Green Tea Extract Rich in Epigallocatechin-3-Gallate Prevents Fatty Liver by AMPK Activation via LKB1 in Mice Fed a High-Fat Diet

Bridging the gap: Integrating exercise mimicry into chronic disease management through suppressing chronic inflammation

BACKGROUND

Chronic inflammation is a common hallmark of many chronic diseases. Although exercise holds paramount importance in preventing and managing chronic diseases, adherence to exercise programs can be challenging for some patients. Consequently, there is a pressing need to explore alternative strategies to emulate the anti-inflammatory effects of exercise for chronic diseases.

AIM OF REVIEW

This review explores the emerging role of green tea bioactive components as potential mitigators of chronic inflammation, offering insights into their capacity to mimic the beneficial effects of exercise. We propose that bioactive components in green tea are promising agents for suppressing chronic inflammation, suggesting their unique capability to replicate the health benefits of exercise.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review focuses on several key concepts, including chronic inflammation and its role in chronic diseases, the anti-inflammatory effects of regular exercise, and bioactive components in green tea responsible for its health benefits. It elaborates on scientific evidence supporting the anti-inflammatory properties of green tea bioactive components, such as epigallocatechin gallate (EGCG), and theorizes how these bioactive components might replicate the effects of exercise at a molecular level. Through a comprehensive analysis of current research, this review proposes a novel perspective on the application of green tea as a potential intervention strategy to suppress chronic inflammation, thereby extending the benefits akin to those achieved through exercise.

Tea Polyphenol Epigallocatechin Gallate Protects Against Nonalcoholic Fatty Liver Disease and Associated Endotoxemia in Rats via Modulating Gut Microbiota Dysbiosis and Alleviating Intestinal Barrier Dysfunction and Related Inflammation

Nonalcoholic fatty liver disease (NAFLD) is characterized by fat accumulation and inflammation. Epigallocatechin gallate (EGCG) has been proven to be effective against NAFLD, but its hepatoprotective mechanisms based on the "gut microbiota-barrier-liver axis" are still not fully understood. Herein, the results demonstrated that EGCG effectively ameliorated NAFLD phenotypes and metabolic disorders in rats fed a high-fat diet (HFD), and inhibited intestinal barrier dysfunction and inflammation, which is also supported in the experiment of Caco-2 cells. Moreover, EGCG could restore gut microbiota diversity and composition, particularly promoting beneficial microbes, including short-chain fatty acids (SCFAs) producers, such as Lactobacillus, and suppressing Gram-negative bacteria, such as Desulfovibrio. The microbial modulation raised SCFA levels, decreased lipopolysaccharide levels, inhibited the TLR4/NF-κB pathway, and strengthened intestinal barrier function via Nrf2 pathway activation, thereby alleviating liver steatosis and inflammation. Spearman's correlation analysis showed that 24 key OTUs, negatively or positively associated with NAFLD and metabolic disorders, were also reshaped by EGCG. Our results suggested that a combinative improvement of EGCG on gut microbiota dysbiosis, intestinal barrier dysfunction, and inflammation might be a potential therapeutic target for NAFLD.

Extracts of tropical green seaweed Caulerpa lentillifera reduce hepatic lipid accumulation by modulating lipid metabolism molecules in HepG2 cells

Seaweed has attracted attention as a bioactive source for preventing different chronic diseases, including liver injury and non-alcoholic fatty liver disease, the leading cause of liver-related mortality. Caulerpa lentillifera is characterized as tropical edible seaweed, currently being investigated for health benefits of its extracts and bioactive substances. This study examined the effects of C. lentillifera extract in ethyl acetate fraction (CLEA) on controlling lipid accumulation and lipid metabolism in HepG2 cells induced with oleic acid through the in vitro hepatic steatosis model. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that CLEA contained diverse organic compounds, including hydrocarbons, amino acids, and carboxylic acids. Docked conformation of dl-2-phenyltryptophane and benzoic acid, two major bioactive CLEA components, showed high affinity binding to SIRT1 and AMPK as target molecules of lipid metabolism. CLEA reduced lipid accumulation and intracellular triglyceride levels in HepG2 cells stimulated with oleic acid. The effect of CLEA on regulating expression of lipid metabolism-related molecules was investigated by qPCR and immunoblotting. CLEA promoted expression of the SIRT1 gene in oleic acid-treated HepG2 cells. CLEA also reduced expression levels of SREBF1, FAS, and ACC genes, which might be related to activation of AMPK signaling in lipid-accumulated HepG2 cells. These findings suggest that CLEA contains bioactive compounds potentially reducing triglyceride accumulation in lipid-accumulated HepG2 hepatocytes by controlling lipid metabolism molecules.

Chinese herbal medicines: The modulator of nonalcoholic fatty liver disease targeting oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Plants are a natural treasure trove; their secondary metabolites participate in several pharmacological processes, making them a crucial component in the synthesis of novel pharmaceuticals and serving as a reserve resource foundation in this process. Nonalcoholic fatty liver disease (NAFLD) is associated with the risk of progression to hepatitis and liver cancer. The "Treatise on Febrile Diseases," "Compendium of Materia Medica," and "Thousand Golden Prescriptions" have listed herbal remedies to treat liver diseases.

AIM OF THE REVIEW

Chinese herbal medicines have been widely used for the prevention and treatment of NAFLD owing to their efficacy and low side effects. The production of reactive oxygen species (ROS) during NAFLD, and the impact and potential mechanism of ROS on the pathogenesis of NAFLD are discussed in this review. Furthermore, common foods and herbs that can be used to prevent NAFLD, as well as the structure-activity relationships and potential mechanisms, are discussed.

METHODS

Web of Science, PubMed, CNKI database, Google Scholar, and WanFang database were searched for natural products that have been used to treat or prevent NAFLD in the past five years. The primary search was performed using the following keywords in different combinations in full articles: NAFLD, herb, natural products, medicine, and ROS. More than 400 research papers and review articles were found and analyzed in this review.

RESULTS

By classifying and discussing the literature, we obtained 86 herbaceous plants, 28 of which were derived from food and 58 from Chinese herbal medicines. The mechanism of NAFLD was proposed through experimental studies on thirteen natural compounds (quercetin, hesperidin, rutin, curcumin, resveratrol, epigallocatechin-3-gallate, salvianolic acid B, paeoniflorin, ginsenoside Rg1, ursolic acid, berberine, honokiol, emodin). The occurrence and progression of NAFLD could be prevented by natural antioxidants through several pathways to prevent ROS accumulation and reduce hepatic cell injuries caused by excessive ROS.

CONCLUSION

This review summarizes the natural products and routinely used herbs (prescription) in the prevention and treatment of NAFLD. Firstly, the mechanisms by which natural products improve NAFLD through antioxidant pathways are elucidated. Secondly, the potential of traditional Chinese medicine theory in improving NAFLD is discussed, highlighting the safety of food-medicine homology and the broader clinical potential of multi-component formulations in improving NAFLD. Aiming to provide theoretical basis for the prevention and treatment of NAFLD.

Antidiabetic features of AdipoAI, a novel AdipoR agonist

Adiponectin is an antidiabetic endogenous adipokine that plays a protective role against the unfavorable metabolic sequelae of obesity. Recent evidence suggests a sinister link between hypoadiponectinemia and development of insulin resistance/type 2 diabetes (T2D). Adiponectin's insulin-sensitizing property is mediated through the specific adiponectin receptors R1 and R2, which activate the AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR) α pathways. AdipoAI is a novel synthetic analogue of endogenous adiponectin with possibly similar pharmacological effects. Thus, there is a need of orally active small molecules that activate Adipoq subunits, and their downstream signaling, which could ameliorate obesity related type 2 diabetes. In the study we aim to investigate the effects of AdipoAI on obesity and T2D. Through in-vitro and in-vivo analyses, we investigated the antidiabetic potentials of AdipoAI and compared it with AdipoRON, another orally active adiponectin receptors agonist. Our results showed that in-vitro treatment of AdipoAI (0-5 µM) increased adiponectin receptor subunits AdipoR1/R2 with increase in AMPK and APPL1 protein expression in C2C12 myotubes. Similarly, in-vivo, oral administration of AdipoAI (25 mg/kg) observed similar effects as that of AdipoRON (50 mg/kg) with improved control of blood glucose and insulin sensitivity in diet-induced obesity (DIO) mice models. Further, AdipoAI significantly reduced epididymal fat content with decrease in inflammatory markers and increase in PPAR-α and AMPK levels and exhibited hepatoprotective effects in liver. Further, AdipoAI and AdipoRON also observed similar results in adipose tissue. Thus, our results suggest that low doses of orally active small molecule agonist of adiponectin AdipoAI can be a promising therapeutic target for obesity and T2D.

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.

