Acute toxicity evaluation of homeopathic preparation of Gymnema sylvestre and analysis of its chemical constituents

In many countries, homeopathic preparation is believed to be an effective medicine for various ailments.However, there are limited scientific evidences in regard to its usage, safety, and efficacy. It is necessary toupdate this age-old scientific wisdom in different aspects, including pharmacologic and therapeutic potentials.In this study, we assessed the safety profile of homeopathic preparation of Gymnema sylvestre (HPGS). Itschemical constituents were deciphered using LCMS approaches. HPGS was subjected to an acute toxicitystudy (OECD-423 guidelines) using Sprague Dawley rats. The administration of HPGS did not produce anytoxic symptoms or show mortality at the dose level of 300 mg/kg body weight. Phytochemical analysis revealedthat HPGS contained alkaloids, saponins, and flavonoids. These results demonstrated the non-toxic nature ofHPGS in vivo, suggesting a long-term usage in clinical practices when administered orally

De novo in vitro shoot morphogenesis from shoot tip-induced callus cultures of Gymnema sylvestre (Retz.) R. Br. ex Sm

BACKGROUND: Gymnema sylvestre is a medicinal woody perennial vine known for its sweetening properties and antidiabetic therapeutic uses in the modern and traditional medicines. Its over-exploitation for the therapeutic uses and to meet the demand of pharmaceutical industry in raw materials supply for the production of anti-diabetic drugs has led to considerable decline in its natural population. RESULTS: An efficient system of shoot bud sprouting from nodal segment explants and indirect plant regeneration from apical meristem-induced callus cultures of G. sylvestre have been developed on Murashige and Skoog (MS) medium amended with concentrations of cytokinins. Of the three growth regulators tested, N6-benzylaminopurine (BAP) was the most efficient and 2.0 mg L-1 gave the best shoot formation efficiency. This was followed by thidiazuron (TDZ) and kinetin (Kin) but, most of the TDZ-induced micro shoots showed stunted growth. Multiple shoot formation was observed on medium amended with BAP or TDZ at higher concentrations. The produced micro shoots were rooted on half strength MS medium amended with auxins and rooted plantlets acclimatized with 87% survival of the regenerates. CONCLUSIONS: The developed regeneration system can be exploited for genetic transformation studies, particularly when aimed at producing its high yielding cell lines for the anti-diabetic phytochemicals. It also offers opportunities for exploring the expression of totipotency in the anti-diabetic perennial vine.

A comparative study of antihyperglycemic effect of Gymnema sylvestre and metformin in streptozotocin induced diabetic rats

Background: Diabetes mellitus (DM) is a metabolic disorder that has the phenotype of hyperglycemia. According to World Health Organization (WHO) there were 65.1 million diabetics in India in 2013, International Diabetes Federation estimates this to increase to 190 million by 2035. Although a number of drugs are available for treatment of DM, their cost and safety profile are major concern. Medicinal plants are used by clinicians for treatment of diabetes. Gymnema sylvestre (GS) extract has been reported to increase insulin levels in diabetic rats. This study was designed to compare the antihyperglycemic effect of Gymnema sylvestre with metformin.Methods: Diabetes was induced in Sprague-Dawley rats using streptozotocin 45mg/kg. Methanolic extract of Gymnema sylvestre 120mg/kg p.o. prepared using Soxhlet apparatus.Results: GS extract reduced blood glucose levels but not statistically significant. GS extract increased HDL and triglycerides, reduced both serum ALT and AST but no statistical significance seen. Metformin significantly increased serum urea, which was not seen in GS extract group. GS extract showed regenerative changes in pancreas, liver and kidney.Conclusions: The study investigation demonstrates that methanolic extract of GS possesses antihyperglycemic and hypolipidaemic activity and so it can be considered as a promising natural remedy in a prediabetic state and in mild hyperlipidaemia to prevent its progression. Increase in ? cell regeneration activity could be a probable mechanism of action. However, further long term clinical studies are recommended to define its possible role in diabetes mellitus and hyperlipidaemia. Role of GS as a potential hepatoprotective agent also needs further evaluation.

