Ginsenoside Rg1 attenuates hepatic insulin resistance induced by high-fat and high-sugar by inhibiting inflammation

Natural Saponins on Cholesterol-Related Diseases: Treatment and Mechanism

Saponins are compounds composed of lipophilic aglycones linked to hydrophilic sugars. Natural saponins are isolated from plants and some Marine organisms. As important cholesterol-lowering drugs, natural saponins have attracted wide attention for their therapeutic potential in a variety of cholesterol-related metabolic diseases. To review the effects of natural saponins on cholesterol-related metabolic diseases, and to deepen the understanding of the cholesterol-lowering mechanism of saponins. The literature related to saponins and cholesterol-lowering diseases was collected using keywords "saponins" and "cholesterol" from PubMed, Web of Science, and Google Scholar from January 2000 to May 2024. The total number of articles related to saponins and cholesterol-lowering diseases was 240 after excluding irrelevant articles. Natural saponins can regulate cholesterol to prevent and treat a variety of diseases, such as atherosclerosis, diabetes, liver disease, hyperlipidemia, cancer, and obesity. Mechanistically, natural saponins regulate cholesterol synthesis and uptake through the AMPK/SREBP2/3-hydroxy-3-methyl-glutaryl coenzyme A reductase pathway and PCSK9/LDLR pathway, and regulate cholesterol efflux and esterification targeting Liver X receptor/ABC pathway and ACAT family. Natural saponins have broad application prospects in regulating cholesterol metabolism, for the development of more cholesterol-lowering drugs provides a new train of thought. However, it is still necessary to further explore the molecular mechanism and expand clinical trials to provide more evidence.

Ginsenoside Rg1: A bioactive therapeutic agent for diverse liver diseases

Diverse liver diseases are characterised by late diagnosis and rapid progression and have become one of the major threats to human health. To delay the transition from benign tissue lesions to a substantial organ injury, scientists have gradually applied natural compounds derived from plants as a complementary therapy in the field of hepatology. Ginseng (Panax ginseng C. A. Meyer) is a tonic traditional Chinese herbal medicine, and natural products, including ginsenoside Rg1 (G-Rg1), which is a kind of 20(S)-protopanaxatriol saponin with a relatively high biological activity, can be isolated from the roots or stems of ginseng. Given these information, this review aimed to summarise and discuss the metabolic mechanisms of G-Rg1 in the regulation of diverse liver diseases and the measures to improve its bioavailability. As a kind of monomer in Chinese medicine with multitarget pharmacological effects, G-Rg1 can provide significant therapeutic benefits in the alleviation of alcoholic liver disease, nonalcoholic fatty liver disease, liver fibrosis, viral hepatitis, etc., which mainly rely on the inhibition of apoptosis, strengthening endogenous anti-inflammatory and antioxidant mechanisms, activation of immune responses and regulation of efflux transport signals, to improve pathological changes in the liver caused by lipid deposition, inflammation, oxidative stress, accumulation of hepatotoxic product, etc. However, the poor bioavailability of G-Rg1 must be overcome to improve its clinical application value. In summary, focusing on the hepatoprotective benefits of G-Rg1 will provide new insights into the development of natural Chinese medicine resources and their pharmaceutical products to target the treatment of liver diseases.

Saponin monomers: Potential candidates for the treatment of type 2 diabetes mellitus and its complications

Type 2 diabetes mellitus (T2DM), a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR), has become one of the most serious health challenges of the 21st century, with considerable economic and societal implications worldwide. Considering the inevitable side effects of conventional antidiabetic drugs, natural ingredients exhibit promising therapeutic efficacy and can serve as safer and more cost-effective alternatives for the management of T2DM. Saponins are a structurally diverse class of amphiphilic compounds widely distributed in many popular herbal medicinal plants, some animals, and marine organisms. There are many saponin monomers, such as ginsenoside compound K, ginsenoside Rb1, ginsenoside Rg1, astragaloside IV, glycyrrhizin, and diosgenin, showing great efficacy in the treatment of T2DM and its complications in vivo and in vitro. However, although the mechanisms of action of saponin monomers at the animal and cell levels have been gradually elucidated, there is a lack of clinical data, which hinders the development of saponin-based antidiabetic drugs. Herein, the main factors/pathways associated with T2DM and the comprehensive underlying mechanisms and potential applications of these saponin monomers in the management of T2DM and its complications are reviewed and discussed, aiming to provide fundamental data for future high-quality clinical studies and trials.

Ginsenosides for the treatment of insulin resistance and diabetes: Therapeutic perspectives and mechanistic insights

Diabetes mellitus (DM) is a systemic disorder of energy metabolism characterized by a sustained elevation of blood glucose in conjunction with impaired insulin action in multiple peripheral tissues (i.e., insulin resistance). Although extensive research has been conducted to identify therapeutic targets for the treatment of DM, its global prevalence and associated mortailty rates are still increasing, possibly because of challenges related to long-term adherence, limited efficacy, and undesirable side effects of currently available medications, implying an urgent need to develop effective and safe pharmacotherapies for DM. Phytochemicals have recently drawn attention as novel pharmacotherapies for DM based on their clinical relevance, therapeutic efficacy, and safety. Ginsenosides, pharmacologically active ingredients primarily found in ginseng, have long been used as adjuvants to traditional medications in Asian countries and have been reported to exert promising therapeutic efficacy in various metabolic diseases, including hyperglycemia and diabetes. This review summarizes the current pharmacological effects of ginsenosides and their mechanistic insights for the treatment of insulin resistance and DM, providing comprehensive perspectives for the development of novel strategies to treat DM and related metabolic complications.

