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This study investigated the chemical constituents, antioxidant potential, and in vitro and in silico antidiabetic activity of Gymnema sylvestre. Column chromatography and spectroscopic techniques identified twelve compounds from the methanol extract, including 4 sterols (1 – 4), 5 triterpenoids (5 – 9), and 3 flavonoids (10 – 12). The chemophenetic significance of all compounds was also investigated. The antioxidant capacity of the extract and compounds (1 – 4) was evaluated using FRAP and DPPH assays. The extract exhibited strong free radical scavenging activity (IC 50 = 48.34 µg/mL), while compounds (1 – 4) displayed varying degrees of efficacy (IC 50 = 98.30–286.13 µg/mL). The FRAP assay indicated significant reducing power for both extract and compounds (58.54, 47.61, 56.61, and 49.11 mg Eq.VitC/g for extract and compounds 1 & 2 , 3 , and 4 , respectively). The antidiabetic potential was assessed through α -amylase and α -glucosidase enzyme inhibition assays. The crude extract demonstrated the most potent inhibition (IC 50 = 218.46 and 57.42 µg/mL for α -glucosidase and α -amylase respectively) suggesting its potential for managing postprandial hyperglycaemia. In silico studies employed molecular docking and dynamics simulations to elucidate the interactions between identified compounds and α -amylase/ α -glucosidase enzymes. The results revealed promising binding affinities between the compounds and target enzymes, with compound 6 demonstrating the highest predicted inhibitory activity with −10 kcal/mol and −9.1 kcal/mol for α -amylase and α -glucosidase, respectively. This study highlights the presence of diverse bioactive compounds in Gymnema sylvestre. The extract exhibits antioxidant properties and inhibits carbohydrate-digesting enzymes, suggesting its potential as a complementary therapeutic approach for managing hyperglycaemia associated with type 2 diabetes. [Display omitted] • Gymnema sylvestre extract contains sterols, triterpenoids, and flavonoids. • The extract exhibits strong free radical scavenging and reducing power, indicating antioxidant potential. • The extract inhibits α-amylase and α-glucosidase enzymes, suggesting potential for managing postprandial hyperglycaemia. • In silico study predicts binding affinity between identified compounds and target enzymes, supporting antidiabetic activity. • Gymnema sylvestre extract warrants further investigation as a complementary therapy for type 2 diabetes. [ABSTRACT FROM AUTHOR]

Understanding the proteins and metabolites produced by plants aids in developing superior planting materials. Gymnema sylvestre , a significant medicinal plant containing beneficial compounds such as oleanane, dammarane, flavonoids and gymnemic acids, exhibiting antioxidant and antidiabetic properties, making it a promising alternative treatment for Type 2 diabetes with minimal side effects. Transcriptomics in G. sylvestre yielded Coding DNA Sequences (CDS) for 12 key genes of flavonoid biosynthesis. Translated protein sequences of those 12 genes underwent characterization using protPARAM and i-TASSER. In silico protein modelling found similarities to validated enzymes, suggesting functional potential of the studied proteins. The study enlightens the first comprehensive insight into key proteins involved in G. sylvestre 's flavonoid biosynthesis pathway. GsCHS (G. sylvestre chalcone synthase), a key enzyme in flavonoid biosynthesis, corroborated its phylogenetic proximity to Vincetoxicum mongolicum 's CHS. Protein docking analysis delineated the distinctive features of GsCHS from cpCHS1 of Cyclosorus parasiticus , particularly in its substrate binding pockets and interactive sites crucial for synthesizing essential flavonoids. • In silico characterization of translated proteins of flavonoid biosynthesis genes. • Predicted proteins compared with publicly available validated enzymes. • Interaction sites of G. sylvestre CHS enzyme with Naringenin and CoA identified. [ABSTRACT FROM AUTHOR]

• Three new pregnane glycosides have been isolated from Gymnema sylvestre. • Gymnepregosides F and R-T showed the inhibitory effect with BSA-MGO. • Gymnepregosides R and S showed potent inhibitory effect with MGO-AGE-protein. Gymnema sylvestre is known for its potent antidiabetic activity. Phytochemical investigations of this plant led to the isolation of three new pregnane glycosides, gymnepregosides R-T (1 - 3) and four known analogues, 12 β -acetyloxy-3 β ,8 β ,14 β ,17 β -tetrahydroxypregn-5-en-20-one 3- O - β - d -glucopyranosyl-(1→4)-6-deoxy-3- O -methyl- β - d -allopyranosyl-(1→4)- β - d -oleandropyranosyl-(1→4)- β - d -cymaropyranosyl-(1→4)- β - d -cymaropyranoside (4), 12- O -(E)-cinnamoylgymnepregoside F (5), gymnepregoside F (6), and stephanoside I (7). Their structures were identified based on spectroscopic evidence and compared with those reported in the literature. All compounds were evaluated for antiglycative inhibitory activity. Compounds 1 , 3 , 5 , and 6 showed the inhibitory effect on BSA-MGO formation ranging from 6.0 to 8.8 % at the concentrations of 400 μM. Compounds 1 and 2 showed significant breaking properties on MGO-AGE-protein crosslink with percent modification ranging from 54.6 to 58.4 %. Notably, a novel AGEs inhibitor (1) may inhibit the formation and accumulation of MGO-AGEs and protect cells from MGO-AGEs cross-linking damage. [ABSTRACT FROM AUTHOR]