Natural products in non-alcoholic fatty liver disease (NAFLD): Novel lead discovery for drug development

With changing lifestyles, non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease worldwide. A substantial increase in the incidence, mortality, and associated burden of NAFLD-related advanced liver disease is expected. Currently, the initial diagnosis of NAFLD is still based on ultrasound and there is no approved treatment method. Lipid-lowering drugs, vitamin supplementation, and lifestyle improvement treatments are commonly used in clinical practice. However, most lipid-lowering drugs can produce poor patient compliance and specific adverse effects. Therefore, the exploration of bio-diagnostic markers and active lead compounds for the development of innovative drugs is urgently needed. More and more studies have reported the anti-NAFLD effects and mechanisms of natural products (NPs), which have become an important source for new drug development to treat NAFLD due to their high activity and low side effects. At present, berberine and silymarin have been approved by the US FDA to enter clinical phase IV studies, demonstrating the potential of NPs against NAFLD. Studies have found that the regulation of lipid metabolism, insulin resistance, oxidative stress, and inflammation-related pathways may play important roles in the process. With the continuous updating of technical means and scientific theories, in-depth research on the targets and mechanisms of NPs against NAFLD can provide new possibilities to find bio-diagnostic markers and innovative drugs. As we know, FXR agonists, PPARα agonists, and dual CCR2/5 inhibitors are gradually coming on stage for the treatment of NAFLD. Whether NPs can exert anti-NAFLD effects by regulating these targets or some unknown targets remains to be further studied. Therefore, the study reviewed the potential anti-NAFLD NPs and their targets. Some works on the discovery of new targets and the docking of active lead compounds were also discussed. It is hoped that this review can provide some reference values for the development of non-invasive diagnostic markers and new drugs against NAFLD in the clinic.

Preventive and therapeutic effects of natural products and herbal extracts on nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a common condition that is prevalent in patients who consume little or no alcohol, and is characterized by excessive fat accumulation in the liver. The disease is becoming increasingly common with the rapid economic development of countries. Long-term accumulation of excess fat can lead to NAFLD, which represents a global health problem with no effective therapeutic approach. NAFLD is a complex, multifaceted pathological process that has been the subject of extensive research over the past few decades. Herbal medicines have gained attention as potential therapeutic agents to prevent and treat NAFLD due to their high efficacy and low risk of side effects. Our overview is based on a PubMed and Web of Science database search as of Dec 22 with the keywords: NAFLD/NASH Natural products and NAFLD/NASH Herbal extract. In this review, we evaluate the use of herbal medicines in the treatment of NAFLD. These natural resources have the potential to inform innovative drug research and the development of treatments for NAFLD in the future.

Reduction of obesity and hepatic adiposity in high-fat diet-induced rats by besunyen slimming tea

Objective

Obesity is a significant risk factor for metabolic syndrome, type 2 diabetes mellitus, hypertension, nonalcoholic fatty liver disease, and cardiovascular disorders. As a well-known Chinese tea product, Besunyen Slimming Tea (BST) is believed to effectively reduce body weight (BW) and lipid profile. In this study, we aimed to elucidate the mechanisms and effects of BST on treating obesity and hepatic steatosis using a rat model fed with a high-fat diet (HFD).

Methods

Sprague-Dawley rats were subjected to random separation into three categories: Animals were fed (1) a normal diet food (ND); (2) HFD, and (3) HFD + BST (n = 12/category). After successfully establishing the obesity model at week 8, the HFD + BST received BST (0.6 g/0.6 kg) orally, and the ND and HFD received the same amount (2 ml) of distilled water orally.

Results

HFD + BST reduced waist circumference (7.84%, P = 0.015), food intake (14.66%, P = 0.011), final BW (12.73%, P = 0.010), BW gain (964.16%, P < 0.001), and body mass index (8.97%, P = 0.044) compared with the HFD. BST supplementation also decreased hyperlipidemia, inflammation, and insulin resistance in rats with HFD. Furthermore, BST suppressed hepatic lipidosis by decreasing de novo lipogenesis and increasing fatty acid oxidation.

Conclusions

The results of this study offer evidence supporting the potential health benefits of BST in the management of metabolic disorders and obesity.

A Metabolic Enhancer Protects against Diet-Induced Obesity and Liver Steatosis and Corrects a Pro-Atherogenic Serum Profile in Mice

OBJECTIVE

Metabolic Syndrome (MetS) affects hundreds of millions of individuals and constitutes a major cause of morbidity and mortality worldwide. Obesity is believed to be at the core of metabolic abnormalities associated with MetS, including dyslipidemia, insulin resistance, fatty liver disease and vascular dysfunction. Although previous studies demonstrate a diverse array of naturally occurring antioxidants that attenuate several manifestations of MetS, little is known about the (i) combined effect of these compounds on hepatic health and (ii) molecular mechanisms responsible for their effect.

METHODS

We explored the impact of a metabolic enhancer (ME), consisting of 7 naturally occurring antioxidants and mitochondrial enhancing agents, on diet-induced obesity, hepatic steatosis and atherogenic serum profile in mice.

RESULTS

Here we show that a diet-based ME supplementation and exercise have similar beneficial effects on adiposity and hepatic steatosis in mice. Mechanistically, ME reduced hepatic ER stress, fibrosis, apoptosis, and inflammation, thereby improving overall liver health. Furthermore, we demonstrated that ME improved HFD-induced pro-atherogenic serum profile in mice, similar to exercise. The protective effects of ME were reduced in proprotein convertase subtilisin/kexin 9 (PCSK9) knock out mice, suggesting that ME exerts it protective effect partly in a PCSK9-dependent manner.

CONCLUSIONS

Our findings suggest that components of the ME have a positive, protective effect on obesity, hepatic steatosis and cardiovascular risk and that they show similar effects as exercise training.

Green Tea and Java Pepper Mixture Prevents Obesity by Increasing Energy Expenditure and Modulating Hepatic AMPK/MicroRNA-34a/370 Pathway in High-Fat Diet-Fed Rats

This study was performed to evaluate the anti-obesity effects of green tea and java pepper mixture (GJ) on energy expenditure and understand the regulatory mechanisms of AMP-activated protein kinase (AMPK), microRNA (miR)-34a, and miR-370 pathways in the liver. Sprague-Dawley rats were divided into four groups depending on the following diets given for 14 weeks: normal chow diet (NR), 45% high-fat diet (HF), HF + 0.1% GJ (GJL), and HF + 0.2% GJ (GJH). The results revealed that GJ supplementation reduced body weight and hepatic fat accumulation, improved serum lipids, and increased energy expenditure. In the GJ-supplemented groups, the mRNA levels of genes related to fatty acid syntheses, such as a cluster of differentiation 36 (CD36), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), and stearoyl-CoA desaturase 1 (SCD1) were downregulated, and mRNA levels of peroxisome proliferator-activated receptor alpha (PPARα), carnitine/palmitoyl-transferase 1 (CPT1), and uncoupling protein 2 (UCP2), which participate in fatty acid oxidation, were upregulated in the liver. GJ increased the AMPK activity and decreased the miR-34a and miR-370 expression. Therefore, GJ prevented obesity by increasing energy expenditure and regulating hepatic fatty acid synthesis and oxidation, suggesting that GJ is partially regulated through AMPK, miR-34a, and miR-370 pathways in the liver.

Coffee or tea: Anti-inflammatory properties in the context of atherosclerotic cardiovascular disease prevention

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of premature death worldwide. Inflammation and its biomarkers, like C-reactive protein (CRP), among the risk factors, such as hypertension, lipid disorders, and diabetes, may be also responsible for the residual cardiovascular disease (CVD) risk. Modern lipid-lowering treatment with statins, ezetimibe, PCSK9 inhibitors, or bempedoic acid does not fully protect against inflammation. The recommendations of the International Lipid Expert Panel (ILEP) indicate selected nutraceuticals with anti-inflammatory properties. Diet may have a significant impact on inflammation. Especially interesting in the context of inflammation is the consumption of coffee and tea. These drinks in many observational studies significantly reduced cardiovascular risk and mortality. The question is whether the anti-inflammatory effects of these drinks contribute significantly to the observed clinical effects. Thus, in this narrative review, we primarily discuss the anti-inflammatory properties of consuming tea and coffee. Based on a comprehensive analysis of the studies and their meta-analyses, inconsistent results were obtained, which makes it impossible to conclusively state how clinically significant the potential anti-inflammatory properties of black and green tea and coffee are. A number of confounding factors can cause the inconsistency of the available results. Consumption of tea and coffee appears to increase adiponectin concentrations, decrease reactive oxygen species, decrease low density lipoprotein (LDL) cholesterol concentrations (effect of green tea, etc.). Despite the still uncertain anti-inflammatory effect of tea and coffee, we recommend their consumption as a part of the healthy diet.

