Gymnema sylvestre
Gymnema sylvestre is an herb native to the tropical forests of southern and central India. Chewing the leaves suppresses the sensation of sweet. This effect is attributed to the presence of the eponymously named gymnemic acids. G. sylvestre has been used as a natural treatment for diabetes for nearly two millennia.[1] Common names include miracle fruit,[2][3][4] gymnema, cowplant, Australian cowplant, gurmari, gurmarbooti, gurmar, periploca of the woods, and meshasringa.
Description
Gudmar or Gymnema Sylvestre is Large climbers, rooting at nodes, leaves elliptic, acuminate, base acute to acuminate, glabrous above sparsely or densely tomentose beneath; Flowers small, in axillary and lateral umbel like cymes, pedicels long; Calyx-lobes long, ovate, obtuse, pubescent; Corolla pale yellow campanulate, valvate, corona single, with 5 fleshy scales. Scales adnate to throat of corolla tube between lobes; Anther connective produced into a membranous tip, pollinia 2, erect, carpels 2,unilocular; locules many ovuled; Follicle long, fusiform1.
Chemical composition
The major bioactive constituents of Gymnema sylvestris are a group of oleanane-type triterpenoid saponins known as gymnemic acids. The latter contain several acylated (tigloyl, methylbutyroyl etc.,) derivatives of deacylgymnemic acid (DAGA) which is the 3-O-glucuronide of gymnemagenin (3,16,21,22,23,28-hexahydroxy-olean-12-ene). The individual gymnemic acids (saponins) include gymnemic acids I-VII, gymnemosides A-F, and gymnemasaponins.
G. sylvestre leaves contain triterpene saponins belonging to oleanane and dammarene classes. Oleanane saponins are gymnemic acids and gymnemasaponins, while dammarene saponins are gymnemasides. Besides this, other plant constituents are flavones, anthraquinones, hentriacontane, pentatriacontane, α and β-chlorophylls, phytin, resins, d-quercitol, tartaric acid, formic acid, butyric acid, lupeol, β-amyrin-related glycosides and stigmasterol. The plant extract also tests positive for alkaloids. Leaves of this species yield acidic glycosides and anthroquinones and their derivatives.
Gymnemic acids have antidiabetic, antisweetener and anti-inflammatory activities. The antidiabetic array of molecules has been identified as a group of closely related gymnemic acids after it was successfully isolated and purified from the leaves of Gymnema sylvestre. Later, the phytoconstituents of Gymnema sylvestre were isolated, and their chemistry and structures were studied and elucidated.
Use as herbal medicine
While it is still being studied, and the effects of the herb are not entirely known. Gymnema reduces the taste of sugar when it is placed in the mouth, thus some use it to fight sugar cravings. From extract of the leaves were isolated glycosides known as gymnemic acids, which exhibit anti-sweet activity.[5] This effect lasts up to about 2 hours. Some postulate that the herb may reduce cravings for sugar by blocking sugar receptors in the tongue. This effect was observed in rats in a 2003 study conducted by CH Lemon, et al.[6]
The active ingredients are thought to be the family of compounds related to gymnemic acid: purified gymnemic acids are widely used as experimental reagents in taste physiology[7] and have also an anti-diabetic effect in animal models,[8] reduce intestinal transport of sugars.[9] and fatty acids.[10]
Historically, the leaves were used for stomach ailments, constipation, water retention, and liver disease; however, these claims are not supported by scientific studies.[11] According to the Sushruta of the Ayurveda it helps to treat Madhumeha ie glycosuria.
In 2005, a study made by King’s College, London, United Kingdom, showed that a water-soluble extract of Gymnema sylvestre, caused reversible increases in intracellular calcium and insulin secretion in mouse and human β-cells when used at a concentration (0.125 mg/ml) without compromising cell viability. These data suggest that extracts derived from Gymnema sylvestre may be useful as therapeutic agents for the stimulation of insulin secretion in individuals with type 2 diabetes.[12] According to research done by Persaud and colleagues in 1999, the raise in insulin levels may be due to regeneration of the cells in the pancreas.[13] Gymnema can also help prevent adrenal hormones from stimulating the liver to produce glucose, thereby reducing blood sugar levels [14] Clinical trials with diabetics in India have used 400 mg per day of water-soluble acidic fraction of the Gymnema leaves. However, Gymnema cannot be used in place of insulin to control blood sugar by people with either type 1 or type 2 diabetes.[15]
Alternative names
Despite the part used being the leaf, one common name of this species is miracle fruit,[2][16][17] a name shared by two other species: Synsepalum dulcificum and Thaumatococcus daniellii.[2] Both species are used to alter the perceived sweetness of foods.
In English the species is also known as gymnema, cowplant, and Australian cowplant.