• Five new Δ15 oleanane-type gymnemic acids are reported from the leaves of Gymnema sylvestre. • These gymnemic acids are found to truncate the metabolism of carbohydrates via the inhibition of α-glucosidase. • The inhibition of α-glucosidase by these compounds is dose dependent. • Pre-treatment with isolated compounds (1 and 4) significantly blunted the effect of oral sucrose challenge in mice. A mixture of gymnemic acids was precipitated from the water extract of leaves of Gymnema sylvestre (Retz.) R.Br. ex Sm. (Asclepiadaceae) by acidification with 2 N H 2 SO 4. The chromatographic separation of the mixture afforded five new gymnemic acids (1 - 5). The compounds were characterized as Δ15 oleanane glycosides on the basis of extensive spectral data analysis. The compounds (1 - 5) showed dose dependent inhibition of α-glucosidase, which was found to be comparable to acarbose (IC 50 95 μg/ml). Maximum inhibition was achieved with compound 4 (IC 50 57 μg/ml) followed by 3 (IC 50 62 μg/ml), 1 (IC 50 80 μg/ml), 2 (IC 50 120 μg/ml) and 5 (IC 50 128 μg/ml). The results revealed that the overall pattern of hydroxyl and acyl substitutions of compounds affected their inhibitory activity. In oral sucrose tolerance test, pre-treatment with crude gymnemic acid mixture and isolated compounds 1 and 4 at a dose of 10 mg/Kg b.w. significantly blunted the effect of sucrose challenge in mice. Based on these results, the antihyperglycemic effect of G. sylvestre can be, at least partly, attributed to the inhibition of α-glucosidase by its gymnemic acids. The current study provides relatively more direct evidence explaining the effectiveness of G. sylvestre against hyperglycemia. [ABSTRACT FROM AUTHOR]

Abstract Wound care management presents one of the substantial and tenacious challenges to the healthcare systems worldwide. Microbial colonization and subsequent biofilm formation after injury have garnered much attention, as there is an appreciable correlation between biofilms formation and delayed healing in chronic wounds. Nanotechnology has emerged as a potential platform for the management of treating acute and chronic wounds. This study presents the utility of electrospun nanofiber mats containing a natural extract (Gymnema sylvestre) that averts biofilm formation but supports human dermal fibroblasts (hDFs) attachment. The scaffolds exhibited good wettability, enhanced mechanical properties and contact mediated inhibition of Gram-positive and Gram-negative bacteria. MTS viability assay and confocal imaging further confirmed that the natural extract loaded mats remained non-cytotoxic for hDFs. Overall these findings evidenced the suitability of the Gymnema sylvestre (GS) functionalized electrospun poly-ε-caprolactone (PCL) nanofibers, as an effective wound dressing with broad spectrum anti-bacterial properties. Graphical abstract Unlabelled Image Highlights • Gymnema sylvestre extract based nanofibrous mats prepared using electrospinning for wound healing and infection control. • Mats exhibited superior mechanical properties and good wettability. • Nanofibrous mats possess cell discriminating properties. • Gymnema sylvestre laden mats have great potential as antimicrobial wound dressing. [ABSTRACT FROM AUTHOR]

Created with Biorender.com. [Display omitted] • Oral application of sweetness inhibitors acutely decreases consumption of sugary beverages. • Repeated application of gurmarin maintains the reduction in consumption across sessions. • No rebound effect on sugar consumption after administration of the sweetness inhibitor. Excessive consumption of added sugars is linked to chronic diseases, such as obesity, diabetes, dyslipidaemia or cardiovascular disease; and public health is searching for new strategies to reduce it. Although plant-derived bioactive compounds with inhibitory properties of sweet taste like Gymnema sylvestre show the potential to reduce sugar intake acutely, their impact after repeated administration is unknown. Therefore, we examined the changes of single and repeated exposures of a Gymnema sylvestre constituent, gurmarin, in sweet beverage consumption and preference in a preclinical model. 24 Wistar rats (50 % females) were divided into experimental (gurmarin) and two control groups (gymnemic acids or phosphate buffer solutions) according to the substances orally applied. Then acceptance and preference tests with sugar were performed within (Experiment 1) and between sessions (Experiment 2). We found that administering gurmarin decreased sucrose intake significantly, even after multiple treatments, without rebound effects. These findings suggest that sweet taste suppressors could be an effective tool for reducing long-term sugar consumption when repeatedly administrated. [ABSTRACT FROM AUTHOR]

Gymnema sylvestre (Retz.) R.Br. ex Sm. (Asclepiadaceae) is a well-known Ayurvedic anti-sweet plant for the treatment of type 2 diabetes mellitus. Although it was previously proposed that G. sylvestre exhibits chemical variation based on geography, most research on G. sylvestre has used material originating from India. Morphological and anatomical descriptions, ITS1-5.8S-ITS2 DNA sequencing, and acid hydrolysis analyses showed that G. sylvestre samples from Vietnam are distinguishable from those of Indian origin and thus suggest a dissimilarity among G. sylvestre samples with different geographic distributions. An LC-MS-guided strategy targeting 3 β -glucuronide oleane-triterpenes in the Vietnamese G. sylvestre variety led to the isolation of four known compounds and nine previously undescribed compounds, named gymnemosides ND1-ND9. None of the isolated compounds were reported in the Indian sample, further supporting the geo-diversity of G. sylvestre . Three compounds, gymnemosides ND7-9, exerted significant stimulatory effects on the uptake of 2-NBDG in 3T3-L1 adipocyte cells and thus have potential as lead molecules for anti-diabetes agents. [ABSTRACT FROM AUTHOR]