Genistein activated SIRT1-AMPK signaling pathway mediated by ERβ-FOXO1-Nampt to reduce fat accumulation in chicken hepatocytes

Excessive fat accumulation in broiler chickens would seriously threaten the poultry industry. It leads to lower feed conversion rate and worse meat quality. Even worse, it harms the consumers' health due to the intake of high-fat chicken products. Dietary supplements with bioactive ingredients have been considered an effective way to solve this problem. Genistein is the primary phytoestrogen in soybean. Its fat-reduction effect has been reported, but the molecular mechanism is unclear. The present study found that genistein reduced lipid droplets accumulation by regulating lipid metabolism-related factors expression in chicken hepatocytes. The research showed that genistein significantly increased phosphor (p)-AMP-activated protein kinase (p-AMPK) and Sirtuin 1 (SIRT1) protein expressions. The effect of genistein on reducing lipid droplets accumulation and upregulating p-AMPK protein level was blocked entirely when pretreated with SIRT1 inhibitor. These results implied that SIRT1 is required to activate AMPK. Furthermore, genistein treatment significantly upregulated the SIRT1 protein level when pretreated with AMPK inhibitor. We demonstrated that the activation of estrogen receptor β-Forkhead box O1-Nicotinamide phosphoribosyl transferase (ERβ-FOXO1-Nampt) signaling pathway upregulated the NAD⁺ concentration in hepatocytes, and activated SIRT1 ultimately. In summary, we demonstrated that genistein suppressed lipid droplets accumulation in chicken hepatocytes by activating SIRT1-AMPK. The SIRT1-AMPK signaling pathway was mediated by ERβ-FOXO1-Nampt. These findings increase our understanding of the mechanisms of genistein on fat reduction, and provide compelling evidence for it as a nutritional supplement to prevent excessive fat deposition and lipid metabolism-related diseases in animals and even humans.

Dietary tea seed saponin combined with aerobic exercise attenuated lipid metabolism and oxidative stress in mice fed a high-fat diet (HFD)

Tea seed saponins (TSS) are oleanolane-type pentacyclic triterpenoid saponin mixtures with various pharmacological effects. We aimed to explore the effects of a total of 4 weeks intragastric administration of TSS (140 mg/kg·day) combined with aerobic exercise (AE) on lipid metabolism and its associated oxidative stress in HFD-induced obese mice and to investigate the possible molecular mechanisms. TSS + AE intervention significantly reduced body weight and the adiposity index (including subcutaneous, epididymal, perirenal, and abdominal adipose) in obese mice; improved dyslipidemia by lowering serum TC, TG, and LDL-c levels; and increased HDL-c levels. TSS + AE intervention significantly improved hepatic steatosis by inhibiting lipogenetic Acc, Srebp1c, and Scd1 and upregulating lipolysis genes (Pgc1α, Pgc1β, Pparα, and Cpt1). TSS + AE intervention increased the hepatic protein expression of p-AMPK, SIRT1, and PGC-1α, as well as PPAR-γ and GLUT-4 in skeletal muscle compared with expression in the HFD group. In addition, TSS + AE also modulated oxidative stress in obese mice, which was indicated by the increased serum and liver levels of SOD, GSH, and T-AOC and decreased ROS and MDA levels. These results suggest that TSS + AE intervention can reduce fat accumulation and improve HFD-induced lipid metabolism disorders and oxidative stress. PRACTICAL APPLICATIONS: Obesity is a metabolic disease induced by excess nutritional intake and insufficient energy expenditure. Dietary modifications combined with aerobic exercise are currently an effective method for weight loss. Tea seed saponins (TSS) are a variety of biologically active oleanolane-type pentacyclic triterpenoid saponins that naturally exist in tea seeds. Few articles have focused on the effects and mechanisms of TSS combined with aerobic exercise (AE) in regulating lipid metabolism and improving oxidative damage in vivo. Using an HFD-induced obese mice model to explore the mechanism of TSS + AE in regulating lipid metabolism and its associated oxidative stress damage will help provide reliable data for the application of dietary nutrition combined with AE in anti-obesity.

Is it possible to treat nonalcoholic liver disease using a flavanol-based nutraceutical approach? Basic and clinical data

Nonalcoholic fatty liver disease (NAFLD) is characterized by a spectrum of diseases, ranging from simple steatosis to hepatocellular carcinoma. The main factors for NAFLD are closely related to obesity, insulin resistance, intestinal microbiota alterations, hyperinsulinism, low-grade systemic inflammation, nitroxidative stress, lipid peroxidation, and mitochondrial dysfunction. Currently, the treatment of NAFLD is based on diet and exercise because, to date, there is no specific pharmacological agent, already approved, that raises the need for new therapeutic strategies. Nutraceuticals, such as polyphenols, have potential beneficial effects for health. In this article, the beneficial effects of epigallocatechin-3-gallate (EGCG) and (-)-epicatechin (EC) are discussed. EGCG is the main catechin in green tea, which has shown in various studies its potential effect preventing and treating NAFLD since it has shown antihyperlipidemic, anti-inflammatory, antifibrotic, antioxidant, and improvement of liver lipid metabolism. However, it has been found that excessive consumption may cause hepatotoxicity. EC is widely distributed in nature (fruits and vegetables). This flavanol has shown many beneficial effects, including antihypertensive, anti-inflammatory, anti-hyperglycemic, antithrombotic, and antifibrotic properties. It increases mitochondrial biogenesis, and it also has effects on the regulation of synthesis and metabolism of lipids. This flavanol is a nontoxic substance; it has been classified by the United States Food and Drug Administration as harmless. The EC-induced effects can be useful for the prevention and/or treatment of NAFLD.

Citrus maxima and tea regulate AMPK signaling pathway to retard the progress of nonalcoholic fatty liver disease

Background

Nonalcoholic fatty liver disease (NAFLD) is a chronic metabolic disease that easily induces hepatitis, cirrhosis, and even liver cancer. The long-term use of NAFLD therapeutic drugs produces toxicity and drug resistance. Therefore, it is necessary to develop high efficiency and low-toxicity active ingredients to alleviate NAFLD.

Objective

This study aimed to reveal the role and mechanism of a new functional food CMT in alleviating NAFLD.

Results

In the ob/ob fatty liver mice models, the CMT extracts significantly inhibited the weight gain of the mice and reduced the accumulation of white fat. The anatomical and pathological results showed that CMT relieved fatty liver in mice and reduced excessive lipid deposition and inflammatory infiltration. Serological and liver biochemical indicators suggest that CMT reduced dyslipidemia and liver damage caused by fatty liver. CMT obviously activated the adenosine 5′-monophosphate-activated protein kinase (AMPK)/acetyl-coA carboxylase (ACC) and AMPK/fatty acid synthase (FAS) signaling pathways, promoted fat oxidation, and inhibited synthesis. Moreover, CMT regulated the expression of inflammatory factors to relieve hepatitis caused by NAFLD.

Conclusion

The study explained the role and mechanism of CMT in alleviating NAFLD and suggested that the active ingredients of CMT might be beneficial in NAFLD therapy.

Effects of Different Green Teas on Obesity and Non-Alcoholic Fatty Liver Disease Induced by a High-Fat Diet in Mice

Non-alcoholic fatty liver disease (NAFLD) and obesity are serious public health problems. Green tea is widely consumed in the world and different green teas could possess different bioactivities. In this study, the effects of 10 selected green teas on obesity and NAFLD were evaluated and compared. The mice fed with a high-fat diet were intervened with green tea extract (200 mg/kg body weight) for 15 weeks. Most of these teas were first evaluated for their effects on obesity and NAFLD. The results showed that Selenium-Enriched Chaoqing Green Tea and Jieyang Chaoqing Tea showed the most prominent inhibition of obesity and body weight gains of mice in these two tea intervention groups and model groups were 5.3, 5.5, and 13.7 g, respectively. In addition, Jieyang Chaoqing Tea, Taiping Houkui Tea, and Selenium-Enriched Chaoqing Green Tea exerted the most notable effect on NAFLD, which was attributed to decreasing body weight, and lipid content and ameliorating oxidative stress. Furthermore, 13 phytochemicals were determined in these teas by high-performance liquid chromatography and the correlation analysis found that epigallocatechin gallate, gallocatechin, and epigallocatechin might contribute to the decrease of hepatic weight, while epicatechin might reduce oxidative stress. In general, several green teas could prevent the development of obesity and NAFLD and could be developed into functional foods. This study was also helpful for the public to select appropriate tea to prevent obesity and NAFLD.

A water soluble extract of radish greens ameliorates high fat diet-induced obesity in mice and inhibits adipogenesis in preadipocytes

Radish (Raphanus sativus L.) is a rich source of nutrients and its greens have reported functionalities. This study aimed to investigate the effects of a water-soluble extract from radish greens (WERG) on adipogenesis in 3T3-L1 adipocytes and high-fat diet-induced obesity in model mice. We also quantified the phytochemical composition of WERG such as glucoraphenin and ferulic acid. These findings show that treatment with 100 μg mL^-1 WERG reduced lipid accumulation in 3T3-L1 adipocytes, whereas in mice, the administration of 100 mg kg^-1 WERG reduced weight gain and hepatic lipid accumulation and improved the levels of serum lipid biomarkers. Furthermore, WERG treatment improved intestinal permeability and suppressed the activities of harmful intestinal enzymes in feces, thus improving gut health. It also inhibited metabolic endotoxemia and inflammatory marker levels in serum. Moreover, WERG reduced the expression of lipid-metabolism-related proteins in the liver and white adipose tissue. Collectively, these results indicate that WERG may potentiate the anti-obesity effect by improving gut health and regulating lipid metabolism.

