Chemoprevention of nonalcoholic fatty liver disease by dietary natural compounds

Unravelling the complexities of non-alcoholic steatohepatitis: The role of metabolism, transporters, and herb-drug interactions

Nonalcoholic fatty liver disease (NAFLD) is a mainstream halting liver disease with high prevalence in North America, Europe, and other world regions. It is an advanced form of NAFLD caused by the amassing of fat in the liver and can progress to the more severe form known as non-alcoholic steatohepatitis (NASH). Until recently, there was no authorized pharmacotherapy reported for NASH, and to improve the patient's metabolic syndrome, the focus is mainly on lifestyle modification, weight loss, ensuring a healthy diet, and increased physical activity; however, the recent approval of Rezdiffra (Resmetirom) by the US FDA may change this narrative. As per the reported studies, there is an increased articulation of uptake and efflux transporters of the liver, including OATP and MRP, in NASH, leading to changes in the drug's pharmacokinetic properties. This increase leads to alterations in the pharmacokinetic properties of drugs. Furthermore, modifications in Cytochrome P450 (CYP) enzymes can have a significant impact on these properties. Xenobiotics are metabolized primarily in the liver and constitute liver enzymes and transporters. This review aims to delve into the role of metabolism, transport, and potential herb-drug interactions in the context of NASH.

Icariin alleviates high-fat diet-induced nonalcoholic fatty liver disease via up-regulating miR-206 to mediate NF-κB and MAPK pathways

Nonalcoholic fatty liver disease (NAFLD) is an abnormal lipid accumulation disease in hepatocytes. The existing drugs for NAFLD have some side effects, so new therapeutic agents are required to be explored. In this study, the effect and mechanism of icariin (ICA) on high-fat diet-induced NAFLD were investigated. Firstly, a high-fat diet was used to construct a NAFLD rat model and HepG2 cells were treated with 1 mM free fatty acid (FFA). After ICA treatment, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were measured; liver injury and lipid deposition were observed by H&E and Oil Red O staining; interleukin-1β (IL-1β), IL-12, and IL-6 were measured by enzyme-linked immunosorbent assay. Additionally, qRT-PCR and western blot were performed to detect miR-206 expression and NF-κB/MAPK pathway-related protein expression in liver tissues and cells. After a variety of trials, we discovered that compared with the NAFLD group, ICA significantly reduced ALT, AST, TBil, TG, TC, and LDL-C levels and increased HDL-C levels, and improved liver tissue injury and lipid deposition. Moreover, ICA reduced IL-1β, IL-12, and IL-6 levels in liver tissues and cells as well as inhibited MAPK and NF-κB-related protein expression in the liver tissues. Notably, ICA could significantly increase miR-206 expression in liver tissues and cells. Further experiments confirmed that inhibition of miR-206 was able to reverse the effect of ICA on NAFLD. In conclusion, ICA can alleviate NAFLD by upregulating miR-206 to mediate NF-κB and MAPK pathways.

Effects of curcumin on non-alcoholic fatty liver disease: A scientific metrogy study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases encountered in clinical practice. Curcumin can alleviate insulin resistance, inhibit oxidative stress response, reduce inflammation, reduce liver fat deposition, and effectively improve NAFLD through various modalities, inhibiting the progression into cirrhosis and fibrosis.

PURPOSE

To explore the current status, hot spots, and developing trends of curcumin in NAFLD treatment through quantitative scientific analysis to serve as a reference for subsequent studies.

STUDY DESIGN

A comprehensive analysis of the mechanism of action of curcumin in the treatment of NAFLD and methods to increase curcumin bioavailability using bibliometric analysis and literature review.

METHODS

This study used VOSviewer software to analyze the literature related to curcumin treatment of NAFLD in the Web of Science (WOS) core set database. A comprehensive and in-depth review was conducted based on the results of scientific econometric research and literature review.

RESULTS

The review observed that curcumin can activate various signaling pathways such as AMPK and NF-κB to inhibit oxidative stress and apoptosis, thereby reflecting its pharmacological effects: lowering lipid, anti-inflammatory, reducing insulin resistance, and anti-fibrosis. These mechanisms improve or even reverse the complex pathological features of lipid metabolism disorders associated with NAFLD. Curcumin also can potentially serve as a primary regulatory target for treating hepatic steatosis using gut microbiota. However, these pharmacological effects of curcumin were limited owing to its low bioavailability.

CONCLUSION

This review discusses NAFLD treatment with curcumin, analyzes the reasons for its low bioavailability, and introduces models for studying and methods for improving curcumin bioavailability. As research on NAFLD grows, future research should capture the trend of basic research, pay attention to clinical research, and continuously explore the therapeutic potential of curcumin.

Molecular Mechanisms of Curcumin in the Pathogenesis of Metabolic Dysfunction Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial condition characterized by insulin resistance, oxidative stress, chronic low-grade inflammation, and sometimes fibrosis. To date, no effective pharmacological therapy has been approved for the treatment of metabolic-associated steatohepatitis (MASH), the progressive form of MASLD. Recently, numerous in vitro and in vivo studies have described the efficacy of nutraceutical compounds in the diet has been tested. Among them, curcumin is the most widely used polyphenol in the diet showing potent anti-inflammatory and antifibrotic activities. This review aims to summarize the most important basic studies (in vitro and animal models studies), describing the molecular mechanisms by which curcumin acts in the context of MASLD, providing the rationale for its effective translational use in humans.

Natural compounds against nonalcoholic fatty liver disease: A review on the involvement of the LKB1/AMPK signaling pathway

Although various therapeutic approaches are used to manage nonalcoholic fatty liver disease (NAFLD), the best approach to NAFLD management is unclear. NAFLD is a liver disorder associated with obesity, metabolic syndrome, and diabetes mellitus. NAFLD progression can lead to cirrhosis and end-stage liver disease. Hepatic kinase B1 (LKB1) is an upstream kinase of 5'-adenosine monophosphate-activated protein kinase (AMPK), a crucial regulator in hepatic lipid metabolism. Activation of LKB1/AMPK inhibits fatty acid synthesis, increases mitochondrial β-oxidation, decreases the expression of genes encoding lipogenic enzymes, improves nonalcoholic steatohepatitis, and suppresses NAFLD progression. One potential opening for new and safe chemicals that can tackle the NAFLD pathogenesis through the LKB1-AMPK pathway includes natural bioactive compounds. Accordingly, we summarized in vitro and in vivo studies regarding the effect of natural bioactive compounds such as a few members of the polyphenols, terpenoids, alkaloids, and some natural extracts on NAFLD through the LKB1/AMPK signaling pathway. This manuscript may shed light on the way to finding a new therapeutic agent for NAFLD management.

