Effects of compound K on hyperglycemia and insulin resistance in rats with type 2 diabetes mellitus

Ginsenoside compound K plays an anti-inflammatory effect without inducing glucose metabolism disorder in adjuvant-induced arthritis rats

Ginsenoside compound K (GCK) possesses a glucocorticoid (GC)-like structure and functions as an agonist of the glucocorticoid receptor (GR), thereby exerting anti-inflammatory effects through GR activation. However, it remains unclear whether GCK leads to hyperglycemia, which is a known adverse reaction associated with classical GCs. In this study, we have successfully demonstrated that GCK exerts its anti-inflammatory effects in a rat model of adjuvant arthritis without impacting gluconeogenesis and pentose phosphate pathways, thus avoiding any glucose metabolism disorders. By employing the GR mutant plasmid, we have identified the binding site between GCK and GR as GRM560T, which differs from the binding site shared by dexamethasone (DEX) and GR. Notably, compared to DEX, GCK induces distinct levels of phosphorylation at S211 on GR upon binding to activate steroid receptor coactivator 1 (SRC1)-a co-factor responsible for mediating anti-inflammatory effects-while not engaging peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)-an associated coactivator involved in gluconeogenesis.

Bioconversion, Pharmacokinetics, and Therapeutic Mechanisms of Ginsenoside Compound K and Its Analogues for Treating Metabolic Diseases

Rare ginsenoside compound K (CK) is an intestinal microbial metabolite with a low natural abundance that is primarily produced by physicochemical processing, side chain modification, or metabolic transformation in the gut. Moreover, CK exhibits potent biological activity compared to primary ginsenosides, which has raised concerns in the field of ginseng research and development, as well as ginsenoside-related dietary supplements and natural products. Ginsenosides Rb1, Rb2, and Rc are generally used as a substrate to generate CK via several bioconversion processes. Current research shows that CK has a wide range of pharmacological actions, including boosting osteogenesis, lipid and glucose metabolism, lipid oxidation, insulin resistance, and anti-inflammatory and anti-apoptosis properties. Further research on the bioavailability and toxicology of CK can advance its medicinal application. The purpose of this review is to lay the groundwork for future clinical studies and the development of CK as a therapy for metabolic disorders. Furthermore, the toxicology and pharmacology of CK are investigated as well in this review. The findings indicate that CK primarily modulates signaling pathways associated with AMPK, SIRT1, PPARs, WNTs, and NF-kB. It also demonstrates a positive therapeutic effect of CK on non-alcoholic fatty liver disease (NAFLD), obesity, hyperlipidemia, diabetes, and its complications, as well as osteoporosis. Additionally, the analogues of CK showed more bioavailability, less toxicity, and more efficacy against disease states. Enhancing bioavailability and regulating hazardous variables are crucial for its use in clinical trials.

Therapeutic potential of ginsenoside compound K in managing tenocyte apoptosis and extracellular matrix damage in diabetic tendinopathy

The prevalence of tendinopathy in patients with diabetes is well documented. Despite efforts to improve diabetes management, there is a lack of research on therapeutic agents targeting the core features of tendinopathy, namely, tenocyte apoptosis and extracellular matrix (ECM) damage. In this study, we investigated the potential of ginsenoside compound K (CK), known for its antidiabetic properties, to mitigate tenocyte apoptosis, inflammation, oxidative stress, and the metalloproteinase (MMP) system under hyperglycemic conditions. Our research also aimed to unravel the molecular mechanism underlying the effects of CK. The assessment of apoptosis involved observing intracellular chromatin condensation and measuring caspase 3 activity. To gauge oxidative stress, we examined cellular ROS levels and hydrogen peroxide and malondialdehyde concentrations. Western blotting was employed to determine the expression of various proteins. Our findings indicate that CK treatment effectively countered high glucose-induced apoptosis, inflammation, and oxidative stress in cultured tenocytes. Furthermore, CK normalized the expression of MMP-9, MMP-13, and TIMP-1. Notably, CK treatment boosted the expression of PPARγ and antioxidant enzymes. We conducted small interfering (si) RNA experiments targeting PPARγ, revealing its role in mediating CK's effects on tendinopathy features in hyperglycemic tenocytes. In conclusion, these in vitro results offer valuable insights into the potential therapeutic role of CK in managing tendinopathy among individuals with diabetes. By addressing crucial aspects of tendinopathy, CK presents itself as a promising avenue for future research and treatment development in this domain.

Type 2 diabetes mellitus in obesity promotes prolongation of cardiomyocyte contractile function, impaired Ca2+ handling and protein carbonylation damage

AIMS

To investigate whether the obesity associated to T2DM presented cardiomyocyte myocardial contractility dysfunction due to damage in Ca²⁺ handling, concomitantly with increased biomarkers of oxidative stress.

METHODS

Male Wistar rats were randomized into two groups: control (C): fed with standard diet; and obese (Ob) that fed a saturated high-fat. After the characterization of obesity (12 weeks), the Ob animals were submitted to T2DM induction with a single dose of intraperitoneal (i.p.) injection of streptozotocin (30 mg/kg). Thus, remained Ob rats that were characterized as to the presence (T2DMOb; n = 8) and/or absence (Ob; n = 10) of T2DM. Cardiac remodeling was measured by post-mortem morphological, isolated cardiomyocyte contractile function, as well as by intracellular Ca²⁺-handling analysis.

RESULTS

T2DMOb presented a significant reduction of all fat pads, total body fat and adiposity index. T2DMOb group presented a significant increase in protein carbonylation and superoxide dismutase (SOD) activity, respectively. T2DMOb promoted elevations in fractional shortening (15.6 %) and time to 50 % shortening (5.8 %), respectively. Time to 50 % Ca²⁺ decay was prolonged in T2DMOb, suggesting a possible impairment in Ca²⁺recapture and/or removal.

CONCLUSION

Type 2 diabetes mellitus in obesity promotes prolongation of cardiomyocyte contractile function with protein carbonylation damage and impaired Ca²⁺ handling.

Selenium-Enriched and Ordinary Black Teas Regulate the Metabolism of Glucose and Lipid and Intestinal Flora of Hyperglycemic Mice

Black tea is one of the six major tea categories and has a variety of bioactivities. However, little is known about its comprehensive evaluation of hypoglycemic effects and potential mechanisms. In this study, we investigated the in vivo hypoglycemic activity and potential mechanism for aqueous extracts of ordinary black tea (BT) and selenium-enriched black tea (Se-BT) by using an established high-fat diet together with streptozotocin (STZ)-induced hyperglycemic mouse model. Additionally, we also explored their α-glucosidase inhibition activity. The results show that both BT and Se-BT had a favorable glycosidase inhibitory activity. Moreover, the intervention of BT and Se-BT could regulate the mRNA expression and the level of serum parameters related to glucose and lipid metabolisms. Accordingly, they could activate the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) signaling pathway and alleviate insulin resistance (IR) and hyperglycemia. Moreover, supplementation of BT and Se-BT increased the richness and diversity of intestinal flora and altered the abundance of beneficial and harmful bacteria. Both BT and Se-BT could regulate glucose metabolism, alleviate tissue damage, and restore intestinal flora dysbiosis, suggesting that they could be used as a natural functional food for preventing hyperglycemia.

