Fructus Corni suppresses hepatic gluconeogenesis related gene transcription, enhances glucose responsiveness of pancreatic beta-cells, and prevents toxin induced beta-cell death

Loganin reduces diabetic kidney injury by inhibiting the activation of NLRP3 inflammasome-mediated pyroptosis

Diabetic kidney disease (DKD) is an essential cause of end-stage renal disease. The ongoing inflammatory response in the proximal tubule promotes the progression of DKD. Timely and effective blockade of the inflammatory process to protect the kidney during DKD progression is a proven strategy. The purpose of this study was to investigate the protective effect of loganin on diabetic nephropathy in vivo and in vitro and whether this effect was related to the inhibition of pyroptosis. The results indicated that loganin reduced fasting blood glucose, blood urea nitrogen and serum creatinine concentrations, and alleviated renal pathological changes in DKD mice. In parallel, loganin downregulated the expression of pyroptosis related proteins in the renal tubules of DKD mice and decreased serum levels of interleukin-1beta (IL-1β) and interleukin-18 (IL-18). Furthermore, in vitro experiments showed that loganin attenuated high glucose-induced HK-2 cell injury by reducing the expression of pyroptosis-related proteins, and cytokine levels were also decreased. These fundings were also confirmed in the polyphyllin VI (PPVI) -induced HK-2 cell pyroptosis model. Loganin reduces high glucose induced HK-2 cells pyroptosis by inhibiting reactive oxygen species (ROS) production and NOD-like receptor protein 3 (NLRP3) inflammasome activation. In conclusion, the inhibition of pyroptosis via inhibition of the NLRP3/Caspase-1/Gasdermin D (GSDMD) pathway might be an essential mechanism for loganin treatment of DKD.

Diterpenoids and Their Glycosides from the Stems of Tinospora crispa with Beta-Cell Protective Activity

Seven previously undescribed diterpenoids, tinocrisposides A-D (1-4) and borapetic acids A (5), B (6), and C (7), together with 16 known compounds, were isolated from the stem of Tinospora crispa (Menispermaceae). The structures of the new isolates were elucidated by spectroscopic and chemical methods. The β-cell protective effect of the tested compounds was examined on insulin-secreting BRIN-BD11 cells under dexamethasone treatment. Diterpene glycosides 12, 14-16, and 18 presented a substantial protective effect on BRIN-BD11 cells treated with dexamethasone in a dose-dependent manner. Compounds 4 and 17 with two sugar moieties exhibited clear protective effects on β-cells.

Effective Therapeutic Verification of Crocin I, Geniposide, and Gardenia (Gardenia jasminoides Ellis) on Type 2 Diabetes Mellitus In Vivo and In Vitro

For many centuries, Gardenia (Gardenia jasminoides Ellis) was highly valued as a food homologous Chinese herbal medicine with various bioactive compounds, including crocin I and geniposide. However, the functional mechanism underlying the hypoglycemic effect of gardenia is absent in the literature. To evaluate the effect of gardenia and its different extracts on type 2 diabetes mellitus (T2DM) in in vivo and in vitro experiments, the dried gardenia powder was extracted using 60% ethanol and eluted at different ethanol concentrations to obtain the corresponding purified fragments. After that, the active chemical compositions of the different purified gardenia fragments were analyzed using HPLC. Then, the hypoglycemic effects of the different purified gardenia fragments were compared using in vitro and in vivo experiments. Finally, the different extracts were characterized using UPLC-ESI-QTOF-MS/MS and the mass spectrometric fragmentation pathway of the two main compounds, geniposide and crocin I, were identified. The experimental results indicated that the inhibitory effect of the 40% EGJ (crocin I) on the α-glucosidase was better than the 20% EGJ (geniposide) in vitro. However, the inhibitory effect of geniposide on T2DM was better than crocin I in the animal experiments. The different results in vivo and in vitro presumed potentially different mechanisms between crocin I and geniposide on T2DM. This research demonstrated that the mechanism of hypoglycemia in vivo from geniposide is not only one target of the α-glucosidase but provides the experimental background for crocin I and the geniposide deep processing and utilization.

Proteomic examination of Cornus officinalis stimulated 1.1B4 human pancreatic cells reveals activation of autophagy and Keap1/Nrf2 pathway

Type 1 diabetes (T1D) is an autoimmune disease initiated by genetic predisposition and environmental influences culminating in the immunologically mediated destruction of pancreatic β-cells with eventual loss of insulin production. Although T1D can be accurately predicted via autoantibodies, therapies are lacking that can intercede autoimmunity and protect pancreatic β-cells. There are no approved interventional modalities established for this purpose. One such potential source for clinical agents of this use is from the frequently utilized Cornus officinalis (CO) in the field of ethnopharmacology. Studies by our lab and others have demonstrated that CO has robust proliferative, metabolic, and cytokine protective effects on pancreatic β-cells. To identify the molecular mechanism of the biological effects of CO, we performed a proteomic and phosphoproteomic analysis examining the cellular networks impacted by CO application on the 1.1B4 pancreatic β-cell line. Our label-free mass spectrometry approach has demonstrated significant increased phosphorylation of the selective autophagy receptor of p62 (Sequestosome-1/SQSTM1/p62) and predicted activation of the antioxidant Kelch-like ECH-associated protein 1 (Keap1)/Nuclear factor-erythroid factor 2-related factor 2 (Nrf2) pathway. Further validation by immunoblotting and immunofluorescence revealed markers of autophagy such as increased LC3-II and decreased total p62 along with nuclear localization of Nrf2. Both autophagy and the Keap1/Nrf2 pathways have been shown to be impaired in human and animal models of T1D and may serve as an excellent potential therapeutic target stimulated by CO.

An Overview of Traditional Uses, Phytochemical Compositions and Biological Activities of Edible Fruits of European and Asian Cornus Species

Cornus species are widely distributed in central and southern Europe, east Africa, southwest Asia, and America. Several species are known for edible fruits, especially Cornus mas and Cornus officinalis. These delicious fruits, characterized by their remarkable nutritional and biological values, are widely used in traditional medicine. In contrast to the other edible Cornus species, C. mas and C. officinalis are the most studied for which little information is available on the main phytochemicals and their biological activities. Fruits are characterised by several classes of secondary metabolites, such as flavonoids, phenolic acids, lignans, anthocyanins, tannins, triterpenoids, and iridoids. The available phytochemical data show that the different classes of metabolites have not been systematically studied. However, these edible species are all worthy of interest because similarities have been found. Thus, this review describes the traditional uses of Cornus species common in Europe and Asia, a detailed classification of the bioactive compounds that characterize the fruits, and their beneficial health effects. Cornus species are a rich source of phytochemicals with nutritional and functional properties that justify the growing interest in these berries, not only for applications in the food industry but also useful for their medicinal properties.

