Astragaloside IV inhibits protein tyrosine phosphatase 1B and improves insulin resistance in insulin-resistant HepG2 cells and triglyceride accumulation in oleic acid (OA)-treated HepG2 cells

Role of formyl peptide receptor 2 in steatosis of L02 cells exposed to Mono-(2-ethylhexyl) phthalate

Mono-(2-ethylhexyl) phthalate (MEHP) can accumulate in the liver and then lead to hepatic steatosis, while the underlying mechanism remains unclear. Inflammation plays an important role in the disorder of hepatic lipid metabolism. This study aims to clarify the role of the inflammatory response mediated by formyl peptide receptor 2 (FPR2) in steatosis of L02 cells exposed to MEHP. L02 cells were exposed to MEHP of different concentrations and different time. A steatosis model of L02 cells was induced with oleic acid and the cells were exposed to MEHP simultaneously. In addition, L02 cells were incubated with FPR2 antagonist and then exposed to MEHP. Lipid accumulation was determined by oil red O staining and extraction assay. The indicators related to lipid metabolism and inflammatory response were measured with appropriate kits. The relative expression levels of FPR2 and its ligand were determined by Western blot, and the interaction of them was detected by co-immunoprecipitation. As a result, MEHP exposure could promote the occurrence and progression of steatosis and the secretion of chemokines and inflammatory factors in L02 cells. MEHP could also affect the expression and activation of FPR2 and the secretion of FPR2 ligands. In addition, the promotion effect of MEHP on the secretion of total cholesterol and interleukin 1β in L02 cells could be significantly inhibited by the FPR2 antagonist. We concluded that FPR2 might affect the promotion effect of MEHP on steatosis of L02 cells by mediating inflammatory response.

Examining the Pathogenesis of MAFLD and the Medicinal Properties of Natural Products from a Metabolic Perspective

Metabolic-associated fatty liver disease (MAFLD), characterized primarily by hepatic steatosis, has become the most prevalent liver disease worldwide, affecting approximately two-fifths of the global population. The pathogenesis of MAFLD is extremely complex, and to date, there are no approved therapeutic drugs for clinical use. Considerable evidence indicates that various metabolic disorders play a pivotal role in the progression of MAFLD, including lipids, carbohydrates, amino acids, and micronutrients. In recent years, the medicinal properties of natural products have attracted widespread attention, and numerous studies have reported their efficacy in ameliorating metabolic disorders and subsequently alleviating MAFLD. This review aims to summarize the metabolic-associated pathological mechanisms of MAFLD, as well as the natural products that regulate metabolic pathways to alleviate MAFLD.

Study of active components and mechanisms mediating the hypolipidemic effect of Inonotus obliquus polysaccharides

Hyperlipidemia is a multifaceted metabolic disease, which is the major risk factor for atherosclerosis and cardiovascular diseases. Traditional Chinese medicine provides valuable therapeutic strategies in the treatment of hyperlipidemia. Inonotus obliquus has been used in traditional medicine to treat numerous diseases for a long time. To screen and isolate the fractions of I. obliquus polysaccharides (IOP) that can reduce blood lipid in the hyperlipemia animals and cell models, and investigate its mechanisms. The active component IOP-A2 was isolated, purified, and identified. In vivo, rats were randomly divided into blank control group (NG), the high-fat treatment group (MG), lovastatin group (PG), and IOP-A group. Compared with MG, the hyperlipidemic rats treated with IOP-A2 had decreased body weight and organ indexes, with the level of serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) significantly decreased (p < .05), and level of serum high-density lipoprotein cholesterol (HDL-C) significantly increased (p < .05). Hepatocyte steatosis in hepatic lobules was significantly reduced. In vitro, the accumulation of lipid droplets in the model of fatty degeneration of HepG2 cells was significantly alleviated, and cellular TC and TG content was significantly decreased (p < .01). Moreover, the expression of recombinant cytochrome P450 7A1 (CYP7A1) and Liver X Receptor α (LXRα) were up-regulated (p < .05) both in vivo and in vitro. The results showed that IOP-A2 may exert its hypolipidemic activity by promoting cholesterol metabolism and regulating the expression of the cholesterol metabolism-related proteins CYP7A1, LXRα, SR-B1, and ABCA1.