Protective effects of epigallocatechin-3-o-gallate combined with organic selenium against transforming growth factor-beta 1-induced fibrosis in LX-2 cells

In this study, we investigated the protective effects and possible mechanism of epigallocatechin-3-o-gallate (EGCG) combined with organic selenium in transforming growth factor (TGF)-β1-activated LX-2 cells. After 12 h of starvation, LX-2 cells were treated with 10 ng/ml of recombinant TGF-β1 and different concentrations of EGCG, L-selenomethionine (L-SeMet), or L-selenomethylcysteine (L-SeMC) for 24 h. We found that 100 and 200 μM EGCG combined with 1 mM L-SeMet or L-SeMC showed a synergistic effect in decreasing the survival rate of activated LX-2 cells. In addition, the combination of 100 mM EGCG and 1 mM L-SeMet or L-SeMC promoted the apoptosis of activated LX-2 cells. Compared with the EGCG treatment group, the combination intervention group had significantly suppressed levels of hepatic stellate cell activation markers including alpha-smooth muscle actin, collagen type I alpha 1, collagen type III alpha 1, 5-hydroxytryptophan (5-HT), and 5-HT receptors 2A and 2B. Moreover, interleukin-10 levels were decreased, while TGF-β1 levels were increased after TGF-β1 activation in LX-2 culture medium, whereas the combin1ation intervention reversed this phenomenon. The combination treatment had a more pronounced effect than any single treatment at the same dose. These results demonstrated that the combination of EGCG and organic selenium synergistically improves the TGF-β1-induced fibrosis of LX-2 cells to some extent by promoting apoptosis and inhibiting cell activation. PRACTICAL APPLICATIONS: Here, we found that the effects of epigallocatechin-3-o-gallate (EGCG) + L-selenomethionine or L-selenomethylcysteine were more pronounced than those of EGCG alone. Future studies should investigate the protective effects of green tea and selenium-enriched green tea against hepatic fibrosis and explore the differences in their molecular mechanisms. The results of this study will be helpful for the development and utilization of selenium-enriched tea for food processing and health supplement production.

Epigallocatechin-3-gallate ameliorates hepatic damages by relieve FGF21 resistance and promotion of FGF21-AMPK pathway in mice fed a high fat diet

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is considered to be one of the most common chronic liver diseases across worldwide. Epigallocatechin-3-gallate (EGCG) derived from extract of green tea and is well known for beneficial effects on anti-oxidative, anti-inflammatory, and anti-tumor activity. The present study aimed to implore its underlying mechanism for protective effect of NAFLD.

METHODS

Mice were fed either high fat diet (HFD) or chow diet with or without EGCG treatment in HFD group, for up to 16 weeks. Histopathology, expression of lipid and glucose metabolism and lipogenesis-related gene expression were assessed. Primary mouse hepatocytes were treated with free fatty acids combined with different doses of EGCG for 48 h, expression of lipid and lipogenesis-related gene expression were assessed.

RESULTS

The results showed that EGCG attenuated HFD- and FFA-induced lipid accumulation in vivo and in vitro. EGCG can decrease the oxidative stress and promote Nrf2 level. Meanwhile EGCG alleviated FGF21 resistance and elevated FGFR/AMPK expression, which suggested an unrecognized mechanism of EGCG in ameliorating NAFLD.

CONCLUSIONS

EGCG attenuated hepatocytes damage and dysfunction in NAFLD by alleviating FGF21 resistance and improve FGFR/AMPK pathway, mitigating oxidative stress. Our studies verified that EGCG may become a promising drug to treat or relieve NAFLD.

The Symbiotic Effect of a New Nutraceutical with Yeast β-Glucan, Prebiotics, Minerals, and Silybum marianum (Silymarin) for Recovering Metabolic Homeostasis via Pgc-1α, Il-6, and Il-10 Gene Expression in a Type-2 Diabetes Obesity Model

The use of natural products and derivatives for the prevention and control of non-communicable chronic diseases, such as type-2 diabetes (T2D), obesity, and hepatic steatosis is a way to achieve homeostasis through different metabolic pathways. Thus, male C57BL/6 mice were divided into the following groups: high-fat diet (HFD) vehicle, HFD + Supplemented, HFD + Supplemented_S, and isolated compounds. The vehicle and experimental formulations were administered orally by gavage once a day over the four weeks of the diet (28 consecutive days). We evaluated the energy homeostasis, cytokines, and mitochondrial gene expression in these groups of mice. After four weeks of supplementation, only the new nutraceutical group (HFD + Supplemented) experienced reduced fasting glycemia, insulin, HOMA index, HOMA-β, dyslipidemia, ectopic fat deposition, and hepatic fibrosis levels. Additionally, the PPARγ coactivator 1 α (Pgc-1α), interleukin-6 (Il-6), and interleukin-10 (Il-10) gene expression were augmented, while hepatic steatosis decreased and liver parenchyma was recovered. The glutathione-S-transferase activity status was found to be modulated by the supplement. We discovered that the new nutraceutical was able to improve insulin resistance and hepatic steatosis mainly by regulating IL-6, IL-10, and Pgc-1α gene expression.

Preventive effects of black soybean polyphenols on non-alcoholic fatty liver disease in three different mouse models

Non-alcoholic fatty liver disease (NAFLD) and its advanced stage, non-alcoholic steatohepatitis (NASH), are a major health issue throughout the world. Certain food components such as polyphenols are expected to possess preventive effects on NAFLD and NASH. In this study, the preventive effects of black soybean polyphenols were examined by using three NAFLD/NASH animal models. In a choline-deficient and L-amino acid-defined high-fat diet-induced NASH model, the intake of black soybean polyphenols decreased oxidative stress, but failed in attenuating liver injury and decreasing the expression of alpha-smooth muscle actin (α-SMA). In a Western diet with sucrose and fructose containing sweetened water-induced NAFLD model, black soybean polyphenols suppressed hepatic lipid accumulation, oxidative stress, aminotransferase activities in the plasma, inflammatory cytokine expression, and α-SMA expression accompanied by modulation of lipid metabolism. In a combination of Western diet and carbon tetrachloride model, black soybean polyphenols also suppressed hepatic lipid accumulation, oxidative stress, aminotransferase activities in the plasma, and α-SMA expression. In conclusion, black soybean is an attractive food for the prevention of NAFLD and NASH due to its strong antioxidant activity.

Enhancement of Swimming Endurance by Herbal Supplement M3P

OBJECTIVE

To investigate the effect of M3P (containing Deer antler, Cordyceps sinensis, Rhodiola rosea, and Panax ginseng); an herbal remedy with the function of tonifying Kidney (Shen) and invigorating Spleen (Pi), replenishing qi and nourishing blood; on fatigue alleviation, endurance capacity and toxicity.

METHODS

Swimming with weight-loading of 24 male ICR mice was used to evaluate the endurance capacity, and fatigue-related plasma biomarkers were determined. Mice were randomly assigned to control or M3P treatment groups with 6 mice for each group and were orally administered with M3P everyday for 8 weeks at doses 0, 10, 33 or 100 mg/kg. Swimming time to exhaustion was measured in a specialized water tank. Lliver and kidney functions, body weight, and hematological profile were determined to evaluate the safety and toxicity after long-term M3P administration.

RESULTS

M3P supplementation 100 mg/kg significantly increased swimming endurance time up to approximate 2.4 folds of controls (P<0.05). The plasma concentrations of cortisol and hepatic glycogen content were significantly increased in mice received M3P (P<0.05, P<0.01 respectively). The lactic acid level and blood glucose were not changed after M3P treatment (P>0.05). The liver and kidney functions muscle damage biomarker creatine, body weight, and hemograms were not altered in M3P supplementation (P>0.05).

CONCLUSION

M3P supplementation may improve swimming endurance accompanied by increasing hepatic glycogen content and serum cortisol level without major toxicity.