Individualized intervention for patients with metabolic fatty liver disease based on Dietary Guidelines for Chinese Residents

BACKGROUND

Metabolic associated fatty liver disease (MAFLD) is widely prevalent. Poor dietary and living habits are closely related to the development of MAFLD. Diet and exercise intervention is one of the important measures for the prevention and treatment of MAFLD, but the intervention strategies are still inconclusive, and further research is still required.

AIM

To explore the effect of individualized intervention through limited energy balanced diet and exercise on MAFLD.

METHODS

MAFLD patients were divided into either an intervention group or a control group according to whether they received individualized diet and exercise intervention or not. At the time of enrollment (T0), the anthropometric information and laboratory indicators of the patients were collected, and the general information, family history, dietary and living habits, and food frequency of the patients were collected by questionnaire survey. Individualized diet and exercise intervention was executed in the intervention group, while routine health education without individualized intervention was executed in the control group. We collected the above parameters after 6 mo (T1) for the second time, and then compared their differences between T0 and T1.

RESULTS

Among 127 MAFLD patients included, those with daily travelling by car accounted for 62.99%, and those preferring sedentary lifestyle (>8 h/d), heavy flavor food, and extra meal accounted for 48.82%, > 50%, and 37.01%, respectively. Five main factors were extracted after factor analysis, including "fungus and vegetable", "grain and milk", "meat and egg", "aquatic", and "snack". The upper quintile (Q5) of the "meat and egg" factor could increase the risk of high triglyceride (odds ratio [OR] = 5.60, 95% confidence interval [CI]: 1.41-22.24) and high cholesterol (OR = 6.45, 95%CI: 1.51-27.63) compared with the lower quintile (Q1); the middle quintile (Q3) of the "aquatic" factor could also increase the risk of high cholesterol (OR = 4.54, 95%CI: 1.10-18.78). The differences in anthropometric information and laboratory test indicators (except glycosylated hemoglobin in the control group) between T0 and T1 were statistically significant (P < 0.05) both in the intervention group and in the control group.

CONCLUSION

Individualized dietary and exercise intervention based on the Dietary Guidelines for Chinese Residents can help MAFLD patients reduce body weight, body mass index, waist circumference, visceral fat area, body fat ratio, etc. and improve their glucose and lipid metabolism effectively.

Preclinical and clinical evidence for the treatment of non-alcoholic fatty liver disease with soybean: A systematic review and meta-analysis

Non-alcoholic fatty liver disease (NAFLD), a prevalent public health issue, involves the accumulation of triglycerides in hepatocytes, which is generally considered to be an early lesion of liver fibrosis and cirrhosis. Thus, the development of treatments for NAFLD is urgently needed. This study explored the preclinical and clinical evidence of soybeans to alleviate NAFLD. Studies indexed in three relevant databases-Web of Science, PubMed, and Embase-between January 2002 and August 2022 were retrieved. A total of 13 preclinical studies and five RCTs that included 212 animals and 260 patients were included in the present analysis. The preclinical analysis showed that liver function indices (AST, SMD = -1.41, p < 0.0001 and ALT, SMD = -1.47, p < 0.0001) were significantly improved in the soybean group compared to the model group, and fatty liver indicators (TG, SMD = -0.78, p < 0.0001; TC, SMD = -1.38, p < 0.0001) and that oxidative stress indices (MDA, SMD = -1.09, p < 0.0001; SOD, SMD = 1.74, p = 0.022) were improved in the soybean group. However, the five RCTs were not entirely consistent with the preclinical results; however, the results confirmed the protective effect on the liver. The results of the clinical RCTs showed that soybean significantly affected liver function, fatty liver, and oxidative stress indicators (ALT, SMD = -0.42, p = 0.006; TG, SMD = -0.31, p = 0.039; MDA, SMD = -0.76, p = 0.007). The current meta-analysis combined preclinical and clinical studies and verified that soybean could protect the liver in NAFLD by regulating lipid metabolism and oxidative stress factors via the Akt/AMPK/PPARα signaling pathway. Soybean might be a promising therapeutic agent for treating non-alcoholic fatty liver disease. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/#myprospero), identifier (CRD42022335822).

Low-molecular weight oligosaccharides from gum tragacanth (Astragalus gossypinus) ameliorate nonalcoholic fatty liver disease (NAFLD) in Wistar male rats

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease affecting 25% of the world's population. The effects of oligosaccharides from Gum tragacanth (Astragalus gossypinus) (GT) on oxidative stress, glucose metabolism, and expression of autophagy genes were investigated in induced non-alcoholic fatty liver. Twenty-four male healthy rats were divided into four groups, Control; high-fat diet, high-fat diet + 100 mg GT oligosaccharides/kg body weight, high-fat diet + 200 mg GT oligosaccharides/kg body weight and fed with the trial diets for 70 days. At the end of the experiment, the results indicated that GT oligosaccharides affected the weight gain and liver weight in NAFLD-induced rats. In addition, the results showed that the use of GT oligosaccharides significantly decreased oxidative stress, liver injury, and hyperglycemia (p < .05) and upregulated the expression of autophagy genes in NAFLD-induced rats.

Practical applications

Overall, the results of the current study demonstrated that the use of GT oligosaccharides obtained from Gum tragacanth (Astragalus gossypinus) showed significant antioxidant properties and hypoglycemia in NAFLD induced rats and could be used as a useful nutritional strategy for the prevention and treatment of NAFLD.