Mechanism Study on Gymnema Sylvestre Total Saponins Alleviating Insulin Resistance via Regulation of PI3κ/AKT Signal Transduction Pathway in Adipose Tissues / 世界科学技术-中医药现代化

This study was aimed to observe the effects of gymnema sylvestre total saponins (GA) on insulin resistance (IR) in adipose tissues of KKay mice,in order to discuss the action mechanism from the PI3K/AKT signal transduction pathway.A total of 27 KKay mice were randomly divided into the model group (DM),Pioglitazone group (BG) and GA group.Nine normal C57BL/6J mice were used as the normal control group (NC).Intragastric administration of drugs was given for eight weeks.The bodyweight and food intake of all mice were tested each week.After the experiment was completed,fasting plasma insulin (Fins) and fasting plasma glucose (FPG) were detected and the insulin sensitive index (ISI) was calculated.Expressions of PDK-1,AKT,P-AKT (Ser473),P-AKT (Thr308) in adipose tissues of epididymis in mice were detected.And expressions of PI3K-p85 mRNA,PTEN mRNA,APN mRNA were also measured.The results showed that compared with DM group,bodyweight of BG and GA groups were decreased (P＜0.05,P＜0.05);FPG and Fins level of BG and GA groups were decreased (P＜0.05,P＜0.05,P＜0.05,P＜0.05),ISI increased (P＜0.05,P＜0.05);APN mRNA increased in BG and GA group (P＜0.01,P＜0.01);PI3K-p85 mRNA increased in GA group (P＜0.05);P-AKT (Thr308) protein expression increased in BG and GA group (P＜0.05,P＜0.01);P-AKT (Ser473) protein expression increased in GA group (P＜0.05);the phosphorylation of AKT (Thr 308) was enhanced in BG and GA group (/9＜0.01,P＜ 0.01);the phosphorylation of AKT (Ser473) was enhanced in GA group (P＜0.01,P＜0.01).PDK-1 protein expression was decreased in BG and GA group (P＜0.05);PTEN mRNA decreased in BG and GA group (P＜0.05,P＜0.01).It was concluded that GA can ameliorate IR by sensitizing PI3κ/AKT signal pathway in adipose tissues of KKAy mice.

Effects of feeding a diet containing Gymnema sylvestre extract: Attenuating progression of obesity in C57BL/6J mice

Objective To investigate the effect of Gymnema sylvestre extract (GS) on initial anti-obesity, liver injury, and glucose homeostasis induced by a high-fat diet (HFD). Methods The dry powder of GS was extracted with methanol, and gymnemic acid was identified by high performance liquid chromatography as deacyl gymnemic acid. Male C57BL/6J mice that fed on either a normal diet, normal diet containing 1 g/kg GS (CON+GS), HFD, or HFD containing 1.0 g/kg GS (HFD + GS) for 4 weeks were used to test the initial anti-obesity effect of GS. Body weight gain and food intake, and serum levels about lipid and liver injury markers were measured. Histopathology of adipose tissue and liver stained with hematoxylin and eosin (H&E) and oil-red O were analyzed. After 4 weeks of GS extract feeding, intraperitoneal glucose tolerance test (IPGTT) was performed. Results The methanol extracts of GS exerted significant anti-obesity effects in HFD + GS group. They decreased body weight gain, a lower food and energy efficiency ratio, and showed lower serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL)-cholesterol, very-low density lipoprotein (VLDL)-cholesterol and leptin compared with the HFD group. The decreases of abdominal as well as epididymal fat weight and adipocyte hypertrophy, lipid droplets in liver, and serum levels of aspartate aminotransferase (AST) and alanine transaminase (ALT) were also observed. The CON + GS group showed an effect of glucose homeostasis compared to the CON group. Conclusions This study shows that GS provide the possibility as a key role in an initial anti-obesity effects feeding with a HFD.

