipoprotein (LDL)-cholesterol, despite a significant increase in food intake. Exon microarray analysis of hepatic gene expression revealed down-regulation of genes related to triglyceride and ceramide synthesis, immune response, oxidative stress, and inflammation and upregulation of genes related to fatty acid oxidation, cholesterol, and bile acid synthesis. In conclusion, the effects of ChrSd supplementation in a HF diet on weight gain, insulin resistance, and progression of hepatic steatosis in DIO mice were associated with modulation of hepatic genes related to oxidative stress, inflammation, ceramide synthesis, and lipid and cholesterol metabolism.

Adenosine monophosphate-activated protein kinase in diabetic nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, and its pathogenesis is complex and has not yet been fully elucidated. Abnormal glucose and lipid metabolism is key to understanding the pathogenesis of DN, which can develop in both type 1 and type 2 diabetes. A hallmark of this disease is the accumulation of glucose and lipids in renal cells, resulting in oxidative and endoplasmic reticulum stress, intracellular hypoxia, and inflammation, eventually leading to glomerulosclerosis and interstitial fibrosis. There is a growing body of evidence demonstrating that dysregulation of 5′ adenosine monophosphate–activated protein kinase (AMPK), an enzyme that plays a principal role in cell growth and cellular energy homeostasis, in relevant tissues is a key component of the development of metabolic syndrome and type 2 diabetes mellitus; thus, targeting this enzyme may ameliorate some pathologic features of this disease. AMPK regulates the coordination of anabolic processes, with its activation proven to improve glucose and lipid homeostasis in insulin-resistant animal models, as well as demonstrating mitochondrial biogenesis and antitumor activity. In this review, we discuss new findings regarding the role of AMPK in the pathogenesis of DN and offer suggestions for feasible clinical use and future studies of the role of AMPK activators in this disorder.

Dietary sweet cherry anthocyanins attenuates diet-induced hepatic steatosis by improving hepatic lipid metabolism in mice

OBJECTIVE

Anthocyanins have been reported to have beneficial effects on obesity and obesity-related metabolic disorders (e.g., insulin resistance and dyslipidemia). The objective of this study was to examine the beneficial effects of sweet cherry anthocyanins (SWCN) on high-fat diet-induced liver steatosis and investigate the underlying molecular mechanism.

METHODS

C57 BL/6 J mice were fed low-fat diet, high-fat diet, or high-fat diet supplemented with SWCN of 200 mg/kg for 15 wk. The hepatic gene expression profile was analyzed by DNA microarray analysis.

RESULTS

SWCN supplementation alleviated high-fat diet-induced liver steatosis in mice. Microarray analysis of hepatic gene expression profiles indicated that SWCN treatment significantly changed the expression profiles of 1119 genes which were enriched in 16 pathways, such as PPAR signaling pathway, steroid biosynthesis, fatty acid metabolism, and biosynthesis of unsaturated fatty acids.

CONCLUSION

These results confirmed the previous findings regarding the occurrence and development of hepatic steatosis under high-fat-diet conditions, elucidated that SWCN protected from diet-induced hepatic steatosis and the beneficial effects might be involved in multiple molecular pathways, especially the PPARγ pathway.

Natural antioxidants for non-alcoholic fatty liver disease: molecular targets and clinical perspectives