Characteristics of elderly diabetes patients: focus on clinical manifestation, pathogenic mechanism, and the role of traditional Chinese medicine

Diabetes mellitus has become a major public health issue globally, putting an enormous burden on global health systems and people. Among all diseased groups, a considerable part of patients are elderly, while their clinical features, pathogenic processes, and medication regimens are different from patients of other ages. Despite the availability of multiple therapies and techniques, there are still numerous elderly diabetes patients suffering from poor blood glucose control, severe complications, and drug adverse effects, which negatively affect the quality of life in their golden years. Traditional Chinese Medicine (TCM) has been widely used in the treatment of diabetes for several decades, and its relevant clinical practice has confirmed that it has a satisfactory effect on alleviating clinical symptoms and mitigating the progression of complications. Chinese herbal medicine and its active components were used widely with obvious clinical advantages by multiple targets and signaling pathways. However, due to the particular features of elderly diabetes, few studies were conducted to explore Traditional Chinese Medicine intervention on elderly diabetic patients. This study reviews the research on clinical features, pathogenic processes, treatment principles, and TCM treatments, hoping to provide fresh perspectives on the prevention and management strategies for elderly diabetes.

Ginsenoside Rg1, lights up the way for the potential prevention of Alzheimer's disease due to its therapeutic effects on the drug-controllable risk factors of Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine, Shen Nong, BenCao Jing, and Compendium of Materia Medica (Bencao Gangmu), Panax ginseng, and its prescriptions have been used for the treatment of dementia, depression, weight loss, Xiaoke disease (similar to diabetes), and vertigo. All these diseases are associated with the drug-controllable risk factors for Alzheimer's disease (AD), including depression, obesity, diabetes, and hypertension. Ginsenoside Rg1, one of the main active ingredients of P. ginseng and its congener Panax notoginseng, possesses therapeutic potentials against AD and associated diseases. This suggests that ginsenoside Rg1 might have the potential for AD prevention and treatment. Although the anti-AD effects of ginsenoside Rg1 have received more attention, a systematic review of its effects on depression, obesity, diabetes, and hypertension is not available.

AIM OF THE REVIEW

This systematic literature review comprehensively summarized existing literature on the therapeutic potentials of ginsenoside Rg1 in AD prevention for the propose of providing a foundation of future research aimed at enabling the use of such drugs in clinical practice.

METHODS

Information on ginsenoside Rg1 was collected from relevant published articles identified through a literature search in electronic scientific databases (PubMed, Science Direct, and Google Scholar). The keywords used were "Ginsenoside Rg1," "Panax ginseng," "Source," "Alzheimer's disease," "Brain disorders," "Depression," "Obesity," "Diabetes," and "Hypertension."

RESULTS

The monomer ginsenoside Rg1 can be relatively easily obtained and has therapeutic potentials against AD. In vitro and in vivo experiments have demonstrated the therapeutic potentials of ginsenoside Rg1 against the drug-controllable risk factors of AD including depression, obesity, diabetes, and hypertension. Thus, ginsenoside Rg1 alleviates diseases resulting from AD risk factors by regulating multiple targets and pathways.

CONCLUSIONS

Ginsenoside Rg1 has the potentials to prevent AD by alleviating depression, obesity, diabetes, and hypertension.

Traditional herbs: mechanisms to combat cellular senescence

Cellular senescence plays a very important role in the ageing of organisms and age-related diseases that increase with age, a process that involves physiological, structural, biochemical and molecular changes in cells. In recent years, it has been found that the active ingredients of herbs and their natural products can prevent and control cellular senescence by affecting telomerase activity, oxidative stress response, autophagy, mitochondrial disorders, DNA damage, inflammatory response, metabolism, intestinal flora, and other factors. In this paper, we review the research information on the prevention and control of cellular senescence in Chinese herbal medicine through computer searches of PubMed, Web of Science, Science Direct and CNKI databases.

Notoginsenoside-R1 ameliorates palmitic acid-induced insulin resistance and oxidative stress in HUVEC via Nrf2/ARE pathway

Panax notoginseng, a Chinese traditional food and herb medicine, possesses notable cardiovascular health-promoting properties, with notoginsenoside (NG)-R1 being a key active compound. Insulin resistance represents a global health concern associated with various metabolic disorders. This study investigated the effects of NG-R1 on palmitic acid (PA)-induced insulin resistance and oxidative stress in human umbilical vein endothelial cells (HUVECs). Our findings demonstrate that NG-R1 significantly alleviated impaired glucose uptake, enhanced the phosphorylation of protein kinase B (PKB/Akt) at Ser473, and reduced the phosphorylation of insulin receptor substrate 1 (IRS-1) at Ser307 in PA-treated HUVECs. Furthermore, NG-R1 treatment significantly lowered the levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), while increasing the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG). Additionally, NG-R1 activated the Nrf2/ARE signaling pathway, leading to a substantial increase in the expression of antioxidant enzymes. Notably, knockdown of Nrf2 attenuated the beneficial effects of NG-R1 on PA-induced insulin resistance and oxidative stress in HUVECs, suggesting that NG-R1 exerts its effects through the Nrf2/ARE pathway. In summary, our study reveals that NG-R1 ameliorated PA-induced insulin resistance in HUVECs via Nrf2/ARE pathway, providing novel insights into its potential for alleviating metabolic disorders and cardiovascular disease.

