Herbal remedies in the management of diabetes: lessons learned from the study of ginseng

Optimized extraction, enrichment, identification and hypoglycemic effects of triterpenoid acids from Hippophae rhamnoides L pomace

The Hippophae rhamnoides L. pomace was generated in the production process for juice, wine of food industry. To expand the application of pomace, the extraction process optimization, enrichment and identification of triterpene acids were performed in this study. The extraction yield was 14.87% under optimal ultrasound-assisted extraction techniques performed via response surface methodology. The extract was subsequently purified to obtain the triterpenoid acid enrichment fraction (TPF) with the content of 75.23% ± 1.45%. 13 triterpenoid acids were identified via UPLC-Triple-TOF MS/MS and further semi-quantified through comparison with triterpenoid acid standards. TPF exhibited a strong inhibitory effect on α-glucosidase with IC50 value of 5.027 ± 0.375 μg/mL, as determined via enzyme inhibition experiment and molecular docking. Additionally, the TPF significantly reduced postprandial glucose levels, as revealed via carbohydrate tolerance tests, as well as ameliorate serum lipid profiles. Therefore, pomace may be a promising resource of functional food components with therapeutic and commercial values.

Evaluation of suppressor behavior of guanidine-derived metformin and galegine as novel potential drugs for cancer treatment: an in silico study

There are some natural products from plants that can prevent and treat disease. Metformin, a derivative of galegine, is the basic drug to treat diabetes. Moreover, this molecule has anticancer properties that inhibit cancer cell growth and proliferation. In this study, the main interactions of galegine and metformin with various cancer-involved proteins, including mitochondrial alpha-glycerophosphate dehydrogenase, yeast NADH dehydrogenase, and transforming growth factor-β1, were surveyed by molecular docking and molecular dynamics simulations. The results showed that each of the proteins makes complexes with the ligands via favorable non-bonded interactions, especially hydrogen bond interactions. There is greater stability for complexes containing galegine based on the root mean square deviation results. The higher structure compactness is also found in galegine receptors than in metformin receptors. Calculation of ΔGbinding, using the MM/PBSA methodology, shows that the binding energy values for metformin and galegine in interaction with each of the receptors are almost the same, and galegine has similar binding properties with metformin in interaction with the studied protein receptors. Therefore, galegine, a natural ingredient with better binding properties to cancer-involved proteins than metformin (with various side effects), can be applied as a new drug for cancer treatment.

Systematic exploration of therapeutic effects and key mechanisms of Panax ginseng using network-based approaches

Background

Network pharmacology has emerged as a powerful tool to understand the therapeutic effects and mechanisms of natural products. However, there is a lack of comprehensive evaluations of network-based approaches for natural products on identifying therapeutic effects and key mechanisms.

Purpose

We systematically explore the capabilities of network-based approaches on natural products, using Panax ginseng as a case study. P. ginseng is a widely used herb with a variety of therapeutic benefits, but its active ingredients and mechanisms of action on chronic diseases are not yet fully understood.

Methods

Our study compiled and constructed a network focusing on P. ginseng by collecting and integrating data on ingredients, protein targets, and known indications. We then evaluated the performance of different network-based methods for summarizing known and unknown disease associations. The predicted results were validated in the hepatic stellate cell model.

Results

We find that our multiscale interaction-based approach achieved an AUROC of 0.697 and an AUPR of 0.026, which outperforms other network-based approaches. As a case study, we further tested the ability of multiscale interactome-based approaches to identify active ingredients and their plausible mechanisms for breast cancer and liver cirrhosis. We also validated the beneficial effects of unreported and top-predicted ingredients, in cases of liver cirrhosis and gastrointestinal neoplasms.

Conclusion

our study provides a promising framework to systematically explore the therapeutic effects and key mechanisms of natural products, and highlights the potential of network-based approaches in natural product research.

Effect of crocin and treadmill exercise on oxidative stress and heart damage in diabetic rats

Diabetes increases the production of free radicals and inflammatory agents in the heart tissue and alters the expression of genes associated with the induction of apoptosis. Considering the importance of common cardiovascular disorders in diabetes, this study investigated the effect of eight weeks of aerobic exercise and crocin use, as well as tissue damage and oxidative stress caused by diabetes in the hearts of adult rats. Streptozotocin 50 mg/kg was injected as a single dose intraperitoneally to cause the diabetes. After 72 hours, a glucometer monitored blood glucose levels, and blood glucose above 250 mg/dl was considered diabetes. Continuous treadmill exercise was performed for eight weeks by placing the animal on the treadmill. Next, the animals were anesthetized, and samples were taken from the hearts and frozen in liquid nitrogen. Then, superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) were measured in the cardiac tissue. Finally, the hearts of half of the animals were immediately immersed in a formalin solution for histological changes. According to our findings, diabetes increased lipid peroxidation, characterized by increased MDA levels in the control diabetes group and decreased SOD and GPx levels (P <0.05). It also changes the balance of expression of genes associated with apoptosis control, increased Bcl-2-associated X (Bax) expression, and decreased Bcl-2 expression (P <0.05). Also, we observed the induction of apoptosis in cardiac tissue. Using eight weeks of continuous exercise and administration of crocin significantly reduced blood sugar levels and lipid peroxidation and increased the activity of antioxidant enzymes and Bcl-2 gene expression compared to the diabetes control group. In addition, continuous exercise and crocin improved the oxidative stress parameters in the control group. This study showed that diabetes could cause oxidative stress and heart dysfunction. Moreover, simultaneously and separately, aerobic exercise with a treadmill and crocin administration can reduce these disorders and prevent apoptosis in the heart tissue.

Treatment on Nature’s lap: Use of herbal products in the management of hyperglycemia

Diabetes mellitus (DM) is characterized by persistently elevated blood glucose concentration that lead to multisystem complications. There are about 400 medicinal plants cited to have a beneficial effect on DM. We must choose products wisely based on data derived from scientific studies. However, a major obstacle in the amalgamation of herbal medicine in modern medical practices is the lack of clinical data on its safety, efficacy and drug interaction. Trials of these herbal products often underreport the side effects and other crucial intervention steps deviating from the standards set by Consolidated Standards of Reporting Trials. Due to a lack of knowledge of the active compounds present in most herbal medicines, product standardization is difficult. Cost-effectiveness is another issue that needs to be kept in mind. In this mini-review, we focus on the anti-hyperglycemic effect of herbal products that are commonly used, along with the concerns stated above.

MicroRNA-21: A critical underestimated molecule in diabetic retinopathy

Diabetes mellitus (DM) has grown in attention in recent years as a result of its debilitating complications and chronic disabilities. Diabetic retinopathy (DR) is a chronic microvascular complication of DM and is considered as the primary reason for blindness in adults. Early diagnosis of diabetes complications along with targeted therapy options are critical in avoiding morbidity and mortality associated with complications of diabetes. miR-21 is an important and widely studied non-coding-RNA (ncRNA) with considerable roles in various pathologic conditions including diabetic complications. miR-21 is one of the most elevated miRNAs in response to hyperglycemia and its role in angiogenesis is a major culprit of a wide range of disorders including DR. The main role of miR-21 in DR pathophysiology is believed to be through regulating angiogenesis in retina. This article aims to outline miR-21 biogenesis and distribution in human body along with discussions about its role in DR pathogenesis and its biomarker value in order to facilitate understanding of the new characteristics of miR-21 in DR management.