The interplay between herbal medicines and gut microbiota in metabolic diseases

Globally, metabolic diseases are becoming a major public health problem. Herbal medicines are medicinal materials or preparations derived from plants and are widely used in the treatment of metabolic diseases due to their good curative effects and minimal side effects. Recent studies have shown that gut microbiota plays an important role in the herbal treatment of metabolic diseases. However, the mechanisms involved are still not fully understood. This review provides a timely and comprehensive summary of the interactions between herbal medicines and gut microbiota in metabolic diseases. Mechanisms by which herbal medicines treat metabolic diseases include their effects on the gut microbial composition, the intestinal barrier, inflammation, and microbial metabolites (e.g., short-chain fatty acids and bile acids). Herbal medicines can increase the abundance of beneficial bacteria (e.g., Akkermansia and Blautia), reduce the abundance of harmful bacteria (e.g., Escherichia-Shigella), protect the intestinal barrier, and alleviate inflammation. In turn, gut microbes can metabolize herbal compounds and thereby increase their bioavailability and bioactivity, in addition to reducing their toxicity. These findings suggest that the therapeutic effects of herbal medicines on metabolic diseases are closely related to their interactions with the gut microbiota. In addition, some methods, and techniques for studying the bidirectional interaction between herbal medicines and gut microbiota are proposed and discussed. The information presented in this review will help with a better understanding of the therapeutic mechanisms of herbal medicines and the key role of gut microbiota.

Pharmacokinetic Comparison of Ginsenosides between Fermented and Non-Fermented Red Ginseng in Healthy Volunteers

Fermentation of red ginseng (RG) produces fermented red ginseng (FRG), thereby increasing the relative amount of downstream ginsenosides, including compound Y (CY), F2, Rh2, compound K (CK), compound O, protopanaxadiol (PPD), and protopanaxatriol (PPT). These downstream ginsenosides have beneficial pharmacological effects, and are easily absorbed by the human body. Based on these expectations, a randomized, single-dose, two-period, crossover clinical trial was planned to compare the pharmacokinetic characteristics of seven types (Rb1, CY, F2, CK, Rh2, PPD, and PPT) of ginsenoside components after FRG and RG administration. The safety and tolerability profiles were assessed in this clinical trial. Sixteen healthy Korean male subjects were administered 6 g of FRG or RG. All ginsenosides except Rb1 showed higher systemic exposure after FRG administration than after RG administration, based on comparisons of ginsenoside C_max and area under the concentration-time curve (AUC) between FRG and RG. CK, the main ginsenoside component produced during the fermentation process, had 69.23/74.53-fold higher C_max/AUC_last after administration of FRG than RG, and Rh2 had 20.27/18.47-fold higher C_max/AUC_last after administration of FRG than RG. In addition, CY and F2 were detected in FRG; however, all plasma concentrations of CY and F2, except in one subject, were below the lower limit of quantification in RG. There were no clinically significant findings with respect to clinical laboratory tests, blood pressures, or adverse events. Therefore, regular administration of FRG may exert better pharmacological effects than RG.

Ameliorated effects of a lipopeptide surfactin on insulin resistance in vitro and in vivo

Surfactin, produced by Bacillus amyloliquefaciens fmb50, was used to treat insulin-resistant (IR) hepatocyte. It was found that surfactin increased glucose consumption in insulin-resistant HepG2 (IR-HepG2) cells and ameliorated IR by increasing glucose transporter 4 (GLUT4) protein expression and AMP-activated protein kinase (AMPK) mRNA expression, promoting GLUT4 translocation and activating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) in IR-HepG2 cells. Meanwhile, surfactin downregulated protein expression of phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphatase (G6Pase), further inhibiting hepatic gluconeogenesis. In addition, surfactin played important roles in eliminating reactive oxygen species (ROS), improving mitochondrial dysfunction, and inhibiting proinflammatory mediators. We observed that surfactin promoted glucose consumption, meanwhile increased translocation and protein expression of GLUT4 in Caco-2 cells. These results confirmed the conclusion in hepatic cells. Furthermore, surfactin supplement decreased body weight, food intake, and fasting blood glucose of type 2 diabetes mellitus (T2DM) mice induced by streptozotocin (STZ)/high-fat diet (HFD). Our data indicated that surfactin ameliorated insulin resistance and lowered blood glucose in intro and in vivo.

Anti-Diabetic Potential of Chlorella Pyrenoidosa-Based Mixture and its Regulation of Gut Microbiota

The aim of the present study was to investigate the anti-diabetic effect of CGSGCG and its beneficial effects on gut microbiota in type 2 diabetes (T2D) mice induced by streptozotocin and high sucrose and high fat diet. The results showed that treatment with CGSGCG reduced fasting blood glucose, improved oral glucose tolerance test, protected the liver from injury, and reduced inflammation in T2D mice. The contents of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid and isovaleric acid in CGSGCG group were 2.49-, 1.74-, 3.31-, 1.93-, 1.36- and 1.30-fold than that of the model group. Moreover, administration of CGSGCG up-regulated the expression of INSR/IRS-1/PI3K/AKT/GLUT4 and mTOR but down-regulated the P38MAPK expression. Furthermore, the abundance of beneficial bacteria such as Verrucomicrobia, Proteobacteria, Osillibacter, Dubosiella and Lactococcus in intestinal tract increased, indicating that CGSCGG regulated and improved the bacterial community structure of T2D mice, which were closely related to glycometabolism.

Ginsenoside compound K inhibits obesity-induced insulin resistance by regulation of macrophage recruitment and polarization via activating PPARγ

Obesity disrupts the immune system of adipose tissue, and the activation of its macrophages constantly infiltrating adipose tissue is a crucial cause of insulin resistance induced by obesity. We previously reported for the first time in vitro that the antidiabetic effect of CK may be through the inhibition of macrophage activation and we further explored the specific mechanism in vivo. In order to clarify it, the C57BL/6J mice were fed with a high fat diet and then administered with CK orally. The related biochemical indices were detected, the inflammatory factors in serum and tissues were measured, and the related protein expression levels in insulin pathways and inflammatory signaling pathways were observed. The results showed that CK could dose-dependently reduce macrophage M1-type inflammatory factor expression in serum and adipose tissue, improve insulin resistance and glucose tolerance effectively, upregulate PPARγ expression and block TLR4/TRAF6/TAK1/NF-κB activation in obese mice. In addition, CK promoted the expression of IRS1/PI3K/AKT. Furthermore, our study showed that ginsenoside CK could improve insulin resistance by reducing inflammation through the PPARγ/NF-κB signaling pathway, which implies that ginsenoside CK may be an effective agent against obesity or early diabetes.

Fucoidan ameliorates glucose metabolism by the improvement of intestinal barrier and inflammatory damage in type 2 diabetic rats

It has been reported that fucoidan possesses anti-diabetic activities by inhibiting α-glucosidase activity, improving β-cell dysfunction, and enhancing insulin sensitivity. However, as a macromolecular carbohydrate, fucoidan is rarely absorbed and indigestible in gastrointestinal tract. The study aimed to explore whether the fucoidan can regulate glucose metabolism by improving intestinal barrier and inflammation in type 2 diabetes mellitus (T2DM) rats. A high-fat diet combined with streptozotocin was used to induce T2DM rats. Different doses of fucoidan (50, 100 and 200 mg/kg) were administered respectively by lavage to T2DM rats for 8 weeks and saline was given to controls. The results showed that in addition to hyperglycemia and hyperlipidemia, T2DM rats were also characterized by increased intestinal permeability and proinflammatory cytokines. Notably, fucoidan reduced fasting blood glucose and insulin resistance index along with alleviated the accumulation of proinflammatory cytokines in T2DM rats. Furthermore, fucoidan repaired the intestinal barrier function, which was accompanied by the up-regulation of tight junction proteins and the improvement of intestinal inflammation via inhibiting TLR4/NF-κB signaling. Meanwhile, fucoidan also mitigated the liver damage, and alleviated insulin resistance by activating PI3K/AKT signaling. Collectively, these findings supported the potential of fucoidan to be used as a functional ingredient to prevent T2DM.