Role of polyphenols in combating Type 2 Diabetes and insulin resistance

Compromised carbohydrate metabolism leading to hyperglycemia is the primary metabolic disorder of non-insulin-dependent diabetes mellitus. Reformed digestion and altered absorption of carbohydrates, exhaustion of glycogen stock, enhanced gluconeogenesis and overproduced hepatic glucose, dysfunction of β-cell, resistance to insulin in peripheral tissue, and impaired insulin signaling pathways are essential reasons for hyperglycemia. Although oral anti-diabetic drugs like α-glucosidase inhibitors, sulfonylureas and insulin therapies are commonly used to manage Type 2 Diabetes (T2D) and hyperglycemia, natural compounds in diet also play a significant role in combating the effect of diabetes. Due to their vast bioavailability and anti-hyperglycemic effect with least or no side effects, polyphenolic compounds have gained wide popularity. Polyphenols such as flavonoids and tannins play a significant role in carbohydrate metabolism by inhibiting key enzymes responsible for the digestion of carbohydrates to glucose like α-glucosidase and α-amylase. Several polyphenols such as resveratrol, epigallocatechin-3-gallate (EGCG) and quercetin enhanced glucose uptake in the muscle and adipocytes by translocating GLUT4 to plasma membrane mainly by the activation of the AMP-activated protein kinase (AMPK) pathway. This review provides an insight into the protective role of polyphenols in T2D, highlighting the aspects of insulin resistance.

Effects of Bushen-Jiangya granules on blood pressure and pharmacogenomic evaluation in low-to-medium-risk hypertensive patients: study protocol for a randomized double-blind controlled trial

INTRODUCTION

Hypertension is one of the most important risk factors for cardiovascular disease, and its control rates remain low worldwide. The most effective strategy is that patients with hypertension should be diagnosed and treated early. Preliminary studies showed that the Bushen Jiangya granule (BSJY) could suppress ventricular hypertrophy and inflammatory responses, lower blood pressure, and protect the target organs of hypertension. We designed a randomized, double-blind, placebo-controlled trial to evaluate the efficacy of BSJY in patients with low-to-medium risk hypertension.

METHODS AND ANALYSIS

This trial is a one-center, randomized, double-blind, placebo-controlled study. A total of 260 participants will be randomized in a 1:1 ratio to an experimental group (BSJY plus amlodipine) and a control group (placebo plus amlodipine). The trial cycle will last 8 weeks. The primary outcome is the change in 24-h average systolic and diastolic blood pressure. The secondary outcomes include heart rate variability, pharmacogenomic evaluation, improvement in TCM syndrome, and serum pro-inflammatory/anti-inflammatory cytokines between the two groups. The safety of medication will also be evaluated. All the data will be recorded in electronic case report forms and analyzed by SPSS V.22.0.

ETHICS AND DISSEMINATION

This study has been approved by the Research Ethics Committee of Guang'anmen Hospital, China Academy of Chinese Medical Sciences in Beijing, China (No. 2019-186-KY-01). The participants are volunteers, understand the process of this trial, and sign an informed consent. The results of this study will be disseminated to the public through peer-reviewed journals and academic conferences.

DISCUSSION

We hypothesize that patients with low-to-medium-risk hypertension will benefit from BSJY. If successful, this study will provide evidence-based recommendations for clinicians.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiMCTR1900002876. Registered in November 2019.

Evidence and Potential Mechanisms of Jin-Gui Shen-Qi Wan as a Treatment for Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Background: Type 2 diabetes mellitus (T2DM) is a subtype of diabetes mellitus characterized by progressive dysfunction of β-cell insulin secretion and insulin resistance. Jīn-Guì Shèn-Qì Wán (JGSQW) has for many years been widely used in clinical practice as a treatment for T2DM. However, its effect remains unknown.

Objectives: This study aims to summarize the clinical evidence of the effect of JGSQW on glucose and lipid metabolism in T2DM and the potential mechanisms underlying this effect.

Methods: Six databases were searched without language or publication status restrictions. Data were extracted to a predefined template for synthesis.

Results: Fourteen studies with 1586 participants were included in this meta-analysis. All 14 studies were judged to be at high risk of bias. JGSQW is safe for T2DM patients. Pooled results indicated that combination treatment results in a reduction in glycated hemoglobin (HbA1c) (mean difference (MD) −0.49%; 95% CI −0.67 to −0.31), fasting blood glucose (FBG) (MD −0.84; 95% CI −1.19 to −0.49), and 2-hour postprandial glucose 2hBG (MD −1.38; 95% CI −1.60 to −1.16). No significant difference in glucose metabolism was observed between JGSQW and hypoglycemic agents. The available evidence was insufficient to determine the effects on lipid metabolism. Sensitivity analyses indicated that these results were robust.

Conclusion: By combining the available evidence, we found that JGSQW is safe for T2DM patients. Compared with hypoglycemic agents alone, combination treatment with JGSQW enhances the effect on glucose metabolism in patients with T2DM. We found no difference in the efficacy of JGSQW alone compared to hypoglycemic agents alone. In terms of lipid metabolism, the current evidence is insufficient and too inconsistent for us to draw firm conclusions, so further studies are needed.

Plant/algal polysaccharides extracted by microwave: A review on hypoglycemic, hypolipidemic, prebiotic, and immune-stimulatory effect

Microwave-assisted extraction (MAE) is an emerging technology to obtain polysaccharides with an extensive spectrum of biological characteristics. In this study, the hypoglycemic, hypolipidemic, prebiotic, and immunomodulatory (e.g., antiinflammatory, anticoagulant, and phagocytic) effects of algal- and plant-derived polysaccharides rich in glucose, galactose, and mannose using MAE were comprehensively discussed. The in vitro and in vivo results showed that these bioactive macromolecules with the low digestibility rate could effectively alleviate the fatty acid-induced lipotoxicity, acute hemolysis, and dyslipidemia status. The optimally extracted glucomannan- and glucogalactan-containing polysaccharides revealed significant antidiabetic effects through inhibiting α-amylase and α-glucosidase, improving dynamic insulin sensitivity and secretion, and promoting pancreatic β-cell proliferation. These bioactive macromolecules as prebiotics not only improve the digestibility in gastrointestinal tract but also reduce the survival rate of pathogens and tumor cells by activating macrophages and producing pro-inflammatory biomarkers and cytokines. They can effectively prevent gastrointestinal disorders and microbial infections without any toxicity.

Therapeutic effects of Chinese herbal medicines and their extracts on diabetes

With the improvement of people's living standards and changes in the environment, the incidence of diabetes has increased rapidly. It has gradually become one of the main diseases threatening the health and life of modern people, bringing a great burden to the society. Although the existing treatment methods can effectively control the symptoms of diabetes and delay its progression, they have not brought satisfactory improvement in the quality of life and treatment of patients. Traditional Chinese herbal medicines and their extracts combine thousands of years of experience and the scientific basis provided by modern experimental research, which is expected to bring a qualitative leap in the clinical management of diabetes. Therefore, this article systematically reviews studies on the effects of Chinese herbal medicine and its extracts on diabetes and its complications, and aims to bring new ideas and options for the clinical treatment of diabetes.