Potential therapeutic effects of green tea on obese lipid profile - a systematic review

Background: Green tea, obtained from the plant Camellis sinensis, is one of the oldest drinks in the world and contains numerous bioactive compounds. Studies have demonstrated the efficacy of green tea in preventing obesity and cardiovascular diseases that may be related to the reduction of lipid levels. Aim: This study aimed to evidence, through a systematic review, the therapeutic potential of green tea on the lipid profile in preclinical studies in obese animals and clinical studies in obese individuals. Methods: This systematic review follows the recommendations of the preferred report items for systematic reviews and meta-analyses. The electronic databases, PubMed (Medline), Science Direct, Scopus, and Web of Science were consulted. Articles from January 2009 to December 2019 were selected. Results: This search resulted in twenty-nine articles were included cirtically reviewed. In experimental studies, green tea administration has been shown to reduce total cholesterol, triglycerides and low-density lipoprotein cholesterol in animals exposed to obesity-inducing diet. In humans' studies green tea was not shown to be effective for obese lipid control. Because supplementation with green tea extract reduced total cholesterol, triglycerides, low-density lipoprotein for three months at a specific dose. Conclusion: Therefore, green tea appears to act as a protective agent for dyslipidemia in obesity-induced animals. In human studies, green tea has not been shown to be effective in controlling obese lipids.

Grape seed extract supplementation modulates hepatic lipid metabolism in rats. Implication of PPARβ/δ

Grape seed extract supplementationat low doses (25 mg per kg BW per day) modulates the transcriptional programs that controls the hepatic lipid metabolism in lean normolipidemic Wistar rats through PPARβ/δ activation.

Design of Hepatic Targeted Drug Delivery Systems for Natural Products: Insights into Nomenclature Revision of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), recently renamed metabolic-dysfunction-associated fatty liver disease (MAFLD), affects a quarter of the worldwide population. Natural products have been extensively utilized in treating NAFLD because of their distinctive advantages over chemotherapeutic drugs, despite the fact that there are no approved drugs for therapy. Notably, the limitations of many natural products, such as poor water solubility, low bioavailability in vivo, low hepatic distribution, and lack of targeted effects, have severely restricted their clinical application. These issues could be resolved via hepatic targeted drug delivery systems (HTDDS) that boost clinical efficacy in treating NAFLD and decrease the adverse effects on other organs. Herein an overview of natural products comprising formulas, single medicinal plants, and their crude extracts has been presented to treat NAFLD. Also, the clinical efficacy and molecular mechanism of active monomer compounds against NAFLD are systematically discussed. The targeted delivery of natural products via HTDDS has been explored to provide a different nanotechnology-based NAFLD treatment strategy and to make suggestions for natural-product-based targeted nanocarrier design. Finally, the challenges and opportunities put forth by the nomenclature update of NAFLD are outlined along with insights into how to improve the NAFLD therapy and how to design more rigorous nanocarriers for the HTDDS. In brief, we summarize the up-to-date developments of the NAFLD-HTDDS based on natural products and provide viewpoints for the establishment of more stringent anti-NAFLD natural-product-targeted nanoformulations.

Antenatal corticosteroid therapy modulates hepatic AMPK phosphorylation and maternal lipid metabolism in early lactating rats

Antenatal corticosteroid therapy is used to reduce neonatal mortality in preterm infants but it is currently unknown whether this intervention affects lipid metabolism at the peripartum. This study aimed to evaluate if antenatal corticosteroid therapy in pregnant rats and women affects lipid metabolism during early lactation. We evaluated women at risk of preterm delivery that received corticosteroid therapy (CASE) and women that were not exposed to corticosteroid and were not at risk of preterm delivery (CONTROL). Samples were collected to measure serum and milk triacylglycerol (TAG) three days after delivery. Rats were treated with dexamethasone (DEX) between the 15th and the 20th days of pregnancy. Samples were collected at different days after delivery (L3, L8 and L14). TAG was measured in serum, liver and mammary gland (MG). TAG appearance rates were measured after tyloxapol injection and gavage with olive oil. We also evaluated the expression of key genes related to lipid metabolism in the liver and in the MG and hepatic phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC). CASE volunteers delivered earlier than CONTROL but presented unaltered milk and serum TAG concentrations. Early lactating DEX rats exhibited increased TAG in serum, MG and milk. No changes in CD36 and LPL were detected in the MG and liver. Early lactating DEX rats displayed increased TAG appearance rate and reduced hepatic AMPK/ACC phosphorylation. Our data revealed that antenatal corticosteroid therapy reduces hepatic AMPK/ACC phosphorylation during early lactation that reflects in increased TAG concentration in serum, MG and milk.

MicroRNA-506-3p targets SIRT1 and suppresses AMPK pathway activation to promote hepatic steatosis

Nonalcoholic fatty liver disease (NAFLD) is a complex type of liver disease that represents an important global health threat. The mechanistic basis of this disease remains incompletely understood. The present study sought to explore whether microRNA (miR)-506-3p served a functional role in the onset and/or progression of NAFLD. To that end, high levels of glucose were used to treat liver cancer cell lines (HepG2 and Huh7) to model hepatic steatosis, and the expression levels of miR-506-3p and its downstream target genes were assessed. The cells of this hepatic steatosis model were transfected with miR-506-3p mimic molecules to explore the effect of miR-506-3p overexpression on cell viability, target gene expression and AMP-activated protein kinase (AMPK) phosphorylation. Via bioinformatics approaches, sirtuin 1 (SIRT1) was identified as a potential miR-506-3p target gene with relevance in NAFLD, and this interaction was confirmed via luciferase reporter assay. In the hepatic steatosis model of the present study, miR-506-3p expression level was significantly increased, whereas SIRT1 mRNA/protein levels and AMPK phosphorylation levels were markedly decreased. Transfection of the cells with miR-506-3p mimics led to significant SIRT1 downregulation, while miR-506-3p inhibitor molecules exhibited the opposite effect, with similar trends observed in the phosphorylation status of AMPK. These results suggested that miR-506-3p can inhibit SIRT1 expression and associated AMPK phosphorylation in HepG2 and Huh7 cells in an in vitro hepatic steatosis model system. These data indicated that the miR-506-3p/SIRT1/AMPK axis may be valuable as a therapeutic target in patients affected by NAFLD.

A Novel Multi-Ingredient Supplement Activates a Browning Program in White Adipose Tissue and Mitigates Weight Gain in High-Fat Diet-Fed Mice

We investigated the effects of a novel multi-ingredient supplement comprised of polyphenol antioxidants and compounds known to facilitate mitochondrial function and metabolic enhancement (ME) in a mouse model of obesity. In this study, 6-week-old male C57/BL6J mice were placed on a high-fat diet (HFD; ~60% fat) for 6 weeks, with subsequent allocation into experimentalgroups for 4 weeks: HFD control, HFD + ME10 (10 components), HFD + ME7 (7 components), HFD + ME10 + EX, HFD + EX (where '+EX' animals exercised 3 days/week), and chow-fed control. After the intervention, HFD control animals had significantly greater body weight and fat mass. Despite the continuation of HFD, animals supplemented with multi-ingredient ME or who performed exercise training showed an attenuation of fat mass and preservation of lean body mass, which was further enhanced when combined (ME+EX). ME supplementation stimulated the upregulation of white and brown adipose tissue mRNA transcripts associated with mitochondrial biogenesis, browning, fatty acid transport, and fat metabolism. In WAT depots, this was mirrored by mitochodrial oxidative phosphorylation (OXPHOS) protein expression, and increased in vivo fat oxidation measured via CLAMS. ME supplementation also decreased systemic and local inflammation markers. Herein, we demonstrated that novel multi-ingredient nutritional supplements induced significant fat loss independent of physical activity while preserving muscle mass in obese mice. Mechanistically, these MEs appear to act by inducing a browning program in white adipose tissue and decreasing other pathophysiological impairments associated with obesity, including mitochondrial respiration alterations induced by HFD.

Green Tea and Epigallocatechin Gallate (EGCG) for the Management of Nonalcoholic Fatty Liver Diseases (NAFLD): Insights into the Role of Oxidative Stress and Antioxidant Mechanism

Nonalcoholic fatty liver diseases (NAFLD) represent a set of liver disorders progressing from steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma, which induce huge burden to human health. Many pathophysiological factors are considered to influence NAFLD in a parallel pattern, involving insulin resistance, oxidative stress, lipotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, inflammatory cascades, fibrogenic reaction, etc. However, the underlying mechanisms, including those that induce NAFLD development, have not been fully understood. Specifically, oxidative stress, mainly mediated by excessive accumulation of reactive oxygen species, has participated in the multiple NAFLD-related signaling by serving as an accelerator. Ameliorating oxidative stress and maintaining redox homeostasis may be a promising approach for the management of NAFLD. Green tea is one of the most important dietary resources of natural antioxidants, above which epigallocatechin gallate (EGCG) notably contributes to its antioxidative action. Accumulative evidence from randomized clinical trials, systematic reviews, and meta-analysis has revealed the beneficial functions of green tea and EGCG in preventing and managing NAFLD, with acceptable safety in the patients. Abundant animal and cellular studies have demonstrated that green tea and EGCG may protect against NAFLD initiation and development by alleviating oxidative stress and the related metabolism dysfunction, inflammation, fibrosis, and tumorigenesis. The targeted signaling pathways may include, but are not limited to, NRF2, AMPK, SIRT1, NF-κB, TLR4/MYD88, TGF-β/SMAD, and PI3K/Akt/FoxO1, etc. In this review, we thoroughly discuss the oxidative stress-related mechanisms involved in NAFLD development, as well as summarize the protective effects and underlying mechanisms of green tea and EGCG against NAFLD.