Non-alcoholic steatohepatitis (NASH), the progressive form of non-alcoholic fatty liver disease (NAFLD), is emerging as a main health problem in industrialized countries. Lifestyle modifications are effective in the treatment of NAFLD; however, the long-term compliance is low. Therefore, several pharmacological treatments have been proposed but none has shown significant efficacy or long-term safety. Natural polyphenols are a heterogeneous class of polyphenolic compounds contained in vegetables, which are being proposed for the treatment of different metabolic disorders. Although the beneficial effect of these compounds has traditionally related to their antioxidant properties, they also exert several beneficial effects on hepatic and extra-hepatic glucose and lipid homeostasis. Furthermore, natural polyphenols exert antifibrogenic and antitumoural effects in animal models, which appear relevant from a clinical point of view because of the association of NASH with cirrhosis and hepatocellular carcinoma. Several polyphenols, such anthocyanins, curcumin and resveratrol and those present in coffee, tea, soy are available in the diet and their consumption can be proposed as part of a healthy diet for the treatment of NAFLD. Other phenolic compounds, such as silymarin, are commonly consumed worldwide as nutraceuticals or food supplements. Natural antioxidants are reported to have beneficial effects in preclinical models of NAFLD and in pilot clinical trials, and thus need clinical evaluation. In this review, we summarize the existing evidence regarding the potential role of natural antioxidants in the treatment of NAFLD and examine possible future clinical applications.

Treatment of nonalcoholic fatty liver disease: Where do we stand? an overview

Nonalcoholic fatty liver disease (NAFLD) is currently the most common liver disease worldwide, the prevalence of which had progressively increased over the past 10 years where other liver diseases remained at the same prevalence rates or are expected to decrease as in the case of hepatitis C virus (HCV). The treatment of NAFLD is of prime concern to health care professionals and patients due to the significant mortality and morbidity it implies; the problem is further escalated by the fact that standard of care medications targeting NAFLD remain experimental and without evidence base. Treatment nowadays is focused on lifestyle modification and managing the comorbid associated diseases, with a possible role for some hepatic protective agents. This review presents all the medications that had been proposed and used for the treatment of NAFLD with or without scientific rationale and includes agents for weight loss, insulin sensitizers, drugs that reduce blood lipids, glucagon-mimetics, drugs that may reduce fibrosis, angiotensin receptor blockers, and medicines believed to reduce endoplasmic reticular stress such as vitamin E, ursodeoxycholic acid, and S-adenosyl methionine. A quick review of the newer agents that proved to be promising such as obeticholic acid and GFT505 and the medicines that are still in the pipeline is also presented.

Adzuki bean ameliorates hepatic lipogenesis and proinflammatory mediator expression in mice fed a high-cholesterol and high-fat diet to induce nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a simple steatosis, in which fat accumulates more than 5% in the liver, and regarded as most common liver diseases worldwide. Because NAFLD can be developed to severe liver disease and correlated with metabolic disease, its importance is currently emphasized. Occurrence of NAFLD is strongly related to dietary patterns and lifestyles; therefore, the suggestion of physiologically beneficial food is essential. Based on these, adzuki beans containing anthocyanin, catechin, and adzukisaponin are suggested as a health-beneficial food. Moreover, the effects of adzuki beans on metabolic improvement are not well established through the in vivo studies. Therefore, this study hypothesized that adzuki beans can alleviate lipid accumulation and oxidative stress-mediated inflammation in high-cholesterol and high-fat diet-induced NALFD mice. To demonstrate its effects, 6-week-old C57BL/6 male mice were allocated into 4 groups and fed a normal diet (ND), a high-cholesterol and high-fat diet (HCD), and HCD with 10% and 20% adzuki bean for 10 weeks. The result shows that fasting blood glucose, serum and hepatic triglyceride and cholesterol levels, and antioxidative enzyme activity ameliorated in the adzuki bean groups (P < .05). The transcriptional factors of hepatic lipogenesis, such as adiponectin, AMP-activated protein kinase α, sterol regulatory element-binding protein 1c, fatty acid synthase, carnitine palmitoyltransferase 1, 3-hydroxy-3-methyl-glutaryl-CoA reductase, and apolipoprotein B, as well as proinflammatory mediators, such as tumor necrosis factor α, nuclear factor κB, and caspase-3, improved in both experimental groups (P < .05). These results suggested that adzuki beans attenuate lipid accumulation and oxidative stress-induced inflammation by suppressing hepatic messenger RNA expression of lipogenic and inflammatory mediators in NAFLD.