Ursolic acid ameliorates adipose tissue insulin resistance in aged rats via activating the Akt-glucose transporter 4 signaling pathway and inhibiting inflammation

Ageing often results in insulin resistance (IR) and chronic inflammation, and adipose is one of the tissues in which inflammation and IR occur earliest during this process. The present study investigated the effect and underlying mechanisms of ursolic acid (UA) on adipose IR and inflammation in ageing rats. Specific pathogen-free male Sprague-Dawley rats were randomly divided into 4 groups: i) Young normal (young); ii) untreated ageing (aged); and groups supplemented with UA either iii) low-UA 10 mg/kg (UA-L) or iv) high-50 mg/kg (UA-H). Animals in the UA-treated groups received 10 or 50 mg/kg UA (suspended in 5% Gum Arabic solution). The rats in the corresponding aged group and young groups received vehicle (5% Gum Arabic) alone. All rats were intragastrically treated once daily by oral gavage for 7 weeks. The day before the experiment terminated, overnight fasting blood (~700 µl) was collected and plasma was prepared to measure biochemical indicators; western blotting was performed to analyze the expression of insulin signaling proteins [(insulin receptor substrate 1 (IRS-1), phosphorylated (p)-IRS-1, PI3K, glucose transporter 4 (GLUT4), Akt and p-Akt)] and inflammatory factors (NF-κB, IL-6 and IL-1β) in the epididymis white adipose tissue (eWAT). The results revealed that treatment with UA-H decreased eWAT weight, the ratio of eWAT weight/body weight, fasted insulin and triglyceride levels, the homeostasis model assessment of insulin resistance and adipose tissue insulin resistance index in ageing rats, indicating the amelioration of systemic and adipose tissue IR, compared with the aged group. Mechanistically, UA-H administration upregulated p-protein kinase B, the ratio of p-Akt to protein kinase B and total and cellular membrane GLUT4 protein levels in eWAT of ageing rats. Conversely, UA inhibited the increase in NF-κB expression and proinflammatory cytokines IL-6 and IL-1β. However, these alterations were not observed in the rats of the aged group. Taken together, the findings of the present study indicated that UA may ameliorate adipose IR, which is associated with activation of the Akt-GLUT4 signaling pathway and inhibition of inflammation in ageing rats. These data provide a basis for the development of effective and safe drugs or functional substances, such as UA, for the prevention and treatment of metabolic diseases.

A comprehensive review on the phytochemistry, pharmacokinetics, and antidiabetic effect of Ginseng

BACKGROUND

Radix Ginseng, one of the well-known medicinal herbs, has been used in the management of diabetes and its complications for more than 1000 years.

PURPOSE

The aim of this review is devoted to summarize the phytochemistry and pharmacokinetics of Ginseng, and provide evidence for the antidiabetic effects of Ginseng and its ingredients as well as the underlying mechanisms involved.

METHODS

For the purpose of this review, the following databases were consulted: the PubMed Database (https://pubmed.ncbi.nlm.nih.gov), Chinese National Knowledge Infrastructure (http://www.cnki.net), National Science and Technology Library (http://www.nstl.gov.cn/), Wanfang Data (http://www.wanfangdata.com.cn/) and the Web of Science Database (http://apps.webofknowledge.com/).

RESULTS

Ginseng exhibits glucose-lowering effects in different diabetic animal models. In addition, Ginseng may prevent the development of diabetic complications, including liver, pancreas, adipose tissue, skeletal muscle, nephropathy, cardiomyopathy, retinopathy, atherosclerosis and others. The main ingredients of Ginseng include ginsenosides and polysaccharides. The underlying mechanisms whereby this herb exerts antidiabetic activities may be attributed to the regulation of multiple signaling pathways, including IRS1/PI3K/AKT, LKB1/AMPK/FoxO1, AGEs/RAGE, MAPK/ERK, NF-κB, PPARδ/STAT3, cAMP/PKA/CERB and HIF-1α/VEGF, etc. The pharmacokinetic profiles of ginsenosides provide valuable information on therapeutic efficacy of Ginseng in diabetes. Although Ginseng is well-tolerated, dietary consumption of this herb should follow the doctors' advice.

CONCLUSION

Ginseng may offer an alternative strategy in protection against diabetes and its complications through the regulations of the multi-targets via various signaling pathways. Efforts to understand the underlying mechanisms with strictly-controlled animal models, combined with well-designed clinical trials and pharmacokinetic evaluation, will be important subjects of the further investigations and weigh in translational value of this herb in diabetes management.

Production of minor ginsenosides by combining Stereum hirsutum and cellulase

Minor ginsenosides (MGs) (include ginsenoside F2, Compound K, PPT, etc), which are generally not produced by ginseng plants naturally, are obtained by deglycosylation of major ginsenosides. However, the conventional processes used to produce deglycosylated ginsenosides focus on the use of intestinal microorganisms for transformation. In this study, an edible and medicinal mushroom Stereum hirsutum JE0512 was screened from 161 β-glucosidase-producing soil microorganisms sourced from wild ginseng using the plate coloration method. Furthermore, JE0512 was used for the production of CK from ginseng extracts (GE) in solid-state fermentation (SSF) using 20 g corn bran as substrate, 4 g GE, and 20% inoculation volume, and the results showed that the highest CK content was 29.13 mg/g. After combining S. hirsutum JE0512 with cellulase (Aspergillus niger), the MGs (F2, CK, and PPT) content increased from 1.66 to 130.79 mg/g in the final products. Our results indicate that the Stereum genus has the potential to biotransform GE into CK and the combination of S. hirsutum JE0512 and cellulase could pave the way for the production of MGs from GE.

Ginsenoside Rh1 Improves Type 2 Diabetic Nephropathy through AMPK/PI3K/Akt-Mediated Inflammation and Apoptosis Signaling Pathway

Although ginseng (Panax ginseng C.A. Meyer) has received extensive attention in the treatment and prevention of type 2 diabetes mellitus (T2DM) in the past few decades, there are few studies on the complications of T2DM. At present, obesity-linked diabetic nephropathy (DN) has become the most prevailing element of the end-stage renal failure in the world. The aim of this work is to evaluate the ameliorative effects of ginsenoside Rh1 (G-Rh1) on DN induced by high fat diet plus streptozotocin (HFD/STZ) through some potential and combined mechanisms of action. The results showed that G-Rh1 treatment at 5 and 10 mg/kg for 8 weeks exerted excellent effects in controlling fasting blood glucose (FBG), improving glucose tolerance, and increasing insulin level. In addition, G-Rh1 effectively prevents the excessive production of advanced glycation end products (AGEs), a diabetic nephropathy marker, in HFD/STZ induced DN mice. Meanwhile, oxidation indicators including SOD, GSH, and MDA were improved by G-Rh1 treatment to varying degrees. It is worth noting that G-Rh1 not only inhibits the secretion of Nox1 and Nox4 in kidney tissues, but also has an inhibitory effect on inflammatory factors and NF-[Formula: see text]B signaling pathway. Importantly, further in-depth research on molecular mechanisms provides vital evidence that the ameliorative effect of G-Rh1 on DN is related to the inhibition of apoptosis and the AMPK/PI3K/Akt signaling pathway. In summary, G-Rh1 may be of great value in improving the treatment of DN although more experimental data is needed.