Adipogenesis and therapeutic potentials of antiobesogenic phytochemicals: Insights from preclinical studies

Obesity is one of the most serious public health problems in both developed and developing countries in recent years. While lifestyle and diet modifications are the most important management strategies of obesity, these may be insufficient to ensure long-term weight reduction in certain individuals and alternative strategies including pharmacotherapy need to be considered. However, drugs option remains limited due to low efficacy and adverse effects associated with their use. Hence, identification of safe and effective alternative therapeutic agents remains warranted to combat obesity. In recent years, bioactive phytochemicals are considered as valuable sources for the discovery of new pharmacological agents for the treatment of obesity. Adipocyte hypertrophy and hyperplasia increases with obesity and undergo molecular and cellular alterations that can affect systemic metabolism giving rise to metabolic syndrome and comorbidities such as type 2 diabetes and cardiovascular diseases. Many phytochemicals have been reported to target adipocytes by inhibiting adipogenesis, inducing lipolysis, suppressing the differentiation of preadipocytes to mature adipocytes, reducing energy intake, and boosting energy expenditure mainly in vitro and in animal studies. Nevertheless, further high-quality studies are needed to firmly establish the clinical efficacy of these phytochemicals. This review outlines common pathways involved in adipogenesis and phytochemicals targeting effector molecules of these pathways, the challenges faced and the way forward for the development of phytochemicals as antiobesity agents.

Epigenetics in NAFLD/NASH: Targets and therapy

Recently non-alcoholic fatty liver disease (NAFLD) has grabbed considerable scientific attention, owing to its rapid increase in prevalence worldwide and growing burden on end-stage liver diseases. Metabolic syndrome including obesity, diabetes, and hypertension poses a grave risk to NAFLD etiology and progression. With no drugs available, the mainstay of NAFLD management remains lifestyle changes with exercise and dietary modifications. Nonselective drugs such as metformin, thiazolidinediones (TZDs), ursodeoxycholic acid (UDCA), silymarin, etc., are also being used to target the interrelated pathways for treating NAFLD. Considering the enormous disease burden and the unmet need for drugs, fresh insights into pathogenesis and drug discovery are required. The emergence of the field of epigenetics offers a convincing explanation for the basis of lifestyle, environmental, and other risk factors to influence NAFLD pathogenesis. Therefore, understanding these epigenetic modifications to target the primary cause of the disease might prove a rational strategy to prevent the disease and develop novel therapeutic interventions. Apart from describing the role of epigenetics in the pathogenesis of NAFLD as in other reviews, this review additionally provides an elaborate discussion on exploiting the high plasticity of epigenetic modifications in response to environmental cues, for developing novel therapeutics for NAFLD. Besides, this extensive review provides evidence for epigenetic mechanisms utilized by several potential drugs for NAFLD.

Investigating the Opposing Effect of Two Different Green Tea Supplements on Oxidative Stress, Mitochondrial Function and Cell Viability in HepG2 Cells

Green tea extract (GTE) improves exercise outcomes and reduces obesity. However, case studies indicate contradictory physiology regarding liver function and toxicity. We studied the effect of two different decaffeinated GTE (dGTE) products, from a non-commercial (dGTE1) and commercial (dGTE2) supplier, on hepatocyte function using the human cell model, HepG2. dGTE1 was protective against hydrogen peroxide (H₂O₂)-induced apoptosis and cell death by attenuating oxidative stress pathways. Conversely, dGTE2 increased cellular and mitochondrial oxidative stress and apoptosis. A bioavailability study with dGTE showed the major catechin in GTE, EGCG, reached 0.263 µg·ml^-1. In vitro, at this concentration, EGCG mimicked the protective effect of dGTE1. GC/MS analysis identified steric acid and higher levels of palmitic acid in dGTE2 versus dGTE1 supplements. We demonstrate the significant biological differences between two GTE supplements which may have potential implications for manufacturers and consumers to be aware of the biological effects of supplementation.

Comparative analysis of fecal metabolite profiles in HFD-induced obese mice after oral administration of huangjinya green tea extract

To explore the impact of Huangjinya on metabolic disorders and host endogenous metabolite profiles, high-fat diet (HFD)-fed mice were administrated with Huangjinya green tea extract (HGT) at the dose of 150 or 300 mg/kg for 9 weeks. Epigallocatechin gallate was the main catechin derivative, followed by epigallocatechin and catechin presented in HGT, which contained high levels of free amino acids (50.30 ± 0.60 mg/g). HGT significantly alleviated glucose and insulin intolerance, reduced hepatic lipid accumulation and liver steatosis, and prevented white adipose tissue expansion in HFD-fed mice. Untargeted mass spectrometry-based metabolomics analysis revealed that HGT reduced the abundance of fecal branched-chain amino acids, aromatic amino acids, sphingolipids, and most acyl cholines, modulated bile acid metabolism by increasing chenodeoxycholate and reducing cholic acid content, and increased unsaturated fatty acids content. Fatherly, HGT activated insulin/PI3K/Akt and AMPK signaling pathways in the liver, reduced adipogenic and lipogenic genes expression, and promoted the genes expression related to lipolysis and adipocyte browning in white adipose tissue, contributed to improving metabolic syndrome in HFD-fed mice. The current study reported the impact of HGT supplementation on endogenous metabolite profiles, and highlights the positive roles of HGT in preventing diet-induced obesity and the related metabolic disorders.

Maternal green tea extract intake during lactation attenuates hepatic lipid accumulation in adult male rats exposed to a continuous high-fat diet from the foetal period

Background

Maternal lipid intake in the early postnatal period has a long-term effect on the possibility of fatty liver formation in children; besides, the importance of lipid consumption during lactation for children’s health has been suggested. Green tea extract (GTE) contains abundant catechins, and it has been reported to improve lipid metabolism and prevent fatty liver.

Objective

The aim of this study was to examine the effects of maternal GTE intake during lactation on hepatic lipid accumulation in adult male rats exposed to a continuous high-fat (HF) diet from the foetal period.

Methods

Pregnant Wistar rats received diets containing 13% (control-fat, CON) or 45% (high-fat, HF) fat. CON-fed mothers received the same diet during lactation, whereas HF-fed mothers received either HF diet alone or HF diet supplemented with 0.24% GTE. At weaning, male offspring were divided into three groups, i.e. CON/CON/CON, HF/HF/HF (HF-offspring) or HF/HF+GTE/HF (GTE-offspring), and were fed until 51 weeks.

Results

A significant hepatic triglyceride (Tg) accumulation was observed in the HF-offspring when compared with the other offspring. This is presumed to be caused by the promotion of Tg synthesis derived from exogenous fatty acid due to a significant increase in diacylglycerol O-acyltransferase 1 and a decrease in Tg expenditure caused by decreasing microsomal triglyceride transfer protein (MTTP) and long-chain acyl-CoA dehydrogenase. On the other hand, attenuated hepatic Tg accumulation was observed in the GTE-offspring. The levels of the hepatic lipid metabolism-related enzymes were improved to the same level as the CON-offspring, and particularly, MTTP was significantly increased as compared with the HF-offspring.

Conclusion

This study indicates the potential protective effects of maternal GTE intake during lactation on HF diet-induced hepatic lipid accumulation in adult male rat offspring and the possible underlying mechanisms.

The impact of catechins included in high fat diet on AMP-dependent protein kinase in apoE knock-out mice

Due to their health-promoting effects green tea catechins have gained a keen interest in recent years in the context of bodyweight reduction treatments and alleviation of inflammatory diseases. This study was designed to evaluate the impact of native and thermally modified catechins (TMC) on the body weight gain, fatty acid profile in subcutaneous adipose tissue and the activity of the enzymes involved in lipid metabolism regulation: AMP-dependent protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) in apoE-deficient mice maintained on a high-fat diet. We observed that TMC decreased bodyweight gain as compared to the control group. Furthermore, TMC increased AMPK activity and reduced ACC activity in the metabolically important tissues: intestine, liver and subcutaneous adipose tissue and affected adipose tissue fatty acid composition. Native catechins produced less pronounced effects. These results suggest that TMC down-regulate endogenous fatty acid synthesis, which should be taken into account in dietary applications of catechins.

Sorghum (Sorghum bicolor) Extract Affects Plasma Lipid Metabolism and Hepatic Macrophage Infiltration in Diabetic Rats

Background:

Chronic hyperglycemia is known to be a high-risk factor for progressive chronic liver diseases, such as abnormal lipid metabolism. The activation of AMP-activated protein kinase (AMPK) has a beneficial effect on dyslipidemia. Polyphenols derived from various plants are involved in AMPK activation.