A systematic review of astragaloside IV effects on animal models of diabetes mellitus and its complications

Context

Diabetes mellitus (DM) is one of the fastest-growing diseases worldwide; however, its pathogenesis remains unclear. Complications seriously affect the quality of life of patients in the later stages of diabetes, ultimately leading to suffering. Natural small molecules are an important source of antidiabetic agents.

Objective

Astragaloside IV (AS-IV) is an active ingredient of Astragalus mongholicus (Fisch.) Bunge. We reviewed the efficacy and mechanism of action of AS-IV in animal and cellular models of diabetes and the mechanism of action of AS-IV on diabetic complications in animal and cellular models. We also summarized the safety of AS-IV and provided ideas and rationales for its future clinical application.

Methods

Articles on the intervention in DM and its complications using AS-IV, such as those published in SCIENCE, PubMed, Springer, ACS, SCOPUS, and CNKI from the establishment of the database to February 2022, were reviewed. The following points were systematically summarized: dose/concentration, route of administration, potential mechanisms, and efficacy of AS-IV in animal models of DM and its complications.

Results

AS-IV has shown therapeutic effects in animal models of DM, such as alleviating gestational diabetes, delaying diabetic nephropathy, preventing myocardial cell apoptosis, and inhibiting vascular endothelial dysfunction; however, the potential effects of AS-IV on DM should be investigated.

Conclusion

AS-IV is a potential drug for the treatment of diabetes and its complications, including diabetic vascular disease, cardiomyopathy, retinopathy, peripheral neuropathy, and nephropathy. In addition, preclinical toxicity studies indicate that it appears to be safe, but the safe human dose limit is yet to be determined, and formal assessments of adverse drug reactions among humans need to be further investigated. However, additional formulations or structural modifications are required to improve the pharmacokinetic parameters and facilitate the clinical use of AS-IV.

Anti-diabetic effect of anthocyanin cyanidin-3-O-glucoside: data from insulin resistant hepatocyte and diabetic mouse

BACKGROUND

Anthocyanins are a group of natural products widely found in plants. They have been found to alleviate the disorders of glucose metabolism in type 2 diabetes mellitus (T2DM), while the underlying mechanisms remain unclear.

METHODS

HepG2 and L02 cells were incubated with 0.2 mM PA and 30 mM glucose for 24 h to induce IR, and cells treated with 5 mM glucose were used as the control. C57BL/6 J male mice and db/db male mice were fed with a chow diet and gavaged with pure water or cyanidin-3-O-glucoside (C3G) solution (150 mg/kg/day) for 6 weeks.

RESULTS

In this study, the anthocyanin C3G, extracted from red bayberry, was found to alleviate disorders of glucose metabolism, which resulted in increased insulin sensitivity in hepatocytes, and achieved by enhancing the glucose consumption as well as glycogen synthesis in insulin resistance (IR) hepatpcytes. Subsequently, the expression of key proteins involved in IR was detected by western blotting analysis. Protein tyrosine phosphatase-1B (PTP1B), a negative regulator of insulin signaling, could reduce cellular sensitivity to insulin by inhibiting the phosphorylation of insulin receptor substrate-2 (IRS-2). Results of this study showed that C3G inhibited the increase in PTP1B after high glucose and palmitic acid treatment. And this inhibition was accompanied by increased phosphorylation of IRS proteins. Furthermore, the effect of C3G on improving IR in vivo was validated by using a diabetic db/db mouse model.

CONCLUSION

These findings demonstrated that C3G could alleviate IR in vitro and in vivo to increase insulin sensitivity, which may offer a new insight for regulating glucose metabolism during T2DM by using the natural dietary bioactive components. C3G promotes the phosphorylation of IRS-2 proteins by suppressing the expression of PTP1B, and then enhances the sensitivity of hepatocyte to insulin.

Targeting Protein Phosphatases for the Treatment of Chronic Liver Disease

There exists a huge number of patients suffering from chronic liver disease worldwide. As a disease with high incidence and mortality worldwide, strengthening the research on the pathogenesis of chronic liver disease and the development of novel drugs is an important issue related to the health of all human beings. Phosphorylation modification of proteins plays a crucial role in cellular signal transduction, and phosphatases are involved in the development of liver diseases. Therefore, this article summarized the important role of protein phosphatases in chronic liver disease with the aim of facilitating the development of drugs targeting protein phosphatases for the treatment of chronic liver disease.