Ginsenoside CK inhibits obese insulin resistance by activating PPARγ to interfere with macrophage activation

Obesity is often accompanied by chronic low-grade inflammation, which aggravates the disorder of lipid metabolism and leads to insulin resistance (IR). Macrophage activation plays an important role in inflammation. Ginsenoside Compound K (CK) is an active metabolite of ginsenoside Rb1, which is adopting to an anti-inflammatory effective substance. In order to clarify the mechanism of ginsenoside CK on the regulation of macrophage activation in adipose tissue, the macrophage model was incubated with the supernatant of hypertrophic adipocytes, and the co-culture models of Raw264.7 and 3T3-L1 were established. The levels of related cytokines, macrophage polarization and protein expression in inflammatory signaling pathway were measured. The results showed that ginsenoside CK significantly inhibited the increase of MCP-1 and TNF-α induced by the supernatant of hypertrophic adipocytes, promoted the expression of IL-10, inhibited the activation of inflammatory macrophages and increased the expression of anti-inflammatory macrophages. Similarly, ginsenoside CK inhibited the migration of Raw264.7, blocked the activation of NF-κB, and up-regulated the expression of PPARγ. In addition, ginsenoside CK also promotes the expression of IRS-1 in insulin signal pathway. The experimental results proved that ginsenoside CK plays a crucial role in alleviating inflammation and insulin resistance in obesity, and inhibits macrophage activation through the key protein PPARγ.

Total Saponins Isolated from Corni Fructus via Ultrasonic Microwave-Assisted Extraction Attenuate Diabetes in Mice

Saponins have been extensively used in the food and pharmaceutical industries because of their potent bioactive and pharmacological functions including hypolipidemic, anti-inflammatory, expectorant, antiulcer and androgenic properties. A lot of saponins-containing foods are recommended as nutritional supplements for diabetic patients. As a medicine and food homologous material, Corni Fructus (CF) contains various active ingredients and has the effect of treating diabetes. However, whether and how CF saponins attenuate diabetes is still largely unknown. Here, we isolated total saponins from CF (TSCF) using ultrasonic microwave-assisted extraction combined with response surface methodology. The extract was further purified by a nonpolar copolymer styrene type macroporous resin (HPD-300), with the yield of TSCF elevated to 13.96 mg/g compared to 10.87 mg/g obtained via unassisted extraction. When used to treat high-fat diet and streptozotocin-induced diabetic mice, TSCF significantly improved the glucose and lipid metabolisms of T2DM mice. Additionally, TSCF clearly ameliorated inflammation and oxidative stress as well as pancreas and liver damages in the diabetic mice. Mechanistically, TSCF potently regulated insulin receptor (INSR)-, glucose transporter 4 (GLUT4)-, phosphatidylinositol 3-kinase (PI3K)-, and protein kinase B (PKB/AKT)-associated signaling pathways. Thus, our data collectively demonstrated that TSCF could be a promising functional food ingredient for diabetes improvement.

Effects of screw configuration on chemical properties and ginsenosides content of extruded ginseng

BACKGROUND

The purpose of this study was to investigate the effects of screw configuration on chemical properties and ginsenosides content of extruded ginseng and to select the most suitable screw configuration for the processing of ginseng.

METHOD

The extrusion conditions were set as follows: moisture content (20%), barrel temperature (140°C), screw speed (200 rpm), and feeding rate (100 g/min).

RESULT

The extruded ginseng of screw configuration 6 has the highest DPPH free radical scavenging rate, reducing power and total phenol, which is the most suitable configuration for the development of ginseng extract products. In addition, the extruded ginseng of screw configuration 9 has the highest content of total saponin, and the content of rare ginsenoside Rg3 which is scarcely present in the ginseng raw material powder was significantly increased. This intended that twin-screw extrusion process enables the mutual conversion between ginsenosides and rare ginsenoside Rg3 had achieved.

CONCLUSION

The extrusion process promotes the development and utilization of ginseng and provides theoretical basis for the design and development of screw configuration of twin-screw extruded ginseng.

Herbal Medicine for Slowing Aging and Aging-associated Conditions: Efficacy, Mechanisms and Safety

Aging and aging-associated diseases are issues with unsatisfactory answers in the medical field. Aging causes important physical changes which, even in the absence of the usual risk factors, render the cardiovascular system prone to some diseases. Although aging cannot be prevented, slowing down the rate of aging is entirely possible to achieve. In some traditional medicine, medicinal herbs such as Ginseng, Radix Astragali, Ganoderma lucidum, Ginkgo biloba, and Gynostemma pentaphyllum are recognized by the "nourishing of life" and their role as anti-aging phytotherapeutics is increasingly gaining attention. By mainly employing PubMed here we identify and critically analysed 30 years of published studies focusing on the above herbs' active components against aging and aging-associated conditions. Although many plant-based compounds appear to exert an anti-aging effect, the most effective resulted in being flavonoids, terpenoids, saponins, and polysaccharides, which include astragaloside, ginkgolide, ginsenoside, and gypenoside specifically covered in this review. Their effects as antiaging factors, improvers of cognitive impairments, and reducers of cardiovascular risks are described, as well as the molecular mechanisms underlying the above-mentioned effects along with their potential safety. Telomere and telomerase, PPAR-α, GLUTs, FOXO1, caspase-3, bcl-2, along with SIRT1/AMPK, PI3K/Akt, NF-κB, and insulin/insulin-like growth factor-1 pathways appear to be their preferential targets. Moreover, their ability to work as antioxidants and to improve the resistance to DNA damage is also discussed. Although our literature review indicates that these traditional herbal medicines are safe, tolerable, and free of toxic effects, additional well-designed, large-scale randomized control trials need to be performed to evaluate short- and long-term effects and efficacy of these medicinal herbs.

Remote ischemic conditioning: A potential therapeutic strategy of type 2 diabetes

Type 2 diabetes (T2D) is one of the major public diseases which is characterized by peripheral insulin resistance (IR) and progressive pancreatic β-cell failure. While in the past few years, some new factors, such as inflammation, oxidative stress, immune responses and other potential pathways, have been identified to play critical roles in T2D, and thereby provide novel promising targets for the treatment of T2D. Remote ischemic conditioning (RIC) is a non-invasive and convenient operation performed by transient, repeated ischemia in distant place. Nowadays, RIC has been established as a potentially powerful therapeutic tool for many diseases, especially in I/R injuries. Through activating a series of neural, humoral and immune pathways, it can release multiple protective signals, which then regulating inflammation, oxidative stress, immune response and so on. Interestingly, several recent studies have discovered that the beneficial effects of RIC on I/R injuries might be abolished by T2D, wherein the higher basal levels of inflammation and oxidative stress, dysregulation of immune system and some potential pathways secondary to hyperglycemia may play critical roles. In contrast, a higher intensity of conditioning could restore the protective effects. Based on the overlapped mechanisms RIC and T2D performs, we provide a hypothesis that RIC may also play a protective role in T2D via targeting these signaling pathways.

The ginsenoside metabolite compound K stimulates glucagon-like peptide-1 secretion in NCI-H716 cells by regulating the RhoA/ROCKs/YAP signaling pathway and cytoskeleton formation

Ginsenoside Rb1 has been shown to have antidiabetic and anti-inflammatory effects. Its major metabolite, compound K (CK), can stimulate the secretion of glucagon-like peptide-1 (GLP1), a gastrointestinal hormone that plays a vital role in regulating glucose metabolism. However, the mechanism underlying the regulation of GLP1 secretion by compound K has not been fully explored. This study was designed to investigate whether CK ameliorates incretin impairment by regulating the RhoA/ROCKs/YAP signaling pathway and cytoskeleton formation in NCI-H716 cells. Using NCI-H716 cells as a model cell line for GLP1 secretion, we analyzed the effect of CK on the expression of RhoA/ROCK/YAP pathway components. Our results suggest that the effect of CK on GLP1 secretion depends on the anti-inflammatory effect of CK. We also demonstrated that CK can affect the RhoA/ROCK/YAP pathway, which is downstream of transforming growth factor β1 (TGFβ1), by maintaining the capacity of intestinal differentiation. In addition, this effect was mediated by regulating F/G-actin dynamics. These results provide not only the mechanistic insight for the effect of CK on intestinal L cells but also the molecular basis for the further development of CK as a potential therapeutic agent to treat type 2 diabetes mellitus (T2D).