The therapeutic role of lactobacillus and montelukast in combination with metformin in diabetes mellitus complications through modulation of gut microbiota and suppression of oxidative stress

Male reproductive dysfunction is one of the overlooked findings of diabetes mellitus (DM) that deserves greater scientific attention. This study is designed to explore the therapeutic potential of metformin and montelukast, in combination with Lactobacillus, for modulation of intestinal flora and suppression of oxidative stress in testicular and liver damage in diabetic male rats. A DM model was induced by streptozotocin (STZ)which caused functional, biochemical, and inflammatory injuries to the testicular and liver tissues. The experimental panel included nine rat groups: normal control, normal control plus metformin, normal control plus montelukast, DM control, DM plus montelukast, DM plus a combination of metformin and Lactobacillus, DM plus a combination of montelukast and Lactobacillus, and DM plus a combination of metformin and montelukast. In parallel, clinical evaluation of microscopic examination scoring, and hepatic and testicular injuries, were evaluated. Biochemical markers including glucose level, lipid profile, inflammatory markers (tumor necrosis factor- (TNF-α) and interleukin-17 (IL-17), Caspase-3, and Bax proteins expressions were measured. The change in the microbiota abundance was investigated using conventional and real-time PCR. The current study revealed a significant difference in the relative abundance of microbiota, where DM is associated with an enormous increase of Bacteroides spp., Clostridium spp., E. coli, and Fusobacterium spp., and a significant decrease in Bifidobacteria spp., and Lactobacillus spp., in contrast with normal control. Metformin and montelukast, in combination with Lactobacillus, significantly reversed the testicular and liver damage caused by STZ. Moreover, the drugs significantly reduced the oxidative, inflammatory, and apoptotic activities induced by STZ.

Active Components and Pharmacological Effects of Cornus officinalis: Literature Review

Cornus officinalis Sieb. et Zucc. (Shanzhuyu), a herb and food plant in east Asia, has the properties of tonifying the liver and kidney, and nourishing the essence according to the theory of traditional Chinese medicine. C. officinalis has been commonly used to treat asthenia diseases, liver, and kidney diseases, and reproductive system diseases since ancient times. The objectives of this article were to review the pharmacological effects and phytochemistry of C. officinalis. We conducted a literature review of the pharmacological effects of C. officinalis by different systems and compared the effects with the traditional usages, discussed the research status and potential blanks to be filled. The experimental studies showed that C. officinalis extract and its active components had various pharmacological effects such as anti-oxidation, anti-apoptosis, anti-inflammation, anti-diabetes, anti-osteoporosis, immunoregulation, neuroprotection, and cardiovascular protection, but clinical studies are still needed to assess whether the reported pharmacological activities have confirmed efficacy.

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.

Traditional Chinese medicine protects against hypertensive kidney injury in Dahl salt-sensitive rats by targeting transforming growth factor-β signaling pathway

This study investigated the therapeutic efficacy of Bu-Shen-Jiang-Ya decoction (BSJYD) on hypertensive renal damage to determine whether it regulates the expression of transforming growth factor-β (TGF-β)/SMADs signaling pathways, thereby relieving renal fibrosis in Dahl salt-sensitive (SS) rats. Dahl SS rats on a high-sodium diet were prospectively treated with BSJYD (n = 12) or valsartan (n = 12) for 8 weeks. The blood pressure (BP) of these rats was measured and their kidneys were subjected to biochemical analysis, including serum creatinine (Scr) and blood urea nitrogen (BUN); hematoxylin and eosin staining; Masson trichrome staining; real-time polymerase chain reaction; and western blot analysis. The primary outcome was that BSJYD significantly reduced BP, debased BUN, and Scr and ameliorated renal pathological changes. As underlying therapeutic mechanisms, BSJYD reduces TGFβ1 and Smad2/3 expression and suppresses renal fibrosis, as suggested by the decreased expression of connective tissue growth factor(CTGF). These data suggest that BSJYD acts as an optimal therapeutic agent for hypertensive renal damage by inhibiting the TGF-β/SMADs signaling pathway.

Structures and anti-atherosclerotic effects of 1,6-α-glucans from Fructus Corni

In this study, two homogeneous polysaccharides (PFC-1 and PFC-2) having anti-atherosclerotic activity were isolated from Fructus Corni. PFC-1 and PFC-2 were 1,6-α-glucans with the molecular weight of 4.4 kDa and 82.0 kDa, respectively. In the in vitro experiments, PFC-1 and PFC-2 showed significant inhibitory effects on the cholesterol accumulation in RAW264.7 macrophages induced by oxidized low-density lipoproteins (ox-LDL), and the inhibitory rate of PFC-2 was 81.62%. Apolipoprotein E-deficient (ApoE^-/-) mice fed high-fat diet (HFD) were used to evaluate the anti-atherosclerotic effects of PFC-2 in vivo. The aortic root lipid area decreased by 55.01% in the PFC-2-administered group as compared to the model group. PFC-2 decreased the levels of serum low-density lipoprotein cholesterol, total cholesterol, triglycerides, and malondialdehyde, increased the superoxide dismutase activity, and reduced the contents of lipid and macrophages in the aortic sinus plaque in ApoE^-/- mice fed with HFD. Furthermore, PFC-2 markedly inhibited the expression of type A1 scavenger receptor (SR-A1) and cluster of differentiation 36 (CD36) in ox-LDL-treated macrophages. Taken together, 1,6-α-glucans from Fructus Corni showed significant anti-atherogenic effect, and the mechanism is related to enhanced antioxidant activity of the ApoE^-/- mice and down-regulated the expression of SR-A1 and CD36 proteins in macrophages.

Kampo medicines, Rokumigan, Hachimijiogan, and Goshajinkigan, significantly inhibit glucagon-induced CREB activation

The pathophysiology of type 2 diabetes mellitus (T2DM) is characterized by not only insulin resistance, but also the abnormal regulation of glucagon secretion, suggesting that antagonizing the glucagon-induced signaling pathway has therapeutic potential in the treatment of T2DM. Although various Kampo medicines (traditional herbal medicines) are often utilized to ameliorate the symptoms of T2DM, their effects on glucagon signaling have not yet been clarified. In the present study, we examined the effects of nine types of representative Kampo formulations prescribed for T2DM on glucagon-induced CREB activation in HEK293T cells stably expressing glucagon receptor (Gcgr) and a hepatic cell line HepG2. Among these Kampo medicines, Rokumigan, Hachimijiogan, and Goshajinkigan significantly suppressed the glucagon-induced transactivation of the cAMP-responsive element (CRE)-binding protein (CREB) by inhibiting its interaction with CREB-binding protein (CBP), which led to a reduction in the expression of phosphoenolpyruvate carboxykinase (PEPCK) mRNA. Furthermore, among the crude drugs commonly contained in these three Kampo medicines, Rehmannia Root (Jio), Moutan Bark (Botampi), and Cornus Fruit (Shanzhuyu) exerted inhibitory effects on glucagon-induced CREB activation. Collectively, the present results provide a novel mechanism, the inhibition of glucagon signaling, by which Rokumigan, Hachimijiogan, and Goshajinkigan improve the symptoms of T2DM.