A mixture of gymnemic acids was precipitated from the water extract of leaves of Gymnema sylvestre (Retz.) R.Br. ex Sm. (Asclepiadaceae) by acidification with mineral acid. The chromatographic separation of gymnemic acids mixture afforded four new arylated gymnemic acids ( 1 – 4) along with a gymnemasaponin ( 5 ). The compounds were characterized on the basis of extensive spectral data analysis. The arylated compounds ( 1 – 4 ) showed dose dependent inhibition of α-glucosidase that was found to be comparable to acarbose (IC 50 265 μg/ml). Maximum α-glucosidase inhibition was achieved with compound 2 (IC 50 145 μg/ml) followed by 3 (IC 50 220 μg/ml), 1 (IC 50 230 μg/ml) and 4 (IC 50 310 μg/ml). The results revealed that the overall pattern of acyl/aryl substitution and glycosylation of compounds affected their inhibitory activity. The bidesmosidic glycosides ( 2 and 3 ) showed improved potency than the monodesmosidic glycosides ( 1 and 4) possibly because the additional glucose unit in the former facilitated stronger hydrogen bonding at the catalytic site. The current study provides relatively direct evidence of effectiveness of G. sylvestre against hyperglycemia. [ABSTRACT FROM AUTHOR]

Gymnema sylvestre (GS) is a medicinal herb used for diabetes mellitus (DM). Herbs are gaining popularity as medicines in DM for its safety purpose. The aim of the present study was to evaluate in vivo pharmacokinetic (PK) interaction between allopathic drugs tolbutamide (TOLBU), amlodipine (AMLO), and phenacetin (PHENA) at low (L) and high (H) doses with ethanolic extract (EL) from GS. EL was extracted and subjected to TLC, total triterpenoid content (19.76 ± 0.02 W/W) and sterol content (0.1837 ± 0.0046 W/W) estimation followed by identification of phytoconstituents using HRLC-MS and GC-MS. PK interaction study with CYP2C9, CYP3A4 and CYP1A2 enzymes were assessed using TOLBU, AMLO and PHENA respectively to index cytochrome (CYP) mediated interaction in rats after concomitant administration of EL extract (400 mg/kg) from GS for 7 days. The rats were divided into four groups for each PK study where, group I and II were positive control for low and high dose of test drugs (CYP substrates) while group II and IV were orally administered EL. The PK study result of PHENA indicated that area under the plasma concentration–time curve (AUC 0-24 ) was significantly (P < 0.0001) increased by 1.4 (L) and 1.3–fold (H), plasma concentration (C max ) was significantly (P < 0.001) increased by 1.6 (L) and 1.4–fold (H). Whereas for TOLBU; clearance rate (CL) was significantly (P < 0.0001) decreased by 2.4 (L) and 2.3-fold (H), C max, was significantly (P < 0.001) decreased by 26.5% (L) and 50.4% (H) and AUC 0-24 was significantly (P < 0.0001) decreased by 59.8% (L) and 57.5% (H). Thus, EL is seen to be interacting with CYP1A2 by inhibiting its metabolic activity. HRLC-MS and GC-MS helped identify the presence of gymnemic acid (GA), triterpenoids and steroids in EL which could be the reason for PK interaction of CYP1A2 and CYP2C9. Also, in silico structure based site of metabolism study showed Fe accessibility and intrinsic activity for GA-IV, GA-VI, GA-VII and GA-X with CYP2C9. PK parameters of AMLO were not significantly affected by pre-treatment of EL. Thereby our findings indicate that co-administration of GS with drugs that are metabolized by CYP2C9 and CYP1A2 could lead to potential HDI. [ABSTRACT FROM AUTHOR]

Gymnema sylvestre is a potent antidiabetic plant used in indigenous system of medicine. It targets several of the etiological factors connected with diabetes and obesity and thus can offer holistic treatment. However the dosage form in which it is administered is traditional and conventional resulting in reduced efficacy of the drug. The method by which a drug is delivered can have a significant effect on its efficacy, if the modern drug delivery technology is applied to G. sylvestre , it has a potential to synergize benefits of both the drug and the delivery system. Diabetes is one of the diseases where the constant drug levels are not preferred but needs a pulse of therapeutic concentration when the blood sugar levels are high. Chronotherapeutic drug delivery systems has a specificity in delivering therapeutic amount of drug in a burst at circadian timings correlated with specific pathological need to achieve maximum drug effect. The objective of the current study is to apply chronotherapeutic drug delivery based on time controlled approach to G. sylvestre . The drug delivery system is designed to achieve three pulsatile drug deliveries from a single formulation at the time when the blood sugar levels are high. The various components of the system were formulated, evaluated and optimized for the desired drug release. Also, as one of the main mechanisms of action of Gymnema is inhibition of glucose absorption which is exerted in the small intestine and as oral use of Gymnema may cause irritation of the gastric mucous membrane and reflux, the chronotherapeutic formulations were modified so as to make the drug available at the site of action and probably the site of absorption, as well as to prevent the side effects in the stomach. The developed system was able to achieve the objective of integrating modern method of drug delivery with herbal drug for once a day therapy of G. sylvestre with enhanced therapeutic efficacy. But further clinical studies should be warranted to test the efficacy of this system. [ABSTRACT FROM AUTHOR]