Antioxidant and anti-inflammatory properties of ginsenoside Rg1 for hyperglycemia in type 2 diabetes mellitus: systematic reviews and meta-analyses of animal studies

Background: According to existing laboratory data, ginsenoside Rg1 may help cure diabetes and its complications by reducing oxidative stress (OS) and managing inflammation. However, this conclusion lacks reliability and is unclear. As a result, the purpose of this systematic review and meta-analysis was to evaluate the antioxidant and anti-inflammatory effects of ginsenoside Rg1 in the treatment of diabetes and its complications. Methods: We searched for relevant studies published through December 2022, including electronic bibliographic databases such as PubMed, EMBASE, Web of Science, CNKI, and Wanfang. The SYstematic Review Center for Laboratory Animal Experimentation Risk of Bias (SYRCLE RoB) tool was used to conduct a meta-analysis to assess the methodological quality of animal research. The meta-analysis was conducted using RevMan5.4 software, following the Cochrane Handbook for Systematic Reviews of Interventions. This study is registered in the International Systems Review Prospective Registry (PROSPERO) as CRD42023386830. Results: Eighteen eligible studies involving 401 animals were included. Ginsenoside Rg1 was significantly correlated with blood glucose (BG), insulin levels, body weight, superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels. In addition, according to subgroup analysis, the hypoglycemic, anti-inflammatory, and antioxidant effects of ginsenoside Rg1 in type 2 diabetic animals were not affected by experimental species, modeling, experimental drug dosage, or course of treatment. Conclusion: This meta-analysis presents a summary of the hypoglycemic effects of ginsenoside Rg1, which are achieved through anti-inflammatory and antioxidant mechanisms. These findings provide evidence-based support for the medical efficacy of ginsenoside Rg1. Specifically, ginsenoside Rg1 reduced MDA levels and restored SOD activity to exert its antioxidant activity. It had a positive effect on the reduction of IL-6 and TNF-α levels. However, the inclusion of studies with low methodological quality and the presence of publication bias may undermine the validity of the results. Further investigation with a more rigorous experimental design and comprehensive studies is necessary to fully understand the specific glycemic mechanisms of ginsenosides. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier https://CRD42023386830.

Ginsenoside Rg1 activates brown adipose tissue to counteract obesity in high-fat diet-fed mice by regulating gut microbes and bile acid composition

Obesity is a global health problem strongly linked to gut microbes and their metabolites. In this study, ginsenoside Rg1 (Rg1) reduced lipid droplet size and hepatic lipid accumulation by activating uncoupling protein 1 expression in brown adipose tissue (BAT), which in turn inhibited high-fat diet (HFD)-induced weight gain in mice. Furthermore, the intestinal flora of mice was altered, the abundance of Lachnoclostridium, Streptococcus, Lactococcus, Enterococcus and Erysipelatoclostridium was upregulated, and the concentrations of fecal bile acids were altered, with cholic acid and taurocholic acid concentrations being significantly increased. In addition, the beneficial effects of Rg1 were eliminated in mice treated with a combination of antibiotics. In conclusion, these results suggest that Rg1 activates BAT to counteract obesity by regulating gut microbes and bile acid composition in HFD-fed mice.

Ginsenoside Rh4 inhibits breast cancer growth through targeting histone deacetylase 2 to regulate immune microenvironment and apoptosis

High expression of histone deacetylase 2 (HDAC2) is recognized as a marker of invasive breast cancer (BC). HDAC2 is not only responsible for enhancing tumor cell growth, development, and anti-apoptosis, but also plays a significant role in regulating PD-L1 on the surface of tumor cells. Continuous expression of PD-L1 allows tumor cells to escape immune surveillance. There is not much research on how HDAC2 affects the immune system in breast cancer. Ginsenoside Rh4 (Rh4) is a major rare saponin in heat-treated ginseng, which is widely applied in treating and preventing various diseases because of its potent medicinal value and stable safety. However, it is unclear how Rh4 affects the tumor immune microenvironment in breast cancer. Therefore, this paper aims to investigate the effect of Rh4 on HDAC2 in breast cancer, specifically the effect of HDAC2 on apoptosis and the immune microenvironment to inhibit breast cancer growth. According to our study, ginsenoside Rh4 has been shown to significantly suppress breast cancer cell proliferation without any adverse effects. The molecular docking results of Rh4 and HDAC2 indicate a binding energy of -6.06 kcal/mol, suggesting the potential of Rh4 as a targeting modulator of HDAC2. Mechanistically, Rh4 induces apoptosis of breast cancer cells by the HDAC2-mediated caspase pathway and inhibits the HDAC2-mediated JAK/STAT pathway to regulate the immune microenvironment, which inhibits breast cancer growth. Specifically, Rh4 was shown for the first time to blockade immune checkpoints (PD-1/PD-L1) and increase levels of T-lymphocytes in the tumor. In a word, our study establishes a theoretical framework for applying Rh4 as an immune checkpoint inhibitor as part of breast cancer treatment.

The Efficacy of Panax ginseng for the Treatment of Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Preclinical Studies

Although tremendous research has reported the protective effects of natural compounds in nonalcoholic fatty liver disease (NAFLD), there is still no approved drug. This study aimed to examine the efficacy of Panax ginseng in NAFLD in preclinical studies. A total of 41 studies were identified by searching the PubMed, Web of Science, and Cochrane Library databases. The methodological quality was assessed by the risk of bias tool from the Systematic Review Center for Laboratory Animal Experimentation. The standardized mean difference (SMD) with a 95% confidence interval was calculated, and the random effects model was used to examine overall efficacy or heterogeneity. The publication bias was analyzed by Egger's test. The results showed that Panax ginseng treatment significantly reduced the systemic levels of alanine aminotransferase (SMD: -2.15 IU/L; p < 0.0001), aspartate aminotransferase (SMD: -2.86 IU/L; p < 0.0001), triglyceride (SMD: -2.86 mg/dL; p < 0.0001), total cholesterol (SMD: -1.69 mg/dL; p < 0.0001), low-density lipoprotein (SMD: -1.46 mg/dL; p < 0.0001), and fasting glucose (SMD: -1.45 mg/dL; p < 0.0001) while increasing high-density lipoprotein (SMD: 1.22 mg/dL; p = 0.0002) in NAFLD regardless of animal models or species. These findings may suggest that Panax ginseng is a promising therapeutic agent for NAFLD treatment.