Dietary Polyphenols and Gene Expression in Molecular Pathways Associated with Type 2 Diabetes Mellitus: A Review

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder with various contributing factors including genetics, epigenetics, environment and lifestyle such as diet. The hallmarks of T2DM are insulin deficiency (also referred to as β-cell dysfunction) and insulin resistance. Robust evidence suggests that the major mechanism driving impaired β-cell function and insulin signalling is through the action of intracellular reactive oxygen species (ROS)-induced stress. Chronic high blood glucose (hyperglycaemia) and hyperlipidaemia appear to be the primary activators of these pathways. Reactive oxygen species can disrupt intracellular signalling pathways, thereby dysregulating the expression of genes associated with insulin secretion and signalling. Plant-based diets, containing phenolic compounds, have been shown to exhibit remedial benefits by ameliorating insulin secretion and insulin resistance. The literature also provides evidence that polyphenol-rich diets can modulate the expression of genes involved in insulin secretion, insulin signalling, and liver gluconeogenesis pathways. However, whether various polyphenols and phenolic compounds can target specific cellular signalling pathways involved in the pathogenesis of T2DM has not been elucidated. This review aims to evaluate the modulating effects of various polyphenols and phenolic compounds on genes involved in cellular signalling pathways (both in vitro and in vivo from human, animal and cell models) leading to the pathogenesis of T2DM.

Compositional analysis and biological characterization of Cornus officinalis on human 1.1B4 pancreatic β cells

Type 1 diabetes (T1D) is an autoimmune disease resulting from the loss of pancreatic β cells and subsequent insulin production. Novel interventional therapies are urgently needed that can protect existing β cells from cytokine-induced death and enhance their function before symptomatic onset. Our initial evidence is suggesting that bioactive ingredients within Cornus officinalis (CO) may be able to serve in this function. CO has been extensively used in Traditional Chinese Medicine (TCM) and reported to possess both anti-inflammatory and pro-metabolic effects. We hypothesize that CO treatment may provide a future potential candidate for interventional therapy for early stage T1D prior to significant β cell loss. Our data demonstrated that CO can inhibit cytokine-mediated β cell death, increase cell viability and oxidative capacity, and increase expression of NFATC2 (Nuclear Factor of Activated T Cells, Cytoplasmic 2). We have also profiled the bioactive components in CO from multiple sources by HPLC/MS (High Performance Liquid Chromatography/Mass Spectrometry) analysis. Altogether, CO significantly increases the energy metabolism of β cells while inducing the NFAT pathway to signal for increased proliferation and endocrine function.

Protective effect of triterpenes against diabetes-induced β-cell damage: An overview of in vitro and in vivo studies

Accumulative evidence shows that chronic hyperglycaemia is a major factor implicated in the development of pancreatic β-cell dysfunction in diabetic patients. Furthermore, most of these patients display impaired insulin signalling that is responsible for accelerated pancreatic β-cell damage. Indeed, prominent pathways involved in glucose metabolism such as phosphatidylinositol 3-kinase/ protein kinase B (PI3-K/AKT) and 5' AMP-activated protein kinase (AMPK) are impaired in an insulin resistant state. The impairment of this pathway is associated with over production of reactive oxygen species and pro-inflammatory factors that supersede pancreatic β-cell damage. Although several antidiabetic drugs can improve β-cell function by modulating key regulators such as PI3-K/AKT and AMPK, evidence of their β-cell regenerative and protective effect is scanty. As a result, there has been continued exploration of novel antidiabetic therapeutics with abundant antioxidant and antiinflammatory properties that are essential in protecting against β-cell damage. Such therapies include triterpenes, which have displayed robust effects to improve glycaemic tolerance, insulin secretion, and pancreatic β-cell function. This review summarises most relevant effects of various triterpenes on improving pancreatic β-cell function in both in vitro and in vivo experimental models. A special focus falls on studies reporting on the ameliorative properties of these compounds against insulin resistance, oxidative stress and inflammation, the well-known factors involved in hyperglycaemia associated tissue damage.

Cornus mas and Cornus Officinalis-Analogies and Differences of Two Medicinal Plants Traditionally Used

Among 65 species belonging to the genus Cornus only two, Cornus mas L. and Cornus officinalis Sieb. et Zucc. (Cornaceae), have been traditionally used since ancient times. Cornus mas (cornelian cherry) is native to southern Europe and southwest Asia, whereas C. officinalis (Asiatic dogwood, cornel dogwood) is a deciduous tree distributed in eastern Asia, mainly in China, as well as Korea and Japan. Based on the different geographic distribution of the closely related species but clearly distinct taxa, the ethnopharmacological use of C. mas and C. officinalis seems to be independently originated. Many reports on the quality of C. mas fruits were performed due to their value as edible fruits, and few reports compared their physicochemical properties with other edible fruits. However, the detailed phytochemical profiles of C. mas and C. officinalis, in particular fruits, have never been compared. The aim of this review was highlighting the similarities and differences of phytochemicals found in fruits of C. mas and C. officinalis in relation to their biological effects as well as compare the therapeutic use of fruits from both traditional species. The fruits of C. mas and C. officinalis are characterized by the presence of secondary metabolites, in particular iridoids, anthocyanins, phenolic acids and flavonoids. However, much more not widely known iridoids, such as morroniside, as well as tannins were detected particularly in fruits of C. officinalis. The referred studies of biological activity of both species indicate their antidiabetic and hepatoprotective properties. Based on the available reports antihyperlipidemic and anticoagulant activity seems to be unique for extracts of C. mas fruits, whereas antiosteoporotic and immunomodulatory activities were assigned to preparations of C. officinalis fruits. In conclusion, the comparison of phytochemical composition of fruits from both species revealed a wide range of similarities as well as some constituents unique for cornelian cherry or Asiatic dogwood. Thus, these phytochemicals are considered the important factor determining the biological activity and justifying the use of C. mas and C. officinalis in the traditional European and Asiatic medicine.

Corni Fructus: a review of chemical constituents and pharmacological activities

Cornus officinalis Sieb. et Zucc. is part of the genus Cornus of the family Cornaceae. Ripening and dry fruits (Corni Fructus) are recognized as an essential herb medicine in the traditional Chinese medicine (TCM) and have been widely used for over 2000 years. This review provides a comprehensive summary of Corni Fructus (CF), including the botany, phytochemistry, traditional use, and current pharmacological activities. According to the basic theory of TCM, CF usually participates in various Chinese medicinal formulae to exert the essential roles in replenishing liver and kidney, arresting seminal emission and sweat. Based on modern pharmacological studies, about 90 compounds have been isolated and identified from CF. In vivo and in vitro experimental studies indicate that CF exhibits extensive pharmacological activities including hypoglycemic, antioxidant, anti-inflammatory, anticancer, neuroprotective, hepatoprotective, and nephroprotective activities. However, only about 18% of chemical constituents in CF were tested. It means the potential pharmacological activities and clinical values of CF need to be further investigated.