New dammarane-type triterpenoids from hydrolyzate of total Gynostemma pentaphyllum saponins with protein tyrosine phosphatase 1B inhibitory activity

Protein tyrosine phosphatase 1B (PTP1B) is a key factor and regulator of glucose, lipid metabolism throughout the body, and a promising target for treatment of type 2 diabetes mellitus (T2DM). Gynostemma pentaphyllum is a famous oriental traditional medicinal herbal plant and functional food, which has shown many beneficial effects on glucose and lipid metabolism. The aim of the present study is to assess the inhibitory activity of five new and four known dammarane triterpenoids isolated from the hydrolysate product of total G. pentaphyllum saponins. The bioassay data showed that all the compounds exhibited significant inhibitory activity against PTP1B. The structure-activity relationship showed that the strength of PTP1B inhibitory activity was mainly related to the electron-donating group on its side chain. Molecular docking analysis suggested that its mechanism may be due to the formation of competitive hydrogen bonding between the electron-donating moiety and the Asp48 amino acid residues on the PTP1B protein.

Effects of soda water on blood lipid and metabolic profiling of urine in hyperlipidemia rats using UPLC/Triple-TOF MS

The effects of a natural soda water (Shi Han Quan, SHQ) on hyperlipidemia and the changes of urine metabolic profiling by metabolomics techniques were investigate. Thirty six Wistar rats weighing 160-200 g were divided into control group, hyperlipidemia (HL) group, and hyperlipidemia + SHQ water (SHQ) group. The metabolites in urine were determined using ultra high performance liquid chromatography-triple-time of flight-mass spectrometry (UPLC/Triple-TOF MS). At the end of 1 month and 3 months, the total glyceride (TG) level was significantly lower in SHQ group compared to HL group. There was no significantly difference in total cholesterol (TC) levels in HL group compared with SHQ group. The results showed that dinking SHQ water can improve the TG, but with no effects on TC. After drinking SHQ water for 3 months, the rats in different groups could be classified into different clusters according to the metabolites in urine. Total 15 important metabolites were found and correlated with disturbance of amino acid, phospholipid, fatty acid and vitamin metabolism, which suggested the changes of metabolism in the body and possible mechanism by which SHQ improved the TG. These findings provide a new insight for the prevention and control of hyperlipidemia.

Could Cyclosiversioside F Serve as a Dietary Supplement to Prevent Obesity and Relevant Disorders?

Obesity is the basis of numerous metabolic diseases and has become a major public health issue due to its rapidly increasing prevalence. Nevertheless, current obesity therapeutic strategies are not sufficiently effective, so there is an urgent need to develop novel anti-obesity agents. Naturally occurring saponins with outstanding bio-activities have been considered promising drug leads and templates for human diseases. Cyclosiversioside F (CSF) is a paramount multi-functional saponin separated from the roots of the food-medicinal herb Astragali Radix, which possesses a broad spectrum of bioactivities, including lowering blood lipid and glucose, alleviating insulin resistance, relieving adipocytes inflammation, and anti-apoptosis. Recently, the therapeutic potential of CSF in obesity and relevant disorders has been gradually explored and has become a hot research topic. This review highlights the role of CSF in treating obesity and obesity-induced complications, such as diabetes mellitus, diabetic nephropathy, cardiovascular and cerebrovascular diseases, and non-alcoholic fatty liver disease. Remarkably, the underlying molecular mechanisms associated with CSF in disease therapy have been partially elucidated, especially PI3K/Akt, NF-κB, MAPK, apoptotic pathway, TGF-β, NLRP3, Nrf-2, and AMPK, with the aim of promoting the development of CSF as a functional food and providing references for its clinical application in obesity-related disorders therapy.