New Therapeutic Approaches to and Mechanisms of Ginsenoside Rg1 against Neurological Diseases

Neurological diseases, including Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), stroke, cerebral infarction, ischemia-reperfusion injury, depression and, stress, have high incidence and morbidity and often lead to disability. However, there is no particularly effective medication against them. Therefore, finding drugs with a suitable efficacy, low toxicity and manageable effects to improve the quality of life of patients is an urgent problem. Ginsenoside Rg1 (Rg1) is the main active component of ginseng and has a variety of pharmacological effects. In this review, we focused on the therapeutic potential of Rg1 for improving neurological diseases. We introduce the mechanisms of Ginsenoside Rg1 in neurological diseases, including apoptosis, neuroinflammation, the microRNA (miRNA) family, the mitogen-activated protein kinase (MAPK) family, oxidative stress, nuclear factor-κB (NF-κB), and learning and memory of Rg1 in neurological diseases. In addition, Rg1 can also improve neurological diseases through the interaction of different signal pathways. The purpose of this review is to explore more in-depth ideas for the clinical treatment of neurological diseases (including PD, AD, HD, stroke, cerebral infarction, ischemia–reperfusion injury, depression, and stress). Therefore, Rg1 is expected to become a new therapeutic method for the clinical treatment of neurological diseases.

Ginsenoside Rh4 Suppresses Metastasis of Esophageal Cancer and Expression of c-Myc via Targeting the Wnt/β-Catenin Signaling Pathway

The metastasis of esophageal squamous cell carcinoma (ESCC) is a leading cause of death worldwide, however, it has a poor prognosis. Ginsenoside Rh4 is a rare saponin that has been shown to have potential antitumor effectiveness in ESCC. However, the utility of Rh4 in ESCC metastasis and its undiscovered mode of action has not yet been explored. In this study, we found that Rh4 could inhibit ESCC metastasis by regulating the Wnt/β-catenin signaling pathway and the level of c-Myc, which is an important transcription factor in cancer. In in vitro experiments, Rh4 could inhibit the migration and invasion of ESCC cells without affecting cell viability. In in vivo experiments, Rh4 restrained ESCC metastasis to the lymph nodes and lungs via the suppression of epithelial-mesenchymal transition (EMT). The Wnt agonist HLY78 promoted EMT and migration of ESCC cells, whereas treatment of Rh4 can attenuate the promotion effect of HLY78. The siRNA knocking out c-Myc can also significantly reduce the expression of EMT-related marker proteins. This study illustrates a new concept for further research on the mechanism of Rh4 in ESCC.

Scutellarin Improves Type 2 Diabetic Cardiomyopathy by Regulating Cardiomyocyte Autophagy and Apoptosis

Diabetes cardiomyopathy has metabolic disorder and abnormality of cardiomyocytes, which is closely related to autophagy or apoptosis of cardiomyocytes. Scutellarin (SCU) is an important monomer extracted from Erigeron breviscapus (vant.) Hand.-Mazz. This study was conducted to investigate the function of SCU on apoptosis and autophagy of myocardial cells. We established a model of type 2 diabetic cardiomyopathy by high-fat and high-sugar diet. The results indicated that SCU downregulated blood glucose, total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) levels and upregulated high-density lipoprotein (HDL) level. In addition, SCU downregulated lactic dehydrogenase 1 (LDH1) and creatine kinase (CK) levels. Meanwhile, SCU improved the myocardium morphology and reduced myocardial apoptosis. Furthermore, SCU promoted the mRNA and protein expression of autophagy-related factors (Beclin-1 and LC3-II) and inhibited the mRNA and protein expression of apoptosis-related factors (caspase-3, caspase-8, caspase-9, caspase-12, Bax, and Cyt-C). In conclusion, SCU can promote autophagy signal pathway by upregulating the autophagy-related factors and inhibit the apoptotic signal pathway by downregulating apoptosis-related factors, thereby relieving type 2 diabetic cardiomyopathy (T2DC).

Ginsenoside Rh4 Suppresses Metastasis of Gastric Cancer via SIX1-Dependent TGF-β/Smad2/3 Signaling Pathway

Gastric cancer (GC) is the leading causes of cancer-related death worldwide. Surgery remains the cornerstone of gastric cancer treatment, and new strategies with adjuvant chemotherapy are currently gaining more and more acceptance. Ginsenoside Rh4 has excellent antitumor activity. Conversely, the mechanisms involved in treatment of GC are not completely understood. In this study, we certified that Rh4 showed strong anti-GC efficiency in vitro and in vivo. MTT and colony formation assays were performed to exhibit that Rh4 significantly inhibited cellular proliferation and colony formation. Results from the wound healing assay, transwell assays, and Western blotting indicated that Rh4 restrained GC cell migration and invasion by reversing epithelial–mesenchymal transition (EMT). Further validation by proteomic screening, co-treatment with disitertide, and SIX1 signal silencing revealed that SIX1, a target of Rh4, induced EMT by activating the TGF-β/Smad2/3 signaling pathway. In summary, our discoveries demonstrated the essential basis of the anti-GC metastatic effects of Rh4 via suppressing the SIX1–TGF-β/Smad2/3 signaling axis, which delivers a new idea for the clinical treatment of GC.