Protective effect of Fructus corni polysaccharide on hippocampal tissues and its relevant mechanism in epileptic rats induced by lithium chloride-pilocarpine

The aim of the present study was to investigate the potential effect of Fructus corni polysaccharide (PFC) on the hippocampus tissues in epileptic rats induced by lithium chloride-pilocarpine, and to explore the underlying mechanism. The epileptic rat models were established using lithium chloride-pilocarpine treatment. According to the dosage of PFC, the rat models were divided into three groups: The low-dose (100 mg/kg/day), middle-dose (200 mg/kg/day) and high-dose (300 mg/kg/day) groups. The intervention for rat models lasted for 24 days. Subsequently, the production levels of reactive oxygen species (ROS) and malondialdehyde (MDA), the activity of superoxide dismutase (SOD), the mitochondrial membrane potential and the expressions of mitogen-activated protein kinase [P-38, Janus kinase (JNK) and extracellular signal-regulated kinase 1/2], cytochrome-C and caspase-3 in hippocampal tissues were detected. In addition, the structure of the CA-1 region of the hippocampus was also observed. Compared with the control group, the production levels of ROS were increased and the mitochondrial membrane potential was decreased in the hippocampus tissues of rats in the model group. In addition, in the model group, it was observed that MDA content was increased, SOD activity was decreased, and the expressions of phosphorylated (p)-p38, p-JNK, cytochrome-c and caspase-3 were increased, compared with the control group. Furthermore, those abnormal variations of the indicators were reversed by the intervention of PFC. These findings suggest that PFC can ameliorate the secondary damage to the hippocampi of epileptic rats, and that the anti-oxidation and -apoptosis effects of PFC may be associated with the mechanism that provides a protective effect for hippocampal tissues.

Ethnopharmacology, phytochemistry, and pharmacology of Cornus officinalis Sieb. et Zucc

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis (Cornaceae), known in Chinese as "Shanzhuyu," is a frequently used traditional Chinese medicine. It tastes sour and is astringent and slightly warm in nature. Its fruits have long been used to treat kidney deficiency, high blood pressure, waist and knee pain, dizziness, tinnitus, impotence, spermatorrhea, menorrhagia, and other diseases in China. The main distribution areas are Shanxi and Gansu.

AIM OF THE STUDY

This review focused on the ethnopharmacological uses of the herb. We also focus on the phytochemical, pharmacological, and toxicological studies on C. officinalis. The recent analytical methods developed for the quality control of the herb's constituents are also reviewed. Additionally, future trends and prospects in the study of this herb are proposed.

MATERIALS AND METHODS

Information on C. officinalis was gathered by searching the internet (PubMed, ScienceDirect, Wiley, ACS, CNKI, Scifinder, Web of Science, Google Scholar, and Baidu Scholar) and libraries.

RESULTS

This review compiled the ethnopharmacological uses, including the classic prescriptions and historical applications. Approximately 300 chemical compounds have been isolated and identified from C. officinalis. The major active components of the plant are organic acids and iridoids, among which morroniside and loganin have been extensively investigated. The fruit of the plant has been used in treating many diseases in traditional medicine. Scientific studies indicated the herb's wide range of pharmacological activities, such as hepatic and renal protection, antidiabetes activity, cardioprotection, antioxidation, neuroprotection, antitumor activity, anti-inflammation, analgesic effects, antiaging activity, antiamnesia, antiosteoporosis, and immunoregulation. The analytical methods developed for the quantitative and qualitative determination of various compounds in the herb were further reviewed.

CONCLUSIONS

In this paper, we reviewed various studies conducted on C. officinalis, especially in areas of its ethnopharmacological use, as well as on its phytochemistry, pharmacology, and modern analytical methods used. Some of the herb's ethnomedical indications have been confirmed by the herb's pharmacological effects, such as its hepatic and renal protection and the antidiabetic effects. In particular, the crude extract and its chemical composition have exerted good therapeutic effect in diabetic treatment. C. officinalis entails additional attention on its pharmacological effects and drug development to expand its effective use clinically. Many advanced technologies are used for quality testing, but the detection component is exceedingly scarce for synthetically evaluating the quality of C. officinalis herbs. Thus, further research is necessary to investigate the quality control and toxicology of the plant, to further elucidate its clinical use, and to control herbal quality.

Can highly cited herbs in ancient Traditional Chinese medicine formulas and modern publications predict therapeutic targets for diabetes mellitus?

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes among all age groups worldwide was estimated to be more than 382 million in 2013. Traditional Chinese medicine (TCM) has been practiced for thousands of years, and substantial valuable experience and prescriptions have been accumulated in the TCM system for the treatment of diabetes. In recent decades, a large amount of experimental and clinical data has been published on the use of herbal medicines related to these ancient TCM prescriptions.

AIM OF THE STUDY

This study aimed to discover a method for the investigation of potential antidiabetic herbs from the large amount of data in ancient TCM formulas and modern publications and to verify this method through an in vitro bioactivity study.

MATERIALS AND METHODS

In our review, the most frequently cited TCM herbs were selected as potential antidiabetic herb candidates on the basis of TCM philosophical theory (ancient TCM formulas) and Western medicine philosophical theory (modern publications). The ethanol and aqueous extracts of the selected herbs were screened for their α-glucosidase inhibitory, glucose-stimulated insulin secretion (GSIS), and intestinal glucose transport inhibitory effects.

RESULTS

Twelve herbs [Terminalia chebula Retz., fructus immaturus, dried; Poria cocos (Schw) Wolf., sclerotium, dried; Zea mays L., stigma, dried; Pueraria lobata (Willd.) Ohwi, radix, dried; Cucurbita moschata (Duch. ex Lam.) Duch. ex Poiret, fructus, dried; Lycium barbarum L., fructus, dried; Glycine max (L.) Merr., semen, fermented; Glycyrrhiza uralensis Fisch., radix and rhizoma, dried; Dioscorea opposita Thunb., rhizoma, dried; Morus alba L., folium, dried, Morus alba L., fructus, dried; and Polygonatum odoratum (Mill.) Druce, rhizoma, dried] were finally selected as candidates with potential glucose-lowering effects after a review was performed of herbs that are frequently cited in ancient TCM formulas and modern publications. The bioactive study results demonstrated that both the ethanol extracts and crude polysaccharides of M. alba L., fructus, dried, and M. alba L., folium, dried, and the crude polysaccharides of T. chebula Retz., fructus immaturus, dried, exhibited α-glucosidase inhibitory effects. Moreover, the crude polysaccharides of P. cocos (Schw) Wolf., sclerotium, dried; Z. mays L., stigma, dried; and T. chebula Retz., fructus immaturus, dried, exhibited favorable GSIS effects, and the ethanol extracts of P. odoratum (Mill.) Druce, rhizoma, dried; T. chebula Retz., fructus immaturus, dried; and G. uralensis Fisch., radix and rhizoma, dried, significantly decreased glucose transport across the cell monolayer.

CONCLUSIONS

Our review and the preliminary bioactive study revealed that 10 of the 12 recommended edible TCM herbs had favorable antidiabetic effects, demonstrating that TCM herbs with a high prescription and publication frequency may provide insights into the potential therapeutic targets of diabetes mellitus and may aid in the discovery of effective compounds complementary to currently used medicines. Such a literature and medicine review is a useful method of exploring potential antidiabetic herbs by using the wealth of information in ancient TCM formulas and modern publications.

Cornusides A-O, Bioactive Iridoid Glucoside Dimers from the Fruit of Cornus officinalis

Fifteen new and rare iridoid glucoside dimers, cornusides A-O (1-15), and 10 known iridoid glucosides (16-25) were isolated from the fruit of Cornus officinalis. These new chemical structures were established through spectroscopic analysis (UV, IR, HRESIMS, 1D and 2D NMR). Compounds 1-25 were tested for their inhibitory activities by measuring IL-6-induced STAT3 promoter activity in HepG2 cells, and 3, 12, 17, 22, and 23 showed inhibitory effects, with IC₅₀ values of 11.9, 12.2, 14.0, 7.0, and 6.9 μM, respectively.

