The Gymnema Sylvestre Leaf

Found in central and western India, tropical Africa and Australia, Gymnema sylvestre is a medicinal climbing plant used in traditional, homeopathic models of medicine. It's a slow growing plant, and its leaves are usually elliptical or oval and its flowers are small and yellow. With anti-microbial, anti-inflammatory and sweet suppressing qualities, it has been used for numerous ailments. Primarily, research has been directed towards its sweet suppressing properties as an antidiabetic [3]. In Hindi, Gymnema sylvestre is known as Gurmar, which literally means “sugar destroyer” [2]. 

Uses

• Diabetes - a common complication caused by the body’s inability to use or produce insulin appropriately [1]. 
• The antidiabetic molecules have been identified as a group of gymnemic acids after isolating from the leaves of the plant [3]. 
• Gymnemic acids have the ability to delay the absorption of glucose in the blood as the atomic arrangement of the molecules is similar to glucose molecules - they are able fill in the receptors on the taste buds and in the intestines, thereby inhibiting actual sugar molecules from binding. As a result, it is preventing sugar absorption and consequently reducing sugar cravings [3]. 
• In studies on animal models, they found that the administration of this plant led to the reduction in insulin levels, protein, triglycerides (fats), cholesterol and glucose, and an overall reduction in body weight [4]. These results show promise for diabetes treatments.
• Additionally, the lack of insulin in diabetes patients leads to high blood sugar levels (since insulin is the hormone responsible for moving sugar from the blood to cells), so here the extract from the leaves of Gymnema sylvestre seems to be inducing insulin production from the body itself [5].  **This clinical study was only conducted on 27 patients, so results cannot be made conclusive.**
• Anticancer Activity
• A component of Gymnema sylvestre, called gymnemagenol, has shown positive anticancer properties [4].
• Significant anticancer activity was observed for melanoma, as well as inhibition for breast cancer resistant proteins [4].
• Antimicrobial Activity 
• Different extracts and isolated compounds of Gymnema sylvestre have reported antimicrobial activity against many microorganisms. 
• For example, plant extract mixed with water and ethanol was found to be active against pathogenic Salmonella species. And, extract mixed with chloroform, ethyl acetate and ethanol reported to be active against E. Coli and other bacteria [4]. 

In general, the leaves provide for diabetes treatment while the leaf extracts (in different mediums) provide for the antimicrobial and anticancer properties [6].

Dosage

As known, when looking at dosage of herbal supplements, it's important to check multiple factors, including age, health conditions and coexisting medications. Despite numerous studies being conducted, we do not have a definitive dosage level for Gymnema sylvestre. 

Dried leaves can be ground into powder and saved for later uses,  for example, in teas or simply chewed and eaten. Supplements in tablet and capsule form are also made which help control for accurate dosage [2].

As always, dosing should be under recommended ranges, and for Gymnema sylvestre, most commonly used dosages in studies were around 200 to 400 milligrams (mg) per [1]. Keep in mind, with no exact specifications, high dosages can be harmful [6].

Side Effects

Common Side Effects (directly correlated to the reduction in blood sugar) 

• Headache
• Dizziness / lightheadedness
• Nausea 
• Shakiness 

** For certain groups of individuals, such as children, pregnant and breastfeeding women, people with diabetes, and those taking blood sugar lowering medication, talking to a healthcare provider is crucial before taking Gymnema sylvestre supplements. **

Drug interaction for those with diabetes taking insulin medication can be debilitating as the effects of insulin increase the effects of Gymnema sylvestre - so please contact your healthcare provider before taking the plant supplements - this also applies to other antidiabetic drugs [1].  

Concluding thoughts 

Apart from certain groups of individuals, Gymnema sylvestre has been used traditionally for ages so consumption of it under low dosage should be appropriate. Coupled with the fact that it is beneficial for the body and relieves several major ailments, Gymnema sylvestre is a promising supplement in up-and-coming research!

References

1. Christiansen S. The Health Benefits of Gymnema Sylvestre [Internet]. Verywell Health. 2020 [cited 2020Dec12]. Available from: https://www.verywellhealth.com/gymnema-sylvestre-4692940
2. Gymnema [Internet]. Monterey Bay Spice Company. [cited 2020Dec12]. Available from: https://www.herbco.com/c-357-gymnema.aspx 
3. Kanetkar P, Singhal R, Kamat M. Gymnema sylvestre: A Memoir [Internet]. Journal of clinical biochemistry and nutrition. the Society for Free Radical Research Japan; 2007 [cited 2020Dec12]. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2170951/.
4. Khan F, Sarker MMR, Ming LC, Mohamed IN, Zhao C, Sheikh BY, et al. Comprehensive Review on Phytochemicals, Pharmacological and Clinical Potentials of Gymnema sylvestre [Internet]. Frontiers. Frontiers; 2019 [cited 2020Dec12]. Available from: https://www.frontiersin.org/articles/10.3389/fphar.2019.01223/full 
5. Shanmugasundaram ERB, Rajeswari G, Baskaran K, Kumar BRR, Shanmugasundaram KR, Ahmath BK. Use of Gymnema sylvestre leaf extract in the control of blood glucose in insulin-dependent diabetes mellitus [Internet]. Journal of Ethnopharmacology. Elsevier; 2002 [cited 2020Dec12]. Available from: https://www.sciencedirect.com/science/article/pii/0378874190901075 
6. Tiwari P, Mishra BN, Sangwan NS. Phytochemical and Pharmacological Properties of Gymnema sylvestre: An Important Medicinal Plant [Internet]. BioMed Research International. Hindawi; 2014 [cited 2020Dec12]. Available from: https://www.hindawi.com/journals/bmri/2014/830285/