Dietary supplements and pediatric non-alcoholic fatty liver disease: Present and the future

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children. High prevalence of pediatric obesity and sedentary lifestyle has augmented the incidence of NAFLD in children. Obesity is associated with an increased risk of NAFLD through various mechanisms such as intensification of insulin resistance and increased levels of inflammatory markers. There is no approved medical intervention for treatment of pediatric NAFLD; the only proven strategy in management of pediatric NAFLD is lifestyle modification. Recently, the effects of nutritional supplements have been examined in the management of pediatric NAFLD. The purpose of this review is to summarize the studies evaluating the effects of nutritional supplements on pediatric NAFLD and explain the future direction in this field.

Functional foods as potential therapeutic options for metabolic syndrome

Obesity as part of metabolic syndrome is a major lifestyle disorder throughout the world. Current drug treatments for obesity produce small and usually unsustainable decreases in body weight with the risk of major adverse effects. Surgery has been the only treatment producing successful long-term weight loss. As a different but complementary approach, lifestyle modification including the use of functional foods could produce a reliable decrease in obesity with decreased comorbidities. Functional foods may include fruits such as berries, vegetables, fibre-enriched grains and beverages such as tea and coffee. Although health improvements continue to be reported for these functional foods in rodent studies, further evidence showing the translation of these results into humans is required. Thus, the concept that these fruits and vegetables will act as functional foods in humans to reduce obesity and thereby improve health remains intuitive and possible rather than proven.

Relevant Aspects of Nutritional and Dietary Interventions in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is the main cause of liver disease worldwide. NAFLD is linked to circumstances such as type 2 diabetes, insulin resistance, obesity, hyperlipidemia, and hypertension. Since the obesity figures and related comorbidities are increasing, NAFLD has turned into a liver problem that has become progressively more common. Currently, there is no effective drug therapy for NAFLD; therefore, interventions in lifestyles remain the first line of treatment. Bearing in mind that adherence rates to this type of treatment are poor, great efforts are currently focused on finding novel therapeutic agents for the prevention in the development of hepatic steatosis and its progression to nonalcoholic steatohepatitis and cirrhosis. This review presents a compilation of the scientific evidence found in the last years showing the results of interventions in lifestyle, diet, and behavioral therapies and research results in human, animal and cell models. Possible therapeutic agents ranging from supplementation with vitamins, amino acids, prebiotics, probiotics, symbiotics, polyunsaturated fatty acids and polyphenols to interventions with medicinal plants are analyzed.

Oral administration of the Aureobasidium pullulans-derived β-glucan effectively prevents the development of high fat diet-induced fatty liver in mice

Aureobasidium pullulans-derived β-glucan (AP-PG) consisting of a β-(1,3)-linked glucose main chain and β-(1,6)-linked glucose branches is taken as a supplement to improve health. This study demonstrates that oral administration of AP-PG is effective to prevent the development of high-fat diet (HFD)-induced fatty liver in mice. Here, C57BL/6N mice were fed with a normal diet or HFD, and AP-PG diluted in drinking water was administered orally. After 16 weeks, the serological analysis showed that HFD-induced high blood cholesterol and triglyceride levels were reduced by the oral administration of AP-PG. Further, HFD induced-fatty liver was significantly reduced by the oral administration of AP-PG. The triglyceride accumulation in the liver was also significantly reduced in mice administered AP-PG. Liver injury as indicated by an increase in serum alanine aminotransferase (ALT) in the HFD-fed mice was significantly reduced in the mice administered AP-PG orally, and the gene expression of cholesterol 7 alpha-hydroxylase (CYP7A1) which is known to be involved in cholesterol degradation in the liver was significantly increased in the AP-PG administered mice. These results suggest the possibility that the oral administration of AP-PG is effective to prevent the development of non-alcoholic fatty liver disease (NAFLD).