An Overview of the Potential of Medicinal Plants Used in the Development of Nutraceuticals for the Management of Diabetes Mellitus: Proposed Biological Mechanisms

Diabetes mellitus (DM) is a chronic metabolic disorder in which the pancreas does not produce enough insulin or the body cannot effectively use it. The prevalence of diabetes is increasing steadily, making it a global public health problem. Several serious complications are associated with this disease. There are a number of different classes of antidiabetic medications. Interestingly, traditional medicine can also be used for the development of novel classes of hypoglycemic therapeutics. This article summarizes an update of the potential of various important medicinal plants used in the development of nutraceuticals for the management of diabetes mellitus, and a proposal of their biological mechanisms.

Ginseng: A bibliometric analysis of 40-year journey of global clinical trials

BACKGROUND

Ginseng has a long history of widespread use and remarkable effects as traditional medicine, adjuvant and dietary supplement. The therapeutic value, diverse functionalities and rapid development of ginseng have driven a significant increase in the number of ginseng clinical trials, ranging from its use in various ailments, formulation to safety concerns. Despite the persistent interest in ginseng clinical research, the medical effectiveness of ginseng is inconclusive and there is a lack of bibliometric analysis of the hundreds of ginseng clinical trials.

AIM OF REVIEW

This review aims to provide an extensive overview of ginseng clinical trials over the past 40 years (1979-2018) in combination with a qualitative and quantitative analysis. The annual clinical trial analysis of time distribution, country and institution network analysis for space cooperation, statistical analysis for various functions, as well as efficiency and effect size were performed for global ginseng clinical trials. Besides, preparation categories, administration routes, and the safety of ginseng clinical trials were also investigated.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The 40-year journey of ginseng clinical trials has experienced emerging, boom, and stable or transitional stages. The global network of ginseng clinical trials has relevant regional distribution in Asia, North America and Europe. South Korea makes a great contribution to building up large research clusters and strong cooperation links. Universities are the key contributors to ginseng clinical trials. The development of ginseng products could be focused on the clinical trial in diseases with higher effectiveness or effect size, such as sexual function and cognitive & behavior and require rigorous investigations and evidence to evaluate safety. More attention should be paid to different effects from different preparations. We believe this review will provide new insights into the understanding of global ginseng clinical trials and identifies potential future perspectives for research and development of ginseng.

In vivo hypoglycemic, antihyperglycemic and antidyslipidemic effects of the solvent fractions of Hagenia abyssinica leaves in mice

Background

Hagenia abyssinica leaves have been used traditionally for the management of different diseases including diabetes mellitus (DM) although the antidiabetic effect of different solvent fractions of hydromethanol H. abyssinica leaf extract has not been scientifically studied. Thus, this study was conducted to investigate the in vivo hypoglycemic, antihyperglycemic and antidyslipidemic effects of the solvent fractions of Hagenia abyssinica leaf extract.

Methods

The antidiabetic effect of the solvent fractions was evaluated in normal, oral glucose loaded and streptozotocin-induced diabetic mice. Hypoglycemic, antihyperglycemic, antidyslipidemic activities and effect on body weight change were evaluated after administration of three different doses of the solvent fractions (100, 200, and 400 mg/kg). One-way ANOVA followed by Tukey's post hoc test was used for data analysis, and p<0.05 was considered as statistically significant.

Results

The crude hydromethanol extract of H. abyssinica leaves did not show any sign of toxicity at the dose of 2000 mg/kg in mice. In normoglycemic mice, both aqueous and ethyl acetate fractions of H. abyssinica leaves showed significant (P<0.05) hypoglycemic activity. In oral glucose loaded mice, the two doses of the aqueous fraction, 200 mg/kg (p<0.05) and 400 mg/kg (p<0.001), showed a significant antihyperglycemic effect at 60 and 120 minute post-oral glucose loading while the ethyl acetate fraction showed significant antihyperglycemic effect at 60 (P<0.05 for 200 mg/kg and P<0.001 for 400 mg/kg) and 120 min (P<0.01 for 400 mg/kg) post-oral glucose loading. In single dose-treated diabetic mice, all doses of the solvent fractions caused a significant (P<0.05) reduction in blood glucose level except 100 mg/kg of the aqueous and chloroform fractions. Additionally, repeated daily treatment with the aqueous fraction significantly reduced hyperglycemia, body weight loss, and improved dyslipidemia of diabetic mice.

Conclusion

This study has revealed that the solvent fractions of H. abyssinica leaves possess in vivo blood-glucose-lowering activities on normal, oral glucose loaded, and streptozotocin-induced diabetic mice. Additionally, the aqueous fraction prevented diabetic body weight loss and dyslipidemia in mice after repeated daily dose administration.

Effect of Phytopreparations Based on Bioreactor-Grown Cell Biomass of Dioscorea deltoidea, Tribulus terrestris and Panax japonicus on Carbohydrate and Lipid Metabolism in Type 2 Diabetes Mellitus

In the present study, we explored the therapeutic potential of bioreactor-grown cell cultures of the medicinal plant species Dioscorea deltoidea, Tribulus terrestris and Panax japonicus to treat carbohydrate metabolism disorders (CMDs) in laboratory rats. In the adrenaline model of hyperglycemia, aqueous suspensions of cell biomass pre-administered at a dose of 100 mg dry biomass/kg significantly reduced glucose level in animal blood 1–2.5 h (D. deltoidea and T. terrestris) or 1 h (P. japonicus) after adrenaline hydrochloride administration. In a streptozotocin-induced model of type 2 diabetes mellitus, the cell biomass of D. deltoidea and T. terrestris acted towards normalization of carbohydrate and lipid metabolism, as evidenced by a significant reduction of daily diuresis (by 39–57%), blood-glucose level (by 46–51%), blood content in urine (by 78–80%) and total cholesterol (25–36%) compared to animals without treatment. Bioactive secondary metabolites identified in the cell cultures and potentially responsible for their actions were deltoside, 25(S)-protodioscin and protodioscin in D. deltoidea; furostanol-type steroidal glycosides and quinic acid derivatives in T. terrestris; and ginsenosides and malonyl-ginsenosides in P. japonicus. These results evidenced for high potential of bioreactor-grown cell suspensions of these species for prevention and treatment of CMD, which requires further investigation.

Evaluation of In Vivo Antidiabetic, In Vitro α-Amylase Inhibitory, and In Vitro Antioxidant Activity of Leaves Crude Extract and Solvent Fractions of Bersama abyssinica Fresen (Melianthaceae)

Background.

The leaves of Bersama abyssinica are used for the treatment of diabetes mellitus in folk medicine system of Ethiopia. The present study was done based on the traditional claim of B abyssinica for the treatment of diabetes mellitus.

Methods.

The α-amylase inhibition and antioxidant activities of B abyssinica extracts were evaluated by using 3,5-dinitrosalicylic acid method and diphenyl-2-picrylhydrazyl assay model, respectively. Blood glucose lowering activity of the extracts was studied in 4 animal models; normoglycemic, oral glucose loaded, and streptozotocin-induced diabetic mice models.

Results.

Among the extracts, the crude extract showed the highest α-amylase enzyme inhibition activity with an IC₅₀ of 6.57 μg/mL. The water fraction showed the strongest antioxidant activity with an IC₅₀ of 3.43 μg/mL. The crude extract at doses of 200, and 400 mg/kg showed significant (P < .05) hypoglycemic activity in normoglycemic mice. All doses of the crude extract significantly (P < .05) reduced blood glucose levels of oral glucose-loaded mice. In streptozotocin-induced diabetic mice models, both the crude and solvent fractions showed a significant (P < .05) blood glucose lowering effect as compared with the negative control group post 8 hour treatment.

Conclusion.

The results demonstrated the beneficial biochemical effects of B abyssinica extract by inhibiting α-amylase and scavenging the free radicals. The crude extract and solvent fractions of B abyssinica had significant blood glucose lowering effect in all animal models.