Abstarct Gymnema sylvestre , important Indian traditional herbal medicine has been used for diabetes from several years and marketed as single or multi-herb formulations globally. People are consuming G. sylvestre along with conventional hypoglycemic drugs. Therefore, there is need of evidence based assessment of risk versus benefits when G. sylvestre co-administered with conventional oral hypoglycemic drugs. In present investigation, pharmacodynamics and pharmacokinetic interactions with oral hypoglycemic drug, glimepiride (GLM) was studied in streptozotocin (STZ) induced diabetic rats. A specific and rapid HPLC-ESI-MS/MS method was established for simultaneous quantification of GLM and gymnemagenin (GMG) in rat plasma. Pharmacokinetic and pharmacodynamic interaction studies were carried out in STZ induced diabetic rats after concomitant administration of 400 mg/kg of G. sylvestre extract and 0.8 mg/kg of GLM for 28 days. The developed HPLC-ESI-MS/MS method was rapid, specific, and precise. Con-comitant oral administration of G. sylvestre extract (400 mg/kg) and GLM (0.8 mg/kg) in diabetic rats for 28 days showed beneficial pharmacodynamic interactions whereas no major alterations in the pharmacokinetics parameters of GLM and GMG were observed. This interaction demonstrated in animal model implies that significant clinical outcome might occur during concomitant administration of G. sylvestre extract and GLM especially in diabetic patients and warrants further studies in the same set up. [ABSTRACT FROM AUTHOR]

In order to supply uniform, genuine, good quality raw material to the pharmaceutical industries and to reduce the burden on natural stocks, cultivation of medicinal crops is the need of the hour. However, improved varieties with optimum levels of active ingredients have so far not been developed in a number of important medicinal crops. Considering this, an investigation was undertaken to assess the extent of variability amongst the natural populations of Gurmar ( Gymnema sylvestre ), an important anti-diabetic plant of the Indian Systems of Medicine. Evaluation of the accessions for morphological parameters revealed highly significant differences for leaf related parameters viz . length, width, fresh as well as dry weight and petiole length, which directly contribute to the biological yield of the plant. Further, a validated high performance liquid chromatography-diode array detection (HPLC-DAD) method was also developed for identification and quantification of bioactive principle i.e., gymnemagenin in a gradient elution mode using solvent mixture composing of acetonitrile (solvent A), potassium dihydrogen orthophosphate (10 mM, solvent B) both solvent A and B containing orthophosphoric acid (0.05%, v/v). Results revealed significant differences for gymnemagenin content amongst the accessions evaluated. These accessions could be used in breeding programs for development of cultivars with optimum levels of gymnemagenin, which in turn may promote the cultivation of this high value medicinal crop. [ABSTRACT FROM AUTHOR]

Aim of the study Gymnema sylvestre is a well-known herb noted for its anti-sweet and antidiabetic properties in both traditional and Ayurvedic medicine. The use of modern phyto-pharmaceutical methods may be used to improve both the palatability and efficacy of herbal medicines previously prepared using old traditional methods. The aim of the present study was to develop an improved formulation of G. sylvestre extract that utilized its anti-sweet properties for diet control in obesity with the added advantage of being patient compliant. Materials and methods The anti-sweet dosage forms of G. sylvestre extract were prepared as oral dispersing tablets for immediate action. The bitter and unpleasant taste of the plant was masked to improve its palatability. The formulation developed was clinically evaluated for bitter taste masking and anti-sweet efficacy in healthy human volunteers. Results The formulation developed was found to be highly palatable and able to produce an anti-sweet effect for a duration of 30 min. Any sweet foods consumed within this duration of time failed to taste sweet. Conclusions The formulation developed may serve as a simple, novel and workable remedy for people to control their sweet cravings, which in turn could help in controlling caloric intake derived from sweet substances and thus help in the control of diabetes and obesity. [ABSTRACT FROM AUTHOR]

The individual chemical components of commercial extract of Gymnema sylvestre , a medicinal plant used in the traditional systems of the Indian medicine for its antidiabetic and hypolipidemic properties, were isolated and evaluated for their capability to act as modulators of nuclear and membrane receptors involved in glucose and lipid homeostasis. The study disclosed for the first time that individual gymnemic acids are potent and selective antagonists for the β isoform of LXR. Indeed the above activity was shared by the most abundant aglycone gymnemagenin ( 10 ) whereas gymnestrogenin ( 11 ) was endowed with a dual LXRα/β antagonistic profile. Deep pharmacological investigation demonstrated that gymnestrogenin, reducing the expression of SREBP1c and ABCA1 in vitro , is able to decrease lipid accumulation in HepG2 cells. The results of this study substantiate the use of G. sylvestre extract in LXR mediated dislypidemic diseases. [ABSTRACT FROM AUTHOR]

Development of novel antidiabetic agents using various organic compounds and biomolecules has been in practice for a long time. Recently, nanomaterials are also being used in antidiabetic studies for their unique properties such as small size, biocompatibility and ability to penetrate cell membrane for carrying drugs. Herein, in vivo antidiabetic activity of gold nanoparticles (AuNPs) synthesized using the antidiabetic potent plant Gymnema sylvestre R. Br on wistar albino rats has been evaluated. The formation of AuNPs and their morphology were confirmed using spectroscopic and microscopic analyses, respectively. The treatment of AuNPs has shown significant reduction in blood glucose level on diabetic rats. AuNPs were also tested for its anti-inflammatory effect by estimating the serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and high-sensitive C-reactive protein (CRP). [ABSTRACT FROM AUTHOR]