Anthocyanin-rich Seoritae extract ameliorates renal lipotoxicity via activation of AMP-activated protein kinase in diabetic mice

BACKGROUND

Anthocyanins are major constituents of food colours and have been reported to possess anti-diabetic activities for potential medicinal use. The precise role of anthocyanins in diabetic nephropathy is poorly understood. We investigated whether anthocyanin-rich Seoritae extract (SE) can potentially prevent oxidative stress and lipotoxicity, which are the main causes of renal damage in diabetic nephropathy, via activation of AMP-activated protein kinase (AMPK) and the consequent effects on its target molecules.

METHODS

Four groups of male C57BLKS/J db/m and db/db mice were used. Diabetic and non-diabetic mice were orally administered 10 mg/kg body weight SE daily for 12 weeks, starting at 8 weeks of age.

RESULTS

db/db mice treated with anthocyanins showed decreased albuminuria. Anthocyanins ameliorated intra-renal lipid concentrations in db/db mice with improvement of glomerular matrix expansion and inflammation, which was related to increased phosphorylation of AMPK and activation of peroxisome proliferator-activated receptor (PPAR) α and PPARγ, and inhibited the activity of acetyl-CoA carboxylase and sterol regulatory element-binding protein 1. Anthocyanins reversed diabetes-induced increases in renal apoptosis and oxidative stress. In cultured human glomerular endothelial cells, anthocyanins prevented high glucose-induced oxidative stress and apoptosis through activation of AMPK in the same manner.

CONCLUSIONS

The results revealed that anthocyanins ameliorated diabetic nephropathy in db/db mice via phosphorylation of AMPK, the major energy-sensing enzyme, and the consequent effects on its target molecules, which appeared to prevent lipotoxicity-related apoptosis and oxidative stress in the kidney.

Mirtoselect, an anthocyanin-rich bilberry extract, attenuates non-alcoholic steatohepatitis and associated fibrosis in ApoE(∗)3Leiden mice

BACKGROUND & AIMS

Anthocyanins may have beneficial effects on lipid metabolism and inflammation and are demonstrated to have hepatoprotective properties in models of restraint-stress- and chemically-induced liver damage. However, their potential to protect against non-alcoholic steatohepatitis (NASH) under conditions relevant for human pathogenesis remains unclear. Therefore, we studied the effects of the standardised anthocyanin-rich extract Mirtoselect on diet-induced NASH in a translational model of disease.

METHODS

ApoE(∗)3Leiden mice were fed a Western-type cholesterol-containing diet without (HC) or with 0.1% (w/w) Mirtoselect (HCM) for 20weeks to study the effects on diet-induced NASH.

RESULTS

Mirtoselect attenuated HC-induced hepatic steatosis, as observed by decreased macro- and microvesicular hepatocellular lipid accumulation and reduced hepatic cholesteryl ester content. This anti-steatotic effect was accompanied by local anti-inflammatory effects in liver, as demonstrated by reduced inflammatory cell clusters and reduced neutrophil infiltration in HCM. On a molecular level, HC diet significantly induced hepatic expression of pro-inflammatory genes Tnf, Emr1, Ccl2, Mpo, Cxcl1, and Cxcl2 while this induction was less pronounced or significantly decreased in HCM. A similar quenching effect was observed for HC-induced pro-fibrotic genes, Acta2 and Col1a1 and this anti-fibrotic effect of Mirtoselect was confirmed histologically. Many of the pro-inflammatory and pro-fibrotic parameters positively correlated with intrahepatic free cholesterol levels. Mirtoselect significantly reduced accumulation and crystallisation of intrahepatic free cholesterol, providing a possible mechanism for the observed hepatoprotective effects.

CONCLUSIONS

Mirtoselect attenuates development of NASH, reducing hepatic lipid accumulation, inflammation and fibrosis, possibly mediated by local anti-inflammatory effects associated with reduced accumulation and crystallisation of intrahepatic free cholesterol.