Hawk Tea Flavonoids as Natural Hepatoprotective Agents Alleviate Acute Liver Damage by Reshaping the Intestinal Microbiota and Modulating the Nrf2 and NF-κB Signaling Pathways

Hawk tea (Litsea coreana Levl. var. lanuginosa) is a traditional herbal tea in southwestern China, and was found to possess hepatoprotective effects in our previous study. However, it is unclear whether hawk tea flavonoids (HTF) can alleviate alcoholic liver damage (ALD). Firstly, we extracted and identified the presence of 191 molecules categorized as HTFs, with reynoutrin, avicularin, guaijaverin, cynaroside, and kaempferol-7-O-glucoside being the most prevalent. After taking bioavailability into consideration and conducting comprehensive sorting, the contribution of guaijaverin was the highest (0.016 mg/mice). Then, by daily intragastric administration of HTF (100 mg/kg/day) to the ALD mice, we found that HTF alleviated liver lipid deposition (inhibition of TG, TC, LDL-C) by reducing liver oxidative-stress-mediated inflammation (up-regulation NRF2/HO-1 and down-regulation TLR4/MyD88/NF-κB pathway) and reshaping the gut microbiota (Lactobacillus, Bifidobacterium, Bacillus increased). Overall, we found HTF could be a potential protective natural compound for treating ALD via the gut–liver axis and guaijaverin might be the key substance involved.

Protective effect of orange essential oil on the formation of non-alcoholic fatty liver disease caused by high-fat diet

The purpose of this study was to investigate the protective effect of sniffing orange essential oil (OEO) on the formation of non-alcoholic fatty liver disease (NAFLD) caused by a high-fat diet. The results confirmed that sniffing OEO could reduce obesity caused by a high-fat diet (HFD) by reducing the levels of triglycerides (TGs), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). In addition, the observation of liver tissue sections showed that sniffing OEO could reduce lipid accumulation in liver cells. Further analysis by western blot analysis showed that OEO treatment made the expression levels of acetyl-CoA carboxylase (ACC) and Cytochrome P450 2E1 (CYP2E1) down-regulated and the expression levels of peroxisome proliferator-activated receptor-α (PPAR-α) and carnitine palmitoyltransferase-1 (CPT-1) up-regulated. These results indicate that the treatment of sniffing OEO could enhance the antioxidant capacity of mice and reduce liver damage caused by a high-fat diet. Furthermore, sniffing OEO could inhibit lipid synthesis and oxidative stress stimulated by a high-fat diet. Overall, OEO treatment had a certain protective effect on NAFLD-related diseases caused by a high-fat diet. Therefore, aromatherapy may be introduced as a treatment of long-term chronic diseases.

Oxidative Stress Is a Key Modulator in the Development of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and scientific studies consistently report that NAFLD development can be accelerated by oxidative stress. Oxidative stress can induce the progression of NAFLD to NASH by stimulating Kupffer cells, hepatic stellate cells, and hepatocytes. Therefore, studies are underway to identify the role of antioxidants in the treatment of NAFLD. In this review, we have summarized the origins of reactive oxygen species (ROS) in cells, the relationship between ROS and NAFLD, and have discussed the use of antioxidants as therapeutic agents for NAFLD.

The effect of pomegranate extract on anthropometric indices, serum lipids, glycemic indicators, and blood pressure in patients with nonalcoholic fatty liver disease: A randomized double-blind clinical trial

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. The beneficial effects of pomegranate have been shown on insulin resistance and obesity, which are linked to NAFLD pathogenesis. The aim of this study was to investigate the efficacy of pomegranate extract in patients with NAFLD. Forty-four NAFLD patients were randomly assigned to receive two pomegranate extract tablets or placebo for 12 weeks. Anthropometric measurements, serum lipids, glycemic indicators, and blood pressure were assessed at baseline and the end of the study. Pomegranate was associated with a reduction in the total cholesterol (p ˂ .001), triglyceride (p ˂ .001), low-density lipoprotein cholesterol (LDL-C)-to-high-density lipoprotein cholesterol (HDL-C) ratio (p ˂ .003), fasting blood sugar (p ˂ .001), homeostatic model assessment of insulin resistance (p = .02), diastolic blood pressure (p = .04), weight (p ˂ .001), body mass index (p ˂ .001), and waist circumference (p = .002), as compared to placebo. A significant increase was observed in serum HDL-C (p ˂ .001) after intervention with the pomegranate extract. However, no significant difference was shown between the two groups in serum insulin and LDL-C. The pomegranate extract supplement could be used as a complementary therapy along with existing therapies to improve glycemic indicators, serum lipids, anthropometric indices, and blood pressure in patients with nonalcoholic fatty liver.

Porphyran-derived oligosaccharides alleviate NAFLD and related cecal microbiota dysbiosis in mice

Porphyran and its derivatives possess a variety of biological activities, such as ameliorations of oxidative stress, inflammation, hyperlipemia, and immune deficiencies. In this study, we evaluated the potential efficacy of porphyran-derived oligosaccharides from Porphyra yezoensis (PYOs) in alleviating nonalcoholic fatty liver disease (NAFLD) and preliminarily clarified the underlying mechanism. NAFLD was induced by a high-fat diet for six months in C57BL/6J mice, followed by treatment with PYOs (100 or 300 mg/kg/d) for another six weeks. We found that PYOs reduced hepatic oxidative stress in mice with NAFLD, which plays a critical role in the occurrence and development of NAFLD. In addition, PYOs could markedly decrease lipid accumulation in liver by activating the IRS-1/AKT/GSK-3β signaling pathway and the AMPK signaling pathway in mice with NAFLD. PYOs also apparently relieved the hepatic fibrosis induced by oxidative stress via downregulation of TGF-β and its related proteins, so that liver injury was markedly alleviated. Furthermore, PYOs treatment relieved cecal microbiota dysbiosis (such as increasing the relative abundance of Akkermansia, while decreasing the Helicobacter abundance), which could alleviate oxidative stress, inflammation, and lipid metabolism, and protect the liver to a certain degree. In summary, PYOs treatment remarkably improved NAFLD via a specific molecular mechanism and reshaped the cecal microbiota.