Insight into Shenqi Jiangtang Granule on the improved insulin sensitivity by integrating in silico and in vivo approaches

ETHNOPHARMACOLOGICAL RELEVANCE

Presently, insulin resistance has been a growing concern that urgently needs to be addressed, because it not only places patients at risk of developing type 2 diabetes mellitus but also results in metabolic syndrome and different aspects of cardiovascular diseases. Shenqi Jiangtang Granule (SJG) is a classic traditional Chinese medicine (TCM) prescription that is widely used to treat diabetes mellitus and its complications in clinical practice. While studies have revealed that SJG with multi-ingredients and multi-targets characteristics possesses potential anti-insulin resistance pharmacological properties, its mechanisms of action and molecular targets for the treatment of insulin resistance are still obscure, which prompt us to conduct an in-depth research.

AIM OF THE STUDY

This study was purposed to uncover the pharmacological mechanism of SJG against insulin resistance through integrating network pharmacology and experimental validation.

MATERIALS AND METHODS

The putative ingredients of SJG and its related targets were discerned from the TCMSP database. Subsequently, insulin resistance-associated targets were retrieved from GeneCard, OMIM, and GEO database. Compound-target, protein-protein interaction (PPI), and compound-target-pathway networks were established using Cytoscape software. GO and KEGG pathway analyses were performed to identify possible enrichment of genes with specific biological themes. Molecular docking was used to verify the correlation between the main active ingredients and hub targets. Optimal docking conformation was further analyzed by molecular dynamics (MD) simulation. Finally, the potential molecular mechanisms of SJG acting on insulin resistance, as predicted by the network pharmacology analyses, were validated experimentally in insulin-resistant rat model.

RESULTS

136 active compounds, 211 corresponding targets in addition to 1463 disease-related targets were collected, of which 94 intersection targets were obtained. 29 key targets including AKT1, VEGFA, IL-6, CASP3, and PTGS2 were identified through PPI network analysis. Hub module of PPI network was closely associated with inflammation. GO and KEGG analyses also revealed that inflammation-related pathways may be a central factor for SJG to modulate insulin resistance. Molecular docking test showed a good binding potency between primary active ingredients and core targets, and the binding mode of optimal docking conformation was stable in MD simulation. A rat model of insulin resistance was successfully induced by chronic high-fat diet (HFD) consumption. Through a series of in vivo studies, including HEC, ITT, and HOMA-IR measurement, it was revealed that SJG exhibited a beneficial effect on ameliorating insulin resistance, as demonstrated by a significant increase of GIR and a significant decrease of AUCITT and HOMA-IR index value. Further molecular biological analysis showed that SJG can decrease the mRNA expression level and serum concentration of inflammatory cytokines (TNF-α, IL-6, and IL-1β), along with suppressing the p-NFκB protein overexpression, indicating its anti-inflammatory activity. Also, it can contribute to the reversal of the impaired hepatic insulin signaling pathway, as evidenced by up-regulated protein expression of p-Akt and GLUT2.

CONCLUSIONS

Through in silico and in vivo approaches, the present study not only provides a unique insight into the possible mechanism of SJG in insulin resistance after successfully filtering out associated key target genes and signaling pathways, but also suggests a novel promising therapeutic strategy for curing insulin resistance.

Potential Natural Compounds for the Prevention and Treatment of Nonalcoholic Fatty Liver Disease: A Review on Molecular Mechanisms

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a kind of metabolic stress-induced liver injury closely related to insulin resistance and genetic susceptibility, and there is no specific drug for its clinical treatment currently. In recent years, a large amount of literature has reported that many natural compounds extracted from traditional Chinese medicine (TCM) can improve NAFLD through various mechanisms. According to the latest reports, some emerging natural compounds have shown great potential to improve NAFLD but are seldom used clinically due to the lacking special research.

PURPOSE

This paper aims to summarize the molecular mechanisms of the potential natural compounds on improving NAFLD, thus providing a direction and basis for further research on the pathogenesis of NAFLD and the development of effective drugs for the prevention and treatment of NAFLD.

METHODS

By searching various online databases, such as Web of Science, SciFinder, PubMed, and CNKI, NAFLD and these natural compounds were used as the keywords for detailed literature retrieval.

RESULTS

The pathogenesis of NAFLD and the molecular mechanisms of the potential natural compounds on improving NAFLD have been reviewed.

CONCLUSION

Many natural compounds from traditional Chinese medicine have a good prospect in the treatment of NAFLD, which can serve as a direction for the development of anti-NAFLD drugs in the future.

Terminalia catappa Extract Palliates Redox Imbalance and Inflammation in Diabetic Rats by Upregulating Nrf-2 Gene