Recent advances in dietary supplementation, in treating non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is currently known as the most common liver problem, characterized by excessive lipid accumulation in hepatocytes, which may progress to other liver diseases such as nonalcoholic steatohepatitis, hepatic tissue fibrosis, liver cirrhosis, and failure or hepatocellular carcinoma. Since NAFLD is positively associated with the development of obesity, insulin resistance, and ultimately type 2 diabetes mellitus, it is often regarded as the hepatic manifestation of the metabolic syndrome. No pharmacologic treatment has yet been proven for this disease. For most patients with presumed or confirmed NAFLD, the only proven strategy is to offer lifestyle advice that can lead to sustained weight loss. Since insulin resistance, oxidative stress, inflammation, and necro-apoptosis are involved in NAFLD pathogenesis, it seems that every potential therapeutic agent should target one or some of these pathologic events. There are many well known anti-oxidants, anti-inflammatory, and insulin sensitizer dietary supplements which have shown beneficial effects on NAFLD improvement in animal and human studies. The purpose of this review is to explore the existing evidences on dietary supplements considered to have hepatoprotective properties, and to present some proposed mechanisms by which they may protect against NAFLD.

Cyanidin and malvidin in aqueous extracts of black carrots fermented with Aspergillus oryzae prevent the impairment of energy, lipid and glucose metabolism in estrogen-deficient rats by AMPK activation

Black carrots (Daucus carota L.) are rich in anthocyanins which contribute many health benefits, but are limited by bioavailability and instability when exposed to oxygen, heat and light. Fermenting black carrots may improve the stability, absorption and bioactivity of its anthocyanins. Here, we examined whether and by what mechanisms the long-term consumption of unfermented black carrot extract (BC) and its extracts fermented with Lactobacillus plantarum (BCLP) or Aspergillus oryzae (BCAO) might prevent menopausal symptoms including impaired energy, glucose and lipid metabolism in estrogen-deficient animals with diet-induced obesity. Ovariectomized (OVX) rats were fed four different high-fat diets containing 2 % dextrin (OVX-control), 2 % BC, 2 % BCLP, or 2 % BCAO for 12 weeks. Sham rats were fed high-fat diets containing 2 % dextrin. The contents of total anthocyanins increased in BCAO compared to BC and BCLP, whereas the contents of cyanidin-3-rutinosides, malvidin-3,5-diglycosides and delphine-3-glucoside were lower and cyanidin and malvidin were much higher in BCLP and BCAO than BC. Fat mass and weight gain were lower in descending order of OVX-control > BC and BCLP > BCAO due to increased energy expenditure and fat oxidation. However, BC, BCLP and especially BCAO all normalized HOMA-IR, an indicator of insulin resistance and glucose intolerance, in OVX rats. OVX increased serum total and LDL cholesterol and triglycerides, but BC, BCLP and BCAO significantly prevented the increases. BCAO markedly decreased hepatic triglyceride levels by increasing gene expressions of CPT-1 and PPAR-α, which are involved in fatty acid oxidation, and decreasing mRNA expressions of FAS and SREBP-1c, which are associated with fatty acid synthesis. This was related to increased pAMPK → pACC signaling and improved hepatic insulin signaling (pAkt → pFOXO-1). Cyanidin and malvidin markedly decreased fat accumulation in 3T3-L1 adipocytes by increasing CPT-1 and decreasing FAS and SREBP-1c expression in comparison with cyanidin-3-rutinoside and malvidin-3,5-diglycosides. In conclusion, with increasing cyanidin and malvidin, BCAO prevented the exacerbation of lipid and glucose metabolism by activating hepatic insulin signaling and AMPK activation by in OVX rats.