Co-administration of viscous fiber, Salba-chia and ginseng on glycemic management in type 2 diabetes: a double-blind randomized controlled trial

PURPOSE

Viscous dietary fiber, functional seeds and ginseng roots have individually been proposed for the management of diabetes. We explored whether their co-administration would improve glycemic control in type 2 diabetes beyond conventional therapy.

METHODS

In a randomized, double-blind, controlled trial conducted at two academic centers (Toronto, Canada and Zagreb, Croatia), individuals with type 2 diabetes were assigned to either an active intervention (10 g viscous fiber, 60 g white chia seeds, 1.5 g American and 0.75 g Korean red ginseng extracts), or energy and fiber-matched control (53 g oat bran, 25 g inulin, 25 g maltodextrose and 2.25 g wheat bran) intervention for 24 weeks, while on conventional standard of care. The prespecified primary endpoint was end difference at week 24 in HbA1c, following an intent-to-treat analysis adjusted for center and baseline.

RESULTS

Between January 2016 and April 2018, 104 participants (60M:44F; mean ± SEM age 59 ± 0.8 years; BMI 29.0 ± 0.4 kg/m²; HbA1c 7.0 ± 0.6%) managed with antihyperglycemic agent(s) (n = 98) or lifestyle (n = 6), were randomized (n = 52 test; n = 52 control). At week 24, HbA1c levels were 0.27 ± 0.1% lower on test compared to control (p = 0.03). There was a tendency towards an interaction by baseline HbA1c (p = 0.07), in which a greater reduction was seen in participants with baseline HbA1c > 7% vs ≤ 7% (- 0.56 ± 0.2% vs 0.03 ± 0.2%). Diet and body weight remained unchanged. The interventions were well tolerated with no related adverse events and with high retention rate of 84%.

CONCLUSIONS

Co-administration of selected dietary and herbal therapies was well-tolerated and may provide greater glycemic control as add-on therapy in type 2 diabetes. Registration: Clinicaltrials.gov NCT02553382 (registered on September 17, 2015).

Mechanisms of action of metformin and its regulatory effect on microRNAs related to angiogenesis

Angiogenesis is rapidly initiated in response to pathological conditions and is a key target for pharmaceutical intervention in various malignancies. Anti-angiogenic therapy has emerged as a potential and effective therapeutic strategy for treating cancer and cardiovascular-related diseases. Metformin, a first-line oral antidiabetic agent for type 2 diabetes mellitus (T2DM), not only reduces blood glucose levels and improves insulin sensitivity and exerts cardioprotective effects but also shows benefits against cancers, cardiovascular diseases, and other diverse diseases and regulates angiogenesis. MicroRNAs (miRNAs) are endogenous noncoding RNA molecules with a length of approximately 19-25 bases that are widely involved in controlling various human biological processes. A large number of miRNAs are involved in the regulation of cardiovascular cell function and angiogenesis, of which miR-21 not only regulates vascular cell proliferation, migration and apoptosis but also plays an important role in angiogenesis. The relationship between metformin and abnormal miRNA expression has gradually been revealed in the context of numerous diseases and has received increasing attention. This paper reviews the drug-target interactions and drug repositioning events of metformin that influences vascular cells and has benefits on angiogenesis-mediated effects. Furthermore, we use miR-21 as an example to explain the specific molecular mechanism underlying metformin-mediated regulation of the miRNA signaling pathway controlling angiogenesis and vascular protective effects. These findings may provide a new therapeutic target and theoretical basis for the clinical prevention and treatment of cardiovascular diseases.

Effects of α-Cyclodextrin on Cholesterol Control and Hydrolyzed Ginseng Extract on Glycemic Control in People With Prediabetes: A Randomized Clinical Trial

IMPORTANCE

Effective strategies for preventing type 2 diabetes are needed. Many people turn to complementary medicines, but there is little well-conducted scientific evidence to support their use.

OBJECTIVE

To assess the efficacy of α-cyclodextrin for cholesterol control and that of hydrolyzed ginseng for glycemic control in people with prediabetes and overweight or obesity.

DESIGN, SETTING, AND PARTICIPANTS

This 6-month double-blind, placebo-controlled, randomized clinical trial, with a 2 × 2 factorial design, was conducted between July 2015 and October 2018 at 2 locations in Sydney, Australia. Eligible participants were aged 18 years or older, had a body mass index (weight in kilograms divided by height in meters squared) of 25 or higher, and had prediabetes within 6 months of study entry according to the American Diabetes Association guidelines. Data analysis was performed from May to August 2019.

INTERVENTIONS

Participants were randomized to 1 of 4 groups to take active or placebo versions of each supplement (α-cyclodextrin plus hydrolyzed ginseng, α-cyclodextrin plus placebo, placebo plus hydrolyzed ginseng, or placebo plus placebo) for 6 months. All participants received dietetic advice for weight loss.

MAIN OUTCOMES AND MEASURES

The primary outcomes were the differences in total cholesterol and fasting plasma glucose between groups after 6 months. The primary analysis used the intention-to-treat principle. Multiple predetermined subsample analyses were conducted.

RESULTS

A total of 401 participants were eligible for the study (248 women [62%]; mean [SD] age, 53.5 [10.2] years; mean [SD] body mass index, 34.6 [6.2]). One hundred one patients were randomized to receive α-cyclodextrin plus hydrolyzed ginseng, 99 were randomized to receive α-cyclodextrin plus placebo, 101 were randomized to receive placebo plus hydrolyzed ginseng, and 100 were randomized to receive placebo plus placebo. For 200 participants taking α-cyclodextrin compared with 201 participants taking placebo, there was no difference in total cholesterol after 6 months (-1.5 mg/dL; 95% CI, -6.6 to 3.5 mg/dL; P = .51). For 202 participants taking hydrolyzed ginseng compared with 199 participants taking placebo, there was no difference in fasting plasma glucose after 6 months (0.0 mg/dL; 95% CI, -1.6 to 1.8 mg/dL; P = .95). Use of α-cyclodextrin was associated with constipation (16 participants vs 4 participants; P = .006) and cough (8 participants vs 1 participant; P = .02). Use of hydrolyzed ginseng was associated with rash and pruritus (13 participants vs 2 participants; P = .006). Only 37 of 401 participants (9.2%) experienced these adverse events.

CONCLUSIONS AND RELEVANCE

Although they are safe for use, there was no benefit found for either α-cyclodextrin for cholesterol control or hydrolyzed ginseng for glycemic control in people with prediabetes and overweight or obesity.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry Identifier: ACTRN12614001302640.

Hypoglycemic, Anti-Hyperglycemic and Anti-Hyperlipidemic Effects of Bersama abyssinica Fresen (Melianthaceae) Leaves' Solvent Fractions in Normoglycemic and Streptozotocin-Induced Diabetic Mice

Background

The leaves of Bersama abyssinica are used by traditional healers and the community for the treatment of diabetes mellitus. Thus, the current study intended to evaluate the hypoglycemic, anti-diabetic, and anti-hyperlipidemic effects of Bersama abyssinica.

Methods

The solvent fractions of Bersama abyssinica leaves were prepared. A total of 132 healthy, male Swiss albino mice weighing 20-28 grams (age of 6-10 weeks) were used. The antidiabetic activity of all the doses (100, 200, and 400 mg/kg) of Bersama abyssinica solvent fractions was evaluated by animal models: normoglycemic mice, oral glucose loaded mice, and diabetic mice. Diabetes was induced by a single intraperitoneal injection of streptozotocin (150mg/kg body weight). The effect of the plant extract on body weight and serum lipid levels were measured in diabetic mice. Statistical analysis was performed by using statistical package for social sciences version 24. The analyses were carried out using one-way ANOVA, followed by Tukey's multiple comparison tests. The result was considered significant when p <0.05.