Effects of feeding a diet containing Gymnema sylvestre extract: Attenuating progression of obesity in C57BL/6J mice

OBJECTIVE@#To investigate the effect of Gymnema sylvestre extract (GS) on initial anti-obesity, liver injury, and glucose homeostasis induced by a high-fat diet (HFD).@*METHODS@#The dry powder of GS was extracted with methanol, and gymnemic acid was identified by high performance liquid chromatography as deacyl gymnemic acid. Male C57BL/6J mice that fed on either a normal diet, normal diet containing 1 g/kg GS (CON+GS), HFD, or HFD containing 1.0 g/kg GS (HFD + GS) for 4 weeks were used to test the initial anti-obesity effect of GS. Body weight gain and food intake, and serum levels about lipid and liver injury markers were measured. Histopathology of adipose tissue and liver stained with hematoxylin and eosin (H&E) and oil-red O were analyzed. After 4 weeks of GS extract feeding, intraperitoneal glucose tolerance test (IPGTT) was performed.@*RESULTS@#The methanol extracts of GS exerted significant anti-obesity effects in HFD + GS group. They decreased body weight gain, a lower food and energy efficiency ratio, and showed lower serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL)-cholesterol, very-low density lipoprotein (VLDL)-cholesterol and leptin compared with the HFD group. The decreases of abdominal as well as epididymal fat weight and adipocyte hypertrophy, lipid droplets in liver, and serum levels of aspartate aminotransferase (AST) and alanine transaminase (ALT) were also observed. The CON + GS group showed an effect of glucose homeostasis compared to the CON group.@*CONCLUSIONS@#This study shows that GS provide the possibility as a key role in an initial anti-obesity effects feeding with a HFD.

In vitro Enhancement of Pancreatic  Cells MIN6 Proliferation by Insulinotropic Gymnema sylvestre Aqueous Extracts: Evidence-based Regenerative Therapeutic Capacity of a Medicinal Herb.

Aim: To show that Gymnema sylvestre (Roxb.) Asclepiadaceae not only has antidiabetic propensities, but it most likely works by regeneration of pancreatic  cells which is imperative in anti-obesity-diabetes therapeutic applications of medicinal plants. Study Design: The present study design investigated the effects of G. sylvestre leaves crude aqueous extracts (AEs), traditionally utilized in diabetes treatment, on the pancreatic β-cell MIN6 proliferation and insulin secretion and extrapancreatic dietary carbohydrate and lipid digestion Place and Duration of Study: Faculty of Pharmacy, The University of Jordan, 2008-2012. Results: Comparable to GLP-1 (500 nM) pancreatic proliferative capacity; G. sylvestre AE concentrations (0.01 and 0.1 mg/mL) induced MIN6 monolayers expansion by respective 130.3% and 127.4% (P<0.001 vs. spontaneous control). Like L-alanine (10 mM) insulinotropic efficacy and without exerting cytotoxicity, glucose-stimulated insulin secretion was potentiated by G. sylvestre AEs (5, 10 and 25 mg/mL) (711.0%, 843.0% and 906.5%, respectively, P<0.001 vs. basal control). The potent plants’ insulin secretory bioactivities were abolished in the depleted Ca2+ conditions (P<0.001). Similar to orlistat antilipolytic efficacy, pancreatic lipase IC50 value for G. sylvestre AEs was 106.3±7.2 μg/mL. Unlike acarbose (100 μg/mL) dual inhibition of α-amylase/α-glucosidase, G. sylvestre AE was inactive at used doses. Dissimilar to guar gum (50 mg/mL) diffusional hindrance in a simple dialysis model, G. sylvestre AEs (10, 25 and 50 mg/mL) proved inactive. This in vitro ineffectiveness was mirrored in respective in vivo oral carbohydrate tolerance tests in overnight fasting normoglycemic rats. Conclusion: This evaluation has revealed that G. sylvestre leaves AEs augmented β-cell expansion and potentiated glucose-evoked Ca2+-regulated insulin secretion; combined with impressive antilipolytic activity. These actions depend on the bioactive water soluble phytoprinciples intact absorption in vivo. Future directives may assess the potential of G. sylvestre as a new alternative for anti-obesity-diabetes pharmacotherapy and prevention.