Identifying subgroups of patients with type 2 diabetes based on real-world traditional chinese medicine electronic medical records

Introduction: Type 2 diabetes (T2D) is a multifactorial complex chronic disease with a high prevalence worldwide, and Type 2 diabetes patients with different comorbidities often present multiple phenotypes in the clinic. Thus, there is a pressing need to improve understanding of the complexity of the clinical Type 2 diabetes population to help identify more accurate disease subtypes for personalized treatment. Methods: Here, utilizing the traditional Chinese medicine (TCM) clinical electronic medical records (EMRs) of 2137 Type 2 diabetes inpatients, we followed a heterogeneous medical record network (HEMnet) framework to construct heterogeneous medical record networks by integrating the clinical features from the electronic medical records, molecular interaction networks and domain knowledge. Results: Of the 2137 Type 2 diabetes patients, 1347 were male (63.03%), and 790 were female (36.97%). Using the HEMnet method, we obtained eight non-overlapping patient subgroups. For example, in H3, Poria, Astragali Radix, Glycyrrhizae Radix et Rhizoma, Cinnamomi Ramulus, and Liriopes Radix were identified as significant botanical drugs. Cardiovascular diseases (CVDs) were found to be significant comorbidities. Furthermore, enrichment analysis showed that there were six overlapping pathways and eight overlapping Gene Ontology terms among the herbs, comorbidities, and Type 2 diabetes in H3. Discussion: Our results demonstrate that identification of the Type 2 diabetes subgroup based on the HEMnet method can provide important guidance for the clinical use of herbal prescriptions and that this method can be used for other complex diseases.

Fabrication, characterization, and lipid-lowering effects of naringenin-zein-sodium caseinate-galactosylated chitosan nanoparticles

Naringenin is a natural flavonoid that is widely distributed in citrus fruits and pharmacologically demonstrated to licit lipid-lowering activity. However, the clinical relevance of naringenin is limited due to its poor water solubility and inefficient absorption. In this study, we designed and developed naringenin-zein-sodium caseinate-galactosylated chitosan nanoparticles (GC-NPs) for hepatocyte-specific targeting, with naringenin-zein-sodium caseinate-chitosan nanoparticles (CS-NPs) as a control. Electrostatic adsorption was the primary binding mode in the GC-NPs and CS-NPs. Moreover, the particle size and zeta potential of GC-NPs were larger than those of CS-NPs and both types of nanoparticles had similar encapsulation rates. In vitro study experiments demonstrated that GC-NPs aggregated inside and outside of the cell membrane and significantly inhibited total triglyceride and cholesterol levels in oleic acid-induced HepG2 cells (p < 0.05). In high-fat diet-fed C57BL/6J mice, GC-NPs administration visibly improved the body weight, total cholesterol, and triglyceride content in the serum and liver, and high-density lipoprotein cholesterol levels improved, which corresponded to liver histological results. Additionally, in vitro and in vivo assays demonstrated that GC-NPs exhibited higher lipid-lowering activity than CS-NPs and naringenin monomers. These results suggest that GC-NPs are effective for oral delivery of naringenin in lipid-lowering therapies.

Modulation of Insulin Resistance by Silybum marianum Leaves, and its Synergistic Efficacy with Gymnema sylvestre, Momordica charantia, Trigonella-foenum graecum Against Protein Tyrosine Phosphatase 1B

Prolonged insulin resistance is considered one of the reasons for Type 2 Diabetes Mellitus. Upregulation of Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signalling, has been well studied as a key regulator in prognosis to insulin resistance. It has been widely studied as a desirable molecular therapeutic target. The study aimed to evaluate the efficacy of leaf extract of the medicinal plants Silybum marianum on the inhibition of PTP1B activity. It also explored the synergistic effect with extracts of Gymnema sylvestre (leaves), Momordica charantia (seeds), and Trigonella foenum graecum (seeds). The S. marianum leaves showed dose-dependent inhibition of PTP1B ranging from 9.48-47.95% (25-1000 μg mL-1). Assay with individual plant extracts showed comparatively lesser inhibition of PTP1B as compared to metformin as a control (38% inhibition). However, a synergistic effect showed nearly 45% PTP1B inhibition (higher than metformin) after the assay was done with selected four plant extracts in combination. The effect of leaf extracts of S. marianum was studied for glucose uptake efficiency in yeast cell lines which was found to be increased by 23% as compared to the control (without extract). Metformin improves glucose upake by yeast cells by ~15-31%. GC-MS analysis revealed 23 phytochemicals, some of which possessed anti-diabetic properties. A dose-dependent increase in antioxidant activity of S. marianum leaves extracts was observed (40-53%). The findings of the study highlighted the presence of various phytochemicals in leaves extracts that are effective against PTP1B inhibition and may help in reinvigorating drug development.