Objective To investigate antidiabetic, hypolipidemic histopathological analysis of Gymnema sylvestre methanolic extract (GSME) in streptozotocin induced diabetic rat by administering oral doses (100, 200 and 400mg/kg body weight). Methods Blood glucose levels were measured using blood glucose test strips with elegance glucometer on weekly intervals till the end of study (i.e. four weeks). Blood glucose, urine sugar, triglycerides (TG), low density lipoprotein (LDL), high density lipoprotein (HDL) and very low density lipoprotein (VLDL) were determined in normal and streptozotocin induced diabetic rats after oral administration of the extract for 28 days. Histopathological changes in diabetic rat organs (pancreas, liver, and kidney) were also observed after extract treatment. Results Daily oral administration GSME (100, 200 and 400mg/kg body weight) and glibenclamide (5mg/kg) showed beneficial effects on blood glucose level (P<0.01) and hyperlipidaemia due to diabetes. The extract treatment also showed to enhance serum insulin level and body weight of diabetic rats as compared to diabetic control group. Furthermore, the extract has a favorable effect on the histopathological studies, in streptozotocin induced diabetes. Conclusions G. sylvestre possesses antidiabetic property as well improve body weight, and total lipid levels. GSME has also favorable effect to inhibit the histopathological changes in streptozotocin-induced diabetes. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Highlights: [•] The present report describes a rapid and efficient protocol for direct multiple shoot bud regeneration from axillary node explants of Gymnema sylvestre. [•] This in vitro propagation method could be used for production of uniform Gymnema sylvestre plants in a relatively short period and with high multiplication rate. [•] This protocol can be utilized for commercial scale propagation and conservation of this important medicinal plant species. [•] The regeneration protocol described in this study will be highly useful for large scale production of this important medicinal plant to the pharmaceutical industry. [Copyright &y& Elsevier]

Abstract: Gymnema sylvestre (Asclepiadaceae) is a highly valued medicinal plant and being used nowadays in many poly-herbal formulations due to its potential antidiabetic activity and other health benefits. Thus, it has become important to analyse certain value standard parameters to give a contribution to the valorisation of this natural source. The present study attempts to identify the efficient extraction procedure including solvent selection and methods, stability assessment in terms of drying as well as storage and changes occurring during annual cycle using an important analytical marker ‘gymnemagenin’ (GM) for quality assurance of this botanical. The yield of the marker was found to be highest in acid–base hydrolysis extract (1.17%) and lowest in cold percolation (0.12%). Among different drying methods adopted, gymnemagenin content was high in shade dried leaves (1.15%) while it was significantly low in sun dried material (0.54%). The changes in the bioactive marker were found to be drastic as to the effect of one year storage. The compound showed higher degradation in polystyrene containers (1.18–0.37%) kept in light conditions while it was minimum in glass vials (1.18–0.85%) kept in dark. Estimate of yield and enriched gymnemagenin (1.01–1.23%) indicated that summer (April–July) is the ideal time to harvest G. sylvestre. [Copyright &y& Elsevier]

Abstract: Gymnema sylvestre R. Br. (G. sylvestre) belonging to the family Asclepiadaceae, has been used as a traditional medicine plant in Africa, Australia and Asia especially in India. Aim of the study: The present study aimed to clarify the effect of G. sylvestre leaves extract on several physiological parameters of diabetic rats. Materials and methods: G. sylvestre leaves extract (18mg/kg body weight) was orally administered for 30days to normal and streptozotocin (STZ) diabetic rats. Results: STZ-diabetic rats exhibited a significant increase in plasma glucose, liver function enzymes [alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST)], triglycerides, total cholesterol, LDL-cholesterol malondialdehyde, catalase, reduced glutathione and a significant decrease in insulin, HDL-cholesterol and erythrocyte superoxide dismutase levels. Treatment diabetic rats with G. sylvestre leaves extract significantly decreased plasma glucose, ALT, AST, triglycerides, total cholesterol, LDL-cholesterol, malondialdehyde and significantly increased insulin, HDL-cholesterol and erythrocyte superoxide dismutase levels compared to untreated diabetic rats. Conclusion: It could be concluded that G. sylvestre leaves extract treated diabetic rats’ complications including hyperglycemia, hypoinsulinemia, hyperlipidemia and oxidative stress. [Copyright &y& Elsevier]

Abstract: Five water-soluble polysaccharides, including GSP11 (xylose:glucose=1:2.47), GSP22 (rhamnose:glucose:galactose=1.6:1:1.22), GSP33 (rhamnose:glucose:galactose=1:1.5:1.1), GSP44 (xylose:glucose:galactose=1:1.03:1.2) and GSP55 (rhamnose:xylose:glucose:galactose=1:1.21:1.81:2.58), were obtained from Gymnema sylvestre and tested for their immunological and anti-tumor activities. The molecular weights of the five water-soluble polysaccharides were 5.3×104, 5.4×105, 9.5×105, 1.0×106 and 1.9×106 Da, respectively. Immunological activity tests revealed that both crude and deproteinated polysaccharides (GPS) possess good immunological activities, especially on blood serum hemolysin formation at 300mg/kg. MTT assays revealed that all samples possessed anti-tumor activities in a dose-dependent manner except for GSP22 in AGS cells. At a concentration of 640μg/mL, GSP11 and GSP33 showed good activities in U937 cells, with inhibitory rates of 78.6% and 83.8%, respectively, and GSP22 showed good activity in SGC cells with an inhibitory rate of 78.2%. [Copyright &y& Elsevier]

