Pachymic acid stimulates glucose uptake through enhanced GLUT4 expression and translocation

A multidimensional perspective on Poria cocos, an ancient fungal traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos occupies a foundational position in Asian medicinal systems, with documented use spanning over 2500 years. Modern applications have expanded its utility across diverse sectors, including functional foods, cosmeceuticals, and veterinary medicine.

AIM OF THE WORK

This review aims to systematically consolidate historical insights, production, phytochemical profiles, pharmacological mechanisms, and modern applications of Poria cocos, while addressing challenges in quality standardization and sustainable development.

MATERIALS AND METHODS

For the collection of pertinent information, extensive searches were conducted across diverse literature and electronic databases. Primary keywords such as "Poria cocos" and "Poria" were utilized, supplemented by secondary search terms including "source", "cultivation", "processing", "chemical composition", "pharmacological effects", "practical applications", "quality standard" and "toxicity and safety". Through integration, systematically summarize and analyze the extracted data to evaluate the research progress of Poria cocos.

RESULTS

This review summarizes the main findings on the history, production, phytochemistry, pharmacology, practical applications, quality standards, and safety of Poria cocos. The medicinal use of Poria cocos has spanned over 2500 years, and its cultivation techniques are constantly evolving. Modern cultivation practices, including pine segment wood and substitute cultivation, highlight trade-offs between yield, cost, and ecological impact. Phytochemical analysis determined that polysaccharides and triterpenes are the main bioactive components, and 120 triterpenoid compounds have been reported. Pharmacological studies have confirmed that Poria cocos has diuretic, liver protective, anti-inflammatory, antitumor, antioxidant, and antidiabetic effects. Practical applications extend beyond medicine to functional foods, cosmeceuticals, and veterinary products. However, there are still challenges in the dynamic balance between resource development and environmental protection, clarification of active ingredients, deepening of pharmacological mechanisms, development of products in practical application fields, and quality standardization, especially in the qualitative and quantitative analysis of active ingredients (polysaccharides and triterpenoids) in Poria cocos, the risk of sulfur fumigation, and heavy metal pollution. Collectively, these findings underscore Poria cocos as a multifaceted resource.

CONCLUSION

Poria cocos remains a promising candidate for global health and wellness initiatives. Combining traditional knowledge with innovative research to ensure the green cultivation of Poria cocos, with clear ingredients, reliable therapeutic effects, controllable quality, safety and effectiveness, is an important direction for future research.

Mechanism of pachymic acid in the treatment of gastric cancer based on network pharmacology and experimental verification

BACKGROUND

Pachymic acid (PA) is derived from Poria cocos. PA has a variety of pharmacological and inhibitory effects on various tumors. However, the mechanism of action of PA in gastric cancer (GC) remains unclear.

AIM

To investigate the mechanism of PA in treating GC via the combination of network pharmacology and experimental verification.

METHODS

The GeneCards and OMIM databases were used to derive the GC targets, while the Pharm Mapper database provided the PA targets. Utilizing the STRING database, a protein-protein interaction network was constructed and core targets were screened. The analyses of Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis were conducted, and molecular docking and clinical correlation analyses were performed on the core targets. Ultimately, the network pharmacology findings were validated through in vitro cell assays, encompassing assessments of cell viability, apoptosis, cell cycle, cloning, and western blot analysis.

RESULTS

According to network pharmacology analysis, the core targets were screened, and the PI3K/AKT signaling pathway is likely to be the mechanism by which PA effectively treats GC, according to KEGG enrichment analysis. The experimental findings showed that PA could control PI3K/AKT signaling to prevent GC cell proliferation, induce apoptosis, and pause the cell cycle.

CONCLUSION

Network pharmacology demonstrated that PA could treat GC by controlling a variety of signaling pathways and acting on a variety of targets. This has also been supported by in vitro cell studies, which serve as benchmarks for further research.

Pachymic acid (PA) inhibits ferroptosis of cardiomyocytes via activation of the AMPK in mice with ischemia/reperfusion-induced myocardial injury

Pachymic acid (PA) is a lanostane-type triterpenoid with various pharmacological effects. However, little is known about the effect of PA on myocardial infarction (MI) induced by ischemia/reperfusion (I/R). In this study, we aimed to investigate the protective effect of PA and its underlying mechanism. A cellular MI model was established by oxygen-glucose deprivation and reperfusion (OGD/R) treatment in HL-1 cardiomyocytes, and we found that OGD/R treatment decreased cell viability and glutathione peroxide (GSH-Px) activity, increased Fe2+ concentration and lactate dehydrogenase (LDH) activity, promoted malondialdehyde (MDA) and reactive oxygen species (ROS) production, and inhibited the expression of ferroptosis marker proteins SLC7A11 and GPX4 in a time-dependent manner. OGD/R-induced HL-1 cells were pretreated with different concentrations of PA (0, 20, 40, 60 μg/mL) for 24 h, and toxicological experiments showed that 150 μg/mL PA decreased cell viability, while low concentrations of PA had no toxic effect on cells. 20 μg/mL PA reversed the inhibitory effect of OGD/R on cell viability, reduced MDA and ROS production, and Fe2+ accumulation, increased GSH-Px activity and the expression of SLC7A11 and GPX4, and decreased LDH activity, especially at 60 μg/mL PA. Meanwhile, PA promoted the phosphorylation of IRS-1, AKT, and AMPK proteins in a dose-dependent manner. AICAR, an AMPK activator, inhibited ferroptosis, while STO-609, an AMPK inhibitor, largely abolished the effect of PA on OGD/R-induced ferroptosis of HL-1 cells. In addition, PA inhibited ferroptosis and myocardial I/R injury in wild-type mice and AMPK knockout (AMPK-/- ) mice. Collectively, PA inhibited ferroptosis of cardiomyocytes through activating of the AMPK pathway, thereby alleviating myocardial I/R injury in mice.

Poria cocos Lanostane Triterpenoids Extract Promotes Collagen and Hyaluronic Acid Production in D-Galactose-Induced Aging Rats

The global aging population is expanding at an increasingly rapid pace, with approximately one-fourth of the world's population expected to be composed of elderly individuals by 2050. Aging skin is one of the major characteristics expressed in the elderly. The study comprehensively utilizes both cell and animal experiments to confirm the skin anti-aging effects of Poria cocos (P. cocos), which is one of the most important traditional Chinese medicines classified as tonic Chinese medicine, commonly used to treat physical weakness and aging-associated diseases. We demonstrate in this study that P. cocos lanostane triterpenoids extract (Lipucan®) ameliorates aging skin and promotes collagen accumulation and hyaluronic acid production in galactose-induced aging rats. Purified lanostane triterpenoids were initially identified as active components in P. cocos, which significantly increased collagen and hyaluronic acid levels in cultured human skin cells.

Efficacy of Poria cocos and Alismatis rhizoma against diet-induced hyperlipidemia in rats based on transcriptome sequencing analysis

Hyperlipidemia, a common metabolic disease, is a risk factor for cardiovascular diseases, Poria cocos (PC) and Alismatis rhizoma (AR) serve as a potential treatment. A systematic approach based on transcriptome sequencing analysis and bioinformatics methods was developed to explore the synergistic effects of PC-AR and identify major compounds and potential targets. The phenotypic characteristics results indicated that the high dose (4.54 g/kg) of PC-AR reduced total cholesterol (TC), elevated high-density lipoprotein cholesterol (HDL-C) levels, and improved hepatocyte morphology, as assessed via hematoxylin and eosin (H&E) staining. Transcriptomic profiling processing results combined with GO enrichment analysis to identify the overlapping genes were associated with inflammatory responses. The cytokine-cytokine receptor interaction pathway was found as a potential key pathway using geneset enrichment analysis. Core enrichment targets were selected according to the PC-AR's fold change versus the model. Real-time quantitative PCR analysis validated that PC-AR significantly downregulated the expression of Cxcl10, Ccl2, Ccl4, Cd40 and Il-1β mRNA (P < 0.05). Molecular docking analysis revealed the significant compounds of PC-AR and the potential binding patterns of the critical compounds and targets. This study provides further evidence that the therapeutic effects of PC-AR on hyperlipidemia in rats through the regulation of inflammation-related targets.