Virtual Screening and Biological Evaluation of Novel Low Molecular Weight Protein Tyrosine Phosphatase Inhibitor for the Treatment of Insulin Resistance

Purpose

Protein tyrosine phosphatases (PTPs) play an essential way in diseases including cancer, obesity, diabetes and autoimmune disorders. As a member of PTPs, low molecular weight PTP (LMPTP) has been a well-recognized anti-insulin resistance target in obesity. However, the number of reported LMPTP inhibitors is limited. Our research aims to discover a novel LMPTP inhibitor and evaluate its biological activity against insulin resistance.

Methods

A virtual screening pipeline based on the X-ray co-crystal complex of LMPTP was constructed. Enzyme inhibition assay and cellular bioassay were used to evaluate the activity of screened compounds.

Results

The screening pipeline rendered 15 potential hits from Specs chemical library. Enzyme inhibition assay identified compound F9 (AN-465/41163730) as a potential LMPTP inhibitor with a K _i value of 21.5 ± 7.3 μM. Cellular bioassay showed F9 could effectively increase the glucose consumption of HepG2 cells as a result of releasing insulin resistance by regulating PI3K-Akt pathway.

Conclusion

In summary, this study presents a versatile virtual screening pipeline for potential LMPTP inhibitor discovery and provides a novel-scaffold lead compound that is worthy of further modification to get more potent LMPTP inhibitors.

The Molecular Basis of the Anti-Inflammatory Property of Astragaloside IV for the Treatment of Diabetes and Its Complications

Astragali Radix is a significant traditional Chinese medication, and has a long history of clinical application in the treatment of diabetes mellitus (DM) and its complications. AS-IV is an active saponin isolated from it. Modern pharmacological study shows that AS-IV has anti-inflammatory, anti-oxidant and immunomodulatory activities. The popular inflammatory etiology of diabetes suggests that DM is a natural immune and low-grade inflammatory disease. Pharmacological intervention of the inflammatory response may provide promising and alternative approaches for the prevention and treatment of DM and its complications. Therefore, this article focuses on the potential of AS-IV in the treatment of DM from the perspective of an anti-inflammatory molecular basis. AS-IV plays a role by regulating a variety of anti-inflammatory pathways in multiple organs, tissues and target cells throughout the body. The blockade of the NF-κB inflammatory signaling pathway may be the central link of AS-IV's anti-inflammatory effect, resulting in a reduction in the tissue structure and function damage stimulated by inflammatory factors. In addition, AS-IV can delay the onset of DM and its complications by inhibiting inflammation-related oxidative stress, fibrosis and apoptosis signals. In conclusion, AS-IV has therapeutic prospects from the perspective of reducing the inflammation of DM and its complications. An in-depth study on the anti-inflammatory mechanism of AS-IV is of great significance for the effective use of Chinese herbal medicine and the promotion of its status and influence on the world.

Terpenoids: Natural Compounds for Non-Alcoholic Fatty Liver Disease (NAFLD) Therapy

Natural products have been the most productive source for the development of drugs. Terpenoids are a class of natural active products with a wide range of pharmacological activities and therapeutic effects, which can be used to treat a variety of diseases. Non-alcoholic fatty liver disease (NAFLD), a common metabolic disorder worldwide, results in a health burden and economic problems. A literature search was conducted to obtain information relevant to the treatment of NAFLD with terpenoids using electronic databases, namely PubMed, Web of Science, Science Direct, and Springer, for the period 2011-2021. In total, we found 43 terpenoids used in the treatment of NAFLD. Over a dozen terpenoid compounds of natural origin were classified into five categories according to their structure: monoterpenoids, sesquiterpenoids, diterpenoids, triterpenoids, and tetraterpenoids. We found that terpenoids play a therapeutic role in NAFLD, mainly by regulating lipid metabolism disorder, insulin resistance, oxidative stress, and inflammation. The AMPK, PPARs, Nrf-2, and SIRT 1 pathways are the main targets for terpenoid treatment. Terpenoids are promising drugs and will potentially create more opportunities for the treatment of NAFLD. However, current studies are restricted to animal and cell experiments, with a lack of clinical research and systematic structure-activity relationship (SAR) studies. In the future, we should further enrich the research on the mechanism of terpenoids, and carry out SAR studies and clinical research, which will increase the likelihood of breakthrough insights in the field.