This species also goes under many other names such as; Gurmari, Gurmarbooti, Gurmar, periploca of the woods and Meshasringa. The Hindi word Gur-mar (Madhunaashini in Sanskrit, Chakkarakolli in Malayalam,Podapatri in Telugu), literally means sugar destroyer. Meshasringa (Sanskrit) translates as "ram's horn", a name given to the plant from the shape of its fruits. Gymnema derives from the Greek words "gymnos" (γυμνὀς) and "nēma" (νῆμα) meaning "naked" and "thread" respectively, the species epitheton sylvestre means "of the forest" in Latin.[18]
References
- ^ "Gymnema sylvestre - Gurmar". Flowersofindia.net. http://www.flowersofindia.net/catalog/slides/Gurmar.html. Retrieved 2011-02-18.
- ^ a b c Wiersema, John Harry; León, Blanca (1999). World Economic Plants: A Standard Reference. CRC Press. p. 661. ISBN 0-8493-2119-0. http://books.google.com/books?id=hQL-2sdxgDAC.
- ^ Rehm, Sigmund, ed (1994). Multilingual dictionary of agronomic plants. Springer. p. 91. ISBN 0-7923-2970-8. http://books.google.com/books?id=qlgY_I_6WpoC.
- ^ Duke, James A., ed (2002). Handbook of medicinal herbs (2nd ed.). CRC Press. p. 855. ISBN 0-8493-1284-1. http://books.google.com/books?id=8AJkBmPDRUUC.
- ^ Kinghorn, A. Douglas; Compadre, César M. (2001). "Less Common High-Potency Sweeteners". In Nabors, Lyn O'Brien. Alternative Sweeteners. CRC Press. pp. 209–33. ISBN 978-0-8247-0437-7. http://books.google.com/books?id=aeMH0F5Z4q4C&pg=PA209.
- ^ Lemon, CH; Imoto, T; Smith, DV (2003). "Differential gurmarin suppression of sweet taste responses in rat solitary nucleus neurons". Journal of neurophysiology 90 (2): 911–23. doi:10.1152/jn.00215.2003. PMID 12702710.
- ^ Hellekant, G; Ninomiya, Y; Danilova, V (1998). "Taste in chimpanzees. III: Labeled-line coding in sweet taste". Physiology & behavior 65 (2): 191–200. doi:10.1016/S0031-9384(97)00532-5. PMID 9855466.
- ^ Sugihara, Y; Nojima, H; Matsuda, H; Murakami, T; Yoshikawa, M; Kimura, I (2000). "Antihyperglycemic effects of gymnemic acid IV, a compound derived from Gymnema sylvestre leaves in streptozotocin-diabetic mice". Journal of Asian natural products research 2 (4): 321–7. doi:10.1080/10286020008041372. PMID 11249615.
- ^ Luo, H; Wang, LF; Imoto, T; Hiji, Y (2001). "Inhibitory effect and mechanism of acarbose combined with gymnemic acid on maltose absorption in rat intestine". World journal of gastroenterology 7 (1): 9–15. PMID 11819725.
- ^ Wang, LF; Luo, H; Miyoshi, M; Imoto, T; Hiji, Y; Sasaki, T (1998). "Inhibitory effect of gymnemic acid on intestinal absorption of oleic acid in rats". Canadian journal of physiology and pharmacology 76 (10–11): 1017–23. doi:10.1139/cjpp-76-10-11-1017. PMID 10100884.
- ^ Shanmugasundaram KR; Panneerselvam C; Sumudram P; Shanmugasundaram ERB (1981). "Insulinotropic activity of G. sylvestre, R.Br. and Indian medicinal herb used in controlling diabetes mellitus". Pharmacol Res Commun 13 (5): 475–486. doi:10.1016/S0031-6989(81)80074-4. PMID 7027275.
- ^ Asare-Anane, H; Huang, GC; Amiel, SA; Jones, PM; Persaud, SJ (2005). "Stimulation of insulin secretion by an aqueous extract of Gymnema sylvestre: role of intracellular calcium". Endocrine Abstracts 10: DP1. http://www.endocrine-abstracts.org/ea/0010/ea0010dp1.htm.
- ^ Persaud SJ; Al-Majed H; Raman A; Jones PM (1999). "Gymnema sylvestre stimulates insulin release in vitro by increased membrane permeability". J Endocrinol 163 (2): 207–212. doi:10.1677/joe.0.1630207. PMID 10556769.
- ^ Gholap S; Kar A (2003). "Effects of Inula racemosa root and Gymnema sylvestre leaf extracts in the regulation of corticosteroid induced diabetes mellitus: involvement of thyroid hormones". Pharmazie 58 (6): 413–415. PMID 12857006.
- ^ Joffe DJ; Freed SH (2001). "Effect of extended release gymnema sylvestre leaf extract (Beta Fast GXR) alone or in combination with oral hypoglycemics or insulin regimens for type 1 and type 2 diabetes". Diabetes in Control Newsletter 76 (1). http://www.diabetesincontrol.com/articles/uncategorized/10355-effect-of-extended-release-gymnema-sylvestre-leaf-extract-beta-fast-gxr.