Rapid identification of α-glucosidase inhibitors from Poria using spectrum-effect, component knock-out, and molecular docking technique

Instruction

Poria (Poria cocos) is known for its health-promoting effects and is consumed as a food due to its potential hypoglycemic activity. However, the composition of Poria is complex, and the bioactive compounds that inhibit α-glucosidase are not clear.

Methods

In this study, the fingerprint of the Poria methanol extract characterized by high-performance liquid chromatography (HPLC) and the model of the corresponding spectrum-effect relationship for α-glucosidase was first established to screen the active compounds from Poria. Then, the predicted bioactive compounds were knocked out and identified using mass spectrometry. Finally, the potential binding sites and main bonds of each compound with α-glucosidase were studied using molecular docking.

Results

The results have shown that at least 11 compounds from Poria could inhibit α-glucosidase effectively. Moreover, eight individual compounds, i.e., poricoic acid B (P8), dehydrotumulosic acid (P9), poricoic acid A (P10), polyporenic acid C (P12), 3- epidehydrotumulosic acid (P13), dehydropachymic acid (P14), 3-O-acetyl-16α-hydroxytrametenolic acid (P21), and pachymic acid (P22), were identified, and they exhibited effective inhibitory activity against α-glucosidase.

Discussion

The possible inhibitory mechanism of them based on molecular docking showed that the binding sites are mainly found in the rings A, B, and C of these compounds, and C-3 C-16 and side chains of C-17, with the phenylalanine, arginine, tyrosine, histidine, and valine of α-glucosidase. The main interactions among them might be alkyl and hydrogen bonds, which theoretically verified the inhibitory activity of these compounds on α-glucosidase. The achievements of this study provided useful references for discovering bioactive compounds with hypoglycemic effects from Poria.

Mitigation of Insulin Resistance by Natural Products from a New Class of Molecules, Membrane-Active Immunomodulators

Insulin resistance (IR), accompanied by an impaired cellular glucose uptake, characterizes diverse pathologies that include, but are not limited to, metabolic disease, prediabetes and type 2 diabetes. Chronic inflammation associated with deranged cellular signaling is thought to contribute to IR. The key molecular players in IR are plasma membrane proteins, including the insulin receptor and glucose transporter 4. Certain natural products, such as lipids, phenols, terpenes, antibiotics and alkaloids have beneficial effects on IR, yet their mode of action remains obscured. We hypothesized that these products belong to a novel class of bioactive molecules that we have named membrane-active immunomodulators (MAIMs). A representative MAIM, the naturally occurring medium chain fatty acid ester diethyl azelate (DEA), has been shown to increase the fluidity of cell plasma membranes with subsequent downstream effects on cellular signaling. DEA has also been shown to improve markers of IR, including blood glucose, insulin and lipid levels, in humans. The literature supports the notion that DEA and other natural MAIMs share similar mechanisms of action in improving IR. These findings shed a new light on the mechanism of IR mitigation using natural products, and may facilitate the discovery of other compounds with similar activities.

Geographical region traceability of Poria cocos and correlation between environmental factors and biomarkers based on a metabolomic approach

The edible values of P. cocos from different origins vary significantly, therefore, it is important to investigate the traceability of geographical regions and identify the geographical biomarkers of P. cocos. The metabolites of P. cocos of the different geographical origins were assessed using liquid chromatography tandem-mass spectrometry, principal component analysis and orthogonal partial least-squares discriminant analysis (OPLS-DA). The OPLS-DA could clearly discriminate the metabolites of P. cocos from the three cultivation regions (YN, Yunnan; AH, Anhui; JZ, Hunan). Finally, three carbohydrates, four amino acids, and four triterpenoids were selected as biomarkers for P. cocos origin tracing. Correlation matrix analysis revealed that the contents of biomarkers were closely related to geographical origin. Altitude, temperature, and soil fertility were the main factors responsible for the differences in biomarker profiles in P. cocos. The metabolomics approach provides an effective strategy for tracing and identifying the biomarkers of P. cocos from different geographical origins.

Benefits of herbal formulae containing Poria cocos (Fuling) for type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Poria cocos (Schw.) Wolf or Fuling is one of the top 10 most frequently prescribed herbs in China for the treatment of type 2 diabetes mellitus (T2DM).

OBJECTIVE

The purpose of this systematic review is to determine the additional benefit of Fuling formulae use in addition to hypoglycaemic agents for T2DM in randomised clinical trials.

METHODS

English (5) and Chinese (4) medical databases were searched from their inception to August 2021. RCTs that included Fuling in herbal formulae for T2DM were included. Risk of bias were assessed using the Cochrane Collaboration's procedures. Stata software (13.0) was used for data analysis.

RESULTS

Seventy-three RCTs (6,489 participants) with herbal formulae containing Fuling were included. Most studies were at risk of bias and strength of the evidence were low to moderate. Meta-analysis findings showed that the addition of formulae containing Fuling to hypoglycaemic agent-treatments could benefit people with T2DM by reducing fasting blood glucose (MD -0.82 [-0.93, -0.71]; I2 = 79.6%, P = 0.00), 2-hour postprandial blood glucose (MD-1.15 [-1.31, -0.98], I2 = 80%, P = 0.00) and haemoglobin A1c (MD-0.64 [-0.75, -0.53], I2 = 84.7%, P = 0.00). Adverse events were also significantly lower in the integrative group than in the hypoglycaemic alone group (RR 0.99 [0.93, 1.06], P = 0.87).

CONCLUSION

Evidence from this study supports the use of Fuling formulae combined with hypoglycaemic agents for T2DM. The combined therapies appear to be well tolerated.

TRAIL REGISTRATION

This review is registered with the PROSPERO international prospective register of systematic reviews (CRD42020214635).

Pharmacological profiles and therapeutic applications of pachymic acid (Review)

Poria cocos is a saprophytic fungus that grows in diverse species of Pinus. Its sclerotium, called fu-ling or hoelen, has been used in various traditional Chinese medicines and health foods for thousands of years, and in several modern proprietary traditional Chinese medicinal products. It has extensive clinical indications, including sedative, diuretic, and tonic effects. Pachymic acid (PA) is the main lanostane-type triterpenoid in Poria cocos. Evidence suggests that PA has various biological properties such as cytotoxic, anti-inflammatory, antihyperglycemic, antiviral, antibacterial, sedative-hypnotic, and anti-ischemia/reperfusion activities. Although considerable advancements have been made, some fundamental and intricate issues remain unclear, such as the underlying mechanisms of PA. The present study aimed to summarize the biological properties and therapeutic potential of PA. The biosynthetic, pharmacokinetic, and metabolic pathways of PA, and its underlying mechanisms were also comprehensively summarized.

Impact of Drug Metabolism/Pharmacokinetics and their Relevance Upon Traditional Medicine-based anti-COVID-19 Drug Research

BACKGROUND

The representative anti-COVID-19 herbs, i.e. Poria cocos, Pogostemon, Prunus, and Glycyrrhiza plants, are commonly used in the prevention and treatment of COVID-19, a pandemic caused by SARS-CoV-2. Diverse medicinal compounds with favorable anti-COVID-19 activities are abundant in these plants, and their unique pharmacological/pharmacokinetic properties are being revealed. However, the current trends of drug metabolism/pharmacokinetic (DMPK) investigations of anti-COVID-19 herbs have not been systematically summarized.

METHODS

Here, the latest awareness, as well as the perception gaps of DMPK attributes, in the anti-COVID-19 drug development and clinical usage was elaborated and critically commented.

