Gymnema (Gymnema sylvestre) and Blood sugar / diabetes support: evidence and sources

There is a growing interest in the considerable health benefits of Gymnema Sylvestre (GS) supplementation, as some studies have reported that it may improve cardiometabolic risk factors. However, the widespread impact of GS supplementation on the parameters mentioned above is not fully resolved. Consequently, this study aimed to examine the effects of GS supplementation on lipid profile, glycemic control, blood pressure, and anthropometric indices in adults. Eligible randomized controlled trials (RCT), published up to November 2021, were identified through PubMed, Scopus, and ISI Web of Science databases. Six studies were included and analyzed using a random-effects model to calculate weighted mean differences (WMDs) with 95% confidence intervals (CI). All studies were conducted in adults that used a GC supplement (>1 week) and assessed our selected cardiovascular risk factors. Outcomes revealed that GS supplementation significantly decreased triglyceride (p < .001), total cholesterol (p < .001), low-density lipoprotein (p < .001), fasting blood sugar (p < .001), and diastolic blood pressure (p = .003). Some limitations, including notable heterogeneity, low quality of studies, and lack of diversity among research participants, should be considered when interpreting our results. Our outcomes suggest that GS supplementation may improve cardiovascular risk factors. Future large-high-quality RCTs with longer duration and various populations are needed to firmly establish the clinical efficacy of the plant.

This systematic review and meta-analysis aims to find the effect of Gymnema sylvestre (GS) supplementation on glycemic control in type-2 diabetes mellitus (T2DM). PubMed, Cochrane library, Google Scholar, and Science Direct were searched from inception to June 2020 to identify the studies that reported GS supplementation on glycemic parameters. Standardized mean difference (SMD) was calculated by comparing the post-intervention data with baseline data. SMDs with 95% confidence intervals (CIs) were pooled using a random-effects model. Our meta-analysis consisting of 10 studies with a total of 419 participants showed that GS supplementation significantly reduces fasting blood glucose (FBG) (SMD 1.57 mg/dl, 95% CI 2.22 to -0.93, p 2 90%), postprandial blood glucose (PPBG) (SMD 1.04 mg/dl, 95% CI 1.53 to -0.54, p 2 80%), and glycated haemoglobin (HbA1c) (SMD 3.91, 95% CI 7.35 to -0.16%, p 2 99%) compared to baseline. Further, our study also found that GS significantly reduces triglycerides (SMD 1.81 mg/dl, 95% CI 2.95 to -0.66, p 2 : 96%), and total cholesterol (SMD 4.10 mg/dl, 95% CI 7.21 to -0.99, p 2 : 98%) compared to baseline. Our study shows that GS supplementation is effective in improving glycemic control and reducing lipid levels in T2DM patients and suggests that such supplementation might be used as an effective therapy for the management of T2DM and its associated complications to an extent.

Natural products have been extensively investigated for antidiabetic therapy. Many of the natural products have direct or indirect effect in diabetes pathways as enzyme inhibitors. The most involved mechanisms are inhibition of intestinal alpha-glucosidase and alpha-amylase, lens aldose reductase, oxidative stress protection, inhibition of formation of advanced glycation end products, inhibition of aldose reductase, lowering plasma glucose levels, altering enzyme activity of hexokinases and glucose-6-phosphate, synthesizing and releasing of insulin, postprandial hyperglycemia inhibition, stimulation of GLUT-4, decreasing activity of G6P, lowering the level of skeletal hexokinases, etc. The following medicinal plants products or extracts showed promising effects as enzyme inhibitors: Abelmoschus moschatus, Alangium salvifolium, Azadirachta indica, Bidens pilosa, Boerhaavia diffusa, Capsicum frutescens, Cassia alata, Eclipta alba, Embellica officinalis, Ficus carica, Gentiana Olivier, Glycyrrhiza glabra, Gymnema sylvestre, Hordeum vulgare, Ipomoea aquatica, Juniperus communis, Mangifera indica, Momordica charantia, Ocimum sanctum, Punica granatum, and Zingiber officinale. Some of the group of phytochemicals isolated with enzyme inhibition activities are Alkaloids, sesquiterpene and saponins, polysaccharides, flavonoids, dietary fibers, ferulic acid, tannins, limonene, and oleuropeoside. This review will provide very useful material to enhance the efficiency of rational antidiabetic drug design.

Across the globe, there are an estimated 150 million people suffering from diabetes mellitus. Each of these people is at increased risk of developing a number of complications, each of which are associated with a reduction in quality of life and an increase in individual morbidity and mortality. However, despite these psychosocial implications, as well as the financial burden associated with the management of the disease, existing treatment options are costly, and have limited, palliative effects. One treatment that is emerging as a potential panacea for the management of diabetes is Gymnema sylvestre. Yet, what evidence is there to support the use of this extract? In order to answer this question, a systematic review of the literature and a discussion of the best available evidence on gymnema are needed. The findings of such a review are presented in this paper.

