Gymnema Sylvestre is a perennially growing woody climbing herb found in central and southern India. On the verge of being extinct, this herb grows very sluggishly and is sometimes grown as a therapeutic plant to treat diabetes or excessive blood sugar levels. Usually, this herb is large and essentially flowering. The leaves of this herb are arranged alternately on the stem and have an ovate or elliptic shape having dimensions of 1.2 inches to 2.0 inches x 0.5 inches to 1.25 inches. Gymnema produces petite, yellow flowers in umbellate (umbel - an inflorescence wherein several flower stalks, almost equivalent in length, extend from a common center) cymes. The follicles of the herb are cylindrical or somewhat tapering and lance-shaped growing up to 3 inches long.
As mentioned above, gymnema possesses strong anti-diabetic properties and has been traditionally used in Ayurvedic (an ancient stream of Indian herbal medicine) as well as homeopathic medicine for long. In addition, this herb is employed in treating health conditions like inflammations, eye complaints, asthma, and family planning as well as to cure snakebite. Gymnema also has antihypercholesterolemic (any substance that is effective against hypercholesterolemia - presence of high cholesterol in blood), antimicrobial, sweet suppressing and hepatoprotective (preventing damage to liver) actions. Apart from the therapeutic properties of the herb mentioned here, gymnema is also used as feeding deterrents to caterpillar (botanical name, Prodenia eridania). The herb is also used in cosmetic products and also to avoid dental caries brought about by Streptococcus mutans.
This species is native to the tropical forest regions of south and central India and also growing in some tropical regions of Africa. Since long, herbalists in India have used Gymnema Sylvestre for various therapeutic purposes. The long lance-shaped leaves of this slender woody climbing herb have been used to treat diabetes for over 2,000 years. The main attributes of this plant and its basic use in traditional Indian medicine is best described by the Hindu term ‘gumar' denoting ‘sugar destroyer'. Gymnema Sylvestre is such a potent herb that its powdered roots has been employed to heal snake bites, stomach disorders, liver ailments, excessive water retention by the body as well as constipation. Physicians in India state that this herb is not only used to effectively treat diabetes mellitus, but also as food additives against caries (decay of bones as in dental caries) and obesity. In addition, Gymnema Sylvestre is also believed to possess antiviral, anti-allergic, lipid lowering as well as other useful actions. It has also been found that the use of this herb facilitates in lowering the levels of cholesterol and triglycerides in the bloodstream.
Ayurvedic physicians in ancient times noted that chewing up a small number of gymnema leaves helped to restrain the flavour of sugar. Currently, the herb is extensively used throughout India to control blood sugar levels.
This herb has been introduced in the United States and Europe only recently. Nevertheless, the extracts obtained from the plant, especially its leaves, have been widely used for long in Indian traditional medicine as well as in countries like Japan, Australia and Vietnam as a part of their folk medicine.
Habitat and cultivation
The herb Gymnema Sylvestre is indigenous to central, southern and western India, Australia and the tropical regions of Africa. It is known to be a vulnerable species.
Clinical experiments on animals in laboratory have hinted that the use of Gymnema Sylvestre helps to augment the ability of the body to break down and absorb lipids or fats. During the course of clinical trials, it was found that rats that were given a diet rich in fat content exhibited health benefits that have been attributed to the use of Gymnema Sylvestre. The enhanced metabolism of lipids led to the reduction of serum cholesterol levels in the bloodstream and facilitated the body to lower the triglyceride count on the whole.
Several researches undertaken in India, where the herb is known to have been used for more than 2,000 years, discovered that treatment using an alcoholic extract of the Gymnema Sylvestre leaves continuously for three weeks led to a considerable decrease in blood glucose and, at the same time, resulted in an augmentation of plasma insulin. In addition, the alcoholic extract of the herb's leaves also led to the reduction of the formation of the harmful free radicals in the plasma of rats enduring diabetes. Therefore, this particular study has shown that Gymnema Sylvestre leaf extract (GLEt) has antihyperglycemic (any substance that helps to lower exceptionally high blood sugar levels) as well as antiperoxidative actions. Again, that GLEt possesses antioxidant attributes is established by the fact that it helps to lower lipid peroxides and, simultaneously facilitates increase in reduced glutathione (GSH), alpha-tocopherol (vitamin E) and ascorbic acid (vitamin C). Besides, the findings of the research also imply that GLEt was more effectual compared to the reference medication glibenclamide.