Results

The solvent fractions of B. abyssinica at all tested doses (100, 200, and 400 mg/kg) exhibited significant (P<0.05-0.001) BGL reduction in all animal models. In hypoglycemic activity, the percentage reduction of baseline BGL was 25.90%, 26.36%, 38.43%, 30.96% and 49.42% for EAF200mg/kg, AQF200mg/kg, EAF400mg/kg, AQF400mg/kg, and GLC 5mg/kg, respectively. B. abyssinica at the dose of AQF 200 mg/kg (p<0.05), AQF 400mg/kg (p<0.001), EAF 200mg/kg (p<0.01), and GLC 5mg/kg (p<0.001) significantly reduced the BGL following 1-hour post-treatment as compared to the negative control. Likewise, the higher doses of the solvent fractions (400mg/kg) significantly (p<0.001) reduced the BGL following 2- and 3-hours post-treatment as compared to the negative control. Daily administration of aqueous fraction of B. abyssinica caused a maximum reduction in fasting BGL at the fourteenth day of administration by 33.29%, 38.59%, 52.71%, and 59.66%, respectively, for AQF100, AQF200, AQF400, and GLC 5mg/kg. The aqueous fraction of B. abyssinica and the glibenclamide significantly (p<0.05) prevent loss of body weight and showed improvement in serum lipid levels.

Conclusion

The solvent fractions of Bersama abyssinica exhibit noticeable antidiabetic activity in all animal models (normoglycemic mice, oral glucose loaded mice, and diabetic mice) and showed improvement in body weight and serum lipid profile levels, which rationalizes the claimed use of the B. abyssinica in the treatment of diabetes mellitus.

Evaluation of in vitro and in vivo Anti-Diabetic, Anti-Hyperlipidemic and Anti-Oxidant Activity of Flower Crude Extract and Solvent Fractions of Hagenia Abyssinica (Rosaceae)

BACKGROUND

The flower of Hagenia abyssinica (Rosaceae) has been used in traditional health systems to treat diabetes mellitus in Ethiopia and Tanzania. However, the antidiabetic activity of this medicinal plant is not scientifically validated and authenticated. The present study aimed to investigate the in vitro and in vivo anti-diabetic activity of flower crude extract and solvent fractions of Hagenia abyssinica.

METHODS

The in vitro α-amylase inhibition and antioxidant activity of the crude extract and solvent fractions of Hagenia abyssinica were evaluated by using 3,5-dinitrosalicylic acid (DNSA) and diphenyl-2-picrylhydrazyl (DPPH) assay model, respectively. Blood glucose lowering activity of 80% methanolic flower crude extract and solvent fraction was studied in four animal models: normoglycemic mice model, oral glucose loaded mice model, single dose-treated streptozotocin-induced diabetic mice model, and repeated dose-treated streptozotocin-induced diabetic mice model. The effect of the crude extract and solvent fraction of Hagenia abyssinica on diabetic lipid profile and body weight was also studied.

RESULTS

The acute toxicity study of Hagenia abyssinica flower extract did not show mortality in the animals at the limit dose of 2g/kg during the observation period. The result of α-amylase enzyme inhibition activity was found in a dose-dependent manner, the strongest activity was shown by ethyl acetate fraction (54.23% inhibition at 800 μg/mL) compared to the standard acarbose having 91.87% inhibition at 800 μg/mL. Among these extracts, the crude extract had the highest antioxidant activity (58.38% inhibition at 500 μg/mL). The crude extract of H. abyssinica showed significant blood glucose-lowering effect on normoglycemic mice and oral glucose loaded mice. In streptozotocin-induced diabetic mice model, the crude extract and ethyl acetate fraction significantly decreased the fasting blood glucose level after 14 days of treatment. There were significant reductions in serum total cholesterol, serum triglycerides, very low-density lipoprotein, and low-density lipoprotein. However, there were significant increments in body weight and high-density lipoprotein as compared to untreated diabetic mice.

CONCLUSION

The result demonstrated the beneficial biochemical effects of Hagenia abyssinica extract by inhibiting α-amylase, scavenging diphenyl-2-picrylhydrazyl (DPPH) and improving serum lipid profile levels. The flower crude extract and solvent fractions of Hagenia abyssinica are effective in lowering blood glucose levels in diabetic and normoglycemic mice. The claimed traditional use as antidiabetic has scientific ground.

Turning Foes to Friends: Knocking Down Diabetes Associated SGLT2 Transporters and Sustaining Life

BACKGROUND

The discovery of Sodium-Glucose co-transporter-2 (SGLT2) inhibitors had rewritten the treatment of diabetes mellitus with an impressive fall in the incidence of death and associated complications.

INTRODUCTION

The SGLT2 inhibitors by inhibiting the SGLT2 in the proximal nephron, helps in reducing the reabsorption of approximately 90% of the filtered glucose and increased urinary glucose excretion (UGE).

METHODS

The literature related to SGLT2 inhibitors has been thoroughly explored from various available public domains and reviewed extensively for this article. Detailed and updated information related to SGLT2 inhibitors with a major focus on the recently approved Ertuglifolzin is structured in this review.

RESULT

The present review is an effort to understand the management of diabetes mellitus over the past few decades with a special focus on the role of SGLT2 receptor in the causes of therapeutic and preventive strategies for diabetes mellitus. Pragmatic placement of the currently available Canagliflozin, Dapagliflozin, and Empagliflozin as oral antidiabetic agents has been done. Well accommodated stereochemistry and a high docking score of Ertugliflozin in ligand-receptor simulation studies attribute to its high potency.

CONCLUSION

This review highlights the unique mechanism of SGLT2 Inhibitors coupled with pleiotropic benefits on weight and blood pressure, which make it an attractive choice of therapy to diabetic patients, not controlled by other medications.

Effects of alpha-cyclodextrin on cholesterol control and Compound K on glycaemic control in people with pre-diabetes: Protocol for a Phase III randomized controlled trial

The prevalence of pre-diabetes and of type 2 diabetes mellitus is increasing. Preventing disease progression is important to improve outcomes. Natural products are becoming popular alternatives to pharmaceutical products for preventative health and treatment of disease; however, the evidence to support the use of natural alternatives for pre-diabetes and type 2 diabetes is lacking. Two such natural medicines include alpha-cyclodextrin (marketed as FBCx), a fibre derived from corn starch that has been found to bind triglycerides in the intestines to prevent its absorption, aiding weight maintenance and lipid control, and hydrolysed ginseng extract (marketed as GINST15), a formula containing high amounts of Compound K, a metabolite of ginsenosides thought to be an active ingredient contributing to the anti-hyperglycaemic effects of ginseng. This paper describes the rationale and design of a 12-month randomized controlled trial to investigate the metabolic effects of these two products in people with pre-diabetes and overweight or obesity. A total of 400 participants will be randomized to one of four groups (FBCx + GINST15, FBCx + placebo, placebo + GINST15, placebo + placebo) for 6 months, followed by 6 months of follow-up. Participants will also receive lifestyle advice for healthy eating and weight loss. Data collected during the trial will include weight, waist circumference, body composition and blood pressure. Blood samples will also be collected to measure lipid profile and glycaemia. If the products are found to improve lipid and glucose levels, it will provide evidence for their use in people with pre-diabetes to help reduce the risk of progression to type 2 diabetes.

Efficacy and safety of American ginseng (Panax quinquefolius L.) extract on glycemic control and cardiovascular risk factors in individuals with type 2 diabetes: a double-blind, randomized, cross-over clinical trial

PURPOSE

Despite the lack of evidence, a growing number of people are using herbal medicine to attenuate the burden of diabetes. There is an urgent need to investigate the clinical potential of herbs. Preliminary observations suggest that American ginseng (Panax quinquefolius [AG]) may reduce postprandial glycemia. Thus, we aimed to evaluate the efficacy and safety of AG as an add-on therapy in individuals with type 2 diabetes (T2DM) controlled by conventional treatment.

