gymnema sylvestre benefits, gymnema side effects, gymnema extract
weight loss, diabetes, blood sugar, dosage    September 3, 2011
Gymnema sylvestre benefits
Gymnema Sylvestre has been widely used in India for years.  Its preparations have profound actions on the
modulating taste, particularly suppressing sweet taste sensations. For this reason gymnema sylvestre is known in
Hindi as gurmar, or "sugar destroyer". It has been believed that gymnema sylvestre has benefits of anti-allergic,
antiviral and lipid lowering activities. Gymnea may also offer health benefits for people suffered from diabetes
mellitus. With very limited information, chemicals of gymnea sylvestre are believed to be able to lower the sugar
available in the stomach for absorption, raise the insulin levels and block the dietary fat absorption. [1-3,7]

Gymnema side effects
Gymnema appears to be safe when used appropriately for up to 20 months. [www.webmd.com; 09-02-2011]

Short-term uses of low gymnema sylvestre dosage of gymnema Sylvesre may have only un-noticeable side effects.
Japanese researchers found that there was no toxic effect in rats treated with Gymnema sylvestre at up to 1.00%
in the diet for 52 weeks. The no-observable-effect level from this study is 1.00% Gymnema sylvestre, i.e.,
gymnema sylvestre dosage of 504 mg/kg/day for male and gymnema sylvestre dosage of 563 mg/kg/day for
female as mean daily intake, for 52 weeks. [4] In another study of rats, long-term uses of the Gymnema sylvestre
leaves extract did not show any influence on hematological and blood chemical parameters. [11]

Though some studies show the safety of gymnema, there may be some unwanted side effects such as high blood
pressure [10] and low blood sugar levels. Though some people may consider "blood sugar lowering" as a benefit,
while, low blood sugar level may lead to shakiness, sweating, confusion, distorted speech, and loss of muscle
control. To avoid these potential gymnema side effects, individuals with diabetes should not overdose themselves
and consult with doctor before use of this herb.

Gymnema side effect - liver intoxication
Toxic hepatitis or drug-induced liver injury encompasses a spectrum of conditions ranging from mild biochemical
abnormalities to acute liver failure. A case of drug-induced liver injury in a patient who was treated with Gymnema
sylvestre for diabetes mellitus was reported. [A1] More studies are needed to support this claim.
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Gymnema sylvestre benefits - Scientific Studies

Gymnema sylvestre weight loss
Hong Kong Scientists determined the ant-sweet activties of Gymnema sylvestre are related to Saponin 1 and the
sodium salt of alternoside II (4). [8] In a randomized, double-blind, placebo-controlled 8 week-study of 60
overweight subjects, combo of (-)-hydroxycitric acid, niacin-bound chromium and gymnema sylvestre extract
facilitated a reduction in excess body weight and BMI, and promoted healthy blood lipid levels. [5]

Gymnema sylvestre benefits - anti-bacterial effects
Indian researchers demonstrated antimicrobial activity of an ethanolic extract of Gymnema sylvestre leaves against
Bacillus pumilis, B. subtilis, Pseudomonas aeruginosa and Staphylococcus aureus. [6]

Gymnema sylvestre benefits on- high fat levels
In a study of rats, extract of Gymnema sylvestre R. Br leaves improved serum cholesterol and triglyceride levels
through influence over a wide range of lipid metabolism. It also increased the excretion of neutral sterols and acid
steroids into feces. [9] However, in another study of rats, extract of Gymnema sylvestre leaves were helpful in
decreasing plasma triglyceride but not total cholesterol in rats with normal fat diets. In the same study, the extract
suppressed body weight gain and accumulation of liver lipids in rats with high fat diets. [11]

Gymnema sylvestre diabetes, gymnema blood sugar
As early as 1980s, researchers have started to study the anti-diabetic effects of Gymnema sylvestre leaf extracts.
Gymnema sylvestre leave extract appears to have the benefits on supporting blood glucose homeostasis of
diabetic rats through increased serum insulin levels via repair or regeneration of the endocrine pancreas. [12] In
diabetic rabbits, dried leaf powder of Gymnema sylvestre regulated the blood sugar levels by increasing the
enzyme activities affording the utilisation of glucose by insulin dependent pathways. [13] Thus, Gymnema sylvestre
appears to correct the metabolic derangements in liver, kidney and muscle of the diabetic animals in the studies.
[12-14]