Effects of several tea extracts on nonalcoholic fatty liver disease in mice fed with a high-fat diet

Nonalcoholic fatty liver disease (NAFLD) is considered as a severe threat to human health. It has been reported that tea has abundant bioactive compounds and beneficial effects. In our study, the effects of 12 tea extracts on NAFLD were assessed and compared at the dose of 200 mg/kg body weight in mice fed with a high-fat diet (HFD) for 15 weeks. Enshi Yulu Tea, Fenghuang Narcissus Tea, and Yihong Tea showed strong effects in suppressing the accumulation of epididymal and perirenal adipose tissue as well as the increases of body weight and liver weight. The histopathological analysis revealed that hepatic steatosis and adipocyte hypertrophy induced by a HFD could be ameliorated by tea supplementation. In addition, Enshi Yulu Tea and Qing Brick Tea exerted more remarkable functions on decreasing the level of serum triglyceride and preventing hepatic fat accumulation, respectively. Furthermore, Fenghuang Narcissus Tea, Enshi Yulu Tea, and Qing Brick Tea could reverse the abnormal change in the levels of glutathione and superoxide dismutase. Moreover, 13 phytoconstituents were detected and quantified in these teas with high-performance liquid chromatography (HPLC) method. The correlation analysis demonstrated that gallic acid might decrease MDA level, and the reduction of liver weight might be attributed to ellagic acid. However, it should be paid attention to some teas that showed hepatotoxicity with elevated levels of aspartate transaminase and alanine aminotransferase. Several teas showed strong effects in the prevention of NAFLD, which could be developed into functional foods against NAFLD.

Lactobacillus casei YRL577 combined with plant extracts reduce markers of non-alcoholic fatty liver disease in mice

Probiotics and plant extracts are considered to prevent the development of non-alcoholic fatty liver disease (NAFLD). The present study explores the effects of using both probiotics and plant extracts on NAFLD. The present study evaluated the effects of plant extracts on lipid droplet accumulation and the growth of probiotics in vitro. A C57BL/6 mouse model was used to examine the effects of probiotics and plant extracts on NAFLD. Body weight and food intake were measured. The levels of serum lipids, oxidative stress and the liver injury index were determined using commercial kits. Haematoxylin and eosin staining, GC and real-time PCR were also used for analysis. The results revealed that administration of Lactobacillus casei YRL577 and L. paracasei X11 with resveratrol (RES) or tea polyphenols (TP) significantly reduced the levels of total cholesterol, TAG and LDL-cholesterol and increased the level of the HDL-cholesterol. The groups of L. casei YRL577 with RES and TP also regulated the liver structure, oxidative stress and injury. Furthermore, L. casei YRL577 with TP exhibited a more positive effect towards improving the NAFLD and increased the concentrations of the butyric acid than other three combined groups. L. casei YRL577 with TP up-regulated the mRNA levels of the farnesoid X receptor and fibroblast growth factor 15 and decreased the mRNA levels of the apical Na-dependent bile acid transporter. These findings showed that L. casei YRL577 + TP-modified genes in the intestinal bile acid pathway improved markers of NAFLD.

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

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

Acute oral treatment with resveratrol and Lactococcus Lactis Subsp. Lactis decrease body weight and improve liver proinflammatory markers in C57BL/6 mice

The present study aimed to evaluate the effects of resveratrol, a nutraceutical polyphenol, and Lactococcus lactis (bacteria probiotic), on metabolic parameters and hepatic proinflammatory markers expression. C57BL/6 mice were divided into 4 groups: Standard (ST), Lactococcus lactis (LL), Resveratrol (RSV), and Lactococcus lactis plus resveratrol (LL + RSV). Lactococcus lactis and resveratrol were administered by orogastric gavage. Blood parameters were assessed (total cholesterol, triglycerides, ALT and AST). IL-6 mRNA expression was evaluated by Real-time PCR and TNF-α protein expression was assessed by immunohistochemistry. The main findings showed that resveratrol and Lactococcus lactis association decreased body weight, aspartate aminotransferase and total cholesterol levels. LL and LL + RSV decreased triglycerides levels and IL-6 and TNF-α expression. These results open a perspective of using resveratrol and Lactococcus lactis to improve metabolic parameters and Lactococcus lactis in preventing inflammation and the hepatic diseases development.

Improvement in Menopause-Associated Hepatic Lipid Metabolic Disorders by Herbal Formula HPC03 on Ovariectomized Rats

Postmenopausal women have an increased risk of developing nonalcoholic fatty liver disease (NAFLD). We formulated a combination of three herb mixtures (HPC03) and observed lipid-lowering efficacy. HepG2 cells were treated with oleic acid to induce an NAFLD model (in vitro). Also, we investigated potential of HPC03 in an ovariectomize- (OVX-) induced NAFLD model (in vivo). We separated the mice into six groups, as follows: SHAM, OVX, OVX + β-estradiol, and OVX + HPC03 (50, 100, and 200 mg/kg). Rats were administered with/without HPC03 for 12 weeks. HPC03 dose dependently inhibited the lipid accumulation involved in lipogenesis in HepG2 cells. The body weight, fat mass, and weights of the liver were decreased in the OVX group than that in the other groups. HPC03 had decreased adiposity that was induced by OVX. HPC03 treatment reduced liver lipid deposition and prevented the increase in serum and liver triglyceride export when there was a deficiency in estradiol. HPC03 improves OVX-induced fatty liver and lipid metabolism. These findings suggest that HPC03 from postmenopausal women has a protective effect during NAFLD conditions.

Semen Cuscutae Administration Improves Hepatic Lipid Metabolism and Adiposity in High Fat Diet-Induced Obese Mice

Since arginase has been shown to compete with nitric oxide (NO) synthase, emerging evidence has reported that arginase inhibition improves obesity by increasing NO production. Semen cuscutae (SC), which is a well-known Chinese medicine, has multiple biological functions such as anti-oxidant function and immune regulation. In this study, we investigated whether the SC as a natural arginase inhibitor influences hepatic lipid abnormalities and whole-body adiposity in high-fat diet (HFD)-induced obese mice. The lipid accumulation was significantly reduced by SC treatment in oleic acid-induced hepatic steatosis in vitro. Additionally, SC supplementation substantially lowered HFD-induced increases in arginase activity and weights of liver and visceral fat tissue, while increasing hepatic NO. Furthermore, elevated mRNA expressions of sterol regulatory element-binding transcription factor 1 (SREBP-1c), fatty-acid synthase (FAS), peroxisome proliferator-activated receptor-gamma (PPAR-γ)1, and PPAR-γ2 in HFD-fed mice were significantly attenuated by SC supplementation. Taken together, SC, as a novel natural arginase inhibitor, showed anti-obesity properties by modulating hepatic arginase and NO production and metabolic pathways related to hepatic triglyceride (TG) metabolism.