Dietary blueberry and bifidobacteria attenuate nonalcoholic fatty liver disease in rats by affecting SIRT1-mediated signaling pathway

NAFLD model rats were established and divided into NAFLD model (MG group), SIRT1 RNAi (SI group), blueberry juice (BJ group), blueberry juice + bifidobacteria (BJB group), blueberry juice + SIRT1 RNAi (BJSI group), and blueberry juice + bifidobacteria + SIRT1 RNAi groups (BJBSI group). A group with normal rats was a control group (CG). BJB group ameliorated NAFLD, which was better than BJ group (P < 0.05). The lipid accumulation was lower in CG, BJ, and BJB groups than that in MG, SI, BJSI, and BJBSI groups (P < 0.05). The levels of SIRT1 and PPAR-α were higher in CG, BJ, and BJB groups than those in MG, SI, BJSI, and BJBSI groups (P < 0.05). The levels of SREBP-1c were lower in CG, BJ, and BJB groups than those in MG, SI, BJSI, and BJBSI groups (P < 0.05). The biochemical indexes SOD, GSH, and HDL-c were improved from CG to BJB group (P < 0.05). Inversely, the levels of AST and ALT, TG, TC, LDL-c, and MDA were decreased from CG to BJB group (P < 0.05). These changes enhance antioxidative capability and biochemical index of rats. Blueberry juice and bifidobacteria improve NAFLD by activating SIRTI-mediating signaling pathway.

JNK inhibitor SP600125 suppresses free fatty acid-induced apoptosis of hepatic stellate cells

AIM: To elucidate the potential effects of c-Jun amino terminal kinase (JNK) inhibitor SP600125 on apoptosis induced by free fatty acids (FFAs) in hepatic stellate cells and the possible mechanism.

METHODS: MTT assay was used to analyze the inhibitory effect of FFAs on growth of hepatic stellate cells, and flow cytometry was used to observe the apoptotic rate of the cells. The expression of p-JNK and p-c-Jun proteins was detected by Western blot assay.

RESULTS: The growth of hepatic stellate cells was significantly inhibited by FFAs in vitro, and FFAs increased the expression of p-JNK and p-c-Jun. JNK inhibitor SP600125 suppressed FFA-induced up-regulation of p-JNK and p-c-Jun.

CONCLUSION: FFAs can inhibit the proliferation of hepatic stellate cells and induce cell apoptosis, which involves the JNK signaling pathway.

Cyanidin-3-O-β-glucoside protects primary mouse hepatocytes against high glucose-induced apoptosis by modulating mitochondrial dysfunction and the PI3K/Akt pathway

Apoptosis is an early event of steatohepatitis in non-alcoholic fatty liver disease (NAFLD), and an increase in oxidative stress induced by hyperglycemia has been linked to an acceleration of apoptosis in hepatocytes. Cyanidin-3-O-β-glucoside (C3G), a classic anthocyanin, has been reported to reduce oxidative stress and attenuate non-alcoholic steatohepatitis in mice. In this study, we evaluated the toxicity of high glucose in primary hepatocytes of mice fed with a high fat diet and amelioration of this toxicity by C3G. Incubation of hepatocytes with 35mM glucose for 12h resulted in a significant decrease in cell viability and increase in apoptotic cell death. Furthermore, hyperglycemia-induced mitochondrial depolarization was accompanied by the release of cytochrome c and altered expression of Bax and Bcl-2, suggesting a mitochondria-mediated apoptotic mode of cell death. Pre-incubation with 50μM C3G induced changes associated with better cell survival and function, including a reduction in reactive species generation, improvement of mitochondrial membrane potential, inactivation of caspase-3 and -9, and down-regulation of the pro-apoptotic Bax protein. We further investigated the role of the phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinases (MAPKs) pathways with respect to the anti-apoptotic action of C3G, and our results showed that C3G could activate Akt. Additionally, C3G inactivated c-Jun N-terminal protein kinase (JNK), but not extracellular signal-regulated kinase or p38 MAPK, in glucose-stressed cells. Interestingly, JNK inhibitor enhanced the protective effect of C3G on cell survival. Our results suggest that anthocyanin C3G may exhibit hepatoprotective potential against NAFLD by promoting functional integrity and survival of hepatocytes.