RESULTS

The extracts and compounds of P. cocos, Pogostemon, Prunus, and Glycyrrhiza plants show distinct and diverse absorption, distribution, metabolism, excretion and toxicity (ADME/T) properties. The complicated herb-herb interactions (HHIs) and herb-drug interactions (HDIs) of anti-COVID-19 Traditional Chinese Medicine (TCM) herb pair/formula dramatically influence the PK/pharmacodynamic (PD) performance of compounds thereof, which may inspire researchers to design innovative herbal/compound formulas for optimizing the therapeutic outcome of COVID-19 and related epidemic diseases. The ADME/T of some abundant compounds in anti-COVID-19 plants have been elucidated, but DMPK studies should be extended to more compounds of different medicinal parts, species and formulations, and would be facilitated by various omics platforms and computational analyses.

CONCLUSION

In the framework of systems pharmacology and pharmacophylogeny, the DMPK knowledge base would promote the translation of bench findings into the clinical practice of anti-COVID-19, and speed up the anti-COVID-19 drug discovery and development.

Wen Dan Tang: A Potential Jing Fang Decoction for Headache Disorders?

BACKGROUND

Chinese herbal medicine is considered relatively safe, inexpensive, and easily accessible. Wen Dan Tang (WDT), a Jing Fang ancient classical Chinese herbal formula with a broad indication profile has been used for several centuries in China to treat various illnesses.

QUESTION

Are there evidence-based clinical trials that show that WDT has a significant impact on the treatment of various diseases, especially in patients with migraine and tension-type headaches (TTH)?

METHODS

This study is based on an online database search using PubMed, Medline, Cochrane Library, AcuTrials, Embase, Semantic Scholar, Jstor, internet research, and review of ancient and modern Chinese medical textbooks regarding WDT and its compounds.

RESULTS

There were no studies on WDT in migraine and TTH; therefore, this work gathers and describes data for every single compound in the formula.

CONCLUSION

This study suggests that the bioactive compounds found in WDT composition show potential in treating patients with neurological, psychiatric disorders, cardiovascular diseases, metabolic syndrome, and digestive disorders. Some coherence between WDT in headache reduction and improvements in the quality of life in patients with migraines and TTH could be evaluated, showing positive results of WDT in these patients.

Metabolome analysis of key genes for synthesis and accumulation of triterpenoids in Wolfiporia cocos

Triterpenoid, the active ingredient in the dried sclerotia of Wolfiporia cocos, has a variety of pharmacological effects. The focus of this research was the cell engineered bacteria modified for triterpenoid biosynthesis, and we aimed to identify the key genes involved in triterpenoid biosynthesis and their roles. Two monospora strains, H and L, were selected from the sexually propagated progeny of W. coco strain 5.78, and their mycelia were cultured for 17, 34, and 51 days. Metabolite analysis showed that there were significantly more down-regulated metabolites of the two strains at three different culture periods than up-regulated metabolites. KEGG indicated that the differential metabolites were mainly concentrated in sterol biosynthesis and ABC transport. STEM analysis suggested that polysaccharide synthesis and accumulation might be greater in the L strain than the H strain. The correlation analysis of DEGs and differential metabolites between the two strain groups showed that erg11 and FDPS, which were closely positively correlated with differential metabolites associated with triterpenoids, were highly expressed in the L strain. This result suggested that the high expression of some genes in the L strain might shunt precursor substances of triterpenoids, which was the possible reason for the decrease in the synthesis and accumulation of triterpenoids.

Exploring the Molecular Mechanism of Action of Yinchen Wuling Powder for the Treatment of Hyperlipidemia, Using Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation

Background

Yinchen Wuling powder is often used to treat clinical hyperlipidemia, although its mechanism of action remains unclear. In this study, we aimed to investigate the active ingredients found in Yinchen Wuling powder and find its mechanism of action when treating hyperlipidemia, using a combination of network pharmacology, molecular docking, and molecular dynamics simulation approaches.

Methods

The TCMSP database was used to obtain the principle active ingredients found in Yinchen Wuling powder and the NCBI and DisGeNet databases were used to obtain the main target genes involved in hyperlipidemia, and the intersectional targets were obtained by EXCEL. We also used Cytoscape 3.7.2 software to construct a “Traditional Chinese Medicine-Active Ingredient-Target” network and use STRING platform to conduct “protein-protein interactional” (PPI) analyses on the intersection targets. Bioconductor software and RX 64 4.0.0 software were then used to perform GO functional enrichment analysis and KEGG pathway enrichment analysis on the targets. Molecular docking of core protein-ligand interactions was modeled using AutoDock Vina software. A simulation of molecular dynamics was conducted for the optimal core protein-ligand obtained by molecular docking using Amber18 software.

Results

A total of 63 active ingredients were found in Yinchen Wuling powder, corresponding to 175 targets, 508 hyperlipidemia targets, and 55 intersection targets in total. Cytoscape 3.7.2 showed that the key active ingredients were quercetin, isorhamnetin, taxifolin, demethoxycapillarisin, and artepillin A. The PPI network showed that the key proteins involved were AKT1, IL6, VEGFA, and PTGS2. GO enrichment analysis found that genes were enriched primarily in response to oxygen levels and nutrient levels of the vesicular lumen and were associated with membrane rafts. These were mainly enriched in AGE-RAGE (advanced glycation end products-receptor for advanced glycation end products) signaling pathway in diabetic complications, fluid shear stress, and atherosclerosis, as well as other pathways. The molecular docking results indicated key binding activity between PTGS2-quercetin, PTGS2-isorhamnetin, and PTGS2-taxifolin. Results from molecular dynamics simulations showed that PTGS2-quercetin, PTGS2-isorhamnetin, and PTGS2-taxifolin bound more stably, and their binding free energies were PTGS2-quercetin -29.5 kcal/mol, PTGS2-isorhamnetin -32 kcal/mol, and PTGS2-taxifolin -32.9 kcal/mol.

Conclusion

This study is based on network pharmacology and reveals the potential molecular mechanisms involved in the treatment of hyperlipidemia by Yinchen Wuling powder.

Biological activity of 2α,3β,23-trihydroxyolean-12-ene on glucose homeostasis

We studied the effect and the mechanisms of action of 2α,3β,23-trihydroxyolean-12-ene (THO), from Croton heterodoxus Baill. (Euphorbiaceae), in glucose uptake in hyperglycemic rats. The effect of in vivo pretreatment with THO in hyperglycemic rats was analyzed. The in vitro effects of THO were observed in adipocytes and in adipose tissue. THO reduced glycemia, in part by increasing serum insulin and augmenting the disposal of glucose as glycogen in hepatocytes but did not change the serum concentration of glucagon-like peptide-1. THO increased glucose uptake in adipocytes and in adipose tissue by a mechanism dependent on phosphatidylinositol 3-kinase vesicular traffic and on the process of vesicle fusion at the plasma membrane in regions containing cholesterol, indicating the involvement of glucose transporter-4 (GLUT4). This triterpene may act solely via the activation and translocation of GLUT4 (rather than via nuclear actions, such as upregulation of GLUT4 synthesis), since THO did not alter the amount of GLUT4 mRNA or the content of GLUT4. Consistent with these data, the stimulatory effect of this triterpene on the quantity of GLUT4 in the membrane fraction was dependent upon p38 phosphorylation. In this experimental model, orally administered 10 mg/kg THO did not modulate extracellular serum lactate dehydrogenase. In conclusion, THO decreases hyperglycemia by increasing serum insulin and hepatic glycogen content. The THO mechanism of action on adipose tissue for glucose uptake is suggested to be via GLUT4 translocation stimulation mediated by a p38-dependent mechanism. THO is a potential antihyperglycemic agent that acts in a target tissue for glucose homeostasis.