Four new iridoid glucosides containing the furan ring from the fruit of Cornus officinalis

Four new and rare iridoid glucosides, cornusfuroside A-D (1-4), containing the furan ring were identified from water extract of the fruit of Cornus officinalis. These new chemical structures were determined through extensive spectroscopic analysis, including 1D and 2D NMR, IR, HRESIMS, experimental and calculated electronic circular dichroism (ECD). Notably, this study is the first report on the isolation of four iridoid glucoside structures with acetal functions in the sugar moiety. The neuroprotective effects of these compounds were also evaluated in vitro.

Potential anti-cholinesterase and β-site amyloid precursor protein cleaving enzyme 1 inhibitory activities of cornuside and gallotannins from Cornus officinalis fruits

Cholinesterase (ChE) and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors are promising agents for the treatment of Alzheimer's disease (AD). In the present study, we examined the inhibitory activity of seven compounds isolated from the fruits of Cornus officinalis, cornuside, polymeric proanthocyanidins, 1,2,3-tri-O-galloyl-β-D-glucose, 1,2,3,6-tetra-O-galloyl-β-D-glucose, tellimagrandin I, tellimagrandin II, and isoterchebin, against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and BACE1. All of the compounds displayed concentration-dependent in vitro inhibitory activity toward the ChEs and BACE1. Among them, tellimagrandin II exhibited the best inhibitory activity toward ChEs, whereas the best BACE1 inhibitor was 1,2,3,6-tetra-O-galloyl-β-D-glucose. Isoterchebin and polymeric proanthocyanidins were also significant ChE inhibitors. The kinetic and docking studies demonstrated that all compounds interacted with both the catalytic active sites and the peripheral anionic sites of the ChEs and BACE1. Tellimagrandin II, isoterchebin, and the polymeric proanthocyanidins exhibited concentration-dependent inhibition of peroxynitrite-mediated protein tyrosine nitration. In conclusion, we identified significant ChE and BACE1 inhibitors from Corni Fructus that could have value as new multi-targeted compounds for anti-AD agents.

Evaluation of the In Vivo Therapeutic Effects of Radix Paeoniae Rubra Ethanol Extract with the Hypoglycemic Activities Measured from Multiple Cell-Based Assays

Background. Radix Paeoniae Rubra (Chi Shao) contains several phytochemicals with hypoglycemic actions. Current research aims to explore potential insulinotropic effects and long-term therapeutic efficacy of such herb against type 2 diabetes. Methods. Composition analysis for the ethanol extract (PRExt) was executed by high performance liquid chromatography. Polyphenol-enriched fraction was characterized by high pressure size exclusion chromatography. Multiple cell platforms were employed to evaluate hypoglycemic bioactivities. In animal experiments, blood glucose, the homeostasis model assessment (HOMA)-index assessment, glucose tolerance test, and in vivo glucose uptake were all measured. Additional effects of PRExt on obesity and hepatic steatosis were evaluated by serum and histological analysis. Results. PRExt provides multiple hypoglycemic effects including the enhancement of glucose-mediated insulin secretion. Pentagalloylglucose and polyphenol-enriched fraction are two insulinotropic constituents. Moreover, PRExt intraperitoneal injection causes acute hypoglycemic effects on fasted db/db mice. Oral administration of PRExt (200 mg/kg b.w.) gradually reduces blood glucose in db/db mice to the level similar to that in C57J/B6 mice after 30 days. The improvement of glucose intolerance, HOMA-index, and in vivo glucose uptake is evident in addition to the weight loss effect and attenuation of hepatic steatosis. Conclusion. PRExt is an effective antidiabetic herbal extract with multiple hypoglycemic bioactivities.

The ethyl acetate fraction of corn silk exhibits dual antioxidant and anti-glycation activities and protects insulin-secreting cells from glucotoxicity

Background

In this study, we aimed to develop a Stigmata Maydis (corn silk) fraction with dual bio-activities against oxidative stress and protein glycation to protect β-cells from diabetes-induced failure.

Methods

Corn silk fractions were prepared by partition and chemically characterised by thin-layer chromatography. Free radical scavenging assay, glycation assay, and cell-based viability test (neutral red) were employed to decide the best fraction. Cell death analysis was executed by annexin V/ Propidium iodide staining. Cell proliferation was measured by WST-1. Finally, β-cell function was evaluated by β-cell marker gene expression (RT-PCR) and acute insulin secretion test.

Results

Four corn silk fractions were prepared from an ethanolic crude extract of corn silk. In vitro assays indicate ethyl acetate fraction (YMS-EA) was the most potent fraction. YMS-EA also attenuated the hydrogen peroxide- or methylglyoxal-induced induction of reactive oxygen species, reduction of cell viability, and inhibition of cell proliferation. However, YMS-EA was unable to prevent hydrogen peroxide-induced apoptosis or advanced glycation end-products-induced toxicity. Under hyperglycemic conditions, YMS-EA effectively reduced ROS levels, improved mRNA expression of insulin, glucokinase, and PDX-1, and enhanced glucose-stimulated insulin secretion. The similarity of bioactivities among apigenin, luteolin, and YMS-EA indicated that dual activities of YMS-EA might be derived from those compounds.

Conclusions

We concluded that YMS-EA fraction could be developed as a preventive food agent against the glucotoxicity to β-cells in Type 2 diabetes.

Cornuside inhibits mast cell-mediated allergic response by down-regulating MAPK and NF-κB signaling pathways

AIMS

The present study is to investigate the effect of cornuside on mast cell-mediated allergic response, as well as its possible mechanisms of action.

METHODS

To test the anti-allergic effects of cornuside in vivo, local extravasation was induced by local injection of anti-dinitrophenyl immunoglobulin E (IgE) followed by intravenous antigenic challenge in passive cutaneous anaphylaxis model rats. Mast cell viability was determined using MTT assay. Histamine content from rat peritoneal mast cells was measured by the radioenzymatic method. To investigate the mechanisms by which cornuside affects the reduction of histamine release, the levels of calcium uptake were measured. To examine whether cornuside affects the expression of pro-inflammatory cytokines, Western blotting and ELISA were carried out.

RESULTS

Oral administration of cornuside inhibited passive cutaneous anaphylaxis in rats. Presence of cornuside attenuated IgE-induced histamine release from rat peritoneal mast cells. The inhibitory effect of cornuside on histamine release was mediated by the modulation of intracellular calcium. In addition, cornuside decreased phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-stimulated production and secretion of pro-inflammatory cytokines such as TNF-α and IL-6 in human mast cells. The inhibitory effect of cornuside on pro-inflammatory cytokines was dependent on nuclear factor-κB and p38 mitogen-activated protein kinase.

CONCLUSIONS

The present study provides evidence that cornuside inhibits mast cell-derived inflammatory allergic reactions by blocking histamine release and pro-inflammatory cytokine expression. Furthermore, in vivo and in vitro anti-allergic effects of cornuside suggest a possible therapeutic application of this agent in inflammatory allergic diseases.