Chitosan Oligosaccharide Attenuates Nonalcoholic Fatty Liver Disease Induced by High Fat Diet through Reducing Lipid Accumulation, Inflammation and Oxidative Stress in C57BL/6 Mice

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease closely associated with metabolic syndrome, but there are no validated pharmacological therapies. The aim of this study was to investigate the effect of chitosan oligosaccharide (COS) on NAFLD. Mice were fed either a control diet or a high-fat diet (HFD) with or without COS (200 or 400 mg/kg body weight (BW)) by oral gavage for seven weeks. Administration with COS significantly lowered serum lipid levels in the HFD-fed mice. The hepatic lipid accumulation was significantly decreased by COS, which was attributed to decreased expressions of lipogenic genes and increased expressions of fatty β-oxidation-related genes. Moreover, pro-inflammatory cytokines, neutrophils infiltration, and macrophage polarization were decreased by COS in the liver. Furthermore, COS ameliorated hepatic oxidative stress by activating the nuclear factor E2-related factor 2 (Nrf2) pathway and upregulating gene expressions of antioxidant enzymes. These beneficial effects were mediated by the activation of the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. Therefore, COS might be a potent dietary supplement to ameliorate NAFLD.

Apple Polyphenol Extract Alleviates High-Fat-Diet-Induced Hepatic Steatosis in Male C57BL/6 Mice by Targeting LKB1/AMPK Pathway

To explore the role of apple polyphenol extract (APE) in ameliorating hepatic steatosis and the potential mechanisms involved, we conducted this study. Thirty-three male C57BL/6 mice were randomly divided into three groups: high-fat diet (HFD) with aseptic water ig. (CON), HFD with 125 or 500 mg/(kg·bw·day) APE ig., namely 100 or 400 mg/(kg·bw·day) apple polyphenols (LAP or HAP) for 12 weeks. Compared with the CON group, the APE treatment significantly decreased the body weight gain and increased the ratio of serum albumin/globulin. High dose of APE treatment significantly decreased the liver weight, reduced the hepatic contents of triglyceride and cholesterol, and improved the histopathological features of hepatic steatosis, accompanied by significantly upregulated protein expressions of LKB1, phosphorylated-AMPK, phosphorylated-ACC, and SIRT1, downregulated mTOR, p70 s6k, and HMGCR in the liver, increased mRNA expressions of Ampk and Cyp27a1, and reduced expressions of Srebp-1c, Fas, and Hmgcr. Our data provided new evidence supporting the preventive role of 500 mg/(kg·bw·day) APE treatment in the HFD-induced hepatic steatosis in C57BL/6 mice via the LKB1/AMPK pathway.

Combinatorial Epigenetics Impact of Polyphenols and Phytochemicals in Cancer Prevention and Therapy

Polyphenols are potent micronutrients that can be found in large quantities in various food sources and spices. These compounds, also known as phenolics due to their phenolic structure, play a vital nutrient-based role in the prevention of various diseases such as diabetes, cardiovascular diseases, neurodegenerative diseases, liver disease, and cancers. However, the function of polyphenols in disease prevention and therapy depends on their dietary consumption and biological properties. According to American Cancer Society statistics, there will be an expected rise of 23.6 million new cancer cases by 2030. Due to the severity of the increased risk, it is important to evaluate various preventive measures associated with cancer. Relatively recently, numerous studies have indicated that various dietary polyphenols and phytochemicals possess properties of modifying epigenetic mechanisms that modulate gene expression resulting in regulation of cancer. These polyphenols and phytochemicals, when administrated in a dose-dependent and combinatorial-based manner, can have an enhanced effect on epigenetic changes, which play a crucial role in cancer prevention and therapy. Hence, this review will focus on the mechanisms of combined polyphenols and phytochemicals that can impact various epigenetic modifications such as DNA methylation and histone modifications as well as regulation of non-coding miRNAs expression for treatment and prevention of various types of cancer.

Natural compounds in the chemoprevention of alcoholic liver disease

Alcoholic liver disease (ALD), caused by excessive consumption of alcohol, is a major cause of chronic liver disease worldwide. Much effort has been expended to explore the pathogenesis of ALD. Hepatic cell injury, oxidative stress, inflammation, regeneration, and bacterial translocation are all involved in the pathogenesis of ALD. Immediate abstinence is the most important therapeutic treatment for affected individuals. However, the medical treatment for ALD had not advanced in a long period. Intriguingly, an increasing body of research indicates the potential of natural compounds in the targeted therapy of ALD. A plethora of dietary natural products such as flavonoids, resveratrol, saponins, and β-carotene are found to exert protective effects on ALD. This occurs through various mechanisms composed of antioxidative, anti-inflammatory, iron chelation, pro-apoptosis, and/or antiproliferation of hepatic stellate cells and hepatocellular carcinoma cells. In this review, we will summarize current knowledge about the pathogenesis and treatments of ALD and focus on the potential of natural compounds in ALD therapies and underlying mechanisms.

Protective effect of genistein on nonalcoholic fatty liver disease (NAFLD)

NAFLD is a vital health problem worldwide; however, no effective treatment is currently available for NAFLD. Intensive studies have indicated the efficacy of genistein (GE), a bioactive isoflavone extracted from soy, in treating NAFLD. In addition to its oestrogen-like effects, GE is known to have multiple molecular effects, for instance, lipid and glucose metabolism-promoting effects and activities against lipid peroxidation, inflammation, fibrosis, and NAFLD-related tumours. Here, this review summarizes the potential role of GE in the treatment and prevention of NAFLD and some of the currently known targets and signalling pathways of GE in NAFLD.

Preventive Efficiency of Green Tea and Its Components on Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a typical chronic liver disease highly correlated with metabolic syndrome. Growing prevalence of NAFLD is supposed to be linked with the unhealthy lifestyle, especially high-calorie diet and lacking enough exercise. Currently, there is no validated pharmacological therapy for NAFLD except for weight reduction. However, many dietary strategies had preventive effects on the development of liver steatosis or its progression. As one of the most common beverages, green tea contains abundant bioactive compounds possessing antioxidant, lipid-lowering, and anti-inflammatory effects, as well as improving insulin resistance and gut dysbiosis that can alleviate the risk of NAFLD. Hence, in this review, we summarized the studies of green tea and its components on NAFLD from animal experiments and human interventions and discussed the potential mechanisms. Available evidence suggested that tea consumption is promising to prevent NAFLD, and further mechanisms and clinical studies need to be investigated.

