Gymnema sylvestre (Retz.) R.Br. ex Sm.

Last updated: 04 May 2016

Scientific Name

Gymnema sylvestre (Retz.) R.Br. ex Sm.

Synonyms

Asclepias geminata Roxb., Cynanchum lanceolatum Poir., Cynanchum subvolubile Schumach. & Thonn., Gymnema affine Decne., Gymnema alterniflorum (Lour.) Merr., Gymnema formosanum Schltr., Gymnema geminatum R.Br., Gymnema humile Decne., Gymnema melicida Edgew., Gymnema mkenii Harv., Gymnema parvifolium Wall., Gymnema subvolubile Decne., Gymnema sylvestre var. affine (Decne.) Tsiang, Gymnema sylvestre var. ceylanica Hook. f., Gymnema sylvestre var. ceylanicum Hook.f., Gymnema sylvestre var. chinense Benth., Marsdenia geminata (R. Br.) P.I. Forst., Marsdenia sylvestris (Retz.) P.I.Forst., Periploca sylvestris Retz., Strophanthus alterniflorus (Lour.) Spreng., Apocynum alterniflorum Lour. (unresolved), Periploca tenuifolia Willd. ex Schult. (unresolved), Vincetoxicum lanceolatum Kuntze (unresolved). [1]

Vernacular Name

English Australian cowplant [2]
China Chi geng teng [2]
India Bedhki, gudmar, gurmar, kober theega, kodapatri, madhumeha, madhunashini, merasingi, meshashingi (mesha=sheep, shingi=horned), padapatri, podapatri, podopatri [2]
Japan Horai-ao-kazura [2].

Geographical Distributions

Gymnema sylvestre is widely distributed in India, Malaysia, Srilanka, Australia, Indonesia, Japan, Vietnam, tropical Africa and the southwestern region of the People’s Republic of China. [3]

Botanical Description

G. sylvestre belongs to the family of Asclepiadaceae. It is a slow growing, perennial, woody climber, in dry forests up to 600 m height. It is mainly present in the tropical forest of Central and Southern India. The plant is a large, more or less pubescent, woody climber. [3]

The leaves are opposite, usually elliptic or ovate (1.25 – 2.0 inch x 0.5-1.25 inch). [3]

The flowers are small, yellow, in axillary and lateral umbel in cymes; Follicles are terete and lanceolate upto 3 inches in length. The Calyx-lobes are long, ovate, obtuse and pubescent. Corolla is pale yellow campanulate, valvate, corona single, with 5 fleshy scales. Scales adnate to throat of corolla tube between lobes; Anther connective produced into a memberanous tip, pollinia 2, erect, carpels 2, unilocular; locules many ovuled. [3]

Cultivation

No documentation

Chemical Constituent

G. sylvestre has been reported to contain gymnemic acids (a complex mixture of saponins and dihydroxy gymnemic triacetate) [4], gurmarin (a polypeptide of 35 amino acids) [5], mixture of glucuronides triterpene [6], tartaric acid, calcium oxalate, glucose, stigmasterol, betaine, and choline [7], flavonoid triglycoside, anthroquinones. Others include hentri-acontane, pentatriacontane, α and β-chlorophylls, phytin, resins, dquercitol, tartaric acid, formic acid, butyric acid, lupeol, β-amyrin related glycosides and stigmasterol [8].

Plant Part Used

No documentation.

Traditional Use

G. sylvestre has been traditionally used to treat asthma, snakebite, avoid caterpillar, skin cosmetic, eye complaints, inflammations, inhibit sweet taste sensation, and more. It is believed due to the similar structure of gymnemic acids and glucose, obesity can be reduced through tastebuds receptor replacement. [7]

Preclinical Data

Pharmacology

Antioxidant activity

G. sylvestre was reported to have antioxidant ability by inhibition of free radical and LDL oxidation in human body that is greater than green tea but lower effect with barley tea. This ability is able to reduce the formation of macrophages that can prevent atherosclerosis which can lead to failure of coronary circulation. [9]