An overview on antidiabetic medicinal plants having insulin mimetic property

Diabetes mellitus is one of the common metabolic disorders acquiring around 2.8% of the world's population and is anticipated to cross 5.4% by the year 2025. Since long back herbal medicines have been the highly esteemed source of medicine therefore, they have become a growing part of modern, high-tech medicine. In view of the above aspects the present review provides profiles of plants (65 species) with hypoglycaemic properties, available through literature source from various database with proper categorization according to the parts used, mode of reduction in blood glucose (insulinomimetic or insulin secretagogues activity) and active phytoconstituents having insulin mimetics activity. From the review it was suggested that, plant showing hypoglycemic potential mainly belongs to the family Leguminoseae, Lamiaceae, Liliaceae, Cucurbitaceae, Asteraceae, Moraceae, Rosaceae and Araliaceae. The most active plants are Allium sativum, Gymnema sylvestre, Citrullus colocynthis, Trigonella foenum greacum, Momordica charantia and Ficus bengalensis. The review describes some new bioactive drugs and isolated compounds from plants such as roseoside, epigallocatechin gallate, beta-pyrazol-1-ylalanine, cinchonain Ib, leucocyandin 3-O-beta-d-galactosyl cellobioside, leucopelargonidin-3- O-alpha-L rhamnoside, glycyrrhetinic acid, dehydrotrametenolic acid, strictinin, isostrictinin, pedunculagin, epicatechin and christinin-A showing significant insulinomimetic and antidiabetic activity with more efficacy than conventional hypoglycaemic agents. Thus, from the review majorly, the antidiabetic activity of medicinal plants is attributed to the presence of polyphenols, flavonoids, terpenoids, coumarins and other constituents which show reduction in blood glucose levels. The review also discusses the management aspect of diabetes mellitus using these plants and their active principles.

Ancient records and modern research on the mechanisms of chinese herbal medicines in the treatment of diabetes mellitus

Over the past decades, Chinese herbal medicines (CHM) have been extensively and intensively studied through from both clinical and experimental perspectives and CHM have been proved to be effective in the treatment of diabetes mellitus (DM). This study, by searching ancient records and modern research papers, reviewed CHM in terms of their clinical application and principal mechanism in the treatment of DM. We summarized the use of CHM mentioned in 54 famous ancient materia medica monographs and searched papers on the hypoglycemic effect of several representative CHM. Main mechanisms and limitations of CHM and further research direction for DM were discussed. On the basis of the study, we were led to conclude that TCM, as a main form of complementary and alternative medicine (CAM), was well recorded in ancient literatures and has less adverse effects as shown by modern studies. The mechanisms of CHM treatment of DM are complex, multilink, and multitarget, so we should find main hypoglycemic mechanism through doing research on CHM monomer active constituents. Many CHM monomer constituents possess noteworthy hypoglycemic effects. Therefore, developing a novel natural product for DM and its complications is of much significance. It is strongly significant to pay close attention to CHM for treatment of DM and its complications.

The crude extract of Corni Fructus inhibits the migration and invasion of U-2 OS human osteosarcoma cells through the inhibition of matrix metalloproteinase-2/-9 by MAPK signaling

Osteosarcoma is the most common primary malignancy of the bone cancers. In the Chinese population, the crude extract of Corni Fructus (CECF) has been used as Traditional Chinese medicine to treat several different diseases for hundreds of years. In the present study, effects of CECF on inhibition of migration and invasion in U-2 OS human osteosarcoma cells were examined. CECF significantly inhibited migration and invasion of U-2 OS human osteosarcoma cells. We also found that CECF inhibited activities of matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9). CECF decreased protein levels of FAK, PKC, SOS1, MKK7, MEKK3, GRB2, NF-κB p65, COX-2, HIF-1α, PI3K, Rho A, ROCK-1, IRE-1α, p-JNK1/2, p-ERK1/2, p-p38, Ras, p-PERK, MMP-2, MMP-9, and VEGF in U-2 OS cells. Results of this study indicate that CECF may have potential as a novel anticancer agent for the treatment of osteosarcoma by inhibiting migration and invasion of cancer cells.

Prescription pattern of chinese herbal products for diabetes mellitus in taiwan: a population-based study

Background. Traditional Chinese medicine (TCM), when given as a therapy for symptom relief, has gained widespread popularity among diabetic patients. The aim of this study is to analyze the utilization of TCM among type 2 diabetic patients in Taiwan. Methods. The use of TCM for type 2 diabetic patients were evaluated using a randomly sampled cohort of 1,000,000 beneficiaries recruited from the National Health Insurance Research Database. Results. Overall, 77.9% (n = 31,289) of type 2 diabetic patients utilized TCM and 13.9% (n = 4,351) of them used TCM for the treatment of type 2 diabetes. Among the top ten most frequently prescribed herbal formulae, four remedies, Zhi-Bo-Di-Huang-Wan, Qi-Ju-Di-Huang-Wan, Ji-Sheng-Shen-Qi-Wan and Ba-Wei-Di-Huang-Wan are derivative formulae of Liu-Wei-Di-Huang-Wan. In other words, Liu-Wei-Di-Huang-Wan and its derivatives were found to be the most common herbal formulae prescribed by TCM doctors for the treatment of diabetes in Taiwan. Conclusion. Although some evidence does support the use TCM to treat diabetes, the results from the current study may have been confounded by placebo effect, which emphasize the need for well conducted, double-blind, randomized, placebo-controlled studies in order to further evaluate the efficacy of Liu-Wei-Di-Huang-Wan on patients with type 2 diabetes.

Treating type 2 diabetes mellitus with traditional chinese and Indian medicinal herbs

Type II diabetes mellitus (T2DM) is a fast-growing epidemic affecting people globally. Furthermore, multiple complications and comorbidities are associated with T2DM. Lifestyle modifications along with pharmacotherapy and patient education are the mainstay of therapy for patients afflicted with T2DM. Western medications are frequently associated with severe adverse drug reactions and high costs of treatment. Herbal medications have long been used in the treatment and prevention of T2DM in both traditional Chinese medicine (TCM) and traditional Indian medicine (TIM). This review examines in vivo, in vitro, and clinical evidence supporting the use of various herbs used in TCM and TIM. The problems, challenges, and opportunities for the incorporation of herbal frequently used in TCM and TIM into Western therapy are presented and discussed.

Schizandra arisanensis extract attenuates cytokine-mediated cytotoxicity in insulin-secreting cells

AIM: To explore the bioactivity of an ethanolic extract of Schizandra arisanensis (SA-Et) and isolated constituents against interleukin-1β and interferon-γ-mediated β cell death and abolition of insulin secretion.

METHODS: By employing BRIN-BD11 cells, the effects of SA-Et administration on cytokine-mediated cell death and abolition of insulin secretion were evaluated by a viability assay, cell cycle analysis, and insulin assay. The associated gene and protein expressions were also measured. In addition, the bioactivities of several peak compounds collected from the SA-Et were tested against cytokine-mediated β cell death.

RESULTS: Our results revealed that SA-Et dose-dependently ameliorated cytokine-mediated β cell death and apoptosis. Instead of suppressing inducible nitric oxide synthase/nitric oxide cascade or p38MAPK activity, suppression of stress-activated protein kinase/c-Jun NH2-terminal kinase activity appeared to be the target for SA-Et against the cytokine mix. In addition, SA-Et provided some insulinotropic effects which re-activated the abolished insulin exocytosis in cytokine-treated BRIN-BD11 cells. Finally, schiarisanrin A and B isolated from the SA-Et showed a dose-dependent protective effect against cytokine-mediated β cell death.