Astragaloside IV Regulates Insulin Resistance and Inflammatory Response of Adipocytes via Modulating CTRP3 and PI3K/AKT Signaling

INTRODUCTION

Emerging evidence showed that adipocytes are important regulators in controlling insulin resistance in type 2 diabetes mellitus (T2DM). So far, compounds isolated from natural plants have been widely studied for their roles in alleviating T2DM-associated complications. This work evaluated the actions of astragaloside IV (AS-IV) on insulin resistance and inflammatory biomarker expression in adipocytes and explored the potential mechanisms.

METHODS

Glucose consumption of the adipocytes was determined by a glucose assay kit; the mRNA expression levels of glucose transporter type 4 (GLUT-4), interleukin-6 (IL-6), TNF-α and C1q tumor necrosis factor-related protein 3 (CTRP3) were measured by quantitative real-time PCR (qRT-PCR); the protein levels were determined by western blot assay and enzyme-linked immunosorbent assay.

RESULTS

AS-IV concentration-dependently increased glucose consumption in the insulin resistance adipocytes. Further qRT-PCR results showed that AS-IV concentration-dependently reduced adipocyte IL-6 and TNF-α expression. Moreover, GLUT-4 expression in adipocytes was also significantly upregulated by AS-IV. Furthermore, we found that AS-IV concentration-dependently increased CTRP3 expression in adipocytes. CTRP3 silence decreased glucose consumption, upregulated IL-6 and TNF-α expression and downregulated GLUT-4 mRNA expression in 200 µM AS-IV-treated adipocytes. Moreover, AS-IV treatment enhanced the activity of phosphoinositide 3-kinase (PI3K)/AKT signaling in adipocytes, which was markedly attenuated by CTRP3 silencing. Importantly, inhibition of PI3K/AKT signaling also attenuated AS-IV induced an increase in glucose consumption and GLUT-4 expression and a decrease in IL-6 and TNF-α expression of adipocytes.

CONCLUSIONS

Collectively, our data indicated that AS-IV attenuated insulin resistance and inflammation in adipocytes via targeting CTRP3/PI3K/Akt signaling.

An Ethnopharmaceutical Study on the Hypolipidemic Formulae in Taiwan Issued by Traditional Chinese Medicine Pharmacies

Globally, approximately one-third of ischemic heart diseases are due to hyperlipidemia, which has been shown to cause various metabolic disorders. This study was aimed to disassemble and analyze hypolipidemic formulae sold by traditional Chinese medicine (TCM) pharmacies. Using commonly used statistical parameters in ethnopharmacology, we identified the core drug combination of the hypolipidemic formulae, thereby exploring the strategy by which the Taiwanese people select hypolipidemic drugs. Most important of all, we preserved the inherited knowledge of TCM. We visited 116 TCM pharmacies in Taiwan and collected 91 TCM formulae. The formulae were mainly disassembled by macroscopical identification, and the medicinal materials with a relative frequency of citation (RFC) >0.2 were defined as commonly used medicinal materials. Subsequently, we sorted the information of medicinal materials recorded in the Pharmacopeia, searched for modern pharmacological research on commonly used medicinal materials using PubMed database, and visualized data based on the statistical results. Finally, the core hypolipidemic medicinal materials used in folk medicine were obtained. Of the 91 TCM formulae collected in this study, 80 traditional Chinese medicinal materials were used, belonging to 43 families, predominantly Lamiaceae. Roots were the most commonly used part as a medicinal material. There were 17 commonly used medicinal materials. Based on medicinal records in Pharmacopeia, most flavors and properties were warm and pungent, the majority traditional effects were “tonifying and replenishing” and “blood-regulating.” Besides, the targeted diseases searching from modern pharmacological studies were diabetes mellitus and dyslipidemia. The core medicinal materials consisted of Astragalus mongholicus Bunge and Crataegus pinnatifida Bunge, and the core formulae were Bu-Yang-Huan-Wu-Tang and Xie-Fu-Zhu-Yu-Tang. In addition, 7 groups of folk misused medicinal materials were found. Although these TCMs have been used for a long period of time, their hypolipidemic mechanisms remain unclear, and further studies are needed to validate their safety and efficacy.