Free fatty acid-induced histone acetyltransferase activity accelerates lipid accumulation in HepG2 cells

BACKGROUND/OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disease triggered by epigenetic alterations, including lysine acetylation at histone or non-histone proteins, affecting the stability or transcription of lipogenic genes. Although various natural dietary compounds have anti-lipogenic effects, their effects on the acetylation status and lipid metabolism in the liver have not been thoroughly investigated.

MATERIALS/METHODS

Following oleic-palmitic acid (OPA)-induced lipid accumulation in HepG2 cells, the acetylation status of histone and non-histone proteins, HAT activity, and mRNA expression of representative lipogenic genes, including PPARγ, SREBP-1c, ACLY, and FASN, were evaluated. Furthermore, correlations between lipid accumulation and HAT activity for 22 representative natural food extracts (NExs) were evaluated.

RESULTS

Non-histone protein acetylation increased following OPA treatment and the acetylation of histones H3K9, H4K8, and H4K16 was accelerated, accompanied by an increase in HAT activity. OPA-induced increases in the mRNA expression of lipogenic genes were down-regulated by C-646, a p300/CBP-specific inhibitor. Finally, we detected a positive correlation between HAT activity and lipid accumulation (Pearson's correlation coefficient = 0.604) using 22 NExs.

CONCLUSIONS

Our results suggest that NExs have novel applications as nutraceutical agents with HAT inhibitor activity for the prevention and treatment of NAFLD.

Prevention of Obesity and Hyperlipidemia by Heptamethoxyflavone in High-fat Diet-induced Rats

Polymethoxyflavones (PMFs) have been shown to prevent obesity, ameliorate type 2 diabetes, and regulate lipid metabolism in vitro and in vivo. However, little is known about the contribution of 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF) to prevent obesity and regulate lipid metabolism in vivo. We aimed to investigate the potential efficacy of HMF on preventing obesity and hyperlipidemia in rats fed a high-fat diet (HFD) and its underlying mechanisms. Male Sprague-Dawley rats were fed a normal diet or an HFD with or without HMF (0.02%, 0.04% and 0.08%, w/w) for 6 weeks. The supplementation of HMF not only significantly decreased body weight gain (HFD, 336.50 ± 18.84 g; LHMF, 309.43 ± 20.74 g; MHMF, 296.83 ± 13.88 g; HHMF, 265.71 ± 19.09 g; respectively, p < 0.05) and adipose tissues weight ( p < 0.05), but also markedly lowered serum levels of total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol ( p < 0.05) in the sixth week in a dose-dependent manner compared with the HFD group. HMF also significantly alleviated hepatic steatosis in the liver (liver weight g/100 g body weight of HFD, 4.86 ± 0.11%; LHMF, 4.02 ± 0.33%; MHMF, 4.05 ± 0.31%; HHMF, 3.72 ± 0.34%; respectively, p < 0.05). Furthermore, transcriptome analysis and real-time quantitative RT-PCR demonstrated that HMF supplementation markedly downregulated hepatic genes related to adipogenesis transcription and inflammatory responses, and significantly upregulated genes related to fatty acid oxidation and energy expenditure. These results indicated that HMF could effectively prevent obesity and hyperlipidemia by regulation of the expression of lipid metabolism-related and inflammatory response-related genes.

Serum levels of advanced glycation end-products (AGEs) and the decoy soluble receptor for AGEs (sRAGE) can identify non-alcoholic fatty liver disease in age-, sex- and BMI-matched normo-glycemic adults

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem affecting ~25% of the global population. While NAFLD pathogenesis is still unclear, multiple NAFLD parameters, including reduced insulin sensitivity, impaired glucose metabolism and increased oxidative stress are hypothesised to foster the formation of advanced glycation end-products (AGEs). Given the link of AGEs with end organ damage, there is scope to examine the role of the AGE/RAGE axis activation in liver injury and NAFLD.

METHODS

Age, sex and body mass index matched normo-glycemic NAFLD adults (n = 58) and healthy controls (n = 58) were enrolled in the study. AGEs were analysed by liquid chromatography-mass spectrometry (CML, CEL), fluorescence (pentosidine, AGE fluorescence), colorimetry (fructosamine) and ELISA (sRAGE). Their association with liver function, inflammation, fibrosis and stage of NAFLD was examined.

RESULTS

Early and advanced glycation end-products, except N^ε-carboxymethyl-L-lysine (CML), were 10-30% higher, sRAGE levels 1.7-fold lower, and glycation/sRAGE ratios 4-fold higher in the NAFLD cases compared to controls. While AGEs presented weak to moderate correlations with indices of liver function and damage (AST/ALT, HOMA-IR, TNF-α and TGF-β1), including sRAGE to characterize the AGEs/sRAGE axis strengthened the associations observed. High glycation/sRAGE ratios were associated with 1.3 to 14-fold likelihood of lower AST/ALT ratios. The sum of AGEs/sRAGE ratios accurately distinguished between healthy controls and NAFLD patients (area under the curve of 0.85). Elevated AGEs/sRAGE (>7.8 mmol/pmol) was associated with a 12-fold likelihood of the presence of NAFLD.

CONCLUSION

These findings strengthen the involvement of AGEs-RAGE axis in liver injury and the pathogenesis of NAFLD.

Long-term fermented soybean paste improves metabolic parameters associated with non-alcoholic fatty liver disease and insulin resistance in high-fat diet-induced obese mice

Recently, Korean traditional fermented soybean paste, called Doenjang, has attracted attention for its protective effect against diet-related chronic diseases such as obesity and type 2 diabetes. Long-term fermented soybean pastes (LFSPs) are made by fermentation with naturally-occurring microorganisms for several months, whereas short-term fermented soybean pastes (SFSPs) are produced by shorter-time fermentation inoculated with a starter culture. Here, we demonstrate that administration of LFSP, but not SFSP, protects high-fat diet (HFD)-fed obese mice against non-alcohol fatty liver disease (NAFLD) and insulin resistance. LFSP suppressed body weight gain in parallel with reduction in fat accumulation in mesenteric adipose tissue (MAT) and the liver via modulation of MAT lipolysis and hepatic lipid uptake. LFSP-treated mice also had improved glucose tolerance and increased adiponectin levels concomitantly with enhanced AMPK activation in skeletal muscle and suppressed expression of pro-inflammatory cytokines in skeletal muscle and the liver. LFSP also attenuated HFD-induced gut permeability and lowered serum lipopolysaccharide level, providing an evidence for its probiotic effects, which was supported by the observation that treatment of a probiotic mixture of LFSP-originated Bacillus strains protected mice against HFD-induced adiposity and glucose intolerance. Our findings suggest that the intake of LFSP, but not SFSP, offers protection against NAFLD and insulin resistance, which is an effect of long-term fermentation resulting in elevated contents of active ingredients (especially flavonoids) and higher diversity and richness of Bacillus probiotic strains compared to SFSP.