- ^ Rehm, Sigmund, ed (1994). Multilingual dictionary of agronomic plants. Springer. p. 91. ISBN 0-7923-2970-8. http://books.google.com/books?id=qlgY_I_6WpoC.
- ^ Duke, James A., ed (2002). Handbook of medicinal herbs (2nd ed.). CRC Press. p. 855. ISBN 0-8493-1284-1. http://books.google.com/books?id=8AJkBmPDRUUC.
- ^ "Gymnema". The New International Encyclopædia. http://en.wikisource.org/wiki/The_New_International_Encyclop%C3%A6dia/Gymnema. Retrieved 2011-05-08.
Further reading
- Ambasta, S. P. (1986). The useful plants of India. New Delhi: Publications & Information Directorate, Council of Scientific & Industrial Research. ISBN 978-81-85038-02-5.
- Anturlikar, S.D. Gopumadhavan,S, Chauhan, School, Mitra, B.L., Mitra, S.K., Probe `V.34(3); P.211-221, 1995 (26 Ref.Eng).
- Mukherjee, P.K.; Rajesh Kumar, M; Saha, K; Giri, S.N.; Pal, M; Saha, B.P. Journal of Scientific and Industrial Research, V.55(3) Page 178-181, 1995 (Eng.14 Ref)
- Chakravarthi, D. (1981). "Isolation of Gymnemagenin, the Sapogenin from Gymnema Sylvestre R.Br. (Asclepiadaceae)". Journal of the Institution of Chemists 53: 155–158. ISSN 0020-3254.
- Glaser, D.; Hellekant, G.; Brouwer, J.N.; Van Der Wel, H. (1984). "Effects of gymnemic acid on sweet taste perception in primates". Chemical Senses 8 (4): 367–74. doi:10.1093/chemse/8.4.367.
- Gupta, SS (1961). "Inhibitory effect of Gymnema sylvestre (Gurmar) on adrenaline-induced hyperglycemia in rats". Indian journal of medical sciences 15: 883–7. PMID 13903013.
- Imoto, T; Miyasaka, A; Ishima, R; Akasaka, K (1991). "A novel peptide isolated from the leaves of Gymnema sylvestre—I. Characterization and its suppressive effect on the neural responses to sweet taste stimuli in the rat". Comparative Biochemistry and Physiology Part A: Physiology 100 (2): 309–14. doi:10.1016/0300-9629(91)90475-R.
- Kennedy, Linda M. (1989). "Gymnemic acids: specificity and competitive inhibition". Chemical Senses 14 (6): 853–8. doi:10.1093/chemse/14.6.853.
- Shanmugasundaram, K; Panneerselvam, C; Samudram, P; Shanmugasundaram, E (1983). "Enzyme changes and glucose utilisation in diabetic rabbits: the effect of Gymnema sylvestre, R.Br". Journal of Ethnopharmacology 7 (2): 205–34. doi:10.1016/0378-8741(83)90021-1. PMID 6865451.
- Stoecklin, Walter (1969). "Chemistry and physiological properties of gymnemic acid, the antisaccharine principle of the leaves of Gymnema sylvestre". Journal of Agricultural and Food Chemistry 17 (4): 704–8. doi:10.1021/jf60164a011.
- Yoshikawa, K (1989). "Structure studies of new antisweet constituents from Gymnema sylvestre". Tetrahedron Letters 30 (9): 1103–6. doi:10.1016/S0040-4039(01)80371-3.
- Yoshikawa, K.; K., Amimoto; S., Arihara; K., Matsuura (1989). "Gymnemic acid V, VI, and VII from Gur-ma, the leaves of Gymnema sylvestre R. Br". Chemical and pharmaceutical bulletin 37 (3): 852–4. ISSN 0009-2363.
- Yoshikawa, K; Arihara, S; Matsuura, K; Miyaset, T (1992). "Dammarane saponins fromGymnema sylvestre". Phytochemistry 31: 237–41. doi:10.1016/0031-9422(91)83044-L.
- Mukherjee, P. K.; M., Rajesh Kumar; K., Saha; N., Giri S.; M., Pal; P., Saha B. (1996). "Preparation and evaluation of Tincture of Gymnema Sylvestre (Family- Asclepiadaceae) by Physico-Chemical, TLC and Spectroscopic characteristics". Journal of scientific & industrial research 55 (3): 178–81. ISSN 0022-4456.
- Anil, K.I., Nazaam,P.A., Joseph, L, Vijay Kumar, N.K. - Response of "Gurmar" for in vitro propagation. V.42(6); P 365-368, 1994 (Eng.Recd 1996,6 ref).
- Liu, Bo; Asare-Anane, Henry; Al-Romaiyan, Altaf; Huang, Guocai; Amiel, Stephanie A.; Jones, Peter M.; Persaud, Shanta J. (2009). "Characterisation of the Insulinotropic Activity of an Aqueous Extract of Gymnema Sylvestre in Mouse β-Cells and Human Islets of Langerhans". Cellular Physiology and Biochemistry 23 (1–3): 125–32. doi:10.1159/000204101. PMID 19255507.
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