In 1990, researchers started to conduct study of Gymnema sylvestre leave extract on human beings. Researchers
from India adminstered a water-soluble extract of the leaves of Gymnema sylvestre to 27 patients with
insulin-dependent diabetes mellitus (IDDM) on therapy. They found that the Gymnema sylvestre leave extract
enhanced endogenous insulin. [15] In another study of 22 Type 2 diabetic patients on conventional oral
anti-hyperglycaemic agents, researchers applied Gymnema sylvestre leave extracts as supplements to these
patients, and five of the 22 diabetic patients were able to discontinue their conventional drug and maintain their
blood glucose homeostasis with Gymnema sylvestre leave extract alone. [16]

In late 1990s, researchers reported that gymnemic acid contributed to the antihyperglycemic effect of Gymnema
sylvestre leave. In a study of rats, high doses of gymnemic acids increased fecal cholesterol and CA-derived bile
acid excretion. [18] While, other studies suggested that the stimulatory effects of gymnemic acid IV [or Gymnema
sylvestre leave] on insulin release may be related to the increasd cell permeability, rather than by stimulating
exocytosis by regulated pathways. [19, 20] There are different kinds of gymnemic acids and related compounds.
Gymnemoside b and gymnemic acids III, V, and VII exhibit a little inhibitory activity against glucose absorption, but
the principal constituents, gymnemic acid I and gymnemasaponin V, lack this activity. [17]

Om Santal Adivasi - benefits
Though we have a thorough discussion of gymnema extract benefits on diabetes or blood sugar levels. Recently,
Al-Romaiyan A group at King's College London reported a novel high molecular weight Gymnema sylvestre
extract, Om Santal Adivasi, on plasma insulin, C-peptide and glucose in a small cohort of patients with Type 2
diabetes mellitus. Oral administration of this novel extract (dosage: 1 g/day, 60 days) induced significant increases
in circulating insulin and C-peptide, which were associated with significant reductions in fasting and post-prandial
blood glucose. In vitro measurements using isolated human islets of Langerhans demonstrated direct stimulatory
effects of OSA(R) on insulin secretion from human ß-cells. [A2]

Gymnema sylvestre benefits on - breast cancer??
The inhibition of intestinal breast cancer resistance protein (BCRP), which restricts the absorption of xenobiotics,
may increase the systemic availability of its substrates. Tamaki H and research fellows at The University of Tokyo
evaluated the inhibitory effects of herbal extracts and their constituents on BCRP-mediated transport. Extracts of
soybean, Gymnema sylvestre, black cohosh and passion flower and rutin strongly inhibited BCRP-mediated
transport of MTX at 1 mg/ml, while inhibition by chlorella, milk thistle and Siberian ginseng extracts was weak. [A3]
This vitro study shows gymnema may have benefit on people at risk of breast cancer, but clinical studies are
needed to support this health claim.

Gymnema sylvestre benefits - radioprotective activity
A Gymnema sylvestre leaves extract rich in gymnemic acids was examined for its antioxidant activities through
various in vitro assays, along with its radioprotective efficacy in mice brain. The total phenolic content in Gymnema
sylvestre leaves extract was equivalent to 18.06 microg/mL of Gallic acid. The rate of *OH radical scavenging
activity of Gymnema sylvestre leaves extract is 0.46 times slower than reference. Results of in vivo studies showed
that radiation (8 Gy)-induced augmentation in the levels of lipid peroxidation and depletion in glutathione and
protein levels in mice brain were significantly ameliorated by Gymnema sylvestre leaves extract pretreatment. [A4]