Chemical constituents from the stems of Gymnema sylvestre / 中国天然药物

AIM@#To study the chemical constituents of stems of Gymnema sylvestre (Retz.) Schult.@*METHODS@#Chromatographic techniques using silica gel, C18 reversed phase silica gel, and prep-HPLC were used. The structures were elucidated on the basis of MS and spectroscopic analysis (1D and 2D NMR), as well as chemical methods.@*RESULTS@#Seven compounds were isolated and their structures were elucidated as conduritol A (1), stigmasterol (2), lupeol (3), stigmasterol-3-O-β-D-glucoside (4), the sodium salt of 22α-hydroxy-longispinogenin-3-O-β-D-glucopyranosyl-(1→3)-β-D-glu-curono-pyranosyl-28-O-α-L-rhamnopyranoside (5), oleanolic acid-3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (6), and the sodium salt of 22α-hydroxy-longispinogenin 3-O-β-D-glucuronopyranosyl-28-O-α-L-rhamnopyranoside (7). The inhibition activities of compounds 1, 5-7 on non-enzymatic glycation of protein in vitro were evaluated.@*CONCLUSION@#Compound 7 is a new triterpenoid saponin. It was shown that compounds 1, 5-7 have weak inhibition activities for non-enzymatic glycation of protein in vitro.

Effect of Gymnema Sylvestre on Protein Kinase B in Adipose Tissues of Insulin Resistance Mice / 世界科学技术-中医药现代化

This article was aimed to study effects and mechanisms of Gymnema sylvestre on protein kinase B (PKB) and its phosphorylation in adipose tissues of KKAy mice which were mainly characterized by insulin resistance (IR). A total of 18 KKAy mice were randomly divided into the diabetes model (DM) group and Gymnema sylvestre (GS) group according to body weight levels. And 9 normal C57BL/6J mice were used as the normal control (NC) group. Intragastric administration of medication was given to mice for 8 weeks. At the end of the experiment, all animals were tested for fasting plasma glucose (FPG) and fasting insulin level (Fins) for evaluation of insulin sensitivity index (ISI). Expressions of phosphoinositide-dependent kinase-1 (PDK1), PKB, P-PKB (Ser473), P-PKB (Thr 308) in adi-pose tissues of epididymis were determined. The expression of phosphatase and tensin homolog (PTEN) mRNA was also determined. The results showed that compared with the DM group, the GS group showed lower FPG and Fins, higher ISI. The expression of P-PKB (Ser473) phosphorylation and P-PKB (Thr 308) were increased, and the PDK1 and PTEN mRNA were decreased. It was concluded that GS can improve insulin sensitivity of KKAy mice through activating PKB by up-regulate the expression of P- PKB (Ser473) and its phosphorylation ratio and P- PKB (Thr 308) in adipose tissues.

Effect of a deacyl gymnemic acid on glucose homeostasis & metabolic parameters in a rat model of metabolic syndrome.

Background & objectives: Metabolic syndrome (MS) comprises several cardio-metabolic risk factors, which include obesity, hypertension, hyperglycaemia, hypertriglyceridaemia and decreased HDL cholesterol. Leaf extract of Gymnema sylvestre has been shown to possess glucose lowering activity in animal models. This study was carried out to evaluate the efficacy of deacyl gymnemic acid (DAGA), active constituent of G. sylvestre, in a rat model of MS. Methods: Six groups consisting of six wistar rats in each, were studied. Group I received the normal diet, while the remaining five groups received high fructose diet (HFD ) for 20 days to induce MS. HFD was continued in these five groups for the next 20 days along with group II received vehicle solution, group III received pioglitazone and groups IV- VI received DAGA in variable doses. Systolic blood pressure (SBP) was measured using tail-cuff method. Oral glucose tolerance test (OGTT) was done at baseline and at days 20 and 40. Blood samples were collected for glucose, insulin and lipid profile. Results: Administration of HFD for 20 days resulted in weight gain (>10%), increase in SBP, fasting plasma glucose (FPG) and triglycerides fulfilling the criteria for MS. Administration of DAGA (200 mg/kg) reduced SBP and significantly improved the FPG and HOMA-IR (homeostatis model assessment-insulin resistance) with modest improvement in lipid profile without decrease in body weight similar to pioglitazone. Interpretation & conclusions: Our findings show that DAGA decreases SBP and improves parameters of glucose-insulin homeostasis in a rat model of MS induced by HFD. Further studies are required to elucidate the mechanism of action.