Potential Biological Effects of (-)-Epigallocatechin-3-gallate on the Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a major health issue throughout the world. However, no validated treatments for NAFLD are currently available. In‐depth studies have demonstrated the efficacy of (‐)‐epigallocatechin‐3‐gallate (EGCG), a main bioactive chemical extracted from green tea, in treating NAFLD. EGCG exhibits multi‐pronged preventive and therapeutic activities, including promoting lipid and glucose metabolism, anti‐lipid peroxidation and anti‐inflammation activities, anti‐fibrosis, and anti‐NAFLD related tumor, thus contributing to the mitigation of NAFLD occurrence and progression. The objectives of this paper are to review and discuss the currently known targets, signaling pathways and roles of EGCG that interfere with NAFLD pathogenesis, then providing additional experimental evidence and the foundation for the further studies and clinical applications of EGCG in the prevention and treatment of NAFLD.

Combination of citrus polymethoxyflavones, green tea polyphenols, and Lychee extracts suppresses obesity and hepatic steatosis in high-fat diet induced obese mice

SCOPE

SlimTrym^® is a formulated product composed of citrus polymethoxyflavones (PMFs), green tea extract, and lychee extract. We investigated the effect of dietary SlimTrym^® on diet-induced obesity and associated non-alcoholic fatty liver disease (NAFLD) in mice.

METHODS AND RESULTS

Male C57BL/6 mice were fed a normal diet (ND), high fat diet (HFD) or HFD containing 0.1% or 0.5% SlimTrym^® for 16 weeks. Dietary SlimTrym^® significantly reduced weight gain and relative perigonadal, retroperitoneal, mesenteric fat weight as well as the size of adipocyte in HFD-fed mice. SlimTrym^® supplementation also effectively diminished hepatic steatosis and the serum levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), triacylglycerol (TG), and total cholesterol (TCHO). Down-regulation of peroxisome proliferator-activated receptor (PPAR)γ, sterol regulatory element-binding protein (SREBP)-1, and the activation of AMP-activated protein kinase (AMPK) signaling by SlimTrym^® in both adipose tissue and liver may be responsible for the observed anti-obesity effects.

CONCLUSION

SlimTrym^® supplementation potentially diminished diet-induced obesity and hepatic steatosis via regulating AMPK signaling and molecules involved in lipid metabolism.

Genistein has beneficial effects on hepatic steatosis in high fat-high sucrose diet-treated rats

Genistein, a kind of phytoestrogen abundant in soybeans, is beneficial for alleviating non-alcoholic fatty liver disease (NAFLD), but the specific mechanism was not clearly understood. This study was designed to determine the effect of genistein on NAFLD and explore the possible mechanism. 36 male Sprague-Dawley rats were divided into 4 groups: the control group, high fat-high sucrose diet (HFS) group, HFS with 4mg/kg body weight genistein, and HFS with 8mg/kg body weight genistein. 12 weeks later, serum and hepatic lipid profiles, liver histopathological examination were characterized. The protein levels of liver AMP-activated protein kinase (AMPK), phosphorylation of AMPK (p-AMPK), acetyl-CoA carboxylase (ACC), phosphorylation of ACC (p-ACC) and sterol regulatory element binding protein 1 (SREBP-1) were determined by western blot. mRNA expressions of fatty acid synthase gene (FAS) and glycerol-3-phosphate acyltransferase (GPAT), peroxisome proliferator-activated receptor α (PPARα), carnitine palmitoyl transfer enzyme-1 (CPT-1) and acyl-CoA oxidase (ACO) were measured by reverse transcription polymerase chain reaction (RT-PCR). Results showed that genistein effectively improved serum and hepatic lipid metabolism and diminished fat accumulation in liver. And the protein level of hepatic p-AMPK and p-ACC were increased, but SREBP-1 was decreased by genistein. Meanwhile, the mRNA levels of FAS and GPAT were lower, but PPARα, CPT-1, ACO were higher in rats treated with genistein compared with HFS group. Collectively, genistein can improve hepatic steatosis via activating AMPK, thus promoting fatty acid oxidation and inhibiting lipid synthesis in liver.

Lycopene and tomato powder supplementation similarly inhibit high-fat diet induced obesity, inflammatory response, and associated metabolic disorders

SCOPE

Several studies have linked the high intake of lycopene or tomatoes products with lower risk for metabolic diseases. The aim of the present study was to evaluate and to compare the effect of lycopene and tomato powder on obesity-associated disorders.

METHODS AND RESULTS

Male C57BL/J6 mice were assigned into four groups to receive: control diet (CD), high fat diet (HFD), high fat diet supplemented with lycopene or with tomato powder (TP) for 12 weeks. In HFD condition, lycopene and TP supplementation significantly reduced adiposity index, organ, and relative organ weights, serum triglycerides, free fatty acids, 8-iso-prostaglandin GF2α and improved glucose homeostasis, but did not affect total body weight. Lycopene and TP supplementation prevented HFD-induced hepatosteatosis and hypertrophy of adipocytes. Lycopene and TP decreased HFD-induced proinflammatory cytokine mRNA expression in the liver and in the epididymal adipose tissue. The anti-inflammatory effect of lycopene and TP was related to a reduction in the phosphorylation levels of IκB, and p65, and resulted in a decrease of inflammatory proteins in adipose tissue.

CONCLUSION

These results suggest that lycopene or TP supplementation display similar beneficial health effects that could be particularly relevant in the context of nutritional approaches to fight obesity-associated pathologies.