Abstract: Gymnema sylvestre is an important medicinal plant which bears bioactive compound namely gymnemic acids. The present work deals with optimization of cell suspension culture system of G. sylvestre for the production of biomass and gymnemic acid and we investigated effects of macro elements (NH4NO3, KNO3, CaCl2, MgSO4 and KH2PO4 – 0.0, 0.5, 1.0, 1.5 and 2.0× strength) and nitrogen source [NH4 +/NO3 − ratio of: 0.00/18.80, 7.19/18.80, 14.38/18.80, 21.57/18.80, 28.75/18.80, 14.38/0.00, 14.38/9.40, 14.38/18.80, 14.38/28.20 and 14.38/37.60 (mM)] of Murashige and Skoog medium on accumulation of biomass and gymnemic acid content. The highest accumulation of biomass (165.00gl−1 FW and 15.42gl−1 DW) was recorded in the medium with 0.5× concentration of NH4NO3 and the highest production of gymnemic acid content was recorded in the medium with 2.0× KH2PO4 (11.32mgg−1 DW). The NH4 +/NO3 − ratio also influenced cell growth and gymnemic acid production; both parameters were greater when the NO3 − concentration was higher than that of NH4 +. Maximum biomass growth (159.72gl−1 of FW and 14.95gl−1 of DW) was achieved at an NH4 +/NO3 − ratio of 7.19/18.80, and gymnemic acid production was also greatest at the same concentration of NH4 +/NO3 − ratio (11.35mgg−1 DW). [ABSTRACT FROM AUTHOR]

Abstract: A methanol extract of Gymnema sylvestre leaf and callus showed anti-diabetic activities through regenerating β-cells. Optimum callus was developed under stress conditions of blue light with 2,4-D (1.5mg/l) and KN (0.5mg/l), which induced maximum biomass of green compact callus at 45 days, as determined by growth curve analysis. Leaf and optimum callus extracts contains gymnemic acid, which was analyzed using TLC, HPTLC and HPLC methods. The research reported here deals with leaf and callus extracts of G. sylvestre, which significantly increase the weight of the whole body, liver, pancreas and liver glycogen content in alloxan-induced diabetic rats (Wistar rats). The gymnemic acid of leaf and callus extracts significantly increases the regeneration of β-cells in treated rats, when compared with the standard diabetic rats. It could have potential as a pharmaceutical drug for insulin-dependent diabetes mellitus (IDDM). [ABSTRACT FROM AUTHOR]

Abstract: An ecofriendly microwave-assisted extraction (MAE) technique with a low carbon output was developed for the rapid extraction of bioactive oleanolic acid from Gymnema sylvestre. Several different influential extraction parameters such as microwave power, extraction time, solvent type, solvent composition, preleaching time, loading ratio and extraction cycle were studied in a systematic fashion for the determination of optimum extraction conditions. Under optimum conditions, 8min of MAE produced a maximum yield of 7.6% (w/w) of oleanolic acid which was found to be 4 times, 3 times and 1.2 times more efficient than maceration, stirring extraction and heat reflux extraction, respectively. Extracts obtained from 8min of MAE showed better antioxidant activity when compared to other conventional methods. No degradation of the target analyte was observed at the optimum conditions as evidenced from the stability studies performed with standard oleanolic acid. The proposed method also showed high degree of reproducibility. From the results of scanning electron microscopy a new synergistic phenomenon of heat transfer and mass transfer was proposed. [Copyright &y& Elsevier]

Abstract: Aim of the study: Gymnema sylvestre (Asclepiadaceae) is emerging as a potential treatment for the management of diabetes. The leaves are used in herbal medicine preparations. The present study was carried out to isolate and identify the putative antidiabetic compound based on bioassay-guided fractionation. Materials and methods: An active compound dihydroxy gymnemic triacetate has been isolated from Gymnema sylvestre acetone extract and its optimum dose has been determined and patented. An optimum dose of dihydroxy gymnemic triacetate (20mg/kg body weight) was orally administered for 45 days to streptozotocin diabetic rats for the assessment of plasma glucose, insulin, glycated hemoglobin (HbA1c), tissue glycogen, lipid parameters such as triglycerides, total cholesterol, LDL-cholesterol, HDL-cholesterol and activities of hepatic marker enzymes, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and acid phosphatase (ACP) in normal and streptozotocin diabetic rats. Results: Dihydroxy gymnemic triacetate at 20mg dose produced significant effects on all biochemical parameters studied compared to diabetic control group. Conclusions: These results indicate that dihydroxy gymnemic triacetate, the compound from Gymnema sylvestre, possessed hypoglycemic and hypolipidemic activity in long-term treatment and hence it could be used as a drug for treating diabetes. [Copyright &y& Elsevier]