Oligostilbenes extracts from Iris lactea Pall. var. chinensis (Fisch.) Koidz improve lipid metabolism in HFD/STZ-induced diabetic mice and inhibit adipogenesis in 3T3-L1 cells

The present study investigated the anti-diabetic effects of Oligostilbenes extracts (Olie) from Iris lactea Pall. var. chinensis (Fisch.) Koidz (I. lactea) and the potential mechanisms, in high-fat-diet (HFD)-induced diabetic mice and 3T3-L1 adipocytes. Olie are a group of major active extracts from I. lactea that have been used as nutraceutical because of their antioxidant activity. Six-week Olie treatment improved fasting blood glucose levels, as well as blood lipid profiles in HFD/streptozocin (STZ)-induced diabetic mice, compared with non-treated mice. Olie treatment upregulated the levels of phosphorylated of AMPK and lipolysis-related proteins, while the hepatic expression of ACC and FAS in diabetic mice was inhibited. In cultured 3T3-L1 cells, Olie (2-15 μg/mL) treatment dose-dependently suppressed the differentiation into mature adipocytes and lowered cellular lipid accumulation. Consistently, Olie reduced expression of adipogenic transcription factors including CCAAT/enhancer-binding protein β (C/EBPβ) and peroxisome proliferator-activated receptor γ (PPARγ). In addition, mitochondrial function in 3T3-L1 adipocytes was improved after Olie treatment. Taken together, our findings indicate that a lipid-lowering effect of Olie in HFD/STZ-induced diabetic mice and adipogenesis/ lipogenesis suppressing effect in 3T3-L1 cells, via regulating the expression of lipid metabolism-related proteins.

Dammarane-type leads panaxadiol and protopanaxadiol for drug discovery: Biological activity and structural modification

Based on the definite therapeutic benefits, such as neuroprotective, cardioprotective, anticancer, anti-diabetic and so on, the Panax genus which contains many valuable plants, including ginseng (Panax ginseng C.A. Meyer), notoginseng (Panax notoginseng) and American ginseng (Panax quinquefolius L.), attracts research focus. Actually, the biological and pharmacological effects of the Panax genus are mainly attributed to the abundant ginsenosides. However, the low membrane permeability and the gastrointestinal tract influence seriously limit the absorption and bioavailability of ginsenosides. The acid or base hydrolysates of ginsenosides, 20 (R,S)-panaxadiol and 20 (R,S)-protopanaxadiol showed improved bioavailability and diverse pharmacological activities. Moreover, relative stable skeletons and active hydroxyl group at C-3 position and other reactive sites are suitable for structural modification to improve biological activities. In this review, the pharmacological activities of panaxadiol, protopanaxadiol and their structurally modified derivatives are comprehensively summarized.

Enhancement of glucose homeostasis through the PI3K/Akt signaling pathway by dietary with Agaricus blazei Murrill in STZ-induced diabetic rats

Agaricus blazei Murrill (ABM) is an edible fungus. This study investigated the protective role of ABM fruiting body against streptozotocin (STZ)-induced diabetic rats. After 4 weeks of ABM supplement, glucose homeostasis was improved in diabetic rats. Quantitative real-time and Western blot analyses suggested that ABM could promote the gene and protein expression level of insulin receptor, pyruvate dehydrogenase kinase, phospho-kinase B, kinase B, phosphatidylinositol 3-kinase, insulin receptor substrate 1, glucose transporter-4, and glutamine synthetase, while inhibiting the expression of glycogen synthase kinase 3β and c-jun N-terminal kinase 1 and 2. According to multivariate and univariate statistical analysis, liver metabolite profiles of the normal and diabetic rats fed basal and experimental diet were clearly separated. The differential liver metabolites from diabetic rats fed basal and ABM diet-related pathways including the glycolysis pathway, pentose phosphate pathway, tricarboxylic acid cycle, and oxidative phosphorylation were analyzed. A total of 18 potential biomarker metabolites were identified as differential biomarkers associated with ABM supplement diet.

Purification of ginseng rare sapogenins 25-OH-PPT and its hypoglycemic, antiinflammatory and lipid-lowering mechanisms

Background

Panax ginseng Meyer has been used as a nourishing edible herb in East Asia for thousands of years. 25-OH-PPT was first discovered as a natural rare triterpenoid saponin in ginseng stems and leaves by our group. Research found that it showed strong inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, and protected cardiocytes (H9c2) through PI3K/Akt pathway.

Methods

In the research, in order to optimize the 25-OH-PPT enrichment process, optimal macroporous resins and optimal purification conditions were studied. Meanwhile, the hypoglycemic effect and mechanism of 25-OH-PPT were evaluated by using STZ to establish insulin-dependent diabetic mice and the spontaneous type 2 diabetes DB/DB mice.

Results and Conclusion

Research found that 25-OH-PPT can reduce blood glucose and enhance glucose tolerance in STZ model mice. It increases insulin sensitivity by upregulating GLUT4 and AMPK in skeletal muscle, and activating insulin signaling pathways. In DB/DB mice, 25-OH-PPT achieves hypoglycemic effects mainly by activating the insulin signaling pathway. Meanwhile, through the influence of liver inflammatory factors and lipids in serum, it can be seen that 25-OH-PPT has obvious anti-inflammatory and lipid-lowering effects. These results provide new insights into the study of ginseng as a functional food.

Tetramethylpyrazine alleviates diabetic nephropathy through the activation of Akt signalling pathway in rats

In the whole world, the principal cause of end-stage renal disease is diabetic nephropathy (DN), which is one of the most relentless complications of diabetes. However, there is a shortfall of compelling DN treatments and the mechanism potentially able to alleviate renal injury remains ambiguous. In this experiment, we estimated the preventive actions of tetramethylpyrazine (TMP) on DN in rats and further investigated the underlying mechanism. The different doses of TMP (100 mg/kg, 150 mg/kg and 200 mg/kg) were orally given each day for 8 weeks in streptozotocin (STZ) - nicotinamide (NCT) - induced type-2 diabetic (T2D) rats. The metabolic parameters of diabetes, blood urea nitrogen (BUN), serum creatinine (SCR), urinary protein and oxidative stress parameters were assessed. Microstructural changes in kidney were observed, and the expression of Akt signalling pathway proteins was measured by western blotting. TMP administration in T2D rats improved diabetic condition, as demonstrated by significant (P < 0.05) increase of body weight and fasting serum insulin (FSI) level, reduction of fasting blood glucose (FBG) and glycosylated haemoglobin (HbA1c) level and regulation of lipid profile and oral glucose tolerance in a dose-dependent manner. TMP treatment also reduced BUN, SCR, urinary protein and oxidative stress and prevented renal injury in diabetic rats. TMP activated Akt signalling pathway, increased the levels of p-Akt and Bcl-2, and diminished the expressions of p-GSK-3β, Bax and cleaved caspase-3. In conclusion, TMP ameliorates diabetic nephropathy in T2D rats by initiating the Akt signalling, improving the metabolic markers of diabetes and suppressing oxidative stress.