Objective:

We investigated the effects of polyphenol-containing sorghum (Sorghum bicolor) extract (SE) on plasma lipid metabolism and macrophage infiltration, and measured the expression and phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) in diabetic rat livers.

Methods:

Streptozotocin-induced diabetic rats received 0, 50, or 250 mg/kg of SE orally for 4 weeks. Blood chemistry, total and phosphorylated protein levels of AMPK and ACC, sterol regulatory element- binding protein-1c (SREBP-1c) mRNA and protein levels, and macrophage infiltration in the livers were examined.

Results:

Plasma glucose and triacylglycerol levels, which were increased in the untreated diabetic rats, were significantly lower in the 250 mg/kg SE-treated diabetic rats. AMPK and ACC phosphorylation levels were significantly increased in the 250 mg/kg SE-treated diabetic rats compared with those in the untreated rats. There was no difference in the hepatic expression of SREBP-1c between the diabetic rat groups. Macrophage infiltration in the liver was suppressed by 250 mg/kg of SEtreatment.

Conclusion:

These data suggest that SE treatment may affect plasma lipid metabolism and chronic inflammation by upregulating phosphorylation of AMPK and ACC in diabetic rat livers.

Beneficial effects of green coffee and green tea extract combination on metabolic syndrome improvement by affecting AMPK and PPAR-α gene expression

Effect of green coffee and green tea extract on metabolic syndrome. To explore green coffee and green tea extract combination effect on metabolic profile and blood pressure improvement through adenosine monophosphate-activated protein kinase (AMPK) and Peroxisome Proliferator-Activated Receptor α (PPARα) gene expression modulation. Experimental laboratory research with pre- and post-control group design. Twenty-five metabolic syndrome rats model were grouped into five groups (n = 5): standard control (normal), metabolic syndrome (SM), green coffee extract (GC), green tea extract (GT), and combination green coffee and green tea extract (CM). The extract was given during 9 weeks. Serum glucose, triglyceride, high-density lipoprotein, and systolic blood pressure level were analyzed before and after the extract administration. At the end of the study, PPAR-α and AMPK-α2 gene were analyzed. Independent t-test. CM group had significantly higher PPAR-α, and AMPK-α2 gene expression compared to those of SM, GC, and GT group. Green coffee and green tea extract combination administration improved metabolic profile and blood pressure on metabolic syndrome through affecting PPAR-α and AMPK-α2 gene expression.

Mitigation of nonalcoholic fatty liver disease in high-fat-fed mice by the combination of decaffeinated green tea extract and voluntary exercise

We have shown that combination treatment with decaffeinated green tea extract (GTE) and voluntary exercise (Ex) reduces obesity and insulin resistance in high-fat (HF)-fed mice to a greater extent than either treatment alone. Here, we investigated the effects of GTE-, Ex- or the combination on the development of obesity-related NAFLD. Male C57BL/6 J mice were treated for 16 weeks with HF diet (60% energy from fat), HF supplemented with 7.7 g GTE/kg, HF plus access to a voluntary running wheel, or the combination. We found that treatment of mice with the combination mitigated the development of HF-induced NAFLD to a greater extent than either treatment alone. Combination-treated mice had lower plasma alanine aminotransferase (92% lower) and hepatic lipid accumulation (80% lower) than HF-fed controls: the effect of the single treatments was less significant. Mitigation of NAFLD was associated with higher fecal lipid and nitrogen levels. Combination treated, but not singly treated mice, had higher hepatic expression of genes related to mitochondrial biogenesis (sirtuin 1 [59%]; peroxisome proliferator-activated receptor γ coactivator 1α [42%]; nuclear respiratory factor 1 [38%]; and transcription factor B1, mitochondrial [89%]) compared to the HF-fed controls. GTE-, Ex-, and the combination-treatment groups also had higher hepatic expression of genes related to cholesterol synthesis and uptake, but the combination was not better than the single treatments. Our results suggest the combination of GTE and Ex can effectively mitigate NAFLD. Future studies should determine if the combination is additive or synergistic compared to the single treatments.

Ginsenoside Rk3 ameliorates high-fat-diet/streptozocin induced type 2 diabetes mellitus in mice via the AMPK/Akt signaling pathway

Ginsenoside Rk3 (G-Rk3) is a main active ingredient of ginsenosides. Several recent studies demonstrated that ginsenosides have potential anti-type 2 diabetes mellitus (T2DM) properties. To evaluate the anti-T2DM effect of G-Rk3 and verify its potential mechanism, a high-fat-diet/streptozocin (HFD/STZ) induced model of T2DM in C57BL/6 mice and a high glucose induced insulin resistance model of HepG2 cells were applied in this research. Our analysis indicated that G-Rk3 reduced HFD/STZ induced hyperglycemia, and serum insulin and inflammation levels, and ameliorated glucose tolerance and insulin resistance, and prevented liver histological changes. Furthermore, it also significantly reduced lipid accumulation as shown by lower TG, LDL-C and TC serum concentrations and Oil Red O staining in liver tissues. The hypoglycemic effect of G-Rk3 seemed to be partially mediated via the inhibition of hepatic gluconeogenesis, which was supported by the activated p-Akt, p-FoxO1 and GLUT2 and inhibited FoxO1, PEPCK and G6pase protein expressions in the liver as well as increased glucose uptake in high glucose induced HepG2 cells. The gene expressions of hepatic gluconeogenesis were also down-regulated by G-Rk3 in HFD/STZ induced T2DM mice. In addition, G-Rk3 suppressed HFD/STZ induced lipid accumulation by regulating related gene and protein expressions such as p-ACC, FAS and SREBP-1, which are the downstream targets of AMPK. AMPK and Akt inhibitors significantly reversed G-Rk3 mediated hepatic gluconeogenesis and lipid accumulation. Thus, our study is the first to illustrate that G-Rk3 mediates hepatic gluconeogenesis and lipid accumulation via activating the AMPK/Akt signaling pathway in HFD/STZ induced T2DM mice.

Green Tea Prevents NAFLD by Modulation of miR-34a and miR-194 Expression in a High-Fat Diet Mouse Model

Background/Aims

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. It is currently the most common chronic liver disease with complex pathogenesis and challenging treatment. Here, we investigated the hepatoprotective role of green tea (GT) and determined the involvement of miRNAs and its mechanism of action.

Methods

Male C57Bl/6 mice were fed with a high-fat diet for 4 weeks. After this period, the animals received gavage with GT (500 mg/kg body weight) over 12 weeks (5 days/week). HepG2 cell lines were transfected with miR-34a or miR-194 mimetics and inhibitors to validate the in vivo results or were treated with TNF-α to evaluate miRNA regulation.

Results

GT supplementation protects against NAFLD development by altering lipid metabolism, increasing gene expression involved in triglycerides and fatty acid catabolism, and decreasing uptake and lipid accumulation. This phenotype was accompanied by miR-34a downregulation and an increase in their mRNA targets Sirt1, Pparα, and Insig2. GT upregulated hepatic miR-194 by inhibiting TNF-α action leading to a decrease in miR-194 target genes Hmgcs/Apoa5.

Conclusion

Our study identified for the first time that the beneficial effects of GT in the liver can be due to the modulation of miRNAs, opening new perspectives for the treatment of NAFLD focusing on epigenetic regulation of miR-34a and miR-194 as green tea targets.

Green Tea Extract Treatment in Obese Mice with Nonalcoholic Steatohepatitis Restores the Hepatic Metabolome in Association with Limiting Endotoxemia-TLR4-NFκB-Mediated Inflammation

SCOPE

Catechin-rich green tea extract (GTE) alleviates nonalcoholic steatohepatitis (NASH) by lowering endotoxin-TLR4 (Toll-like receptor-4)-NFκB (nuclear factor kappa-B) inflammation. This study aimed to define altered MS-metabolomic responses during high-fat (HF)-induced NASH that are restored by GTE utilizing livers from an earlier study in which GTE decreased endotoxin-TLR4-NFκB liver injury.

METHODS AND RESULTS

Mice are fed a low-fat (LF) or HF diet for 12 weeks and then randomized to LF or HF diets containing 0% or 2% GTE for an additional 8 weeks. Global MS-based metabolomics and targeted metabolite profiling of catechins/catechin metabolites are evaluated. GTE in HF mice restores hepatic metabolites implicated in dyslipidemia insulin resistance, and inflammation. These include 122 metabolites: amino acids, lipids, nucleotides, vitamins, bile acids, flavonoids, xenobiotics, and carbohydrates. Hepatic amino acids, B-vitamins, and bile acids are inversely correlated with biomarkers of insulin resistance, liver injury, steatosis, and inflammation. Further, phosphatidylcholine metabolites are positively correlated with biomarkers of liver injury and NFκB inflammation. Thirteen catechin metabolites are identified in livers of GTE-treated mice, mostly as phase II conjugates of parental catechins or microbial-derived valerolactones.