[1] Min BC, Sakamoto K. Influence of sweet suppressing agent on gustatory brain evoked potentials generated by taste stimuli.
Appl Human Sci 1998;17:9-17. [2] Murakami N, Murakami T, and Kadoya M. New hypoglycemic constituents in "gymnemic acid"
from Gymnema sylvestre. Chem Pharm Bull 1996;44:469-471. [3] Shigematsu N, Asano R, and Okazaki M. Effect of
administration with the extract of Gymnema sylvestre leaves on lipid metabolism in rats. Biol Pharm Bull 2001;24:713-717. [4]
Ogawa Y Gymnema sylvestre leaf extract: a 52-week dietary toxicity study in Wistar ratsShokuhin Eiseigaku Zasshi. 2004
Feb;45(1):8-18. 5. Preuss HG et al, Effects of a natural extract of (-)-hydroxycitric acid (HCA-SX) and a combination of HCA-SX
plus niacin-bound chromium and Gymnema sylvestre extract on weight loss. Diabetes Obes Metab. 2004 May;6(3):171-80. [6]
Satdive RK et al, Antimicrobial activity of Gymnema sylvestre leaf extract. Fitoterapia. 2003 Dec;74(7-8):699-701. [7]
Porchezhian E, Dobriyal RM. An overview on the advances of Gymnema sylvestre: chemistry, pharmacology and patents.
Pharmazie. 2003 Jan;58(1):5-12. [8] Ye W et al, Antisweet saponins from Gymnema sylvestre. J Nat Prod. 2001
Feb;64(2):232-5. [9] Shigematsu N et al, Effect of administration with the extract of Gymnema sylvestre R. Br leaves on lipid
metabolism in rats. Biol Pharm Bull. 2001 Jun;24(6):713-7. [10] Preuss HG et al, Comparative effects of chromium, vanadium
and gymnema sylvestre on sugar-induced blood pressure elevations in SHR. J Am Coll Nutr. 1998 Apr;17(2):116-23. [11]
Shigematsu N et al, Effect of long term-administration with Gymnema sylvestre R. BR on plasma and liver lipid in rats. Biol
Pharm Bull. 2001 Jun;24(6):643-9. [12] Shanmugasundaram ER et al, Possible regeneration of the islets of Langerhans in
streptozotocin-diabetic rats given Gymnema sylvestre leaf extracts. J Ethnopharmacol. 1990 Oct;30(3):265-79. [13]
Shanmugasundaram KR et al, Enzyme changes and glucose utilisation in diabetic rabbits: the effect of Gymnema sylvestre,
R.Br. J Ethnopharmacol. 1983 Mar;7(2):205-34. [14] Okabayashi Y et al, Effect of Gymnema sylvestre, R.Br. on glucose
homeostasis in rats. Diabetes Res Clin Pract. 1990 May-Jun;9(2):143-8. [15] Shanmugasundaram ER et al, Use of Gymnema
sylvestre leaf extract in the control of blood glucose in insulin-dependent diabetes mellitus. J Ethnopharmacol. 1990
Oct;30(3):281-94. [16] Baskaran K, et al, Antidiabetic effect of a leaf extract from Gymnema sylvestre in non-insulin-dependent
diabetes mellitus patients. J Ethnopharmacol. 1990 Oct;30(3):295-300. [17] Yoshikawa M, et al, Medicinal foodstuffs. IX. The
inhibitors of glucose absorption from the leaves of Gymnema sylvestre R. BR. (Asclepiadaceae): structures of gymnemosides a
and b. Chem Pharm Bull (Tokyo). 1997 Oct;45(10):1671-6. [18] Nakamura Y, et al, Fecal steroid excretion is increased in rats
by oral administration of gymnemic acids contained in Gymnema sylvestre leaves. J Nutr. 1999 Jun;129(6):1214-22. [19]
Persaud SJ et al, Gymnema sylvestre stimulates insulin release in vitro by increased membrane permeability.  J Endocrinol.
1999 Nov;163(2):207-12. [20] Sugihara Y et al, Antihyperglycemic effects of gymnemic acid IV, a compound derived from
Gymnema sylvestre leaves in streptozotocin-diabetic mice. J Asian Nat Prod Res. 2000;2(4):321-7. [A1] Shiyovich A, Sztarkier I,
Nesher L. Toxic hepatitis induced by Gymnema sylvestre, a natural remedy for type 2 diabetes mellitus. Am J Med Sci. 2010
Dec;340(6):514-7. [A2] Al-Romaiyan A, Liu B, Asare-Anane H, Maity CR, Chatterjee SK, Koley N, Biswas T, Chatterji AK, Huang
GC, Amiel SA, Persaud SJ, Jones PM. A novel Gymnema sylvestre extract stimulates insulin secretion from human islets in vivo
and in vitro. Phytother Res. 2010 Sep;24(9):1370-6. A3 Tamaki H, Satoh H, Hori S, Ohtani H, Sawada Y. Inhibitory effects of
herbal extracts on breast cancer resistance protein (BCRP) and structure-inhibitory potency relationship of isoflavonoids. Drug
Metab Pharmacokinet. 2010;25(2):170-9. [A4] Sharma K, Singh U, Vats S, Priyadarsini K, Bhatia A, Kamal R. Evaluation of
evidenced-based radioprotective efficacy of Gymnema sylvestre leaves in mice brain. J Environ Pathol Toxicol Oncol.
2009;28(4):311-23.
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