Natural Hydrogen Sulfide Donors from Allium sp. as a Nutraceutical Approach in Type 2 Diabetes Prevention and Therapy

Type 2 diabetes mellitus (DM) is a socially relevant chronic disease with high prevalence worldwide. DM may lead to several vascular, macrovascular, and microvascular complications (cerebrovascular, coronary artery, and peripheral arterial diseases, retinopathy, neuropathy, and nephropathy), often accelerating the progression of atherosclerosis. Dietary therapy is generally considered to be the first step in the treatment of diabetic patients. Among the current therapeutic options, such as insulin therapy and hypoglycemic drugs, in recent years, attention has been shifting to the effects and properties-that are still not completely known-of medicinal plants as valid and inexpensive therapeutic supports with limited side effects. In this review, we report the relevant effects of medicinal plants and nutraceuticals in diabetes. In particular, we paid attention to the organosulfur compounds (OSCs) present in plant extracts that due to their antioxidant, hypoglycemic, anti-inflammatory, and immunomodulatory effects, can contribute as cardioprotective agents in type 2 DM. OSCs derived from garlic (Allium sp.), due to their properties, can represent a valuable support to the diet in type 2 DM, as outlined in this manuscript based on both in vitro and in vivo studies. Moreover, a relevant characteristic of garlic OSCs is their ability to produce the gasotransmitter H₂S, and many of their effects can be explained by this property. Indeed, in recent years, several studies have demonstrated the relevant effects of endogenous and exogenous H₂S in human DM, including by in vitro and in vivo experiments and clinical trials; therefore, here, we summarize the effects and the underlying molecular mechanisms of H₂S and natural H₂S donors.

Autophagy and its regulation by ginseng components

Autophagy is the sequential process whereby cell components are degraded, which can occur due to nutrient deprivation. Its regulation has an essential role in many diseases, functioning in both cell survival and cell death. Autophagy starts when mTORC1 is inhibited, resulting in the activation of several complexes to form a cargo that fuses with a lysosome, where it undergoes degradation. In this review, we describe a plant extract that is well known in Korea, namely Korean ginseng extract; we studied how its derivatives and metabolites can regulate autophagy and thus mediate the pathogenesis of certain diseases.

Phenolic Compounds and Ginsenosides in Ginseng Shoots and Their Antioxidant and Anti-Inflammatory Capacities in LPS-Induced RAW264.7 Mouse Macrophages

We conducted this study for the first time to evaluate changes in the composition and contents of phenolic compounds and ginsenosides in ginseng shoot extracts (GSEs) prepared with different steaming times (2, 4, and 6 h) at 120 °C, as well as their antioxidant and anti-inflammatory activities in lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophages (RAW264.7 cells). The results show that total phenol and flavonoid contents were both significantly higher in steamed versus raw GSEs, and the same trend was found for 2,2'-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) scavenging capacities. Among the 18 ginsenosides quantified using high-performance liquid chromatography (HPLC) with the aid of pure standards, polar ginsenosides were abundant in raw GSEs, whereas less-polar or rare ginsenosides appeared after steaming at 120 °C and increased with steaming time. Furthermore, steamed GSEs exhibited a greater ability to inhibit the production of inflammatory mediators and pro-inflammatory cytokines, such as nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)-α in LPS-induced RAW264.7 cells at the same concentration. Relative expression levels of inducible nitric oxide synthase (iNOS), IL-6, TNF-α, and cyclooxygenase-2 (COX-2) mRNAs were attenuated by the GSEs, probably due to the enrichment of less-polar ginsenosides and enhanced antioxidant activity in steamed GSEs. These findings, combined with correlation analysis, showed that less-polar ginsenosides were major contributors to the inhibition of the overproduction of various inflammatory factors, while the inhibitory effects of total phenols and total flavonoids, and their antioxidant abilities, are also important.

Correlations between Insulin Receptor Substrate-1 with Phosphoinositide 3-Kinase and P38 Mitogen-Activated Protein Kinase Levels after Treatment of Diabetic Rats with Puguntano (Curanga Fel-Terrae [Merr.]) Leaf Extract

BACKGROUND

Defects in post-receptor insulin signalling are the major cause of insulin resistance in type 2 diabetes mellitus (T2DM).

AIM

This study aimed to investigate the correlations between insulin receptor substrate (IRS)-1 with phosphoinositide 3-kinase (PI3K) and p38 mitogen-activated protein kinase (MAPK) levels after puguntano (Curanga fel-terrae [Merr.]) leaf extract treatment in a rat model of T2DM.

METHODS

A combination of high-fat diet-feeding (HFD) and multiple low dose intraperitoneal injections of streptozotocin was used to induced T2DM in 48 Wistar rats, which were then randomly divided into control and treatment groups (n = 24 per group). Puguntano leaf extract was administered to the treatment group once daily (200 mg/kg.bw) for 10 days. IRS-1, PI3K and p38 MAPK levels were measured in skeletal muscle using sandwich ELISAs in control group after becoming T2DM and in the treatment group after 10 days of puguntano treatment. Data were analysed using the Wilcoxon test and Spearman's correlation.

RESULTS

IRS-1, PI3K and p38 MAPK levels were significantly higher in the treatment group than in the control group. There were also significant positive correlations between IRS-1 with PI3K and p38 MAPK levels (r = 0.375, p = 0.035; r = 0.552, p = 0.003; respectively) after the treatment.

CONCLUSION

This study demonstrated significant positive correlations between IRS-1 with PI3K and p38 MAPK levels after puguntano leaf extract treatment of T2DM rats.

The Effect of Puguntano Leaf Extract (Curanga Fel - Terrae Merr.) On P38 Mapk Levels and Glut-4 Expression in Type 2 Diabetic Rat Muscle

BACKGROUND

Puguntano (Curanga feel-terrae Merr.) contains flavonoids, saponins, tannins, and steroids/ terpenoids which improved post-receptor insulin signalling in rats model of type 2 diabetes mellitus (T2DM).

AIM

This study aimed to determine the effect of puguntano leaf extract on p38 mitogen-activated protein kinase (MAPK) levels and glucose transporter-4 (GLUT-4) expression in diabetic rats muscle.

METHODS

Forty-eight male Wistar rats had T2DM induced using a combination of feeding a high-fat diet for 5 weeks and multiple intraperitoneal injections of low-dose streptozotocin (30 mg/kg). The diabetic rats were randomly divided into control and treatment groups, and 200 mg/kg/day puguntano extract was administered orally for 10 days to treatment group. Subsequently, p38 MAPK levels were measured by Sandwich Elisa and plasma membrane GLUT-4 expression was evaluated by Immunohistochemistry in their gastrocnemius muscles.

RESULTS

There were significantly higher p38 MAPK levels and GLUT-4 expression in the treatment group than in the control group.

CONCLUSION

These data suggest that a puguntano leaf extract can improve post-receptor insulin signalling by enhancing p38 MAPK levels and GLUT-4 expression in a rat model of T2DM.

Ginsenoside compound K attenuates cognitive deficits in vascular dementia rats by reducing the Aβ deposition

Ginsenoside compound K (CK) is the main metabolite of protopanaxadiol-type ginsenosides and has been demonstrated to exert neuroprotective and cognition-enhancing effects. The effects of CK on cognitive function in vascular dementia (VD) has not been elucidated. Therefore, the present study aims to elucidate the effects of CK on memory function as well as its potential mechanism in VD rats. Sprague-Dawley rats were subjected to Chronic Cerebral Hypoperfusion (CCH) by permanent bilateral common carotid artery occlusion (2VO). CCH induced neuronal damage and aggravated the aggregation of Amyloid-β_1-42 peptides (Aβ_1-42), which plays a critical role in the neurotoxicity and cognitive impairment. CK treatment attenuated CCH-induced Aβ_1-42 deposition and ameliorated cognition impairment. Furthermore, CK enhanced the activity of the pSer9-Glycogen synthase kinase 3β (pSer9-GSK3β) and the insulin degrading enzyme (IDE), which mainly involved the production and clearance of Aβ_1-42. Moreover, CK treatment enhanced the activity of protein kinase B (PKB/Akt), a key kinase in phosphatidylinositol 3 kinase (PI3K)/Akt pathway that can regulate the activity of GSK-3β and IDE. In short, our findings provide the first evidence that CK might attenuate cognitive deficits and Aβ_1-42 deposition in the hippocampus via enhancing the expression of pSer9-GSK-3β and IDE.