This study aims at evaluating the ameliorative role of Terminalia catappa aqueous leaf extract (TCA) on hyperglycaemia-induced oxidative stress and inflammation in a high-fat, low dose streptozotocin-induced type 2 diabetic rat model. Experimental rats were treated orally with 400 and 800 mg/kg bw TCA daily for four weeks. Antioxidant enzyme activities, plasma glucose concentration, protein concentration, oxidative stress, and inflammation biomarkers were assayed using standard methods. Hepatic relative expressions of tumour necrosis factor-alpha (TNF-α), interleukin-six (IL-6), and nuclear factor-erythroid 2 related factor 2 (Nrf-2) were also assessed. Molecular docking and prediction of major TCA phytoconstituents' biological activity related to T2DM-induced oxidative stress were evaluated in silico. Induction of diabetes significantly (p < 0.05) reduced superoxide dismutase, glutathione-S-transferase, and peroxidase activities. Glutathione and protein stores were significantly (p < 0.05) depleted, while glucose, MDA, interleukin-six (IL-6), and tumour necrosis factor-α (TNF-α) concentrations were significantly (p < 0.05) increased. A significant (p < 0.05) upregulation of hepatic TNF-α and IL-6 expression and downregulation (p < 0.05) of Nrf-2 expression were observed during diabetes onset. TCA treatment significantly (p < 0.05) modulated systemic diabetic-induced oxidative stress and inflammation, mRNA expression dysregulation, and dysregulated macromolecule metabolism. However, only 800 mg/kg TCA treatment significantly (p < 0.05) downregulated hepatic TNF-α expression. 9-Oxabicyclo[3.3.1]nonane-2,6-diol and 1,2,3-Benzenetriol bound comparably to glibenclamide in Nrf-2, IL-6, and TNF-α binding pockets. They were predicted to be GST A and M substrate, JAK2 expression, ribulose-phosphate 3-epimerase, NADPH peroxidase, and glucose oxidase inhibitors. These results suggest that TCA ameliorates hyperglycaemia-induced oxidative stress and inflammation by activating Nrf-2 gene.

Ginsenoside Rg1 attenuates mechanical stress-induced cardiac injury via calcium sensing receptor-related pathway

Background

Ginsenoside Rg1 (Rg1) has been well documented to be effective against various cardiovascular disease. The aim of this study is to evaluate the effect of Rg1 on mechanical stress-induced cardiac injury and its possible mechanism with a focus on the calcium sensing receptor (CaSR) signaling pathway.

Methods

Mechanical stress was implemented on rats through abdominal aortic constriction (AAC) procedure and on cardiomyocytes and cardiac fibroblasts by mechanical stretching with Bioflex Collagen I plates. The effects of Rg1 on cell hypertrophy, fibrosis, cardiac function, [Ca²⁺]_i, and the expression of CaSR and calcineurin (CaN) were assayed both on rat and cellular level.

Results

Rg1 alleviated cardiac hypertrophy and fibrosis, and improved cardiac decompensation induced by AAC in rat myocardial tissue and cultured cardiomyocytes and cardiac fibroblasts. Importantly, Rg1 treatment inhibited CaSR expression and increase of [Ca²⁺]_i, which similar to the CaSR inhibitor NPS2143. In addition, Rg1 treatment inhibited CaN and TGF-β1 pathways activation. Mechanistic analysis showed that the CaSR agonist GdCl₃ could not further increase the [Ca²⁺]_i and CaN pathway related protein expression induced by mechanical stretching in cultured cardiomyocytes. CsA, an inhibitor of CaN, inhibited cardiac hypertrophy, cardiac fibrosis, [Ca²⁺]_i and CaN signaling but had no effect on CaSR expression.

Conclusion

The activation of CaN pathway and the increase of [Ca²⁺]_i mediated by CaSR are involved in cardiac hypertrophy and fibrosis, that may be the target of cardioprotection of Rg1 against myocardial injury.

Ginsenoside Rk3 Suppresses Hepatocellular Carcinoma Development through Targeting the Gut-Liver Axis

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Our previous reports showed that ginsenoside Rk3 provided excellent efficacy in alleviating the intestinal inflammatory response and protecting the liver, but its mechanism for HCC prevention remains to be explored. Here, the results suggested that Rk3 displayed potent antitumor effects against a dimethyl nitrosamine- and CCl₄-induced HCC mouse model. Results revealed that Rk3 application inhibited liver injury, fibrosis, and cirrhosis. In parallel, Rk3 lowered the inflammatory response by decreasing the expression of inflammatory cytokines, inducing apoptosis, and blocking the cell cycle. Meanwhile, Rk3 effectively ameliorated the gut microbiota dysbiosis. Furthermore, correlation analysis revealed that the LPS-TLR4 signaling pathway, which was inhibited by Rk3, plays a key role in preventing HCC. To conclude, our research provides valuable insights into how Rk3 application targets the gut-liver axis and suppresses HCC development, suggesting that Rk3 might be a promising candidate for clinical treatment of HCC.

The effects of ginseng on the metabolic syndrome: An updated review

Metabolic syndrome is a group of risk factors including high blood glucose, dyslipidemia, high blood pressure, and high body weight. It can increase the risk of diabetes and cardiovascular disorders, which are the important reasons for death around the world. Nowadays, there are numerous demands for herbal medicine because of less harmful effects and more useful effects in comparison with chemical options. Ginseng is one of the most famous herbs used as a drug for a variety of disorders in humans. The antihyperlipidemia, antihypertension, antihyperglycemic, and anti-obesity effects of ginseng and its active constituents such as ginsenosides have been shown in different studies. In this review article, the different in vitro, in vivo, and human studies concerning the effects of ginseng and its active constituents in metabolic syndrome have been summarized. According to these studies, ginseng can control metabolic syndrome and related diseases.

Ginsenoside-Rg1 acts as an IDO1 inhibitor, protects against liver fibrosis via alleviating IDO1-mediated the inhibition of DCs maturation

BACKGROUND

Indoleamine 2,3-dioxygenase 1 (IDO1) has been reported as a hallmark of hepatic fibrosis. Ginseng Rg1(G-Rg1) is a characterized bioactive component isolated from a traditional Chinese medicinal herb Panax ginseng C. A. Meyer (Ginseng) that used in China widely. However, the anti-hepatic fibrosis property of G-Rg1 and the underlying mechanisms of action are poorly reported.

PURPOSE

Here, we researched the effect of G-Rg1 on experimental liver fibrosis in vivo and in vitro.