METHODS

24 individuals living with T2DM completed the study (F:M = 11:13; age = 64 ± 7 year; BMI = 27.8 ± 4.6 kg/m²; HbA1c = 7.1 ± 1.2%). Utilizing a double-blind, cross-over design, the participants were randomized to receive either 1 g/meal (3 g/day) of AG extract or placebo for 8 weeks while maintaining their original treatment. Following a ≥ 4-week washout period, the participants were crossed over to the opposite 8-week treatment arm. The primary objective was HbA1c, and secondary endpoints included fasting blood glucose and insulin, blood pressure, plasma lipids, serum nitrates/nitrites (NOx), and plasominogen-activating factor-1 (PAI-1). Safety parameters included liver and kidney function.

RESULTS

Compared to placebo, AG significantly reduced HbA1c (- 0.29%; p = 0.041) and fasting blood glucose (- 0.71 mmol/L; p = 0.008). Furthermore, AG lowered systolic blood pressure (- 5.6 ± 2.7 mmHg; p < 0.001), increased NOx (+ 1.85 ± 2.13 µmol/L; p < 0.03), and produced a mean percent end-difference of - 12.3 ± 3.9% in LDL-C and - 13.9 ± 5.8% in LDL-C/HDL. The safety profiles were unaffected.

CONCLUSIONS

AG extract added to conventional treatment provided an effective and safe adjunct in the management of T2DM. Larger studies using physiologically standardized ginseng preparations are warranted to substantiate the present findings and to demonstrate therapeutic effectiveness of AG. CLINICALTRIALS.

GOV IDENTIFIER

NCT02923453.

SWOT analysis and revelation in traditional Chinese medicine internationalization

Traditional Chinese medicine (TCM) is currently the best-preserved and most influential traditional medical system with the largest number of users worldwide. In recent years, the trend of TCM adoption has increased greatly, but the process of TCM internationalization has suffered from a series of setbacks for both internal and external reasons. Thus, the process of TCM internationalization faces formidable challenges, although it also has favourable opportunities. Using SWOT analysis, this paper investigates the strengths, weaknesses, opportunities and threats for TCM. These findings can serve as references for TCM enterprises with global ambitions.

Unproven Therapies for Diabetes and Their Implications

Diabetes is a chronic disease and is one of the leading causes of morbidity and mortality worldwide. Being an ancient disease, many individuals follow complementary and alternative medicinal (CAM) therapies for either the cure or prevention of the disease. The popularity of these practices among the general public is in no way a testimony to their safety and efficacy. Due to the possibility of undesirable interactions with conventional medicines, it is imperative that patients are asked about CAM use during patient assessment. Patient- and physician-targeted awareness programs on various aspects of CAM use must be initiated to create a better understanding of evidence-based use of these practices. In addition, there should be guidelines in place based on clinical trial outcomes, and stricter regulations need to be enforced on CAM practices to ensure their safety and effectiveness.

Alpha-adrenoceptor antagonism by Crassostrea gigas oyster extract inhibits noradrenaline-induced vascular contraction in Wistar rats

OBJECTIVE

Crassostrea gigas oyster extract has been reported to have antioxidant, antihypertensive and lipid-lowering properties that may be useful for treating cardiovascular diseases. This study aimed to evaluate the effect of C. gigas oyster extract on cardiovascular function in tissues from healthy rats.

METHODS

Single-cell microelectrode and isolated thoracic aortic organ bath studies were performed on tissues from 8-week-old healthy Wistar rats, using varying concentrations of C. gigas oyster extract. To elucidate a mechanism of action for the oyster's vasoactive properties, concentration response curves were carried out in the presence of a calcium channel inhibitior (verapamil), a nitric oxide synthase inhibitor (N(G)-nitro-L-arginine methyl ester), a potassium channel inhibitor (4-aminopyridine), in addition to the α-adrenoceptor inhibitor prazosin.

RESULTS

Oyster solution at 7 500 mg/mL inhibited noradrenaline-induced contraction in isolated aortic rings. Cardiac electrophysiology results showed that neither concentration of oyster solution was able to significantly reduce action potential duration at all phases of repolarisation in left ventricular papillary muscles from healthy animals.

CONCLUSION

When administered to healthy vascular tissue, C. gigas oyster extract inhibits contraction induced by noradrenaline. This effect is likely to be mediated through α-adrenoceptor inhibition, and to a lesser extent, calcium modulating activity.

Natural products for the management of type 2 diabetes mellitus and comorbid conditions

OBJECTIVE

To provide pharmacists with practical information to guide consumers in their choices of herbal products and dietary supplements for the management of type 2 diabetes mellitus (T2DM) and its comorbid disease states.

SUMMARY

The herbal and dietary supplement market has grown exponentially over the past decade as Americans increasingly use such agents for generalized health and the prevention and treatment of chronic disease states.1 Pharmacist advice is often requested on the use of these agents for the management of T2DM; however, this is an area that has insufficient evidence to support confident recommendations. Many published studies involving herbal agents and dietary supplements are small and poorly designed, with heterogeneous results. Pharmacists should be aware of the safety and efficacy data available for these agents, recognize potential drug interactions, and identify acceptable manufactured products.

CONCLUSION

The strongest scientific evidence for blood glucose lowering effect is associated with alpha-lipoic acid and fenugreek. There is also good evidence supporting the use of ivy gourd, gymnema, and vitamin E for management of hyperglycemia; however, caution should be used when recommending vitamin E. Pharmacists should advise consumers to disclose use of any of these products to all of their health care providers.

Improved working memory performance following administration of a single dose of American ginseng (Panax quinquefolius L.) to healthy middle-age adults

OBJECTIVE

A ginsenoside-rich extract of American ginseng (Panax quinquefolius L.), Cereboost(TM), was previously shown to improve working memory and mood in healthy young individuals. The present study represented a partial replication investigating whether these effects extended to healthy middle-aged individuals.

METHODS

Fifty-two healthy volunteers (40-60 years old, mean age 51.63) received 200 mg of P. quinquefolius or a matching placebo according to a double-blind, placebo-controlled, balanced, crossover design. The Cognitive Drug Research battery and the Computerised Mental Performance Assessment System were used to evaluate cognitive performance at baseline then 1, 3 and 6 h following treatment. Blood glucose and mood were co-monitored.

RESULTS

Compared with placebo, P. quinquefolius improved cognitive performance on 'Working Memory' factor at 3 h. Similar effects were observed in one of the two tasks making up this factor, spatial working memory. There were no significant effects on mood or blood glucose levels.

CONCLUSIONS

These data confirm that P. quinquefolius can acutely benefit working memory and extend the age range of this effect to middle-aged individuals. These changes are unlikely to be underpinned by modulation of blood glucose in this population.

Ethanol extraction preparation of American ginseng (Panax quinquefolius L) and Korean red ginseng (Panax ginseng C.A. Meyer): differential effects on postprandial insulinemia in healthy individuals

ETHNOPHARMACOLOGICAL RELEVANCE

Ginsenosides are the proposed bioactive constituent of ginseng, especially for the attenuation of postprandial glycemia (PPG). The efficacious proportion of total and specific ginsenosides, remains unknown. Alcohol extraction of whole ginseng root can be used to selectively manipulate the ginsenoside profile with increasing alcohol concentrations producing high yields of total ginsenosides and varying their individual proportions.