CONCLUSION: This is the first report on SA-Et ameliorating cytokine-mediated β cell death and dysfunction via anti-apoptotic and insulinotropic actions.

Active ingredients of traditional Chinese medicine in the treatment of diabetes and diabetic complications

INTRODUCTION

Diabetes mellitus (DM) is a chronic progressive systemic disease caused by metabolic disorder. In recent years, significant amounts of studies have shown that traditional Chinese medicine (TCM) and its active ingredients have obvious hypoglycemic effect.

AREAS COVERED

This paper summarizes single herbs and their active ingredients from TCM with the role of treating DM, and relevant literatures published in the past decades are reviewed. The active ingredients are divided into polysaccharides, saponins, alkaloids, flavonoids, terpenoids and others, which are described in this article from the aspects of active ingredients, sources, models, efficacy, and mechanisms.

EXPERT OPINION

Mechanisms of TCM in treating DM are concluded: i) to promote insulin secretion and increase serum insulin levels; ii) to increase the sensitivity of insulin and improve its resistance; iii) to inhibit glucose absorption; iv) to affect glucose metabolism of insulin receptor; and v) to scavenge radicals and prevent lipid peroxidation. The separation and extraction of effective monomer from TCM is an important direction of anti-diabetic drug discovery currently. Future research about hypoglycemic mechanism of TCM based on the clinical should combine with modern scientific methods and regulatory approach to strive for more meaningful discovery and innovation.

[Effects of ursolic acid in ameliorating insulin resistance in liver of KKAy mice via peroxisome proliferator-activated receptors α and γ]

OBJECTIVE

To explore the effects and mechanism of ursolic acid in improving hepatic insulin resistance in KKAy mice with spontaneous type 2 diabetes.

METHODS

Thirty-five KKAy mice were divided into five groups according to the randomized block design, namely, control, rosiglitazone, fenofibrate, and high- and low-dose ursolic acid groups with seven mice in each group. C57BL/6J mice were used as the normal control group. At the end of the 4th week, free fatty acid (FFA), tumor necrosis factor-α (TNF-α) and adiponectin contents in serum were detected by enzyme-linked immunosorbent assay; the protein expressions of phosphoenolpyruvate carboxykinase (PEPCK), insulin receptor substrate-2 (IRS-2) and glucose transport factor-2 (GLUT-2) were detected by Western blot method; the mRNA expressions of PEPCK, IRS-2 and GLUT-2 were detected by real-time polymerase chain reaction; the expressions of peroxisome proliferator-activated receptor α (PPARα) and peroxisome proliferator-activated receptor γ (PPARγ) in liver tissue were detected by immunohistochemical method.

RESULTS

After four weeks of intervention, the contents of FFA, TNF-α and adiponectin in serum of the high-dose ursolic acid group had changed, showing statistically significant difference compared to those of the control group (P<0.01); high dose of ursolic acid had depressant effect on the expressions of PEPCK protein and PEPCK mRNA (P<0.01); low dose of ursolic acid depressed the expression of PEPCK mRNA and induced phosphorylation of IRS-2 in the liver (P<0.05); both high and low dose of ursolic acid improved the expression of PPARα in the liver (P<0.01).

CONCLUSION

The effects of ursolic acid in improving hepatic insulin resistance in KKAy mice with spontaneous type 2 diabetes may be closely related to affecting the contents of FFA, TNF-α and adiponectin, improving the expression of PPARα protein, regulating transcription of PEPCK protein and inducing phosphorylation of IRS-2.

Screening and identification of potential active components in crude Fructus Corni using solid-phase extraction and LC-LTQ-linear ion trap mass spectrometry

CONTEXT

Fructus Corni is derived from the dry ripe sarcocarp of Cornus officinalis Sieb. et Zucc. (Cornaceae). It has attracted increasingly much attention as one of the most popular and valuable herbal medicine in clinic. This paper applied a rapid and validated method to the intrinsic quality control of Fructus Corni.

MATERIALS AND METHODS

The components of crude Fructus Corni were investigated by means of solid-phase extraction (SPE) and LTQ-linear ion trap mass spectrometry (MS) technique in the negative ion mode.

RESULTS

The 29 detected compounds were identified by comparing the retention time and mass spectrometry data and retrieving the reference literatures.

DISCUSSION AND CONCLUSION

It was concluded that a rapid and validated method was successfully applied based on SPE-LC-DAD-LTQ-linear-MS(n) which showed high sensitivity and resolution that was more suitable for identifying main components in Traditional Chinese medicines (TCMs) and their prescriptions, which would be helpful to their quality control.

Cornuside suppresses lipopolysaccharide-induced inflammatory mediators by inhibiting nuclear factor-kappa B activation in RAW 264.7 macrophages

Cornuside, a secoiridoid glucoside compound, was isolated from the fruit of Cornus officinalis SIEB. et ZUCC. Cornuside has been reported to possess immunomodulatory and anti-inflammatory activities. However, the effects and mechanism of action of cornuside in inflammation have not been fully characterized. The present study was therefore designed to examine whether cornuside suppresses inflammatory response in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Cornuside significantly inhibited the LPS-induced production of nitric oxide, prostaglandin E(2), tumor necrosis factor-alpha, interleukin-6 (IL-6), and IL-1beta. The mRNA and protein expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were also decreased by cornuside. Furthermore, cornuside significantly attenuated the LPS-stimulated phosphorylation and degradation of inhibitory kappa B-alpha and the subsequent translocation of the p65 subunit of nuclear factor-kappa B (NF-κB) to the nucleus. Cornuside also reduced the phosphorylations of extracellular-signal-related kinase (ERK1/2), p38, and c-Jun N-terminal kinase (JNK1/2). These results suggest that the anti-inflammatory property of cornuside is related to the downregulations of iNOS and COX-2 due to NF-κB inhibition as well as the negative regulation of ERK1/2, p38, and JNK1/2 phosphorylations in RAW 264.7 cells.

Review of the effects of the traditional Chinese medicine Rehmannia Six Formula on diabetes mellitus and its complications

Rehmannia Six Formula (RF) is a formula that is commonly used in Traditional Chinese Medicine to treat patients with diabetes. A literature search was performed in PubMed for the years 2000-2009 using the key words RF, Rehmannia glutinosa, Fructus Corni, Dioscorea sp. (D. alata, D. opposita, D. batatas), Poria cocos, Alisma sp. (A. orientalis, A. plantago aquatica), and Paeonia suffruticosa/Cortex Moutan. On the basis of the publications found, RF appears to have beneficial effects on blood glucose, neuropathy, and nephropathy. There is also evidence of anti-inflammatory and antioxidant effects. Although there are many studies on compounds extracted from individual herbs, there are not many studies on RF as a whole. Because there is preliminary evidence that RF may be a useful supplement for the prevention of diabetic complications, clinical studies are warranted. For future clinical studies, it is recommended that details are provided regarding the preparation of RF and that the ratio of the individual components in RF is standardized so that results across studies can be compared.