Ginseng for the treatment of diabetes and diabetes-related cardiovascular complications: a discussion of the evidence 1

Diabetes mellitus (DM) is a chronic metabolic disorder associated with elevated blood glucose levels due either to insufficient insulin production (type 1 DM) or to insulin resistance (type 2 DM). The incidence of DM around the world continues to rise dramatically with more than 400 million cases reported today. Among the most serious consequences of chronic DM are cardiovascular complications that can have deleterious effects. Although numerous treatment options are available, including both pharmacological and nonpharmacological, there is substantial emerging interest in the use of traditional medicines for the treatment of this condition and its complications. Among these is ginseng, a medicinal herb that belongs to the genus Panax and has been used for thousands of years as a medicinal agent especially in Asian cultures. There is emerging evidence from both animal and clinical studies that ginseng, ginseng constituents including ginsenosides, and ginseng-containing formulations can produce beneficial effects in terms of normalization of blood glucose levels and attenuation of cardiovascular complications through a multiplicity of mechanisms. Although more research is required, ginseng may offer a useful therapy for the treatment of diabetes as well as its complications.

Effects of Aerobic Exercise Combined with Panaxatriol Derived from Ginseng on Insulin Resistance and Skeletal Muscle Mass in Type 2 Diabetic Mice

Insulin resistance reduces insulin-induced muscle protein synthesis and accelerates muscle protein degradation. Ginseng ingestion has been reported to improve insulin resistance through the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. We hypothesized that panaxatriol (PT) derived from ginseng in combination with aerobic exercise (EX) may further promote protein synthesis and suppress protein degradation, and subsequently maintain muscle mass through the amelioration of insulin resistance. KKAy insulin-resistant mice were divided into control, panaxatriol only (PT), exercise only (EX), and EX+PT groups. EX and EX+PT ran on the treadmill for 45 min at 15 m/min 5 d/wk for 6 wk. PT and EX+PT groups were fed a standard diet containing 0.2% PT for 6 wk. Homeostasis model assessment for insulin resistance (HOMA-R) values was significantly improved after exercise for 6 wk. Moreover, EX+PT mice showed improved HOMA-R as compared to EX mice. p70S6K phosphorylation after a 4 h fast was significantly higher in EX than in the non-exercise control, and it was higher in EX+PT mice than in EX mice. Atrogin1 mRNA expression was significantly lower in EX than in the non-exercise control, and was significantly lowered further by PT treatment. EX and EX+PT mice showed higher soleus muscle mass and cross-sectional area (CSA) of the soleus myofibers than control animals, with higher values noted for both parameters in EX+PT than in EX. These results suggest that aerobic exercise and PT ingestion may contribute to maintain skeletal muscle mass through the amelioration of insulin resistance.

Therapeutic Potential of Ginsenosides as an Adjuvant Treatment for Diabetes

Ginseng, one of the oldest traditional Chinese medicinal herbs, has been used widely in China and Asia for thousands of years. Ginsenosides extracted from ginseng, which is derived from the roots and rhizomes of Panax ginseng C. A. Meyer, have been used in China as an adjuvant in the treatment of diabetes mellitus. Owing to the technical complexity of ginsenoside production, the total ginsenosides are generally extracted. Accumulating evidence has shown that ginsenosides exert antidiabetic effects. In vivo and in vitro tests revealed the potential of ginsenoside Rg1, Rg3, Rg5, Rb1, Rb2, Rb3, compound K, Rk1, Re, ginseng total saponins, malonyl ginsenosides, Rd, Rh2, F2, protopanaxadiol (PPD) and protopanaxatriol (PPT)-type saponins to treat diabetes and its complications, including type 1 diabetes mellitus, type 2 diabetes mellitus, diabetic nephropathy, diabetic cognitive dysfunction, type 2 diabetes mellitus with fatty liver disease, diabetic cerebral infarction, diabetic cardiomyopathy, and diabetic erectile dysfunction. Many effects are attributed to ginsenosides, including gluconeogenesis reduction, improvement of insulin resistance, glucose transport, insulinotropic action, islet cell protection, hepatoprotective activity, anti-inflammatory effect, myocardial protection, lipid regulation, improvement of glucose tolerance, antioxidation, improvement of erectile dysfunction, regulation of gut flora metabolism, neuroprotection, anti-angiopathy, anti-neurotoxic effects, immunosuppression, and renoprotection effect. The molecular targets of these effects mainly contains GLUTs, SGLT1, GLP-1, FoxO1, TNF-α, IL-6, caspase-3, bcl-2, MDA, SOD, STAT5-PPAR gamma pathway, PI3K/Akt pathway, AMPK-JNK pathway, NF-κB pathway, and endoplasmic reticulum stress. Rg1, Rg3, Rb1, and compound K demonstrated the most promising therapeutic prospects as potential adjuvant medicines for the treatment of diabetes. This paper highlights the underlying pharmacological mechanisms of the anti-diabetic effects of ginsenosides.

Ameliorative effects of ginseng and ginsenosides on rheumatic diseases

Background

Inflammation is a host-defensive innate immune response to protect the body from pathogenic agents and danger signals induced by cellular changes. Although inflammation is a host-defense mechanism, chronic inflammation is considered a major risk factor for the development of a variety of inflammatory autoimmune diseases, such as rheumatic diseases. Rheumatic diseases are systemic inflammatory and degenerative diseases that primarily affect connective tissues and are characterized by severe chronic inflammation and degeneration of connective tissues. Ginseng and its bioactive ingredients, genocides, have been demonstrated to have antiinflammatory activity and pharmacological effects on various rheumatic diseases by inhibiting the expression and production of inflammatory mediators.

Methods

Literature in this review was searched in a PubMed site of National Center for Biotechnology Information.

Results

The studies reporting the preventive and therapeutic effects of ginseng and ginsenosides on the pathogenesis of rheumatic diseases were discussed and summarized.

Conclusion

Ginseng and ginsenosides play an ameliorative role on rheumatic diseases, and this review provides new insights into ginseng and ginsenosides as promising agents to prevent and treat rheumatic diseases.

Glutamine Enhances the Hypoglycemic Effect of Insulin in L6 Cells via Phosphatidylinositol-3-Kinase (PI3K)/Protein Kinase B (AKT)/Glucose Transporter 4 (GLUT4) Signaling Pathway

Background

Diabetes mellitus (DM) is characterized by a decreased blood level of glutamine (Gln), which may contribute to the disturbance in the effect of insulin on skeletal muscle. Therefore, it is crucial to study how to improve the effect of insulin on skeletal muscle by increasing Gln. In the present study, we investigated the effect of Gln on the hypoglycemic action of insulin in skeletal muscle L6 cells at high glucose levels through the insulin signaling pathway and glycogen synthesis pathway.