STUDY DESIGN AND METHODS

We applied a CCL4-induced liver fibrosis in mice (wild-type and those overexpressing IDO1 by in vivo AAV9 vector) and HSC-T6 cells to detect the anti-hepatic fibrosis effect of G-Rg1 in vivo and in vitro.

RESULTS

We found that G-Rg1 reduced serum levels of AST and ALT markedly. Histologic examination indicated that G-Rg1 dramatically improved the extent of liver fibrosis and suppressed the hepatic levels of fibrotic marker α-SMA in vivo and in vitro. The proliferation of HSC-T6 was significantly inhibited by G-Rg1 in vitro. Both TUNEL staining and flow cytometry demonstrated that G-Rg1 attenuated the levels of hepatocyte apoptosis in fibrotic mice. Additionally, G-Rg1 up-regulated the maturation of hepatic DCs via reducing the expression level of hepatic IDO1, which played an inverse role in the maturation of DCs. Furthermore, oral administration of G-Rg1 ameliorated IDO1 overexpression-induced worsen liver fibrosis as well as IDO1 overexpression-mediated more apparent inhibition of maturation of DCs.

CONCLUSION

These results suggest that G-Rg1, which exerts its antifibrotic properties via alleviating IDO1-mediated the inhibition of DCs maturation, may be a potential therapeutic drug in treating liver fibrosis.

Oxidative stress and inflammatory response of ghrelin on myocardial and aortic tissues in insulin-resistant rats

OBJECTIVES

This study was designed to clarify the effects of ghrelin on myocardial and aortic tissues in insulin-resistant rats.

METHODS

Sprague-Dawley rats were divided into the following groups: control (Group 1), insulin resistance (IR, Group 2), ghrelin (Group 3) and IR+Ghrelin (Group 4) groups. Levels of HOMA-IR, fibronectin, hydroxyproline, collagen-1, collagen-3, matrix metalloproteinase-3, and matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1, and oxidative stress parameters as protein carbonyl (PCO), lipid hydroperoxides (LHPs), malondialdehyde, total thiol were determined in myocardial tissue. Expressions of IL-6, NF-κB and TNF-α mRNAs were detected by RT-qPCR. Aorta tissue was stained Masson trichrome.

KEY FINDINGS

The HOMA-IR level decreased in the IR+Ghrelin group compared with the IR group (P < 0.001). The PCO and LHP concentrations were higher in the IR group compared with control rats (P < 0.05). The PCO level was reduced by ghrelin in the IR+Ghrelin group compared with the IR group (P < 0.001). Ghrelin treatment reduced the mRNA expression levels of IL-6, NF-κB and TNF-α in the IR+Ghrelin group compared with the IR group (P < 0.001). There was no difference among the groups in the histology of aortic tissue.

CONCLUSIONS

Ghrelin, a regulator of appetite and energy homeostasis, may be effective in regulating oxidative stress and the inflammatory response when impaired by IR. Therefore, ghrelin may reduce the risks of myocardial dysfunction in IR.

Alleviative effects of 20(R)-Rg3 on HFD/STZ-induced diabetic nephropathy via MAPK/NF-κB signaling pathways in C57BL/6 mice

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic nephropathy (DN) is a major complication of diabetes. The kidney disease develops in nearly 20%-40% of type 2 diabetes (T2D) patients. Ginseng is the root of Panax ginseng C. A. Meyer and has been used in prevention and treatment of diseases for more than 2000 years as a traditional oriental medicine. The 20(R)-ginsenoside Rg3, an active saponin isolated from ginseng, can prevent and treat many diseases. The object of this research was to explore the alleviative effects of 20(R)-Rg3 on DN in mice.

MATERIALS AND METHODS

The T2D animal model was induced by continuous access to a high fat diet (HFD) combined with a single injection of 100 mg/kg streptozotocin (STZ) in C57BL/6 mice. The mice were treated by oral gavage of the 20(R)-Rg3 (10, 20 mg/kg) for 8 weeks. Functional and histopathological analyses of the kidneys were then performed. Protein expression levels of MAPKs and NF-κB signal pathways in the kidney were evaluated by western blotting. The expressions of HO-1 and NF-κB in the kidney were measured by fluorescent labeling staining. Other assessments including fasting blood glucose (FBG) levels, blood lipids, oxidative indicators, and inflammatory factors were all performed.

RESULTS

Abnormally elevated FBG levels were observed in HFD/STZ mice, contributing significantly to the occurrence of DN. Simultaneously, HFD/STZ mice showed the rise of serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) levels, and the decrease in high density lipoprotein cholesterol (HDL-C). DN was evidenced by the overproduction of malondialdehyde (MDA), decreased levels of superoxide dismutase (SOD) and catalase (CAT) enzymatic activities, high levels of serum blood urea nitrogen (BUN) and creatinine (Cr). Simultaneously, the results of the immunofluorescence assay showed an increased expression level in NF-κB p65 while a decrease in antioxidant enzyme HO-1 was observed. Herein, 20(R)-Rg3 treatment for 8 weeks not only attenuated FBG levels and advanced glycation end products (AGEs) levels but also improved insulin (INS) level, blood lipids, oxidative stress, and renal function by regulating MAPKs and NF-κB signal pathways in DN mice.

CONCLUSION

Taken together, the findings from the present study explicitly confirmed that 20(R)-Rg3 exerted ameliorative effects on DN mice via improving anti-oxidative activity and reducing renal inflammation.