Abstract: Cataract is the leading cause of blindness worldwide. Apart from ageing, diabetes has been considered to be one of the major risk factors of cataract. The high sugar levels in diabetes may cause tissue disruption and intumescences by osmotic changes induced via aldose reductase (AR) mediated polyol pathway. Therefore, agents that can inhibit AR and prevent sorbitol accumulation may be helpful to combat sugar-induced cataract. In the present study, AR inhibitory activity of Diabecon (an herbal drug used for diabetes) was studied together with its effect against sugar-induced lens opacity in organ culture. Diabecon aqueous extract (DAE) showed potential inhibitory activity with an IC50 value of 10μg/ml against rat lens AR. Incubation of goat lens with supraphysiological concentrations of glucose (100mM) led to the loss of lens transparency associated with increased AR activity, decreased soluble protein and increased protein carbonyls and glycation. Addition of DAE (0.3mg/ml) to the medium preserved transparency and ameliorated the decrease in lens soluble protein due to hyperglycemia and also prevented the formation of glycated protein. Interestingly DAE inhibited aldose reductase activity in lens incubated with 100mM glucose. DAE decreased protein carbonyls, prevented the loss of βL-crystallin against 100mM of glucose. We have also demonstrated here that most of these effects are mainly due to Gymnema sylvestre, one of the constituent herbs of Diabecon. These results suggest that Diabecon protect the lens against sugar-induced cataract by multiple mechanisms. [Copyright &y& Elsevier]

Two new flavonol glycosides, namely kaempferol 3-O-β-d-glucopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 6)-β-d-galactopyranoside (1) and quercetin 3-O-6″-(3-hydroxyl-3-methylglutaryl)-β-d-glucopyranoside (2), have been isolated from the aerial parts of Gymnema sylvestre and Euphorbia ebracteolata, respectively. Their structures were determined on the basis of chemical and spectroscopic methods. [Copyright &y& Elsevier]

In this pilot study, the efficacy of a novel, natural extract of a highly bioavailable, calcium-potassium salt of (–)-hydroxycitric acid (HCA-SX) alone and in combination with a niacin-bound chromium (NBC) and Gymnema sylvestra extract (GSE) was evaluated for weight loss in moderately obese subjects by monitoring changes in body weight, body mass index (BMI), appetite, lipid profiles, serum leptin and serotonin levels, and enhanced excretion of urinary fat metabolites. Garcinia cambogia-derived (–)-hydroxycitric acid (HCA) has been shown to reduce appetite, inhibit fat synthesis and decrease body weight without stimulating the central nervous system. NBC has shown the ability to restore insulin function, metabolize fat, turn protein into muscle, and convert sugar into energy, which plays a role in appetite regulation and facilitates weight loss. Gymnema sylvestre is a traditional herb that helps to promote weight loss possibly through its ability to reduce cravings for sweets and control blood sugar levels. A randomized, double-blind, placebo-controlled human clinical study was conducted in thirty obese subjects (ages 21-50, BMI>26 kg/m2) for eight weeks in Elluru, India. The subjects were randomly divided into three groups (10 subjects/group) and given HCA-SX 4,667 mg (60% HCA providing 2,800 mg HCA/day) (Group A), a combination of HCA-SX 4,667 mg, NBC 4 mg (providing 400 μg elemental Cr) and GSE 400 mg (providing 100 mg gymnemic acid) (Group B), or placebo (Group C) daily in 3 equally divided doses 30-60 min before each meal. This HCA-SX dose was extrapolated from previously conducted in vitro and in vivo studies. In addition, subjects received 2,000 kcal diet/day and underwent a 30 min/day supervised walking program, 5 days/week. At the end of 8 weeks, body weight and BMI decreased by 6.3%, respectively, in Group A. Food intake was reduced by 4%. Total cholesterol, LDL and triglycerides levels were reduced by 6.3%, 12.3% and 8.6%, respectively, while HDL and serotonin levels increased by 10.7% and 40%, respectively. Serum leptin levels were decreased by 36.6%, and the enhanced excretion of urinary fat metabolites, including malondialdehyde (MDA), acetaldehyde (ACT), formaldehyde (FA) and acetone (ACON), increased by 125-258%. Under these same conditions, Group B reduced body weight and BMI by 7.8% and 7.9%, respectively. Food intake was reduced by 14.1%. Total cholesterol, LDL and triglyceride levels were reduced by 9.1%, 17.9% and 18.1%, respectively, while HDL and serotonin levels increased by 20.7% and 50%, respectively. Serum leptin levels decreased by 40.5% and enhanced excretion of urinary fat metabolites increased by 146-281%. Group C reduced body weight and BMI by only 1.6% and 1.7%, respectively, food intake was increased by 2.8%, and LDL, triglycerides and total cholesterol decreased by 0.8%, 0.2% and 0.8%, respectively. HDL were reduced by 4.1% while serum leptin levels were increased by 0.3%, and excretion of urinary fat metabolites did not change in MDA, ACT and FA, and marginally increased in the case of ACON. No adverse effects were observed. Results demonstrate that HCA-SX and, to a greater degree, the combination of HCA-SX, NBC and GSE can serve as safe weight management supplements. [Copyright &y& Elsevier]