Antidiabetic activity

The leaves of G. sylvestre can increase insulin secretion, and several studies report control of hyperglycemia in moderately diabetic laboratory animals [10][11]. A decrease in body weight was also reported. G. sylvestre reportedly produced blood glucose homeostasis and increased the activity of the enzymes involved in the utilization of glucose by insulin dependent pathways [12]. A laboratory animal study reported that G. sylvestre did have stimulatory effects on insulin release, but results indicated that G. sylvestre may act by increasing cell permeability rather than by stimulating release of insulin from beta cells [12]. Another laboratory animal study reported an alteration of hepatic glycogen content [13]. The G. sylvestre leaf extract failed to alter the hepatic glycogen content in normal rats, yet in glucose fed rats, the leaf extract lowered the glycogen content of the tissue significantly. The glycogen content was further lowered when both exogenous insulin and the G. sylvestre leaf extract was administered. A laboratory animal study also investigated the effects of G. sylvestre constituents on fecal steroid excretion, with the results reporting that a high dose of gymnemic acids increases fecal cholesterol and cholic acid-derived bile acid excretion [14]. A recent study reports significant serum cholesterol lowering effects of G. sylvestre [15]. Gymnemic acids have been reported to inhibit the intestinal absorption of glucose in human and rats [16]. A laboratory animal study reported that gymnemic acid inhibited the absorption of oleic acid in intestine of rats, being dose dependent and reversible [17]. These findings are important in the roles of gymnemic acid in therapy of diabetes mellitus and obesity. Animal studies reported that G. sylvestre has a role in triglyceride esters by inhibiting the absorption of oleic acid in small intestine. It is also reported that G. sylvestre restricts the genetic obesity by improving the metabolism of cholesterol and preventing excessive eating [18].

Toxicity

No documentation

Clinical Data

Clinical findings

Human studies have reported a significant reduction in blood glucose during therapy with G. sylvestre [19][20]. A reduction in glycosylated hemoglobin and glycosylated plasma proteins has also been reported, with a reduction in conventional drug dosage. In studies performed in India, patients with Type 2 diabetes were able to discontinue conventional drugs and maintain their blood glucose homeostasis with G. sylvestre alone [20]. Researchers suggest that beta cells may be regenerated and/or repaired in Type 2 diabetics on G. sylvestre supplementation [21]. They support their claim by the appearance of increased endogenous insulin levels in the serum of individuals after G. sylvestre supplementation. As stated earlier, studies have reported that gymnemic acids suppress the elevation of blood glucose levels by inhibiting glucose uptake in the intestine [22].