Non-alcoholic fatty liver disease and flavonoids: Current perspectives

Non-alcoholic fatty liver disease (NAFLD) is an accumulation of fat in the liver despite a low level of alcohol intake, with signs of hepatomegaly. Although in the past, NAFLD was predominantly viewed as an aspect of metabolic syndrome, it is now considered that it should be classified as an independent condition similar to obesity, diabetes, and hypertension. Therefore, new treatment strategies, not based on correcting insulin resistance, are needed for NAFLD. This work analyzes methods of prevention, therapeutic approaches, and mechanisms involved in NAFLD, focusing on the use of flavonoids (epigallocatechin-3-gallate, resveratrol, anthocyanins, and isoflavones) with high antioxidant capacity. In addition, the mechanisms of cholesterol accumulation in the liver are identified as potential avenues for entirely new approaches to NAFLD treatment, contrasting the well-known relation between neutral fat and NAFLD.

Chemopreventive effect of natural dietary compounds on xenobiotic-induced toxicity

Contaminants (or pollutants) that affect human health have become an important issue, spawning a myriad of studies on how to prevent harmful contaminant-induced effects. Recently, a variety of biological functions of natural dietary compounds derived from consumed foods and plants have been demonstrated in a number of studies. Natural dietary compounds exhibited several beneficial effects for the prevention of disease and the inhibition of chemically-induced carcinogenesis. Contaminant-induced toxicity and carcinogenesis are mostly attributed to the mutagenic activity of reactive metabolites and the disruption of normal biological functions. Therefore, the metabolic regulation of hazardous chemicals is key to reducing contaminant-induced adverse health effects. Moreover, promoting contaminant excretion from the body through Phase I and II metabolizing enzymes is also a useful strategy for reducing contaminant-induced toxicity. This review focuses on summarizing the natural dietary compounds derived from common dietary foods and plants and their possible mechanisms of action in the prevention/suppression of contaminant-induced toxicity.

Pentoxifylline ameliorates non-alcoholic fatty liver disease in hyperglycaemic and dyslipidaemic mice by upregulating fatty acid β-oxidation

Nonalcoholic fatty liver disease (NAFLD), which includes simple steatosis, steatohepatitis, fibrosis, and cirrhosis, is characterised by abnormal fat accumulation in the liver in the absence of excessive alcohol intake. In patients with type 2 diabetes (T2D), concurrent NAFLD might increase the risk of chronic kidney disease and the mortality rate. Although several studies have examined the effectiveness of pentoxifylline (PTX) in NAFLD treatment, no results are available to verify the effectiveness of PTX in treating T2D associated with NAFLD. In this study, we developed a combined high-fat diet-induced obesity and low-dose streptozocin-induced hyperglycaemia mouse model to mimic the concurrent NAFLD and T2D pathological condition. By combining physiological assessments, pathological examinations, metabolomics studies on blood, urine, and liver, and measurements of gene and protein expression, we elucidated the effectiveness and the underlying mechanism of action of PTX in the hyperglycaemic and dyslipidaemic mice. Our results revealed that PTX ameliorated NAFLD in the hyperglycaemic and dyslipidaemic mice by upregulating fatty acid β-oxidation. Furthermore, the glycolysis pathway and branched-chain amino acid-related pathways in these mice were restored by PTX.

EFFECTS OF RESVERATROL ON LIVER FUNCTION OF OBESE FEMALE WISTAR RATS

Abstract Resveratrol has antioxidant, anti-inflammatory, lipolytic, and antifibrotic properties, which may be useful in supplementation of obese patients and with liver problems. This study evaluated the effects of 6-week resveratrol supplementation on the lipid profile and liver function of female Wistar rats fed a high-fat diet to induce obesity. Sixty-four Wistar rats were divided into 4 groups (n = 16): the control group (C); the control obese group (CO); the resveratrol group (R); and the resveratrol obese group (RO). At the end of the experiment, the animals were anesthetized for blood collection and subsequent euthanasia for collection of liver biopsy. The parameters for body weight, liver weight, retroperitoneal fat weight, serum lipid and liver profiles and histopathological analysis were evaluated. The 6-week resveratrol administration did not induce weight loss nor did it reduce the lipid profile; however, it decreased the liver enzymes aspartate aminotransferase (AST) and alkaline phosphatase (ALP) and reduced the incidence of steatosis (75.0%) in group RO compared with group CO (81.2%). Thus, we concluded that resveratrol supplementation for the short period of six weeks had a beneficial effect on liver function by reducing hepatic steatosis and the liver enzymes AST and ALP in obese female rats.

Herbal medicines and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), which is characterized by excessive fat accumulation in the liver of patients who consume little or no alcohol, becomes increasingly common with rapid economic development. Long-term excess fat accumulation leads to NAFLD and represents a global health problem with no effective therapeutic approach. NAFLD is considered to be a series of complex, multifaceted pathological processes involving oxidative stress, inflammation, apoptosis, and metabolism. Over the past decades, herbal medicines have garnered growing attention as potential therapeutic agents to prevent and treat NAFLD, due to their high efficacy and low risk of side effects. In this review, we evaluate the use of herbal medicines (including traditional Chinese herbal formulas, crude extracts from medicinal plants, and pure natural products) to treat NAFLD. These herbal medicines are natural resources that can inform innovative drug research and the development of treatments for NAFLD in the future.

Mediterranean diet and nonalcoholic fatty liver disease: molecular mechanisms of protection

Nutritional habits modifications have shown an important impact in preventing and ameliorating metabolic alterations, such as nonalcoholic fatty liver disease (NAFLD). Among several dietary approaches that exert positive effects in NAFLD patients, the Mediterranean dietary pattern has shown notable benefits. This review explores the molecular mechanisms through which the Mediterranean diet would improve risk factors associated with metabolic syndrome and NAFLD. The main features of the Mediterranean diet acting on metabolism are represented by its whole-grain and low glycemic index cereal-based items, its fatty acid profile, and its content in phytochemical compounds. Carbohydrate-rich foods high in dietary fiber inducing low glycemic response are able to interact with glucose and insulin metabolism. Unsaturated fatty acids are associated with better hepatic lipid metabolism. Finally, phytochemical compounds, such as dietary polyphenols, are thought to ameliorate inflammation, which is considered one of the mechanisms through which NALFD may evolve into nonalcoholic steatohepatitis (NASH).