• Enhanced production of gymnemic acids through cell suspension culture of Gymnema sylvestre. • Callus and suspension culture established at 3.0 mg/ L (2,4-dichlorophenoxy acetic) + 1.0 mg / L (Kinetin). • Sodium nitroprusside treatments enhanced cell biomass production in suspension culture. • Highest content of deacylgymnemic acid and gymnemic acid XVII increased by sodium nitroprusside treatments. • 50 μM salicylic acid enhanced 4.12-fold gymnemagenin content. Gymnemic Acids (GAs) belong to the class of triterpenoid saponins present majorly in the leaves of Gymnema sylvestre. These bioactive compounds are responsible for hypoglycemic activity. Therefore, it is expansively used in Ayurveda treatment for diabetes. This study is aimed to develop an effective method for suspension culture and to investigate the effect of sodium nitroprusside (SNP), salicylic acid (SA) and methyl jasmonate (MeJA) on the enhancement of deacylgymnemic acid, gymnemagenin, gymnemic acid IV and gymnemic acid XVII in G. sylvestre cell suspension culture. To induce callus, in vitro -derived leaf explants were cultivated on Murashige and Skoog's (MS) medium supplemented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) or α-naphthalene-acetic acid (NAA) either alone or in combination with 6-benzylaminopurine (BAP) or kinetin (Kin) at 1.0 to 5.0 mg/L. The highest callus initiation frequency (95.30 ± 1.40%) and better friable callus observed on MS medium supplemented with 3.0 mg/L (2,4-D) + 1.0 mg/L (Kin). Optimized callus induction medium was used to develop cell suspension culture, growth kinetic study, elicitors treatment and quantify the production of major bioactive compounds. At 40 days, the highest fresh cell suspension culture biomass was 339.08 g/L fresh weight (FW). Biomass production, 366.68 g/L FW and 30.30 g/L DW were the highest in the treatment of 20 μM SNP among the tested elicitors. The highest accumulation of deacylgymnemic acid (2936.90 μg/g DW, 96 h treatment) and gymnemic acid XVII (2414.20 μg/g dry weight (DW), 48 h treatment) were obtained in 20 μM SNP treatments which were 6.1 and 5.2 fold higher than the control. Furthermore, the highest values of gymnemagenin (1179.77 μg/g DW at 50 μM treatment) and gymnemic acid IV (731.04 μg/g DW at 10 μM treatment) were obtained in SA treatment which was 4.12 and 5.11 fold greater than the control was studied through our newly developed HPLC method. The findings of the present study showed that the SNP could be a good strategy for large-scale industrial production of triterpenoid saponins in G. sylvestre cell suspension cultures. [ABSTRACT FROM AUTHOR]

Current treatment for diabetic wounds remains a major clinical challenge. The present work was aimed at the fabrication of a novel scaffold consisting of curcumin and Gymnema sylvestre incorporated graphene oxide-polyhydroxybutyrate‑sodium alginate (GO-PHB-SA-CUR&GS) composite as an extracellular matrix platform. The novel graphene oxide-polyhydroxybutyrate‑sodium alginate composite scaffold was prepared by solution casting, into which curcumin and Gymnema sylvestre was incorporated to improve healing of normal and diabetic wounds for better tissue regeneration application. The GO-PHB-SA-CUR&GS composite was evaluated for particle size, surface charge (zeta potential), crystalline nature (XRD), and morphology (SEM). In-vitro studies with normal and diabetic fibroblast cells confirmed that the GO-PHB-SA-CUR&GS composite showed good biocompatible characteristics in terms of increased migration of wounded cells. Thus, the GO-PHB-SA-CUR&GS composite could significantly accelerate the healing of normal and diabetic wounds. Synthesis of a curcumin (CUR) and Gymnema sylvestre (GS) loaded graphene oxide (GO) poly-hydroxybutyrate (PHB)‑sodium alginate (SA) (GO-PHB-SA-CUR&GS) composite for application in wound healing. Unlabelled Image • Synthesized composite act as promising carriers for treating diabetic wounds. • GO-PHB-SA-CUR&GS composites have excellent biocompatibility. • Cell morphology was analyzed with normal and diabetic fibroblast cells. • Multidrug incorporated carrier could significantly accelerate the healing of normal and diabetic wounds. [ABSTRACT FROM AUTHOR]

• Green synthesis of NiO NPs using Gymnema sylvestre leaf extract. • Successful loading of NiO NPs into PCL/Gelatin nanofibers using electrospinning. • Electrospun mats displayed superior mechanical properties, biocompatibility and good wettability. • NiO NPs laden mats has great potential as anti-infective wound dressing. Bacterial infection followed by biofilm formation at the site of injury presents an extensive and tenacious challenge to wound care management as it leads to delayed wound healing. Recently nanoparticles and nanofibers have been widely investigated for their superior physical and biological supportive properties. This study presents the green synthesis of nickel oxide nanoparticles using Gymnema sylvestre extracts. The synthesized nanoparticles were infused into electrospun poly-ε-caprolactone/Gelatin hybrid nanofibrous mats. As synthesized nanofibrous mats exhibited good wettability, enhanced mechanical properties, biocompatibility and potent antibacterial activity. Overall, the bio functionalized nickel oxide nanoparticles infused electrospun nanofibrous mats can serve as an effective anti-infective wound dressing. [ABSTRACT FROM AUTHOR]

The ethanolic extract of Gymnema sylvestre leaves demonstrated antimicrobial activity against Bacillus pumilis, B. subtilis, Pseudomonas aeruginosa and Staphylococcus aureus and inactivity against Proteus vulgaris and Escherichia coli. [Copyright &y& Elsevier]