AIM OF THE STUDY

We aimed to compare the acute efficacy of different ethanol-extraction preparations of American ginseng (AG) and Korean red ginseng (KRG), with their whole-root origins, on PPG and insulin parameters in healthy adults.

MATERIALS AND METHODS

Following an overnight fast, 13 healthy individuals (Gender: 5M:8F, with mean ± SD, age: 28.9 ± 9.2 years, BMI: 26.3 ± 2.7 kg/m(2) and fasting plasma glucose: 4.21 ± 0.04 mmol/L) randomly received 3g of each of the following 10 different ginseng treatments on separate visits: whole root KRG and AG; 30%, 50% or 70% ethanol extracts of KRG and AG and 2 cornstarch placebos. Treatments were consumed 40 min prior to a 50 g oral glucose challenge test with capillary blood samples collected at baseline, 15, 30, 45, 60, 90 and 120 min. Insulin samples were collected at 0, 30, 60 and 120 min.

RESULTS

There was no difference in attenuation of PPG among the tested ginseng preparations. Measures of Insulin Sensitivity Index (ISI) showed increased insulin sensitivity (IS) with KRG-30% and AG-50% extracts compared to placebo (p<0.05).

CONCLUSIONS

The insulin sensitizing effects of KRG-30% and AG-50% extracts suggest that other root parts, including other ginsenosides not typically measured, may influence PPG and insulin parameters. There is potential for AG and KRG extracts to modulate IS, an independent predictor of type 2 diabetes.

The effect of pulp and seed extract of Citrullus Colocynthis, as an antidaibetic medicinal herb, on hepatocytes glycogen stores in diabetic rabbits

Background:

Medicinal herbs such as Citrullus Colocynthis (C.C) have been used traditionally in the treatment of diabetes mellitus. However therapeutic applications and adverse effects of C.C and its natural variants are not determined well. The current work investigates the effects of pulp and seed extract of C.C on hepatocyte's glycogen stores.

Materials and Methods:

Thirty six male rabbits were divided into six groups (control and diabetic) randomly. Alloxan was used in order to induce diabetes mellitus in animals. Among 5 diabetic groups, one remained as control and the rest received 100 and 200 mg/kg/day of either pulp or seed extract. One month later, animals were sacrificed and their liver specimen fixed in 10% Formalin was stained with periodic acid schiff (PAS) for light microscopic scanning.

Results:

PAS staining of hepatocytes revealed large amounts of glycogen stores in diabetic animals treated with pulp and seed extracts of C.C, contrary with non-treated diabetic rabbits. Sites of glycogen deposition were also different in animals treated with seed extract (P < 0.0001). No hepatic congestion was seen in treated animals. Dose escalation has no effect on the obtained results.

Conclusions:

The anti-diabetic effects of C.C can be explained by its effects on accumulation of glycogen stores in hepatocytes. The importance of varied sites of glycogen deposition by the application of C.C needs to be determined.

[Translational research in gestational diabetes mellitus and mild gestational hyperglycemia: current knowledge and our experience]

Maternal diabetes constitutes an unfavorable environment for fetal-placental and embryonic development. It is has important repercussion in modern obstetrics, since it is associated to an increased risk of neonatal and maternal morbidity, and it still is a significant medical challenge. The increased occurrence of diabetes worldwide, the increase in diabetes type 2 in women at reproductive age and the crossed generation of intrauterine programming for diabetes type 2 are the bases for the growing interest in utilization of diabetic experimental samples, with the aim to acquire knowledge about the mechanisms that induce development alterations in gestational diabetes. Several studies have shown the benefits of diabetes prevention, with interventions in lifestyle, metabolic improvement and control of cardiovascular risk factors to substantially prevent the complications of this devastating disease. Despite these findings, the recent revolution in the scientific knowledge, and the infinite number of new therapies for diabetes, there is still a large gap between what was learned through research and what is really done in public, clinical and community health. The negative economic impact of this complacency in people, families, and national economies is alarming. It is expected that translational research in the binomial diabetes and pregnancy are implemented in centers of excellence, in both basic and applied research, and complemented by multicenter clinical studies, conducted in a pragmatic way to increase the level of scientific evidence with more reliable diagnostic and propaedeutic resources.

Korean red ginseng improves glucose control in subjects with impaired fasting glucose, impaired glucose tolerance, or newly diagnosed type 2 diabetes mellitus

This study was designed to evaluate the effect of Korean red ginseng (KRG) supplementation on glucose control in subjects with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or newly diagnosed type 2 diabetes mellitus (T2DM). The study was a 12-week randomized, double-blinded, placebo-controlled (5 g of KRG [n=21] or placebo [n=20] in tablet form) trial. Glucose-related biomarkers, including serum and whole blood levels of glucose, insulin, and C-peptide, were measured by 2-h oral glucose tolerance tests (OGTTs) at baseline and after the 12-week intervention. After the intervention, the test group showed a significant decrease in serum levels of glucose at 30 min (-22.24±10.77 mg/dL) and whole blood levels of glucose at 30 min (-17.52±5.22 mg/dL). In addition, the test group tended to have lower whole blood levels of glucose at 0 min and glucose area under curve (AUC). However, the placebo group did not show any changes in blood glucose-related indices. The changes (difference from baseline) in serum glucose levels at 30 min, whole blood glucose levels at 60 min, and glucose AUC during OGTTs in the test group exhibited a tendency toward a decrease from those in the placebo group. There were significant decreases or trends toward a decrease in both serum insulin and C-peptide concentrations at most time intervals in the test group. In conclusion, KRG supplementation (5 g/day) may be beneficial for controlling serum and whole blood glucose levels compared with placebo among patients with IFG, IGT, or T2DM.

Effects of Korean red ginseng supplementation on muscle glucose uptake in high-fat fed rats

It has been recognized that ginseng has anti-diabetic effects in skeletal muscle, but the mechanism has not been intensively investigated. The aim of this study was to investigate the effects of Korean red ginseng (Panax ginseng) supplementation on muscle glucose uptake in high-fat fed rats. Sixteen rats were randomly divided into two groups: a control group (CON, n = 8) and a Korean red ginseng group (KRG, n = 8). The KRG group ingested RG extract (1 g·kg(-1), 6 days/week) mixed in water for two weeks. After the two-week treatment, plasma lipid profiles, and glucose and insulin concentrations were measured. The triglyceride (TG) and glucose transporter 4 (GLUT-4) contents were measured in the skeletal muscle and liver. The rate of glucose transport was determined under a submaximal insulin concentration during muscle incubation. Plasma FFA concentrations were significantly decreased in KRG (P < 0.05). Liver and muscle triglyceride concentrations were also decreased in the KRG treatment group (P < 0.05) compared to the CON group. In addition, resting plasma insulin and glucose levels were significantly lower after Korean red ginseng treatment (P < 0.05). However, muscle glucose uptake was not affected by Korean red ginseng treatment, as evidenced by the rate of glucose transport in the epitorchealis muscle under submaximal insulin concentrations. These results suggest that while KRG supplementation could improve whole body insulin resistance and plasma lipid profiles, it is unlikely to have an effect on the insulin resistance of skeletal muscle, which is the major tissue responsible for plasma glucose handling.