Dietary Bioactive Ingredients Modulating the cAMP Signaling in Diabetes Treatment

As the prevalence of diabetes increases progressively, research to develop new therapeutic approaches and the search for more bioactive compounds are attracting more attention. Over the past decades, studies have suggested that cyclic adenosine monophosphate (cAMP), the important intracellular second messenger, is a key regulator of metabolism and glucose homeostasis in diverse physiopathological states in multiple organs including the pancreas, liver, gut, skeletal muscle, adipose tissues, brain, and kidney. The multiple characteristics of dietary compounds and their favorable influence on diabetes pathogenesis, as well as their intersections with the cAMP signaling pathway, indicate that these compounds have a beneficial effect on the regulation of glucose homeostasis. In this review, we outline the current understanding of the diverse functions of cAMP in different organs involved in glucose homeostasis and show that a diversity of bioactive ingredients from foods activate or inhibit cAMP signaling, resulting in the improvement of the diabetic pathophysiological process. It aims to highlight the diabetes-preventative or -therapeutic potential of dietary bioactive ingredients targeting cAMP signaling.

14-Deoxy-11,12-Didehydroandrographolide Ameliorates Glucose Intolerance Enhancing the LKB1/AMPK[Formula: see text]/TBC1D1/GLUT4 Signaling Pathway and Inducing GLUT4 Expression in Myotubes and Skeletal Muscle of Obese Mice

14-Deoxy-11,12-didehydroandrographolide (deAND), a bioactive component of Andrographis paniculata, has antidiabetic activity. AMP-activated protein kinase (AMPK) regulates glucose transport and ameliorates insulin resistance. The aim of the present study was to investigate whether activation of AMPK is involved in the mechanism by which deAND ameliorates insulin resistance in muscles. deAND amounts up to 40 [Formula: see text]M dose-dependently activated phosphorylation of AMPK[Formula: see text] and TBC1D1 in C2C12 myotubes. In addition, deAND significantly activated phosphorylation of LKB1 at 6 h after treatment, and this activation was maintained up to 48 h. deAND increased glucose uptake at 18 h after treatment, and this increase was time dependent up to 72 h. Compound C, an inhibitor of AMPK, suppressed deAND-induced phosphorylation of AMPK[Formula: see text] and TBC1D1 and reversed the effect on glucose uptake. In addition, the expression of GLUT4 mRNA and protein in C2C12 myotubes was up-regulated by deAND in a time-dependent manner. Promotion of GLUT4 gene transcription was verified by a pGL3-GLUT4 (837 bp) reporter assay. deAND also increased the nuclear translocation of MEF-2A and PPAR[Formula: see text]. After 16 weeks of feeding, the high-fat diet (HFD) inhibited phosphorylation of AMPK[Formula: see text] and TBC1D1 in skeletal muscle of obese C57BL/6JNarl mice, and deactivation of AMPK[Formula: see text] and TBC1D1 by the HFD was abolished by deAND supplementation. Supplementation with deAND significantly promoted membrane translocation of GLUT4 compared with the HFD group. Supplementation also significantly increased GLUT4 mRNA and protein expression in skeletal muscle compared with the HFD group. The hypoglycemic effects of deAND are likely associated with activation of the LKB1/AMPK[Formula: see text]/TBC1D1/GLUT4 signaling pathway and stimulation of MEF-2A- and PPAR[Formula: see text]-dependent GLUT4 gene expression, which account for the glucose uptake into skeletal muscle and lower blood glucose levels.

Discovery and development of tumor glycolysis rate-limiting enzyme inhibitors

Tumor cells mainly provide necessary energy and substances for rapid cell growth through aerobic perglycolysis rather than oxidative phosphorylation. This phenomenon is called the "Warburg effect". The mechanism of glycolysis in tumor cells is more complicated, which is caused by the comprehensive regulation of multiple factors. Abnormal enzyme metabolism is one of the main influencing factors and inhibiting the three main rate-limiting enzymes in glycolysis is thought to be important strategy for cancer treatment. Therefore, numerous inhibitors of glycolysis rate-limiting enzyme have been developed in recent years, such as the latest HKII inhibitor and PKM2 inhibitor Pachymic acid (PA) and N-(4-(3-(3-(methylamino)-3-oxopropyl)-5-(4'-(trifluoromethyl)-[1,1'-biphenyl]-4-yl)-1H-pyrazol-1-yl)phenyl)propiolamide. The review focuses on source, structure-activity relationship, bioecological activity and mechanism of the three main rate-limiting enzymes inhibitors, and hopes to guide the future research on the design and synthesis of rate-limiting enzyme inhibitors.

Phytochemistry and Biological Activities of Poria

Poria is a common Traditional Chinese Medicine in clinic. In recent years, the chemical and pharmacological studies of Poria have made great progress, triterpenes and polysaccharides have been isolated, and various types of compounds containing lipids, octanoic acids, fatty acids, and trace elements have been found. In this paper, we reviewed the literature, summarized the main compound types, and reviewed in detail their pharmacological effects in antitumor, immunomodulatory, effects on kidney, hepatoprotective activity, effects on blood sugar, antioxidant effects, anti-inflammatory effects, effects on the gut, antidepressant, and so on, and also categorized the compounds with the same or similar pharmacological effects to provide a reference for the in-depth study of the material basis of the pharmacological effect, quality standards, and pharmacological activity of Poria.

The Lanostane Triterpenoids in Poria cocos Play Beneficial Roles in Immunoregulatory Activity

Poria cocos (Schwein) F.A. Wolf (syn. Wolfiporia cocos) dried sclerotium, called fuling, is an edible, saprophytic fungus commonly used as a tonic and anti-aging traditional Chinese medicine. It is traditionally used in combination with other traditional Chinese medicines to enhance immunity. This study showed that P. cocos extract (Lipucan®) containing lanostane triterpenoids has no immunotoxicity and enhances non-specific (innate) immunity though activating natural killer cells and promotes interferon γ (IFN-γ) secretion by Type 1 T-helper (Th1) cells immune response. In addition, P. cocos extract significantly decreased interleukin (IL-4 and IL-5) secretion by Type 2 T-helper (Th2) cells immune response, which are related to the allergy response. The purified lanostane triterpenoids were first identified as active ingredients of P. cocos with enhanced non-specific immunity by promoting interferon γ (IFN-γ) secretion in a preliminary study. Our findings support that the P. cocos extract plays beneficial roles in immunoregulatory activity.

Poricoic acid A activates AMPK to attenuate fibroblast activation and abnormal extracellular matrix remodelling in renal fibrosis

BACKGROUND

In chronic kidney disease, although fibrosis prevention is beneficial, few interventions are available that specifically target fibrogenesis. Poricoic acid A (PAA) isolated from Poria cocos exhibits anti-fibrotic effects in the kidney, however the underlying mechanisms remain obscure.

PURPOSE

We isolated PAA and investigated its effects and the underlying mechanisms in renal fibrosis.

STUDY DESIGN

Unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (Nx) animal models and TGF-β1-induced renal fibroblasts (NRK-49F) were used to investigate the anti-fibrotic activity of PAA and its underlying mechanisms.

METHODS

Western blots, qRT-PCR, immunofluorescence staining, co-immunoprecipitation and molecular docking methods were used. Knock-down and knock-in of adenosine monophosphate-activated protein kinase (AMPK) in the UUO model and cultured NRK-49F cells were employed to verify the mechanisms of action of PAA.

RESULTS

PAA improved renal function and alleviated fibrosis by stimulating AMPK and inhibiting Smad3 specifically in Nx and UUO models. Reduced AMPK activity was associated with Smad3 induction, fibroblast activation, and the accumulation and aberrant remodelling of extracellular matrix (ECM) in human renal puncture samples and cultured NRK-49F cells. PAA stimulated AMPK activity and decreased fibrosis in a dose-dependent manner, thus showing that AMPK was essential for PAA to exert its anti-fibrotic effects. AMPK deficiency reduced the anti-fibrotic effects of PAA, while AMPK overexpression enhanced its effect.