It is important to note that the researchers have stated that Gymnema Sylvestre does not spoil the flavour of sugary foods. Being a ‘sugar destroyer', this herb restrains the cravings for sweets, which makes it a potent medication for weight loss. It has been found that this oriental herb lowers the ability of the body to savour sweetness, thereby, decreasing the ingestion of sweets. In another research that involves fasting patients, some of the subjects were given Gymnema Sylvestre, while others were not. Patients who ingested Gymnema Sylvestre an hour prior to being served a meal consumed less compared to those patients who had not been given the herb. The results of this study hint that the pleasant aspects of taste are of more significance compared to the calories in deciding the interim intake. Therefore, people who have a lesser craving for sweets are not likely to consume sweets. In fact, using the herb Gymnema Sylvestre diminishes the cravings for sweetened foods.
The entire effects caused by Gymnema Sylvestre are still to be ascertained and, hence, scientists are continuing with their research with this herb. However, it has been proved that when the herb is used for a prolonged period, it helps to lower the blood sugar levels. In addition, the herb also lessens the flavour of sugar when it is taken inside the mouth; hence, it is not surprising that some people use Gymnema Sylvestre to reduce their cravings for sugar. Glycosides called gymnemic acids were isolated from the leaf extracts of this plant and these glycosides are known to show anti-sweet actions.
The anti-sweet impact of taking Gymnema Sylvestre remains for around two hours. Some people say that actually this herb lessens the desire for sugar intake by obstructing the sugar receptors located in the tongue. Presently, this herb is being employed in an entirely natural medication for diabetes combined with other elements like bitter melon, cinnamon, zinc, chromium, banaba plant, biotin and huckleberry.
The active elements enclosed by Gymnema Sylvestre are considered to belong to the family of compounds associated with gymnemic acid. In effect, distilled gymnemic acids are extensively used in the form of trial reagents in flavour physiology and they have also shown that they have an influence on experimental diabetes as well as decreasing intestinal transportation of fatty acids and sugars. It is claimed that the extracts of gymnema not only curb sweet tooth, but also treat various problems, including obesity, hyperglycaemia, anemia, high cholesterol levels as well as digestion. Earlier, the leaves of Gymnema Sylvestre were also utilized to treat stomach disorders, excessive water retention by the body, constipation as well as various liver ailments. However, it needs to be mentioned that such claims regarding the therapeutic uses of the herb have not been proved scientifically.
Findings of a research undertaken by scientists at King's College in London in 2005 exhibited that an extract of Gymnema Sylvestre, which is soluble in water, resulted in reversible augmentations in intracellular calcium as well as insulin secretion in mouse as well as human β-cells when it is employed in the intensity of 0.125 mg/ ml without conceding the viability of cells. Therefore, the data collected from the study recommends that the extracts obtained from Gymnema Sylvestre might possibly be helpful as remedial agents for promoting secretion of insulin in people enduring type-2 diabetes.
Earlier, in 1999, Persaud and his colleagues undertook a study which suggests that the augmentation in the insulin levels may possibly be owing to the rejuvenation of the pancreatic cells. In addition, Gymnema Sylvestre is also likely to facilitate in preventing adrenal hormones from invigorating the liver to produce glucose and, in this manner, lower the blood sugar levels in clinical trials with diabetics. Researches undertaken in India have made use of 400 mg of the water-soluble acidic proportion of the herb's leaves to achieve this result. It needs to be mentioned here that it is not possible to use Gymnema Sylvestre as a substitute of insulin to regular blood sugar levels in people suffering from either type-1 diabetes or type-2 diabetes.