American Ginseng Extract (Panax quinquefolius L.) Is Safe in Long-Term Use in Type 2 Diabetic Patients

Aim. The objective of the present study was to test the safety of supplementation with the American ginseng (AG) interventional material as an adjunct to conventional therapy (diet and/or medications) in type 2 diabetes, using a double-blind, randomized, placebo-controlled, parallel design. Methods. Each participant received either AG (10% ginsenosides) or placebo capsules (500 mg/meal = 3 g/day) for a period of 12 weeks. Outcomes included measures of safety including kidney function (urates and creatinine), liver function (AST and ALT), and haemostatic function (PV and INR). Results. Seventy-four participants with well-controlled type 2 diabetes (sex: 28 M and 46 F, age: 63 ± 9.5, BMI: 32 ± 5, and HbA1c: 7 ± 1.3), randomized to either intervention (n = 35) or control (n = 39) group, completed the study. There was no change in any of the measures of safety between treatments from baseline. The number or severity of adverse events did not differ between the AG intervention and placebo. Conclusion. Following 12 weeks of supplementation with AG, safety was not compromised in a high cardiovascular disease (CVD) risk population of patients with type 2 diabetes. This demonstrated that safety is noteworthy, as reviews have continuously warned of possible adverse effects of ginseng consumption.

Cinnamon extract improves insulin sensitivity in the brain and lowers liver fat in mouse models of obesity

Objectives

Treatment of diabetic subjects with cinnamon demonstrated an improvement in blood glucose concentrations and insulin sensitivity but the underlying mechanisms remained unclear. This work intends to elucidate the impact of cinnamon effects on the brain by using isolated astrocytes, and an obese and diabetic mouse model.

Methods

Cinnamon components (eugenol, cinnamaldehyde) were added to astrocytes and liver cells to measure insulin signaling and glycogen synthesis. Ob/ob mice were supplemented with extract from cinnamomum zeylanicum for 6 weeks and cortical brain activity, locomotion and energy expenditure were evaluated. Insulin action was determined in brain and liver tissues.

Results

Treatment of primary astrocytes with eugenol promoted glycogen synthesis, whereas the effect of cinnamaldehyde was attenuated. In terms of brain function in vivo, cinnamon extract improved insulin sensitivity and brain activity in ob/ob mice, and the insulin-stimulated locomotor activity was improved. In addition, fasting blood glucose levels and glucose tolerance were greatly improved in ob/ob mice due to cinnamon extracts, while insulin secretion was unaltered. This corresponded with lower triglyceride and increased liver glycogen content and improved insulin action in liver tissues. In vitro, Fao cells exposed to cinnamon exhibited no change in insulin action.

Conclusions

Together, cinnamon extract improved insulin action in the brain as well as brain activity and locomotion. This specific effect may represent an important central feature of cinnamon in improving insulin action in the brain, and mediates metabolic alterations in the periphery to decrease liver fat and improve glucose homeostasis.

Enzogenol improves diabetes-related metabolic change in C57BL/KsJ-db/db mice, a model of type 2 diabetes mellitus

Objectives

Dietary use of pine bark extract has been associated with reduced risk of inflammation and diabetes. In this study, we investigated the antidiabetic effects of enzogenol, proanthocyanidins-rich bioflavonoid extract derived from the pine bark of New Zealand Pinus radiata trees, using C57BL/KsJ-db/db mice.

Methods

After 1-week acclimation period, the db/db mice were divided into vehicle-treated, Enzogenol-treated (12.5, 25 and 50 mg/kg; EZ) and positive control (tea polyphenol 50 mg/kg; TPP) groups.

Key findings

The administration of EZ improved the glucose tolerance and lowered the glycosylated haemoglobin (HbA1C), insulin and glucagon levels in blood. Interestingly, EZ and TPP treatments resulted in reduced hepatic free fatty acid, cholesterol and triglyceride levels in db/db mice. EZ and TPP treatments significantly elevated hepatic AMPK activity, and the expression of proteins related to glucose homeostasis and lipid metabolism, such as glucokinase, peroxisome proliferator-activated receptor (PPAR)α and long-chain acyl-CoA dehydrogenase protein level with a simultaneous reduction of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase protein expression. In addition, the EZ administration groups had an increased hepatic glycogen synthase expression in db/db mice.

Conclusions

These results suggest that EZ may be beneficial in improving insulin resistance and hyperglycaemia in type 2 diabetic mice by enhancing the glucose and lipids metabolism.

Effect of American ginseng (Panax quinquefolius L.) on arterial stiffness in subjects with type-2 diabetes and concomitant hypertension

ETHNOPHARMACOLOGICAL RELEVANCE

Substantial pre-clinical and some clinical data are available showing that Asian ginseng (Panax ginseng C.A. Meyer) varieties or its particular ginsenosides exert a vasodilatating effect, thus may modulate vascular function. However, the clinical evidence for American ginseng (Panax quinquefolius L.) is scarce. Therefore, this study evaluates the effect of American ginseng (AG) on arterial stiffness, as measured by augmentation index (AI), and blood pressure (BP), in type 2 diabetes patients with concomitant hypertension.

MATERIALS AND METHODS

Using a double-blind, placebo-controlled, parallel design, each participant was randomized to either the selected AG extract or placebo at daily dose of 3g for 12 weeks as an adjunct to their usual antihypertensive and anti-diabetic therapy (diet and/or medications). AI and BP were measured by applanation tonometry at baseline and after 12 weeks of treatment.

RESULTS

A total of 64 individuals with well-controlled essential hypertension and type 2 diabetes (gender: 22 M:42 F, age:63 ± 9.3 years, BP: 145 ± 10.8/84 ± 8.0 mmHg, HbA1c: 7.0 ± 1.3%, fasting blood glucose (FBG): 8.1 ± 2.3 mmol/L) completed the study. Compared to placebo, 3g of AG significantly lowered radial AI by 5.3% (P=0.041) and systolic BP by 11.7% (P<0.001) at 12 weeks. No effect was observed with diastolic BP.

CONCLUSIONS

Addition of AG extract to conventional therapy in diabetes with concomitant hypertension improved arterial stiffness and attenuated systolic BP, thus warrants further investigation on long-term endothelial parameters before recommended as an adjunct treatment.

Interaction of Veratrum nigrum with Panax ginseng against Obesity: A Sang-ban Relationship

Obesity has become a major health threat in developed countries. However, current medications for obesity are limited because of their adverse effects. Interest in natural products for the treatment of obesity is thus rapidly growing. Korean Medicine (KM) is characterized by the wide use of herbal formulas. However, the combination rule of herbal formulas in KM lacks experimental evidence. According to Shennong's Classic of Materia Medica, the earliest book of herbal medicine, Veratrum nigrum (VN) has antagonistic features against Panax ginseng (PG), and the PG-VN pair is strictly forbidden. In this study, we have shown the effects of PG, VN, and their combination on obesity in high-fat (HF) diet-induced obese mice and in 3T3-L1 cells. PG, VN, and PG-VN combination significantly reduced weight gain and the fat pad weight in HF diet-induced obese mice. They also significantly decreased lipid accumulation and the expressions of two major adipogenesis factors, PPARγ and C/EBPα, in 3T3-L1 cells. In addition, the PG-VN combination had synergistic effects compared with the mixture of extracts of PG and VN on inhibition of PPARγ and C/EBPα expressions at lower doses. These results indicate a new potential anti-obese pharmacotherapy and also provide scientific evidence supporting the usage of herbal combinations instead of mixtures in KM.

Antihyperglycemic and antihyperlipidemic activities of 2-(4-[(2-hydroxybenzyl) amino]-phenyl amino-methyl)-phenol in STZ induced diabetic rats

Oral administration of 2-(4-[(2-hydroxybenzyl) amino]-phenyl amino-methyl)-phenol (HBPMP) (30 mg/kg) to Streptozotocin (STZ) rats produced significant antidiabetic activity after 6 h of HBPMP administration. Treatment of the STZ rats with HBPMP (30 mg/kg/day) for 30 days resulted in a significant decrease in their Fasting Blood Glucose (FBG), Serum Total Cholesterol (TC), Low Density Lipoprotein-Cholesterol (LDL-C), Very Low Density Lipoprotein-Cholesterol (VLDL-C) and triglycerides (TG) along with an increase in serum High Density Lipoprotein-Cholesterol (HDL-C) levels. Activities of Serum Aspartate transaminase (AST), Alanine transaminase (ALT) and Alkaline phosphatase (ALP) and levels of blood urea and creatinine were improved to near normal levels in the treated STZ rats indicating the protective role of the HBPMP against liver and kidney damage and its non-toxic property. In conclusion, HBPMP possesses antihyperglycemic and antihyperlipidemic activities.