CONCLUSION

PAA activated AMPK and further inhibited Smad3 specifically to suppress fibrosis by preventing aberrant ECM accumulation and remodelling and facilitating the deactivation of fibroblasts.

Lanostane Triterpenoids with Glucose-Uptake-Stimulatory Activity from Peels of the Cultivated Edible Mushroom Wolfiporia cocos

A chemical study on the peels of the cultivated edible mushroom Wolfiporia cocos led to the isolation and identification of 47 lanostane triterpenoids including 16 new compounds (1-16). The structures of the new compounds were determined by analysis of the NMR, MS, and electronic circular dichroism (ECD) data. Compounds 1 and 2 represent new members of the family of 4,5-secolanostane triterpenes. Compound 3 is a new aromatic lanostane triterpene with an unusual methyl rearrangement from C-10 to C-6. The absolute configurations of 1 and 8 were assigned by ECD spectra calculation. All compounds were evaluated for cytotoxicity (K562, SW480, and HepG2) and glucose-uptake-stimulating effects. Compounds 23, 25, 29, and 31 showed weak inhibition on the K562 cells with IC₅₀ in the range of 25.7 to 68.2 μM, respectively. Compounds 21, 28, and 30 increased the glucose uptake in 3T3-L1 cells by 25%, 14%, and 50% at 5 μM, respectively. In addition, compounds 14, 23, 29, 35, and 43 showed insulin-sensitizing activity by increasing the insulin-stimulated glucose uptake at 2.5 μM in 3T3-L1 adipocytes. A preliminary structure-activity relationship analysis indicates that the 6/6/6/5 ring skeleton and the double bond between C-8 and C-9 are beneficial for the glucose-uptake-stimulating and insulin-sensitizing activities. Furthermore, the alkaline-insoluble fraction mainly containing compounds 22, 24, 28, and 31 were confirmed to have hypoglycemic and hypolipidemic activity on high-fat-diet-induced obese mice. This work confirms the potential of the peels' extracts of W. cocos as a functional food or dietary supplements.

Pachymic acid inhibits growth and induces cell cycle arrest and apoptosis in gastric cancer SGC-7901 cells

The aim of the present study was to elucidate the anticancer effect of pachymic acid (PA) in gastric cancer SGC-7901 cells and the potential molecular mechanisms involved. Cell Count kit-8 assay was performed to examine the effect of PA on the cell proliferation of SGC-7901 cells. Cell cycle, cell apoptosis, mitochondria membrane potential (Dψm) and reactive oxygen species (ROS) analysis were assessed by flow cytometry, respectively. DNA fragmentation assay was performed by Hoechst 33258 staining. Western blotting was performed to detect the effect of various concentrations of PA on the levels of BCL2 associated X protein (Bax) expression as well as B-cell lymphoma 2 (Bcl-2), cytochrome C (cyt-c) and caspase-3 in SGC-7901 cells. It was demonstrated that PA was able to significantly inhibit the viability and induce G₀/G₁ cell cycle arrest of SGC-7901 cells in a concentration-dependent manner. The apoptotic rate and ROS generation were markedly increased, while Dψm was decreased following the treatment of SGC-7901 cells with various concentrations of PA. Moreover, the expression of Bax, cytochrome c and caspase-3 were markedly increased and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) was significantly inactivated and BCL-2 expression was decreased following PA treatment in SGC-7901 cells. Notably, JAK2 inhibitor (AG490) mimics the effects of PA on the viability and apoptosis of SGC-7901 cells. Further in vivo study indicated that treatment with PA significantly inhibited the growth of tumor in nude mice that were transplanted with SGC-7901 cells in a concentration-dependent manner. These results may advance the current understanding of the anticancer mechanisms of PA in gastric cancer.

Itraconazole attenuates hepatic gluconeogenesis and promotes glucose uptake by regulating AMPK pathway

The primarily metabolic abnormality in type 2 diabetes mellitus (T2DM) is the defect in gluconeogenesis and glucose uptake. Itraconazole (ITCZ) is a traditional azole drug with anti-fungal and anticancer properties. However, limited attention has been directed towards the contribution of ITCZ to hepatic gluconeogenesis and glucose uptake in T2DM. The present study aimed to investigate the potential effects of ITCZ on hepatic gluconeogenesis and glucose uptake as well as the underlying mechanisms. No obvious change in cell viability was detected by MTT assay in HepG2 cells with ITCZ treatment at gradually increasing concentrations. Western blot analysis demonstrated that the phosphorylation level of 5' adenosine monophosphate-activated protein kinase (AMPK) was significantly elevated by ITCZ treatment at ≥5 µg/ml (P<0.05). Moreover, ITCZ repressed the gluconeogenesis of HepG2 cells, as evidenced by the dose-dependently increased glycogen synthase kinase 3β phosphorylation level and a notably decreased glucose production rate (P<0.05). Simultaneously, the expression of peroxisome proliferator-activated receptor γ co-activator 1α, phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in HepG2 cells was reduced by ITCZ in a dose-dependent manner (P<0.001). Furthermore, a 2-deoxyglucose uptake assay revealed that the glucose uptake of HepG2 cells was notably enhanced, accompanied by the ITCZ dose-dependent upregulation of glucose transporter-4 (GLUT-4) (P<0.05). Conversely, silencing of AMPK by small interfering RNA resulted in an increase of ITCZ-reduced gluconeogenesis and inhibition of ITCZ-induced glucose uptake with relative upregulation of PEPCK and G6Pase and downregulation of GLUT4 in the presence of 50 µg/ml ITCZ (P<0.05). Overall, the results indicated that AMPK has an important role in regulating ITCZ-induced glucose uptake by stimulating GLUT4 in HepG2 cells. Therefore, ITCZ may become a promising candidate for T2DM therapy.

Effects of Flavonoids and Triterpene Analogues from Leaves of Eleutherococcus sieboldianus (Makino) Koidz. 'Himeukogi' in 3T3-L1 Preadipocytes

Eleutherococcus sieboldianus (Makino) Koidz. is a local product from the area in and around Yonezawa City in Yamagata Prefecture, Japan. It has been used as a medicinal plant for a long time. We isolated and identified four types of flavonoid glycosides [astragalin (1), isoquercetin (2), rhamnocitrin 3-O-glucoside (3), and nicotiflorin (4)], a triterpene [methyl hederagenin (5)], and three types of triterpene glycosides [δ-hederin (6), echinocystic acid 3-O-arabinoside (7), and cauloside B (8)] from the methanol extract of E. sieboldianus, which regulates lipid accumulation in 3T3-L1 preadipocytes. Among the compounds isolated, 2 and 8 up- and down-regulated lipid accumulation and insulin induced adipocyte differentiation in 3T3-L1 preadipocytes. Compound 2 induced up-regulation of lipid accumulation and decreased adipocyte size, while 8 down-regulated lipid accumulations without decreasing cell size. Additionally, 2 increased adipogenic proteins [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and fatty-acid-binding protein 4 (FABP4)]. In contrast, 8 decreased the levels of all adipogenic proteins and glucose transporter type 4 (GLUT4), but increased adiponectin.

Target molecules in 3T3-L1 adipocytes differentiation are regulated by maslinic acid, a natural triterpene from Olea europaea

BACKGROUND

Metabolic syndrome is a set of pathologies among which stand out the obesity, which is related to the lipid droplet accumulation and changes to cellular morphology regulated by several molecules and transcription factors. Maslinic acid (MA) is a natural product with demonstrated pharmacological functions including anti-inflammation, anti-tumor and anti-oxidation, among others.

PURPOSE

Here we report the effects of MA on the adipogenesis process in 3T3-L1 cells.