Melatonin Alleviates PM2.5-Induced Hepatic Steatosis and Metabolic-Associated Fatty Liver Disease in ApoE-/- Mice

Background

Exposure to fine particulate matter (PM_2.5) is associated with the risk of developing metabolic-associated fatty liver disease (MAFLD). Melatonin is the main secreted product of the pineal gland and has been reported to prevent hepatic lipid metabolism disorders. However, it remains uncertain whether melatonin could protect against PM_2.5-induced MAFLD.

Methods and Results

The purpose of our study was to investigate the mitigating effects of melatonin on hepatic fatty degeneration accelerated by PM_2.5 in vivo and in vitro. Histopathological analysis and ultrastructural images showed that PM_2.5 induced hepatic steatosis and lipid vacuolation in ApoE^−/− mice, which could be effectively alleviated by melatonin administration. Increased ROS production and decreased expression of antioxidant enzymes were detected in the PM_2.5-treated group, whereas melatonin showed recovery effects after PM_2.5-induced oxidative damage in both the liver and L02 cells. Further investigation revealed that PM_2.5 induced oxidative stress to activate PTP1B, which in turn had a positive feedback regulation effect on ROS release. When a PTP1B inhibitor or melatonin was administered, SP1/SREBP-1 signalling was effectively suppressed, while Nrf2/Keap1 signalling was activated in the PM_2.5-treated groups.

Conclusion

Our study is the first to show that melatonin alleviates the disturbance of PM_2.5-triggered hepatic steatosis and liver damage by regulating the ROS-mediated PTP1B and Nrf2 signalling pathways in ApoE^−/− mice. These results suggest that melatonin administration might be a prospective therapy for the prevention and treatment of MAFLD associated with air pollution.

Approaches to Decrease Hyperglycemia by Targeting Impaired Hepatic Glucose Homeostasis Using Medicinal Plants

Liver plays a pivotal role in maintaining blood glucose levels through complex processes which involve the disposal, storage, and endogenous production of this carbohydrate. Insulin is the hormone responsible for regulating hepatic glucose production and glucose storage as glycogen, thus abnormalities in its function lead to hyperglycemia in obese or diabetic patients because of higher production rates and lower capacity to store glucose. In this context, two different but complementary therapeutic approaches can be highlighted to avoid the hyperglycemia generated by the hepatic insulin resistance: 1) enhancing insulin function by inhibiting the protein tyrosine phosphatase 1B, one of the main enzymes that disrupt the insulin signal, and 2) direct regulation of key enzymes involved in hepatic glucose production and glycogen synthesis/breakdown. It is recognized that medicinal plants are a valuable source of molecules with special properties and a wide range of scaffolds that can improve hepatic glucose metabolism. Some molecules, especially phenolic compounds and terpenoids, exhibit a powerful inhibitory capacity on protein tyrosine phosphatase 1B and decrease the expression or activity of the key enzymes involved in the gluconeogenic pathway, such as phosphoenolpyruvate carboxykinase or glucose 6-phosphatase. This review shed light on the progress made in the past 7 years in medicinal plants capable of improving hepatic glucose homeostasis through the two proposed approaches. We suggest that Coreopsis tinctoria, Lithocarpus polystachyus, and Panax ginseng can be good candidates for developing herbal medicines or phytomedicines that target inhibition of hepatic glucose output as they can modulate the activity of PTP-1B, the expression of gluconeogenic enzymes, and the glycogen content.