Ginseng and diabetes: the evidences from in vitro, animal and human studies

Panax ginseng exhibits pleiotropic beneficial effects on cardiovascular system, central nervous system, and immune system. In the last decade, numerous preclinical findings suggest ginseng as a promising therapeutic agent for diabetes prevention and treatment. The mechanism of ginseng and its active components is complex and is demonstrated to either modulate insulin production/secretion, glucose metabolism and uptake, or inflammatory pathway in both insulin-dependent and insulin-independent manners. However, human studies are remained obscure because of contradictory results. While more studies are warranted to further understand these contradictions, ginseng holds promise as a therapeutic agent for diabetes prevention and treatment. This review summarizes the evidences for the therapeutic potential of ginseng and ginsenosides from in vitro studies, animal studies and human clinical trials with a focus on diverse molecular targets including an AMP-activated protein kinase signaling pathway.

Syzygium cumini (L.) Skeels., a novel therapeutic agent for diabetes: folk medicinal and pharmacological evidences

OBJECTIVES

During the past few decades numerous folk medicinal and scientific investigations on the antidiabetic effects of jambolan (Syzygium cumini (L.) Skeels) have been reported. However no comprehensive evidence-based review is available. Hence this review was aimed to summarize the antidiabetic effects of different parts and active principles of jambolan.

METHODS

The review is based on the available electronic literature indexed in the PubMed. The search terms were: Syzygium cumini, Eugenia jambolana, jambolan, jamun, and java plum with and without antidiabetic effect.

RESULTS

Based on experimental studies and folk medicinal evidences, we summarized an up to date and comprehensive report on the antidiabetic activity of jambolan. The mode of action of some of the parts and active principles is also included. Preclinical and clinical studies suggest that, different parts of this plant especially fruits, seeds and stem bark were reported for promising activity against diabetes.

CONCLUSIONS

Till date no review is available for the evidence based preclinical/clinical study of jambolan with its antidiabetic effect. There is an immediate attention need for detailed analysis to identify its active principles. It could be used to produce safer drugs to treat diabetes.

The leaf and seed aqueous extract of Phyllanthus amarus improves insulin resistance diabetes in experimental animal studies

ETHNOPHARMACOLOGICAL RELEVANCE

Amongst the Yoruba tribe (Southwest Nigeria), water decoction of the leaf and seed of Phyllanthus amarus Schum. and Thonn. is reputably used for the local management of diabetes mellitus, obesity and hyperlipidemia.

AIM OF THE STUDY

The present study seeks to evaluate the effectiveness and elucidate mechanism(s) of action of the aqueous leaf and seed extract of Phyllanthus amarus (PAE) in normal and 10% sucrose-induced hyperglycemia and dyslipidemia as an experimental model of insulin resistance diabetes mellitus.

MATERIALS AND METHODS

In this study, the repeated oral antihyperglycemic action of 150-600 mg/kg/day of PAE was evaluated in normal and 10% sucrose-induced insulin resistance rats using indicators such as fasting blood glucose (FBG), insulin and insulin resistance indices. The extract's weight losing, antihyperlipidemic and anti-atherogenic effects were also evaluated by measuring the effect of the extract on the body weight, plasma levels of triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c) and atherogenic indices.

RESULTS

In normal rats, PAE caused significant (p<0.05, p<0.01 and p<0.001) and dose related decreases in body weight, FBG, TG, TC, LDL-c, and atherogenic indices. Repeated oral treatment with 10% sucrose drink for 30 days was associated with significant (p<0.001) weight gain, hyperglycemia, insulin resistance indices, hyperlipidemia and atherogenic indices. However, pre-treatment with PAE significantly (p<0.05, p<0.01 and p<0.001) and dose-dependently attenuated increase in any of these measured parameters.

CONCLUSIONS

Overall, results of this study showed PAE to effectively control insulin resistance DM which was mediated via improvement in insulin resistance, thus, validating its ethnomedical use in the local management of DM.

Ginsenoside Re rapidly reverses insulin resistance in muscles of high-fat diet fed rats

OBJECTIVE

In a previous study, it was found that a ginseng berry extract with a high content of the ginsenoside Re normalized blood glucose in ob/ob mice. The objective of this study was to evaluate the effect of the ginsenoside Re on insulin resistance of glucose transport in muscles of rats made insulin resistant with a high-fat diet.

MATERIAL/METHOD

Rats were fed either rat chow or a high-fat diet for 5 weeks. The rats were then euthanized, and insulin stimulated glucose transport activity was measured in epitrochlearis and soleus muscle strips in vitro.

RESULTS

Treatment of muscles with Re alone had no effect on glucose transport. The high-fat diet resulted in ~50% decreases in insulin responsiveness of GLUT4 translocation to the cell surface and glucose transport in epitrochlearis and soleus muscles. Treatment of muscles with Re in vitro for 90 min completely reversed the high-fat diet-induced insulin resistance of glucose transport and GLUT4 translocation. This effect of Re is specific for insulin stimulated glucose transport, as Re treatment did not reverse the high-fat diet-induced resistance of skeletal muscle glucose transport to stimulation by contractions or hypoxia.

CONCLUSIONS

Our results show that the ginsenoside Re induces a remarkably rapid reversal of high-fat diet-induced insulin resistance of muscle glucose transport by reversing the impairment of insulin-stimulated GLUT4 translocation to the cell surface.

Identification of novel human dipeptidyl peptidase-IV inhibitors of natural origin (Part II): in silico prediction in antidiabetic extracts

BACKGROUND

Natural extracts play an important role in traditional medicines for the treatment of diabetes mellitus and are also an essential resource for new drug discovery. Dipeptidyl peptidase IV (DPP-IV) inhibitors are potential candidates for the treatment of type 2 diabetes mellitus, and the effectiveness of certain antidiabetic extracts of natural origin could be, at least partially, explained by the inhibition of DPP-IV.

METHODOLOGY/PRINCIPAL FINDINGS

Using an initial set of 29,779 natural products that are annotated with their natural source and an experimentally validated virtual screening procedure previously developed in our lab (Guasch et al.; 2012) [1], we have predicted 12 potential DPP-IV inhibitors from 12 different plant extracts that are known to have antidiabetic activity. Seven of these molecules are identical or similar to molecules with described antidiabetic activity (although their role as DPP-IV inhibitors has not been suggested as an explanation for their bioactivity). Therefore, it is plausible that these 12 molecules could be responsible, at least in part, for the antidiabetic activity of these extracts through their inhibitory effect on DPP-IV. In addition, we also identified as potential DPP-IV inhibitors 6 molecules from 6 different plants with no described antidiabetic activity but that share the same genus as plants with known antidiabetic properties. Moreover, none of the 18 molecules that we predicted as DPP-IV inhibitors exhibits chemical similarity with a group of 2,342 known DPP-IV inhibitors.

CONCLUSIONS/SIGNIFICANCE

Our study identified 18 potential DPP-IV inhibitors in 18 different plant extracts (12 of these plants have known antidiabetic properties, whereas, for the remaining 6, antidiabetic activity has been reported for other plant species from the same genus). Moreover, none of the 18 molecules exhibits chemical similarity with a large group of known DPP-IV inhibitors.