Gymnema sylvestre (GS) and berberine (BBR) are natural products that have demonstrated therapeutic potential for the management of obesity and its comorbidities, as effective and safe alternatives to synthetic drugs. Although their anti-obesogenic and antidiabetic properties have been widely studied, comparative research on their impact on the gene expression of adipokines, such as resistin (Res), omentin (Ome), visfatin (Vis) and apelin (Ap), has not been reported. Methodology We performed a comparative study in 50 adult Mexican patients with obesity treated with GS or BBR for 3 months. The baseline and final biochemical parameters, body composition, blood pressure, gene expression of Res, Ome, Vis, and Ap, and safety parameters were evaluated. Results BBR significantly decreased ( p p p Conclusion In patients with obesity, BBR has a better effect on body composition, blood pressure, and the gene expression of adipokines related to metabolic risk, while GS has a better effect on fasting glucose and adipokines related to insulin resistance, with minimal side effects.

Gymnemic-acids (GA) block lingual sweet taste receptors, thereby reducing pleasantness and intake of sweet food. Objective: To examine whether a 14-day gymnema-based intervention can reduce sweet foods and discretionary sugar intake in free-living adults. Healthy adults (n = 58) were randomly allocated to either the intervention group (INT) or control group (CON). The intervention comprised of consuming 4 mg of Gymnema sylvestre containing 75% gymnema acids, a fibre and vitamin supplement, and an associated healthy-eating guide for 14 days; participants in the CON group followed the same protocol, replacing the GA with a placebo mint. Amount of chocolate bars eaten and sensory testing were conducted before and after the 14-day intervention (post-GA or placebo dosing on days zero and 15, respectively). Food frequency questionnaires were conducted on days zero, 15 and after a 28-day maintenance period to examine any changes in intake of sweet foods. A range of statistical procedures were used to analyse the data including Chi square, t-test and two-way analysis of variance. Post dosing, INT consumed fewer chocolates (2.65 ± 0.21 bars) at day zero than CON (3.15 ± 0.24 bars; p = 0.02); there were no differences between groups at day 15 (INT = 2.77 ± 0.22 bars; CON = 2.78 ± 0.22 bars; p = 0.81). At both visits, a small substantive effect (r < 0.3) was observed in the change in pleasantness and desire ratings, with INT showing a slight increase while CON showed a small decrease over the 14-day period. No differences were found in the intake of 9 food categories between groups at any timepoint. There were no differences in consumption of low sugar healthy foods between visits, or by group. The 14-day behavioural intervention reduced pleasantness and intake of chocolate in a laboratory setting. There was no habituation to the mint over the 14-day period. This study is the first to investigate the effect of longer-term gymnema acid consumption on sweet food consumption outside of a laboratory setting; further research is needed to assess how long the effect of the 14-day intervention persists.

Diabetes mellitus is a complex metabolic disorder characterized by chronic hyperglycemia, and associated with long-term damage and dysfunction of various organs. Management of diabetes is therefore vital and involves maintaining euglycemia as much as possible by reducing blood glucose and by increasing insulin sensitivity and peripheral glucose uptake. Ayurveda has promoted the management of diabetes by regulating carbohydrate metabolism using several medicinal herbs, one of which is Gymnema sylvestre (GS). GS has been used in parts of India as a hypoglycemic agent and the results have been encouraging. Accordingly, we planned a quasi-experimental study to investigate the efficacy of the herb among type 2 diabetics. Patients enrolled from free-living population were purposively assigned to experimental or control groups, based on their willingness to participate in the study. The experimental group was supplemented with 500 mg of the herb per day for a period of 3 months, and the efficacy of the herb was assessed through a battery of clinical and biochemical tests. Supplementation of the diet with GS reduced polyphagia, fatigue, blood glucose (fasting and post-prandial), and glycated hemoglobin and there was a favorable shift in lipid profiles and in other clinico-biochemical tests. These findings suggest a beneficial effect of GS in the management of diabetes mellitus.

The effectiveness of GS4, an extract from the leaves of Gymnema sylvestre, in controlling hyperglycaemia was investigated in 22 Type 2 diabetic patients on conventional oral anti-hyperglycaemic agents. GS4 (400 mg/day) was administered for 18-20 months as a supplement to the conventional oral drugs. During GS4 supplementation, the patients showed a significant reduction in blood glucose, glycosylated haemoglobin and glycosylated plasma proteins, and conventional drug dosage could be decreased. Five of the 22 diabetic patients were able to discontinue their conventional drug and maintain their blood glucose homeostasis with GS4 alone. These data suggest that the beta cells may be regenerated/repaired in Type 2 diabetic patients on GS4 supplementation. This is supported by the appearance of raised insulin levels in the serum of patients after GS4 supplementation.