METHODS

Cell viability, glucose uptake, cytoplasmic triglyceride droplets, triglycerides quantification, gene transcription factors such as peroxisome proliferator-activated receptor γ (PPARγ) and adipocyte fatty acid-binding protein (aP2) and intracellular Ca²⁺ levels were determined in pre-adipocytes and adipocytes of 3T3-L1 cells.

RESULTS

MA increased glucose uptake. MA also decreased lipid droplets and triglyceride levels, which is in concordance with the down-regulation of PPARγ and aP2. Finally, MA increased the intracellular Ca²⁺ concentration, which could also be involved in the demonstrated antiadipogenic effect of this triterpene.

CONCLUSION

MA has been demonstrated as potential antiadipogenic compound in 3T3-L1 cells.

Arborinane Triterpenoids from Rubia philippinensis Inhibit Proliferation and Migration of Vascular Smooth Muscle Cells Induced by the Platelet-Derived Growth Factor

The abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are associated with cardiovascular diseases and related complications. Such deleterious proliferation and migration events are triggered by cytokines and growth factors, and among them, platelet-derived growth factor (PDGF) is recognized as the most potent inducer. Despite the genus Rubia being researched to identify valuable commercial and medicinal virtues, Rubia philippinensis has rarely been investigated. Nine arborinane-type triterpenoids (1-9) were identified from this underutilized plant species. In particular, 4 was identified as the first arborinane derivative carrying a ketocarbonyl motif at C-19. The presence of the cyclopentanone moiety and the associated configurational assignment were determined by utilizing NOE and coupling constant analysis. These compounds were assessed for their inhibitory potential on PDGF-induced proliferation and the migration of VSMCs. Treatment with 5 μM compound 5 (62.6 ± 10.7%) and compound 9 (41.1 ± 4.7%) impeded PDGF-stimulated proliferation without exerting cytotoxicity. Compound 7 exhibited antimigration activity in a dose-dependent manner (38.5 ± 3.0% at 10 μM, 57.6 ± 3.2% at 30 μM). These results suggest that the arborinane-type triterpenoids may be a pertinent starting point for the development of cardiovascular drugs capable of preventing the intimal accumulation of VSMCs.

Sesquiterpenes from Baizhu Stimulate Glucose Uptake by Activating AMPK and PI3K

Baizhu, the dried rhizome of Atractylodes Macrocephala Koidz (Compositae), is one of the most important traditional Chinese herbal medicines. Baizhu is generally used to treat digestive disorders and diabetes in Asian countries. This study investigates the activity of two sesquiterpenes isolated from Baizhu, atractylenolide I (AT-I) and atractylenolide II (AT-II), for their effects on glucose uptake in mouse skeletal muscle C2C12 cells, and the corresponding mechanism. These compounds show a significant stimulatory effect on glucose uptake in C2C12 myotubes. Both AT-I and AT-II significantly increased GLUT4 but not GLUT1 protein levels, and promoted GLUT4 translocation to the plasma membrane. The increased glucose uptake induced by these compounds is associated with activation of AMP-activated protein kinase (AMPK) and PI3K/Akt pathways in these cells. Further studies have indicated that AT-I and AT-II ameliorate TNF-[Formula: see text]-induced insulin resistance in C2C12 myotubes. In summary, our findings highlight the insulin mimetic activity of Baizhu in myotubes, and provide insights into the action mechanism underlying these effects. Our findings may also prove highly relevant to the development of novel therapeutic applications for these compounds.

Hypoglycemic Constituents Isolated from Trapa natans L. Pericarps

Trapa natans L., called water chestnut or water caltrop, is a floating aquarium plant. Its fruits are widely used as food. Two new tannins, 1 and 2, one new neolignan, 14, one new norlignan, 17, and 20 known compounds, 3-13, 15, 16, and 18-24 were isolated from T. natans pericarps in this study. The 1, 2, 14, and 17 structures were elucidated using a chemical method and extensive spectral evidence. A series of hydrolyzable tannins, 1-8, a lignin, 13, a flavonoid, 16, a norlignan, 17, and phenolic compounds, 18, 20, 21, and 24 resulted in the enhanced glucose uptake activity in C2C12 myotubes. Compounds 4 and 5 significantly increased GLUT4 protein expression in C2C12 myotubes. In addition, 4 and 5 improved the phosphorylation of AMPK, AKT(S473), and AKT(T308). The involvement of AMPK and PI3K in the mechanism of action of compounds 4 and 5 was confirmed by use of AMPK and PI3K inhibitors, which completely suppressed the 4- and 5-mediated activities of glucose uptake in C2C12 myotubes. We also demonstrated that 4 and 5 could increase GLUT4 protein levels in plasma membranes.

A systems pharmacology approach to decipher the mechanism of danggui-shaoyao-san decoction for the treatment of neurodegenerative diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Neurodegenerative diseases (NDs) is a time-dependent course for a sequence of conditions that primarily impact the neurons in the human brain, ultimately, resulting in persistence and progressive degeneration and / or death of nerve cells and reduction of cognition and memory function. Currently, there are no therapeutic approaches to cure neurodegeneration, except certain medicines that temporarily alleviate symptoms, facilitating the improvement of a patients' quality of life. Danggui-shaoyao-san (DSS), as a famous Chinese herbal formula, has been widely used in the treatment of various illnesses, including neurodegenerative diseases. Although well-practiced in clinical medicine, the mechanisms involved in DSS for the treatment of neurodegenerative diseases remain elusive.

MATERIALS AND METHODS

In the present study, a novel systems pharmacology approach was developed to decipher the potential mechanism between DSS and neurodegenerative disorders, implicated in oral bioavailability screening, drug-likeness assessment, target identification and network analysis.

RESULTS

Based on a comprehensive systems approach, active compounds of DSS, relevant potential targets and targets associated with diseases were predicted. Active compounds, targets and diseases were used to construct biological networks, such as, compound-target interactions and target-disease networks, to decipher the mechanisms of DSS to address NDs.

CONCLUSIONS

Overall, a well-understood picture of DSS, hallmarked by multiple herbs-compounds-targets-pathway-cooperation networks for the treatment of NDs, was revealed. Notably, this systems pharmacology approach provided a novel in silico approach for the development paradigm of traditional Chinese medicine (TCM) and the generation of new strategies for the management of NDs.

An Essential Role of cAMP Response Element Binding Protein in Ginsenoside Rg1-Mediated Inhibition of Na+/Glucose Cotransporter 1 Gene Expression

The Na(+)/glucose cotransporter 1 (SGLT1) is responsible for glucose uptake in intestinal epithelial cells. It has been shown that the intestinal SGLT1 level is significantly increased in diabetic individuals and positively correlated with the pathogenesis of diabetes. The development of targeted therapeutics that can reduce the intestinal SGLT1 expression level is, therefore, important. In this study, we showed that ginsenoside Rg1 effectively decreased intestinal glucose uptake through inhibition of SGLT1 gene expression in vivo and in vitro. Transient transfection analysis of the SGLT1 promoter revealed an essential cAMP response element (CRE) that confers the Rg1-mediated inhibition of SGLT1 gene expression. Chromatin immunoprecipitation assay and targeted CRE-binding protein (CREB) silencing demonstrated that Rg1 reduced the promoter binding of CREB and CREB binding protein associated with an inactivated chromatin status. In addition, further studies showed that the epidermal growth factor receptor (EGFR) signaling pathway also plays an essential role in the inhibitory effect of Rg1; taken together, our study demonstrates the involvement of the EGFR-CREB signaling pathway in the Rg1-mediated downregulation of SGLT1 expression, which offers a potential strategy in the development of antihyperglycemic and antidiabetic treatments.