Toxicity of saponin isolated from Gymnema sylvestre R. Br. (Asclepiadaceae) against Culex tritaeniorhynchus Giles (Diptera: Culicidae) Japanese encephalitis vector mosquito in India / Toxicidade da saponina isolada de Gymnema sylvestre R. Br. (Asclepiadaceae) contra Culex tritaeniorhynchus Giles (Diptera: Culicidae) mosquito vetor da encefalite japonesa na Índia

To determine the larvicidal activity of various extracts of Gymnema sylvestre against the Japanese Encephalitis vector, Culex tritaeniorynchus in Tamilnadu, India. To identify the active principle present in the promising fraction obtained in Chlorofom:Methanol extract of Fraction 2. The G. sylvestre leaf extracts were tested, employing WHO procedure against fourth instar larvae of C. tritaeniorhynchus and the larval mortalities were recorded at various concentrations (6.25, 12.5, 25.0, 50 and 100 µg/mL); the 24h LC50 values of the G. Sylvestre leaf extracts were determined following Probit analysis. It was noteworthy that treatment level 100 µg/mL exhibited highest mortality rates for the three different crude extracts and was significantly different from the mean mortalities recorded for the other concentrations. The LC50 values of 34.756 µg/mL (24.475-51.41), 31.351 µg/mL (20.634-47.043) and 28.577 µg/mL (25.159-32.308) were calculated for acetone, chloroform and methanol extract with the chi-square values of 10.301, 31.351 and 4.093 respectively. The present investigation proved that G. Sylvestre could be possibly utilized as an important component in the Vector Control Program.

O presente trabalho é para identificar a atividade larvicida de vários extratos da Gymnema sylvestre contra o vetor da encefalite japonesa, Culex tritaeniorhynchus em Tamilnadu, Índia. Com este propósito o princípio ativo presente na fração mais promissora foi obtida através de um extrato clorofórmio:metanol da fração 2. Os extratos das folhas do G. sylvestre foram testados empregando o procedimento da WHO contra estágios quaternários da larva do C. tritaeniorhynchus e as mortalidades larvais foram registradas após várias concentrações (6,25, 12,5, 25,0 e 100; 34,756 µg/mL (24,475-51,41), 31,351 µg/mL (20,634-47,043) e 28,577 µg/mL (25,159-32,308) g/mL); os valores de LC50 de 24 horas dos extratos das folhas de G. sylvestre foram determinados seguindo a análise Probit. Foi notado que o nível de tratamento de 100 µg/mL exibiu a mortalidade mais alta para os três diferentes extratos crus e foi significantemente diferente das mortalidades médias registradas para as outras concentrações. Os valores de LC50 de 34,756 µg/mL (24,475-51,41), 31,351 µg/mL (20,634-47,043) e 28,577 µg/mL (25,159-32,308) foram calculados para os extratos de acetona, clorofórmio e metanol com os valores de qui-quadrado de 10,301, 31,351 e 4,093 respectivamente. A presente investigação mostra que o G. sylvestre pode ser usado como componente importante no programa de controle do vetor.

Phytochemical screening and antibacterial activity of Gymnema sylvestre (Retz) R . Br ex. Schultes and Morinda pubescens J.E. Smith var. pubescens.

Two medicinal plants namely Gymnema sylvestre and Morinda pubescens var. pubescens were screened for potential antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi. The antibacterial activity was determined in petroleum ether, chloroform, acetone, methanol and aqueous extracts using disc diffusion method. The chloroform and methanol extract of leaf of Gymnema sylvestre showed highest inhibition against Escherichia coli and Klebsiella pneumoniae respectively; whereas, acetone extract of Morinda pubescens var. pubescens leaf exhibited maximum inhibition against Pseudomonas aeruginosa. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, tannins, and terpenoids. The results of these studies revealed most valuable information and also support the continued sustainable use of these plants in traditional systems of medicine.