The Potential Application of Chinese Medicine in Liver Diseases: A New Opportunity

Liver diseases have been a common challenge for people all over the world, which threatens the quality of life and safety of hundreds of millions of patients. China is a major country with liver diseases. Metabolic associated fatty liver disease, hepatitis B virus and alcoholic liver disease are the three most common liver diseases in our country, and the number of patients with liver cancer is increasing. Therefore, finding effective drugs to treat liver disease has become an urgent task. Chinese medicine (CM) has the advantages of low cost, high safety, and various biological activities, which is an important factor for the prevention and treatment of liver diseases. This review systematically summarizes the potential of CM in the treatment of liver diseases, showing that CM can alleviate liver diseases by regulating lipid metabolism, bile acid metabolism, immune function, and gut microbiota, as well as exerting anti-liver injury, anti-oxidation, and anti-hepatitis virus effects. Among them, Keap1/Nrf2, TGF-β/SMADS, p38 MAPK, NF-κB/IκBα, NF-κB-NLRP3, PI3K/Akt, TLR4-MyD88-NF-κB and IL-6/STAT3 signaling pathways are mainly involved. In conclusion, CM is very likely to be a potential candidate for liver disease treatment based on modern phytochemistry, pharmacology, and genomeproteomics, which needs more clinical trials to further clarify its importance in the treatment of liver diseases.

Astragalus Polysaccharides and Saponins Alleviate Liver Injury and Regulate Gut Microbiota in Alcohol Liver Disease Mice

Astragalus, a medical and edible plant in China, shows several bioactive properties. However, the role of astragalus in attenuating alcoholic liver disease (ALD) is less clear. The objective of this project is to investigate the improving effect of astragalus saponins (AS) and astragalus polysaccharides (AP), which are the two primary constituents in astragalus on hepatic injury induced by alcohol, and the potential mechanisms of action. Different doses of AS (50 and 100 mg/kg bw) and AP (300 and 600 mg/kg bw) were orally given to alcohol-treated mice for four weeks. The results demonstrated that both AP and AS could reverse the increase of the levels of TC, TG, FFA, and LDL-C in serum, and the decrease of serum HDL-C content, as well as the elevation of hepatic TC and TG levels induced by alcohol. The activities of AST, ALT, ALP, and γ-GT in ALD mice were raised after AP and AS supplementation. The antioxidant markers (SOD, CAT, GSH, and GSH-Px) were obviously augmented and the pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and hepatic histological variations were alleviated by AP and AS, which was in line with the levels of oxidative stress-associated genes (Keap1, Nfe2l2, Nqo1, and Hmox1) and inflammation-associated genes (Tlr4, Myd88 and Nfkb1). In addition, AS exerted a more efficient effect than AP and the results presented dose proportionality. Moreover, AS and AP could modulate the intestinal microbiota disturbance induced by alcohol. Overall, AS and AP administration could ameliorate lipid accumulation in the serum and liver, as well as hepatic function, oxidative stress, inflammatory response, and gut flora disorders in mice as a result of alcohol.

Evaluation of the Hypoglycemic Activity of Morchella conica by Targeting Protein Tyrosine Phosphatase 1B

Morchella conica (M. conica) Pers. is one of six wild edible mushrooms that are widely used by Asian and European countries for their nutritional value. The present study assessed the anti-diabetic potential of M. conica methanolic extract (100 mg/kg body weight) on streptozotocin (STZ)-induced diabetic mice. STZ was used in a single dose of 65 mg/kg to establish diabetic models. Body weights, water/food intake and fasting blood glucose levels were measured. Histopathological analysis of the pancreas and liver were performed to evaluate STZ-induced tissue injuries. In addition, in vitro assays such as α-amylase and protein tyrosine phosphatase 1B (PTP1B) inhibitory, antiglycation, antioxidant and cytotoxicity were performed. The in vitro study indicated potent PTP1B inhibitory potential of M. conica with an IC₅₀ value of 26.5 μg/ml as compared to the positive control, oleanolic acid (IC₅₀ 36.2 μg/ml). In vivo investigation showed a gradual decrease in blood sugar level in M. conica-treated mice (132 mg/dl) at a concentration of 100 mg/kg as compared to diabetic mice (346 mg/dl). The extract positively improved liver and kidney damages as were shown by their serum glutamic pyruvic transaminase, serum glutamic oxaloacetate, alkaline phosphatase, serum creatinine and urea levels. Histopathological analysis revealed slight liver and pancreas improvement of mice treated with extract. Cytotoxicity assays displayed lower IC₅₀ values. Based on the present results of the study, it may be inferred that M. conica are rich in bioactive compounds responsible for antidiabetic activity and this mushroom may be a potential source of antidiabetic drug. However, further studies are required in terms of isolation of bioactive compounds to validate the observed results.