Deoxyandrographolide promotes glucose uptake through glucose transporter-4 translocation to plasma membrane in L6 myotubes and exerts antihyperglycemic effect in vivo

Skeletal muscle is the principal site for postprandial glucose utilization and augmenting the rate of glucose utilization in this tissue may help to control hyperglycemia associated with diabetes mellitus. Here, we explored the effect of Deoxyandrographolide (DeoAn) isolated from the Andrographis paniculata Nees on glucose utilization in skeletal muscle and investigated its antihyperglycemic effect in vivo in streptozotocin-induced diabetic rats and genetically diabetic db/db mice. In L6 myotubes, DeoAn dose-dependently stimulated glucose uptake by enhancing the translocation of glucose transporter 4 (GLUT4) to cell surface, without affecting the total cellular GLUT4 and GLUT1 content. These effects of DeoAn were additive to insulin. Further analysis revealed that DeoAn activated PI-3-K- and AMPK-dependent signaling pathways, account for the augmented glucose transport in L6 myotubes. Furthermore, DeoAn lowered postprandial blood glucose levels in streptozotocin-induced diabetic rats and also suppressed the rises in the fasting blood glucose, serum insulin, triglycerides and LDL-Cholesterol levels of db/db mice. These findings suggest the therapeutic efficacy of the DeoAn for type 2 diabetes mellitus and can be potential phytochemical for its management.

Pachymic acid induces apoptosis via activating ROS-dependent JNK and ER stress pathways in lung cancer cells

BACKGROUND

Pachymic acid (PA), a lanostane-type triterpenoid from Poria cocos, has been reported to possess anti-emetic, anti-inflammatory, and anti-cancer properties. Nonetheless, the anti-tumor effect of PA in lung cancer cells remains unclear. Herein, we report the chemotherapeutic effects and underlying mechanisms of PA against human lung cancer.

METHODS

The anti-proliferative ability of PA on lung cancer cells was assessed by MTT, colony formation and EdU proliferation assays. Flow cytometric analysis was used to detect cell cycle changes. Apoptosis was determined by annexin V/PI double-staining and the DNA ladder formation assays. The expressions of the apoptosis-related proteins were analysed by western blot. The in vivo efficacy of PA was measured using a NCI-H23 xenograft model in nude mice.

RESULTS

PA exhibited anti-tumor effects in vitro accompanied by induction of G2/M phase arrest and apoptosis in NCI-H23 and NCI-H460 lung cancer cells. Mechanistically, our data showed that PA induced reactive oxygen species (ROS) production, resulting in the activation of both c-Jun N-terminal kinase (JNK) and endoplasmic reticulum (ER) stress apoptotic pathways in lung cancer cells. Moreover, blockage of ROS production reversed PA-induced JNK and ER stress activation. Finally, PA inhibited the growth of NCI-H23 xenograft tumors without causing any host toxicity, and inhibited cell proliferation and induction of apoptosis of tumor cells in tumor xenograft tissues.

CONCLUSIONS

In summary, our study demonstrates that PA induces apoptosis through activation of the JNK and ER stress pathways in human lung cancer cells. Our findings provide a rationale for the potential application of PA in lung cancer therapy.

Aegeline from Aegle marmelos stimulates glucose transport via Akt and Rac1 signaling, and contributes to a cytoskeletal rearrangement through PI3K/Rac1

Aegeline is an alkaloidal-amide, isolated from the leaves of Aegle marmelos and have shown antihyperglycemic as well as antidyslipidemic activities in the validated animal models of type 2 diabetes mellitus. Here we delineate, aegeline enhanced GLUT4 translocation mediated 2-deoxy-glucose uptake in both time and concentration-dependent manner. 2-deoxy-glucose uptake was completely stymied by the transport inhibitors (wortmannin and genistein) in C2C12 myotubes. Pharmacological inhibition of Akt (also known as protein kinase B) and Ras-related C3 botulinum toxin substrate 1 (Rac1) suggest that both Akt and Rac1 operate aegeline-stimulated glucose transport via distinct parallel pathways. Moreover, aegeline activates p21 protein-activated kinase 1 (PAK1) and cofilin (an actin polymerization regulator). Rac1 inhibitor (Rac1 inhib II) and PAK1 inhibitor (IPA-3) completely blocked aegeline-induced phosphorylation of cofilin and p21 protein-activated kinase 1 (PAK1). In summary, these findings suggest that aegeline stimulates the glucose transport through Akt and Rac1 dependent distinct parallel pathways and have cytoskeletal roles via stimulation of the PI3-kinase-Rac1-PAK1-cofilin pathway in the skeletal muscle cells. Therefore, multiple targets of aegeline in the improvement of insulin sensitivity of the skeletal muscle cells may be suggested.

Emodin up-regulates glucose metabolism, decreases lipolysis, and attenuates inflammation in vitro

BACKGROUND

Emodin, the major bioactive component of Rheum palmatum, has many different activities, including antitumor, anti-inflammatory, and antidiabetes effects. Recently, emodin was reported to regulate energy metabolism. In the present study, we further explored the effects of emodin on glucose and lipid metabolism.

METHODS

Differentiated C2C12 myotubes and 3T3-L1 adipocytes were treated with or without different concentrations of emodin (6.25, 12.5, 25 or 50 μmol/L) for different time (1 h, 3 h, 12 h, 24 h or 48 h). Glucose metabolism, oxygen consumption, lactic acid levels, glycerol levels, and inflammation pathways were then evaluated. Cells were collected for quantitative polymerase chain reaction (PCR) and western blot analysis.

RESULTS

Emodin upregulated glucose uptake and consumption in both C2C12 myotubes and 3T3-L1 adipocytes, with glycolysis increased. Furthermore, emodin inhibited lipolysis under basal conditions (as well as in the presence of 10 ng/ml tumor necrosis factor (TNF-)-α in 3T3-L1 adipocytes) and significantly decreased phosphorylated perilipin. Moreover, emodin inhibited the nuclear factor-κB and extracellular signal-regulated kinase pathways in C2C12 myotubes and 3T3-L1 adipocytes.

CONCLUSIONS

Emodin upregulates glucose metabolism, decreases lipolysis, and inhibits inflammation in C2C12 myotubes and 3T3-L1 adipocytes.

An essential role of cAMP response element-binding protein in epidermal growth factor-mediated induction of sodium/glucose cotransporter 1 gene expression and intestinal glucose uptake

The sodium/glucose cotransporter 1 (SGLT1) is responsible for glucose uptake in intestinal epithelial cells. Its expression is decreased in individuals with intestinal inflammatory disorders and is correlated with the pathogenesis of disease. The aim of this study was to understand the regulatory mechanism of the SGLT1 gene. Using the trinitrobenzene sulfonic acid-induced mouse models of intestinal inflammation, we observed decreased SGLT1 expression in the inflamed intestine was positively correlated with the mucosal level of epidermal growth factor (EGF) and activated CREB. Overexpression of EGF demonstrated that the effect of EGF on intestinal glucose uptake was primarily due to the increased level of SGLT1. We identified an essential cAMP binding element (CRE) confers EGF inducibility in the human SGLT1 gene promoter. ChIP assay further demonstrated the increased binding of CREB and CBP to the SGLT1 gene promoter in EGF-treated cells. In addition, the EGFR- and PI3K-dependent CREB phosphorylations are involved in the EGF-mediated SGLT1 expression. This is the first report to demonstrate that CREB is involved in EGF-mediated transcription regulation of SGLT1 gene in the normal and inflamed intestine, which can provide potential therapeutic applications for intestinal inflammatory disorders.

Rhodiola crenulata extract suppresses hepatic gluconeogenesis via activation of the AMPK pathway

BACKGROUND

Rhodiola, a popular herb, has been used for treating high altitude sicknesses, depression, fatigue, and diabetes. However, the detailed mechanisms by which Rhodiola crenulata functions in the liver need further clarification.

PURPOSE

The current study was designed to examine the effects of Rhodiola crenulata root extract (RCE) on hepatic glucose production.