A review of saponin intervention in metabolic syndrome suggests further study on intestinal microbiota

Metabolic syndrome (MetS) is a series of symptoms including insulin resistance, obesity, dyslipidemia, elevated fasting blood glucose levels, and hepatic steatosis. As a key criterion in MetS, the onset of insulin resistance is related to abnormal levels of circulating free fatty acids and adipokines. It has been discovered in recent years that metabolites and pathogen-associated molecular patterns of intestinal/gut microbiota are also important factors that cause insulin resistance and MetS. Saponins are the main components of many botanicals and traditional Chinese medicines (TCMs), such as ginseng, platycodon, licorice, and alfalfa. They have poor bioavailability, but can be transformed into secondary glycosides and aglycones by intestinal microbiota, further being absorbed. Based on in vivo and in vitro data, we found that saponins and their secondary metabolites have a preventive effect on MetS, and the effective targets are distributed in the intestine and other organs in human body. Intestinal targets involve pancreatic lipase, dietary cholesterol, and intestinal microbiota. Other targets include central appetite, nuclear receptors such as PPAR and LXR, AMPK signaling pathway and adipokines levels, etc. In view of the poor bioavailability of saponins, it is inferred that targets for prototype-saponins to interfere with MetS is mainly located in the intestine, and the activation of other targets may be related to secondary glycosides and aglycones transformed from saponins by intestinal flora. We suggest that the role of intestinal microbiota in saponin intervention in MetS should be further investigated.

Skimmin Improves Insulin Resistance via Regulating the Metabolism of Glucose: In Vitro and In Vivo Models

Skimmin is the major pharmacologically active component present in Hydrangea paniculata, in the traditional Chinese medicine as an anti-inflammatory agent, and its anti-inflammation and anti-diabetic effect has had been studied in previous studies. The metabolism of glucose plays an important role in the pathophysiology of diabetes. Therefore, it was identified as an important target for improving diabetic. Herein, we found that skimmin relieved the palmitic acid and high-fat and high sugar-induced insulin resistance. Furthermore, skimmin enhanced the glucose uptake via inhibiting reactive oxygen species (ROS) and reducing the level of inflammatory correlation factor. Meanwhile, skimmin reduced the glucose output by promoting PI3K/Akt signaling pathway and down-regulating the expression of glycogen synthase kinase-3β (GSK3β) and glucose-6-phosphatase (G6Pase). In conclusion, skimmin can improve the insulin resistance by increasing glucose uptake and decreasing glucose output in vitro and in vivo.

Ginsenoside Rg1 Regulates Liver Lipid Factor Metabolism in NAFLD Model Rats

To establish the molecular mechanism of ginsenoside Rg1 in nonalcoholic fatty liver disease (NAFLD), Sprague Dawley (SD) rats (180-220 g) were randomly divided into a control group, model group, ginsenoside Rg1 low-dose group (30 mg/(kg day)), high-dose (60 mg/(kg day)) group, and simvastatin group (1 mg/(kg day)), with 10 SD rats in each group. The control group was given a normal diet. The model group rats were given high-sugar and high-fat diets for 14 weeks. After the model of NAFLD was established successfully, ginsenoside Rg1 was administered orally for 4 or 8 weeks. The results showed that ginsenoside Rg1 decreased the levels of glucose (GLU), insulin (INS), triglyceride (TG), and total cholesterol (TC) and improved liver function. Meanwhile, ginsenoside Rg1 inhibited the secretion of interleukin-1 (IL-1), IL-6, IL-8, IL-18, and tumor necrosis factor-α (TNF-α) and improved hepatocyte morphology and lipid accumulation in the liver. Furthermore, ginsenoside Rg1 promoted the expression of peroxisome proliferator-activated receptor-α (PPAR-α), carnitine palmitoyl transferase 1α (CPT1A), carnitine palmitoyl transferase 2 (CPT2), and cholesterol 7α-hydroxylase (CYP-7A) and inhibited the expression of sterol regulatory element binding proteins-1C (SREBP-1C). In conclusion, ginsenoside Rg1 can inhibit inflammatory reaction, regulate lipid metabolism, and alleviate liver injury in NAFLD model rats.

Ginsenoside Rh4 suppresses aerobic glycolysis and the expression of PD-L1 via targeting AKT in esophageal cancer

Ginsenoside Rh4, as a bioactive component obtained from Panax notoginseng, has excellent pharmacological efficacy especially antitumor effects. However, its anticancer effects and target mechanisms in regulating human esophageal cancer are still poorly understood. Here, the results suggested that Rh4 exhibited potent anti-esophageal cancer effects in vivo and in vitro. Flow cytometric analysis and Western Blot showed that Rh4 significantly inhibited the growth by inducing G1 phase arrest. In parallel, Rh4 inhibited aerobic glycolysis in esophageal cancer cells by hindering lactate production, glucose uptake and ATP production; reducing the extracellular acidification rate (ECAR) and oxygen consumption rate (OCR); suppressing aerobic glycolysis-related protein expression. Mechanistic studies demonstrated that AKT is a possible target of Rh4, which suppresses aerobic glycolysis. Rh4 administration resulted in AKT deregulation, whereas treatment with insulin abolished the inhibitory effect of Rh4 on aerobic glycolysis. In contrast, treatment with AKT inhibitors or siRNA that silenced AKT enhanced the inhibitory effect of Rh4 on aerobic glycolysis. Moreover, molecular docking results indicated that Rh4 was able to bind to the interdomain region of AKT. Interestingly, the results revealed that Rh4 also inhibited the expression of PD-L1 via the AKT/mTOR pathway. Taken together, our findings provide important insights into the anti-esophageal cancer effects of Rh4 via suppressing aerobic glycolysis and PD-L1 expression, which indicated Rh4 could be as promising drug for clinical treatment.