CONCLUSION

The defined anti-inflammatory/metabolic interactions advance an understanding of the mechanism by which GTE catechins protect against NFκB-mediated liver injury in NASH.

miR-122 promotes hepatic lipogenesis via inhibiting the LKB1/AMPK pathway by targeting Sirt1 in non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common hepatic disease with an increasing prevalence but an unclear aetiology. This study aimed to investigate the functional implications of microRNA-122 (miR-122) in the pathogenesis of NAFLD and the possible molecular mechanisms.

METHODS

Both in vitro and in vivo models of NAFLD were generated by treating HepG2 and Huh-7 cells with free fatty acids (FFA) and by feeding mice a high-fat diet (HFD), respectively. HE and Oil Red O staining were used to examine liver tissue morphology and lipid deposition, respectively. Immunohistochemical (IHC) staining was used to examine Sirt1 expression in liver tissues. qRT-PCR and Western blotting were employed to measure the expression of miR-122, Sirt1, and proteins involved in lipogenesis and the AMPK pathway. Enzyme-linked immunosorbent assay (ELISA) was used to quantify triglyceride (TG) levels in HepG2 and Huh-7 cells and in liver tissues. The interaction between miR-122 and the Sirt1 gene was further examined by a dual luciferase reporter assay and RNA-immunoprecipitation (RIP).

RESULTS

NAFLD hepatic tissues and FFA-treated HepG2 and Huh-7 cells presented excess lipid production and TG secretion, accompanied by miR-122 upregulation, Sirt1 downregulation, and potentiated lipogenesis-related genes. miR-122 suppressed Sirt1 expression via binding to its 3'-untranslated region (UTR). Knockdown of miR-122 effectively mitigated excessive lipid production and suppressed the expression of lipogenic genes in FFA-treated HepG2 and Huh-7 cells via upregulating Sirt1. Furthermore, miR-122 knockdown activated the LKB1/AMPK signalling pathway.

CONCLUSION

The inhibition of miR-122 protects hepatocytes from lipid metabolic disorders such as NAFLD and suppresses lipogenesis via elevating Sirt1 and activating the AMPK pathway. These data support miR-122 as a promising biomarker and drug target for NAFLD.

The role of acetyl-coA carboxylase2 in head and neck squamous cell carcinoma

Background

Acetyl-CoA carboxylase (ACC) plays an important role in the metabolism of various cancer cells, but its role in head and neck squamous cell carcinoma (HNSCC) is uncertain. Therefore, in the present study, we explored the role of ACC2 in HNSCC.

Methods

Western blot and immunohistochemistry assays were used to determine ACC2 protein expression levels in laryngocarcinoma and adjacent normal tissues derived from patients with laryngocarcinoma. ACC2 expression was knocked down in the hypopharyngeal cancer cell line FaDu to determine its effect on apoptosis. Lipid oil red staining was used to test the change of intracellular lipid.

Results

The results showed that the ACC2 protein was highly expressed in laryngocarcinoma and that the ACC2 expression level was positively associated with the clinical cancer stage and negatively associated with the degree of laryngocarcinoma cell differentiation. Kaplan-Meier analyses indicated that compared with patients having low levels of ACC2, those with high ACC2 levels had a decreased 5-year survival rate. The results of western blot and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays showed that knockdown of ACC2 accelerated apoptosis in FaDu cells. Furthermore, knockdown of ACC2 significantly reduced the intracellular lipid levels in FaDu cells.

Conclusion

These findings suggest that ACC2 may be an important prognostic marker for patients with HNSCC and that ACC2 may be a potential target in the treatment of HNSCC.

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.

A combination of Pueraria lobata and Silybum marianum protects against alcoholic liver disease in mice

BACKGROUND

Excess alcohol exposure leads to alcoholic liver disease (ALD). Pueraria lobata (PUE) and Silybum marianum (SIL) are two well-known hepatoprotective herbal remedies with various activities. The possible effect of combination of PUE and SIL on ALD has not been elucidated yet.

PURPOSE

We aimed to demonstrate that the combination of PUE and SIL prevents against alcoholic liver injury in mice using a model of chronic-plus-single-binge ethanol feeding.

STUDY DESIGN

Male C57BL/6 mice were randomly divided into five groups (n = 8-10), namely the control group (CON), ethanol-induced liver injury group (ETH), 150 mg/kg PUE treated group (PUE), 60 mg/kg SIL treated group (SIL), 210 mg/kg PUE+SIL treatment group (PUE+SIL). Except control group, all animals were fed a modified Lieber-DeCarli ethanol liquid diet for 10 days. While, control group received Lieber-DeCarli control diet containing isocaloric maltose dextrin substituted for ethanol. On day 11, the mice orally received a single dose of 31.5% (v/v) ethanol (5 g/kg BW) or an isocaloric maltose solution.

RESULTS

Ethanol exposure caused liver injury, as demonstrated by remarkably increased plasma parameters, histopathological changes, the increased lipid accumulation, oxidative stress and inflammation in liver. These alterations were ameliorated by the treatments of PUE, SIL and PUE+SIL. While, the PUE+SIL treatment showed the most effective protection, which was associated with reducing alcohol-induced hepatic steatosis via upregulating LKB1/AMPK/ACC signaling, and inhibiting hepatic inflammation via LPS-triggered TLR4-mediated NF-κB signaling pathway. Our results also indicated that the hepatoprotective effects of SIL+PUE might mainly attribute to the protection of SIL and PUE alone in alcohol-induced hepatic steatosis and hepatic inflammation, respectively.

CONCLUSION

These findings also suggest that the combination of PUE and SIL has a potential to be developed as a functional food for the management of ALD.

Green Tea Extracts Attenuate Brain Dysfunction in High-Fat-Diet-Fed SAMP8 Mice

Unhealthy diet promotes progression of metabolic disorders and brain dysfunction with aging. Green tea extracts (GTEs) have various beneficial effects and alleviate metabolic disorders. GTEs have neuroprotective effects in rodent models, but their effects against brain dysfunction in models of aging fed unhealthy diets are still unclear. Here, we showed that GTEs attenuate high-fat (HF) diet-induced brain dysfunction in senescence-accelerated mouse prone-8 (SAMP8), a murine model of senescence. SAMP8 mice were fed a control diet, HF diet, or HF diet with 0.5% GTEs (HFGT) for four months. The HF diet reduced memory retention and induced amyloid β_1–42 accumulation, whereas GTEs attenuated these changes. In HF diet-fed mice, lipid oxidative stress, assessed by malondialdehyde levels, was increased. The levels of proteins that promote synaptic plasticity, such as brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95), were reduced. These alterations related to brain dysfunction were not observed in HFGT diet-fed mice. Overall, our data suggest that GTEs intake might attenuate brain dysfunction in HF diet-fed SAMP8 mice by protecting synaptic plasticity as well as via anti-oxidative effects. In conclusion, GTEs might ameliorate unhealthy diet-induced brain dysfunction that develops with aging.

A Polyphenol-Enriched Supplement Exerts Potent Epigenetic-Protective Activity in a Cell-Based Model of Brain Ischemia

Bioactive components, due in part to their epigenetic properties, are beneficial for preventing several human diseases including cerebrovascular pathologies. However, no clear demonstration supports the idea that these molecules still conserve their epigenetic effects when acting at very low concentrations reproducing the brain levels achieved after oral administration of a micronutrient supplement. In the present study, we used a cellular model of brain ischemia to investigate the neuroprotective and epigenetic activities of a commercially available micronutrient mixture (polyphenol-enriched micronutrient mixture, PMM) enriched in polyphenols ((-)-epigallocatechin-3-gallate, quercetin, resveratrol), α-lipoic acid, vitamins, amino acids and other micronutrients. Mimicking the suggested dietary supplementation, primary cultures of mouse cortical neurons were pre-treated with PMM and then subjected to oxygen glucose deprivation (OGD). Pre-treatment with PMM amounts to provide bioactive components in the medium in the nanomolar range potently prevented neuronal cell death. The protection was associated with the deacetylation of the lysin 310 (K310) on NF-κB/RelA as well as the deacetylation of H3 histones at the promoter of Bim, a pro-apoptotic target of ac-RelA(K310) in brain ischemia. Epigenetic regulators known to shape the acetylation state of ac-RelA(K310) moiety are the histone acetyl transferase CBP/p300 and the class III histone deacetylase sirtuin-1. In view of that evidence, the protection we here report unveils the efficacy of bioactive components endowed with either inhibitory activity on CBP/p300 or stimulating activity on the AMP-activated protein kinase–sirtuin 1 pathway. Our results support a potential synergistic effect of micronutrients in the PMM, suggesting that the intake of a polyphenol-based micronutrient mixture can reduce neuronal vulnerability to stressful conditions at concentrations compatible with the predicted brain levels reached by a single constituent after an oral dose of PMM.