METHODS

Human hepatoma HepG2 cells were treated with RCE for 6 h. Glucose production, the expression level of p-AMPK, and the expression of key gluconeogenic genes were measured. The effects of RCE were also studied in Sprague-Dawley (SD) rats. The efficacy and underlying mechanism of RCE in the liver were examined.

RESULTS

RCE significantly suppressed glucose production and gluconeogenic gene expression in HepG2 cells while activating the AMPK signaling pathway. Interestingly, RCE-suppressed hepatic gluconeogenesis was eliminated by an AMPK-specific inhibitor, but not by the PI3K/AKT-specific inhibitor. In addition, oral administration of RCE significantly increased phosphorylated AMPK levels and inhibited gluconeogenic gene expression in the rat liver. Furthermore, RCE treatment also decreased plasma glucose concentration in rats.

CONCLUSION

We present in vitro and in vivo evidence that RCE might exert the glucose-lowering effect partly by inhibiting hepatic gluconeogenesis through activating the AMPK signaling pathway. These findings provide evidence that Rhodiola crenulata may be helpful for the management of type II diabetes.

A gut microbial metabolite of ginsenosides, compound K, induces intestinal glucose absorption and Na(+) /glucose cotransporter 1 gene expression through activation of cAMP response element binding protein

SCOPE

The Na(+) /glucose cotransporter 1 (SGLT1) plays a crucial role in glucose uptake in intestinal epithelial cells (IECs), which has been shown essential in ameliorating intestinal inflammation. Ginseng has historically been used to treat inflammatory disorders. Understanding the regulatory mechanism of ginseng-mediated induction of SGLT1 gene expression in human intestinal cells is therefore important.

METHODS AND RESULTS

We demonstrate that ginsenoside compound K (CK) enhances SGLT1-mediated glucose uptake in mice and human intestinal Caco-2 cells. Transient transfection analysis using SGLT1 promoter-luciferase reporters demonstrated that the presence of an essential cAMP response element (CRE) is required for CK-mediated induction of SGLT1 gene expression. The ChIP assays indicated that increased CRE-binding protein (CREB) and CREB-binding protein (CBP) binding to the SGLT1 promoter in CK-treated cells is associated with an activated chromatin state. Our result showed that the increased CREB phosphorylation is directly correlated with SGLT1 expression in IECs. Further studies indicated that the epidermal growth factor receptor (EGFR) signaling pathway is involved in the CK-mediated effect.

CONCLUSION

These findings provide a novel mechanism for the CK-mediated upregulation of SGLT1 expression through EGFR-CREB signaling activation, which could contribute to reducing gut inflammation.

The mechanism of action of ursolic acid as insulin secretagogue and insulinomimetic is mediated by cross-talk between calcium and kinases to regulate glucose balance

BACKGROUND

The effect of in vivo treatment with ursolic acid (UA) on glycemia in hyperglycemic rats and its mechanism of action on muscle were studied.

METHODS

The UA effects on glycemia, glycogen, LDH, calcium and on insulin levels were evaluated after glucose tolerance curve. The β-cells were evaluated through the transmission electron microscopy. UA mechanism of action was studied on muscles through the glucose uptake with/without specific insulin signaling inhibitors. The nuclear effect of UA and the GLUT4 expression on muscle were studied using thymidine, GLUT4 immunocontent, immunofluorescence and RT-PCR.

RESULTS

UA presented a potent antihyperglycemic effect, increased insulin vesicle translocation, insulin secretion and augmented glycogen content. Also, UA stimulates the glucose uptake through the involvement of the classical insulin signaling related to the GLUT4 translocation to the plasma membrane as well as the GLUT4 synthesis. These were characterized by increasing the GLUT4 mRNA expression, the activation of DNA transcription, the expression of GLUT4 and its presence at plasma membrane. Also, the modulation of calcium, phospholipase C, protein kinase C and PKCaM II is mandatory for the full stimulatory effect of UA on glucose uptake. UA did not change the serum LDH and serum calcium balance.

CONCLUSIONS

The antihyperglycemic role of UA is mediated through insulin secretion and insulinomimetic effect on glucose uptake, synthesis and translocation of GLUT4 by a mechanism of cross-talk between calcium and protein kinases.

GENERAL SIGNIFICANCE

UA is a potential anti-diabetic agent with pharmacological properties for insulin resistance and diabetes therapy.

Palmitoleic acid (n-7) increases white adipocytes GLUT4 content and glucose uptake in association with AMPK activation

BACKGROUND

Palmitoleic acid was previously shown to improve glucose homeostasis by reducing hepatic glucose production and by enhancing insulin-stimulated glucose uptake in skeletal muscle. Herein we tested the hypothesis that palmitoleic acid positively modulates glucose uptake and metabolism in adipocytes.

METHODS

For this, both differentiated 3 T3-L1 cells treated with either palmitoleic acid (16:1n7, 200 μM) or palmitic acid (16:0, 200 μM) for 24 h and primary adipocytes from mice treated with 16:1n7 (300 mg/kg/day) or oleic acid (18:1n9, 300 mg/kg/day) by gavage for 10 days were evaluated for glucose uptake, oxidation, conversion to lactate and incorporation into fatty acids and glycerol components of TAG along with the activity and expression of lipogenic enzymes.

RESULTS

Treatment of adipocytes with palmitoleic, but not oleic (in vivo) or palmitic (in vitro) acids, increased basal and insulin-stimulated glucose uptake and GLUT4 mRNA levels and protein content. Along with uptake, palmitoleic acid enhanced glucose oxidation (aerobic glycolysis), conversion to lactate (anaerobic glycolysis) and incorporation into glycerol-TAG, but reduced de novo fatty acid synthesis from glucose and acetate and the activity of lipogenic enzymes glucose 6-phosphate dehydrogenase and ATP-citrate lyase. Importantly, palmitoleic acid induction of adipocyte glucose uptake and metabolism were associated with AMPK activation as evidenced by the increased protein content of phospho(p)Thr172AMPKα, but no changes in pSer473Akt and pThr308Akt. Importantly, such increase in GLUT4 content induced by 16:1n7, was prevented by pharmacological inhibition of AMPK with compound C.

CONCLUSIONS

In conclusion, palmitoleic acid increases glucose uptake and the GLUT4 content in association with AMPK activation.

Comparative study of lanostane-type triterpene acids in different parts of Poria cocos (Schw.) Wolf by UHPLC-Fourier transform MS and UHPLC-triple quadruple MS

Poria cocos (Schw.) Wolf is widely used as a traditional Chinese medicine, and approximately 10% of traditional Chinese medicinal preparations contain this material, according to the Chinese Pharmacopoeia (2010 edition). Although the epidermis (fulingpi in Chinese, or FLP) and the inner parts (baifuling in Chinese, or BFL) of P. cocos had different therapeutic applications in history, studies pertaining to a comparative analysis of their chemical constituents have been scarce. UHPLC-DAD-FT/MS(n) has been used in the current study to identify the triterpene acids present in fungus based on a detailed analysis of the fragmentation behavior of 13 standard compounds. This analysis allowed for the identification of 27 triterpene acids, including five groups of isomers and four potential new compounds. Furthermore, a UHPLC-MS/MS method has been developed for quantifying the amounts of nine bioactive triterpene acids in samples of the FLP and BFL, including three 3,4-seco-lanostane-type triterpene acids. These results revealed significant differences in the amounts of these compounds in the FLP and BFL samples. Principal component analysis and partial least squares discriminant analysis of the results for the FLP and BFL samples clearly demonstrated that dehydrotumulosic acid, trametenolic acid, dehydrotrametenolic acid and poricoic acid A were the main compounds contributing to the clusters in FLP and BFL. The observed differences in the chemical compositions of FLP and BFL could provide some explanation of the differences in their clinic applications. This study represents the first reported comprehensive analysis of lanostane-type triterpene acids in FLP and BFL parts of P. cocos.