Precautions

No documentation

Interaction & Depletion

No documentation

Contraindications

No documentation

Dosage

No documentation

Poisonous Management

No documentation

Line drawing

No documentation

References

  1. The Plant List. Ver 1.1. Gymnema sylvestre (Retz.) R. Br. ex Sm. [homepage on the Internet]. c2013. [updated 2012 Mar 23; cited 2016 May 4]. Available from: http://www.theplantlist.org/tpl1.1/record/kew-2835456
  2. Quattrocchi U. CRC world dictionary of medicinal and poisonous plants: Common names, scientific names, eponyms, synonyms, and etymology. Volume III E-L. Boca Raton, Florida: CRC Press, 2012; p. 402.
  3. Saneja A, Sharma C, Aneja KR, Pahwa R. Gymnema sylvestre (Gurmar): A review. Der Pharmacia Lettre. 2010;2(1):275-284.
  4. Daisy P, Eliza J, Farook KA. A novel dihydroxy gymnemic triacetate isolated from Gymnema sylvestre possessing normoglycemic and hypolipidemic activity on STZ-induced diabetic rats. J Ethnopharmacol. 2009;126(2):339-344.
  5. Sinsheimer JE, Rao GS, McIlhenny HM. Constituents from Gymnema sylvestre leaves V: Isolation and preliminary characterization of the gymnemic acids. J Pharma Sci. 1970;59(5):622-628.
  6. Luo H, Kashiwagi A, Shibahara T, Yamada K. Decreased bodyweight without rebound and regulated lipoprotein metabolism by gymnemate in genetic multifactor syndrome animal. Mol Cel Biochem. 2007;299(1-2):93-98.
  7. Parijat K, Rekha S, Madhusudan K. Gymnema sylvestre: A memoir. J Clin Biochem Nutr. 2007;41(2):77-81.
  8. Lee EJ, Mobin M, Hahn EJ, Paek KY. Effects of sucrose, inoculum density, auxins, and aeration volume on ceil growth of Gymnema sylvestre. J Plant Biol. 2006;49(6):427-431.
  9. Ohmori R, Iwamoto T, Tago M, et al. Antioxidant activity of various teas against free radicals and LDL oxidation. Lipids. 2005;40(8):849-853.
  10. Srivastava Y, Nigam SK, Bhatt HV, Verma Y, Prem AS. Hypoglycemic and life-prolonging properties of Gymnema sylvestre leaf extract in diabetic rats. Isr J Med Sci. 1985;21(6):540.
  11. Okabayashi Y, Tani S, Fujisawa T, et al. Effect of Gymnema sylvestre, R. Br. on glucose homeostasis in rats. Diabetes Res Clin Pract. 1990;9(2):143-148.
  12. Shanmugasundaram KR, Panneerselvam C, Samudram P, Shanmugasundaram ER. Enzyme changes and glucose utilisation in diabetic rabbits: The effect of Gymnema sylvestre R. Br. J Ethnopharmacol. 1983;7(2):205-234.
  13. Chattopadhyay RR. Possible mechanism of antihyperglycemic effect of Gymnema sylvestre leaf extract, part I. Gen Pharmacol. 1998;31(3):495-496.
  14. Nakamura Y, Tsumura Y, Tonogai Y, et al. Fecal steroid excretion is increased in rats by oral administration of gymnemic acids contained in Gymnema sylvestre leaves. J Nutr. 1999;129(6):1214-1222.
  15. Preuss HG, Jarrell ST, Scheckenbach R, Lieberman S, Anderson RA. Comparative effects of chromium, vanadium and Gymnema sylvestre on sugar-induced blood pressure elevations in SHR. J Am Coll Nutr. 1998;17(2):116-123.
  16. Shimizu K, Ozeki M, Tanaka K, et al. Suppression of glucose absorption by extracts from the leaves of Gymnema inodorum. J Vet Med Sci. 1997;59(9):753-757.
  17. Wang LF, Luo H, Miyoshi M, et al. Inhibitory effect of gymnemic acid on intestinal absorption of oleic acid in rats. Can J Physiol Pharmacol. 1998;76(10-11):1017-10123.
  18. Luo H, Kashiwagi A, Shibahara T, Yamada K. Decreased bodyweight without rebound and regulated lipoprotein metabolism by gymnemate in genetic multifactor syndrome animal. Mol Cell Biochem. 2007;299(1-2):93-98.
  19. Baskaran K, Kizar Ahamath B, Radha Shanmugasundaram K, Shanmugasundaam ER. Antidiabetic Effect of a leaf extract from Gymnema sylvestre in non-insulin-dependent diabetes mellitus patients. J Ethnopharmacol. 1990;30(3):295-300.
  20. Shanmugasundaram ER, Rajeswari G, Baskaran K, Rajesh Kumar BR, Radha Shanmugasundaram K, Kizar Ahmath B. Use of Gymnema sylvestre leaf extract in the control of blood glucose in insulin-dependent diabetes mellitus. J Ethnopharmacol. 1990;30(3):281-294.
  21. Shanmugasundaram ER, Gopinath KL, Radha Shanmugasundaram K, Rajendran VM. Possible regeneration of the islets of Langerhans in streptozotocin-diabetic rats given Gymnema sylvestre leaf extracts. J Ethnopharmacol. 1990;30(3):265-279.
  22. Shimizu K, Ozeki M, Tanaka K, et al. Suppression of glucose absorption by extracts from the leaves of Gymnema inodorum. J Vet Med Sci. 1997;59(9):753-757.