Another study was undertaken on Gymnema Sylvestre by Kings' College, London, as recently as 2010. During the course of their research, scientists found that a high molecular weight extract from the herb - OmSantal Adivasi, led to the improvement of the symptoms of type-2 diabetes mellitus. Following the administration of OmSantal Adivasi, glycemic control was associated with enhanced levels of insulin and/ or C-peptide circulation. Experimentation with islets in human pancreas in vitro, showed a quick onset response when exposed to OmSantal Adivasi and it continued for the duration of exposure to OmSantal Adivasi as well as a quick reverse when OmSantal Adivasi was withdrawn. In effect, the high molecular weight extract from the Gymnema Sylvestre established a biphasic pattern of insulin secretion induced by glucose. This, in turn, led to increased insulin secretion rates that sustained during the entire extent of exposure to OmSantal Adivasi.
Other extracts obtained from Gymnema Sylvestre prompt cell damage to membrane resulting in pathological as well as uncontrolled secretion of insulin to BETA cells. Since OmSantal Adivasi possesses a poor saponin content, this extract of the herb results in damage to the cell membranes which are likely to be destroyed during the process of digestion. In addition, the Gymnema Sylvestre extract OmSantal Adivasi invigorated the BETA-cells of the Langerhans islets right away lessening fasting as well as post-prandial (after a meal, especially dinner) blood glucose. In vitro experiments undertaken with OmSantal Adivasi started secretion of insulin at a sub-stimulatory concentration of glucose. In addition, the Gymnema Sylvestre extract OmSantal Adivasi has also exhibited that it is effective in lowering blood glucose levels as well as augment plasma insulin as well as C-peptide levels in humans.
Chemical analysis of the Gymnema Sylvestre leaves has shown to possess triterpene saponis that are members of the dammarene and oleanane categories. While the oleanane saponins include gymnemasaponins and gymnemic acids, the dammarene saponins comprise gymnemasides. Apart from these saponins, the other compounds enclosed by the herb include anthraquinones, flavones, pentatriacontane, hentri-acontane, phytin, α and β-chlorophylls, formic acid, tartaric acid, butyric acid, d-quercitol, resins, stigmasterol, β-amyrin associated glycosides and lupeol. Extracts obtained fro Gymnema Sylvestre plant has also proved to enclose a number of alkaloids. In addition, the leaves of this herb also give out anthroquinones, their derivatives as well as acidic glycosides.
Gymnemic acids enclosed by this herb have anti-inflammatory, anti-sweetener and anti-diabetic actions. The assortment of anti-diabetic molecules has been recognized as a cluster of closely associated gymnemic acids when it was isolated and distilled from the leaves of the herb with success. Afterwards, phytoconstituents contained by Gymnemic Sylvestre were isolated and scientists examined and explained the chemistry as well as the structures of these compounds.
Side effects and cautions
Dietary supplements containing the herb Gymnema Sylvestre is not known to cause any notable adverse after-effects when it is taken as per the recommendations of your healthcare provider. It is advisable that this herb or supplements containing it ought to be taken with some food, as it may result in some kind of gastrointestinal problems when ingested in an empty stomach. Taking the herb in excessive dosages may possibly result in hypoglycemia or exceptionally low blood sugar levels in people who are inclined to suffer hypoglycemic conditions. It is advisable that people suffering from active diabetes should talk to their physician prior to and during the course of using this herb, since the use of Gymnema Sylvestre may require changes in your insulin dosage or any other anti-diabetic medicines that you may be taking.
How it works in the body
Precisely speaking, there are a number of hypothesizes regarding the manner in which the herb Gymnema Sylvestre works or achieves the constructive consequences that it seems to have in the human body. According to the findings of one research, this herb holds back rising levels of glucose in the blood stream by way of slowing down the absorption of glucose in the intestine. However, the study was not conducted on humans, but guinea pigs - the animals commonly used in scientific researches since they possess attributes similar to the humans.
This herb is also used in weight loss treatment, since Gymnema Sylvestre seems to decrease the body's desire for sweets. This action, in turn, lessens the total intake of calories by the body. In effect, lower consumption of food devoid of employing any stimulant is normally deemed to be among the safest procedures to reduce body weight.