Material/Methods

The L6 cells were cultured in and stimulated by Gln and insulin. The glutamine analogue, L-Gamma-Glutamyl-p-nitroanilide (GPNA), was used for verifying the effect of Gln. The expression of insulin signaling molecules, including phosphatidylinositol-3-kinase (PI3K), 3-phosphoinositide-dependent protein kinase-1 (PDK1), protein kinase B (AKT), protein kinase C zeta (PKCζ), and glucose transporter 4 (GLUT4), were detected by real-time PCR and Western blot analysis, GLUT4 translocation was observed by immunofluorescence staining, glycogen synthase kinase (GSK) was analyzed by Western blotting, and glucose uptake was measured by glucose oxidase method (GOD).

Results

The results demonstrated that Gln combined with insulin remarkably up-regulated PI3K and PDK1 and also increased AKT and PKCζ phosphorylation. The present study shows that Gln enhanced the impact of insulin on GLUT4 and its translocation. The results of glucose uptake and GSK phosphorylation further confirmed the hypoglycemic effect of Gln accompanied with insulin. The hypoglycemic effect of Gln was reversed by GPNA.

Conclusions

These findings suggest that Gln enhances the hypoglycemic role of insulin through the PI3K/AKT/GLUT4 signaling pathway and glycogen synthesis pathway.

Isolation and Quantification of Ginsenoside Rh23, a New Anti-Melanogenic Compound from the Leaves of Panax ginseng

A new ginsenoside, named ginsenoside Rh23 (1), and 20-O-β-d-glucopyranosyl-3β,6α,12β,20β,25-pentahydroxydammar-23-ene (2) were isolated from the leaves of hydroponic Panax ginseng. Compounds were isolated by various column chromatography and their structures were determined based on spectroscopic methods, including high resolution quadrupole/time of flight mass spectrometry (HR-QTOF/MS), nuclear magnetic resonance (NMR) spectroscopy, and infrared (IR) spectroscopy. To determine anti-melanogenic activity, the change in the melanin content in melan-a cells treated with identified compounds was tested. Additionally, we investigated the melanin inhibitory effects of ginsenoside Rh23 on pigmentation in a zebrafish in vivo model. Compound 1 inhibited potent melanogenesis in melan-a cells with 37.0% melanogenesis inhibition at 80 µM and also presented inhibition on the body pigmentation in zebrafish model. Although compound 2 showed slightly lower inhibitory activity than compound 1, it also showed significantly decreased melanogenesis in melan-a cell and in zebrafish model. These results indicated that compounds isolated from hydroponic P. ginseng may be used as new skin whitening compound through the in vitro and in vivo systems. Furthermore, this study demonstrated the utility of MS-based compound 1 for the quantitative analysis. Ginsenoside Rh23 (1) was found at a level of 0.31 mg/g in leaves of hydroponic P. ginseng.

Phytotherapy in the Management of Diabetes: A Review

Phytotherapy has long been a source of medicinal products and over the years there have been many attempts to use herbal medicines for the treatment of diabetes. Several medicinal plants and their preparations have been demonstrated to act at key points of glucidic metabolism. The most common mechanisms of action found include the inhibition of α-glucosidase and of AGE formation, the increase of GLUT-4 and PPARs expression and antioxidant activity. Despite the large amount of literature available, the actual clinical effectiveness of medicinal plants in controlling diabetes-related symptoms remains controversial and there is a crucial need for stronger evidence-based data. In this review, an overview of the medicinal plants, which use in the management of diabetes is supported by authoritative monographs, is provided. References to some species which are currently under increasing clinical investigation are also reported.

Fermented ginseng, GBCK25, ameliorates steatosis and inflammation in nonalcoholic steatohepatitis model

Background

Nonalcoholic steatohepatitis (NASH) is one of the chronic inflammatory liver diseases and a leading cause of advanced liver fibrosis, cirrhosis, and hepatocellular carcinoma. The main purpose of this study was to clarify the effects of GBCK25 fermented by Saccharomyces servazzii GB-07 and pectinase, on NASH severity in mice.

Methods

Six-wk-old male mice were fed either a normal diet (ND) or a Western diet (WD) for 12 wks to induce NASH. Each group was orally administered with vehicle or GBCK25 once daily at a dose of 10 mg/kg, 20 mg/kg, 100 mg/kg, 200 mg/kg, or 400 mg/kg during that time. The effects of GBCK25 on cellular damage and inflammation were determined by in vitro experiments.

Results

Histopathologic analysis and hepatic/serum biochemical levels revealed that WD-fed mice showed severe steatosis and liver injury compared to ND-fed mice. Such lesions were significantly decreased in the livers of WD-fed mice with GBCK25 administration. Consistently, mRNA expression levels of NASH-related inflammatory-, fibrogenic-, and lipid metabolism-related genes were decreased in the livers of WD-fed mice administered with GBCK25 compared to WD-fed mice. Western blot analysis revealed decreased protein levels of cytochrome P450 2E1 (CYP2E1) with concomitantly reduced activation of c-Jun N-terminal kinase (JNK) in the livers of WD-fed mice administered with GBCK25. Also, decreased cellular damage and inflammation were observed in alpha mouse liver 12 (AML12) cells and RAW264.7 cells, respectively.

Conclusion

Administration of GBCK25 ameliorates NASH severity through the modulation of CYP2E1 and its associated JNK-mediated cellular damage. GBCK25 could be a potentially effective prophylactic strategy to prevent metabolic diseases including NASH.

Effects of Lactobacillus casei CCFM419 on insulin resistance and gut microbiota in type 2 diabetic mice

The antidiabetic effect of Lactobacillus is increasingly recognized worldwide. In this research, the hypoglycemic activity of Lactobacillus casei CCFM419 was investigated in mice with high-fat and low-dose streptozotocin induced type 2 diabetes. Oral L. casei CCFM419 administration favourably regulated blood glucose balance, increased glucose tolerance and protected islets in the diabetic mice, accompanied by an improvement in lipid metabolism. The homeostasis model of insulin resistance, insulin level and insulin tolerance test and mRNA expression of PI3K/Akt signalling pathway indexes revealed that L. casei CCFM419 had a positive effect on insulin resistance. Furthermore, treatment with L. casei CCFM419 recovered the level of short-chain fatty acids and increased the abundance of butyrate-producing bacteria, such as Allobaculum and Bacteriodes. These results demonstrated that L. casei CCFM419 had the potential ability to ameliorate insulin resistance and hyperglycaemic in type 2 diabetic mice through underlying PI3K/Akt signalling pathway and short-chain fatty acids/gut microbiota pathways.

Bridging Type 2 Diabetes and Alzheimer's Disease: Assembling the Puzzle Pieces in the Quest for the Molecules With Therapeutic and Preventive Potential

Type 2 diabetes (T2D) and Alzheimer's disease (AD) are two age-related amyloid diseases that affect millions of people worldwide. Broadly supported by epidemiological data, the higher incidence of AD among type 2 diabetic patients led to the recognition of T2D as a tangible risk factor for the development of AD. Indeed, there is now growing evidence on brain structural and functional abnormalities arising from brain insulin resistance and deficiency, ultimately highlighting the need for new approaches capable of preventing the development of AD in type 2 diabetic patients. This review provides an update on overlapping pathophysiological mechanisms and pathways in T2D and AD, such as amyloidogenic events, oxidative stress, endothelial dysfunction, aberrant enzymatic activity, and even shared genetic background. These events will be presented as puzzle pieces put together, thus establishing potential therapeutic targets for drug discovery and development against T2D and diabetes-induced cognitive decline-a heavyweight contributor to the increasing incidence of dementia in developed countries. Hoping to pave the way in this direction, we will present some of the most promising and well-studied drug leads with potential against both pathologies, including their respective bioactivity reports, mechanisms of action, and structure-activity relationships.