Estudos de pré-formulação de cápsulas gelatinosas duras contendo formulação de extrato de Gymnema sylvestre em pó / Preformulation studies of Gymnema sylvestre extract powder formulation for hard gelatin capsules

Gymnema sylvestre extract (GSE) is a plant product widely used as an adjuvant in the treatment of diabetes mellitus and commercially available as a powder. Owing to its low flowability, the manufacturing of hard gelatin capsules containing GSE faces specific problems. The purpose of this study was to investigate the best excipient (starch, lactose or microcrystalline cellulose) for hard gelatin capsules containing GSE. The technological properties such us bulk density (ñâ); tapped density (ñt); inter-particle porosity (Ie); Carr index (CI); Hausner ratio (HR); loss on drying (%LOD) and particle size distribution (%Pf) of the various GSE mixtures were investigated with the aim of identifying the best excipient. The need for lubricants (talc/magnesium stearate) was also assessed. GSE was characterized as a fine powder with more than 50% of its particles between 0.149mm to 0.250mm; furthermore, CI=25.6%; RH=1.3 and Ie = 25.6% and, as expected with such properties, it showed poor flowability. All the excipients investigated were able to change the technological properties of GSE and the powder mixture containing microcrystalline cellulose gave the best results.

O extrato seco de Gymnema sylvestre (EGS) é um produto fitoterápico amplamente utilizado como adjuvante no tratamento da diabetes, sendo comercializado na forma de pó. O objetivo do presente estudo foi investigar a influência da adição de adjuvantes (amido, lactose ou celulose microcristalina) à formulação para a preparação de cápsulas gelatinosas duras contendo o EGS. As propriedades tecnológicas como densidade aparente (Da), densidade aparente de compactação (Dc), porosidade interparticulas (Ie), Índice de Carr (IC), Fator de Hausner (FH), perda por dessecação (PD%) e análise do tamanho de partículas (%Pf) das diferentes misturas preparadas foram investigadas com o objetivo de escolher o melhor excipiente. A necessidade de agentes lubrificantes (talco/estearato de magnésio) também foi avaliada. O EGS foi caracterizado como um pó fino, com mais de 50% do material particulado compreendido entre 0,149-0,250mm; IC=25,6%; FH=1,3 and Ie = 25,6%, o que justifica seu fluxo pobre. Todos os excipientes testados foram capazes de modificar as propriedades tecnológicas do EGS, sendo a mistura de pós que apresentou melhores resultados aquela obtida com a adição de celulose microcristalina.

Effects of Gymnema Sylvestre on glucose-lipid metabolism and adipo-cytokines in Type 2 DM Rats / 国际中医中药杂志

Objective To investigate the effects of Gymnema Sylvestre on glucose-lipid metabolism and adipo-cytokines in T2 DM Rats. Methods The T2 DM rats induced by high lipid diet and small dosage intraperitoneal injection of STZ, were randomly divided into model group (DM), high dose GS group (GSH),low dose GS group (GSL) and pioglitazone group (Pio, n= 8 in each). Each group has a DM inserted by gavage.Four weeks later, the levels of fasting blood glucose (FBG), serum insulin (INS), blood lipid (TG, CHOL, HDL and LDL), free fatty acdi (FFA), TNF-α, C-reactive protein (CRP)and adiponcetin(ADPN) were detected.Results Compare to model group, the levels of FBG, INS, Blood lipid, FFA, TNF-α and CRP were decreased in GSH and Pioglitazone groups, adiponcetin were increased in GSH and Pioglitazone groups, except in GSL group. Conclusion GS can improve the glucose-lipid metabolism disorder and insulin resistance in type 2diabetic mellitus rats. The mechanisms may be the amelioration of inflammatory response and adipocytokines,but still need further study to prove the conclusions.

Observation of in Vitro Antibacterial Activity of Gymnema sylvestre Extractant / 中国中医药信息杂志

Objective To evaluate invitro antibacterial activity of Gymnema sylvestre extractant.Methods The antibacterial activity of Gymnema sylvestre extractant against staphyloccus aureus,bacillus coli,bacillus proteus,bacillus aeruginosus was detected by agar dilution method.Results The minimum inhibitory concentration were 0.65,1.25,1.25,2.5 mg/mL respectively.Conclusion Gymnema sylvestre extractant had strong antibacterial activity against various bacteria.