Gymnema sylvestre
(GS) is a woody climbing plant that grows
in the tropical forests of central and
southern India. The leaves are used in
herbal medicine preparations. Gymnema
sylvestre is known as "periploca of the
woods" in English and mesbasringi (meaning
"ram's horn") in Sanskrit. The leaves,
when chewed, interfere with the ability to
taste sweetness, which explains the Hindi
name gurmar - "destroyer of sugar."
Plant constituents include two resins (one
soluble in alcohol), gymnemic acids,
saponins, stigmasterol, quercitol, and the
amino acid derivatives betaine, choline
and trimethylamine.
Gymnema sylvestre is a stomachic,
diuretic, refrigerant, astringent, and
tonic. It has been found to increase urine
output and reduce hyperglycemia in both
animal and human studies.
Gymnema sylvestre has been used in
India for the treatment of diabetes for
over 2,000 years. The primary application
was for adult-onset diabetes, a condition
for which it continues to be recommended
today in India. The leaves were also used
for stomach ailments, constipation, water
retention, and liver disease.
Extracts of Gymnema sylvestre given to
patients with type I diabetes on insulin
therapy reduces insulin requirements and
fasting blood sugar levels, and improves
blood sugar control. In a study of type II
diabetics, Gymnema sylvestre extract given
along with oral hypoglycemic drugs was
shown to improve blood sugar control and
to either lead to discontinuation of the
medicine or a significantly reduced
dosage. Gymnema sylvestre is interesting
to note that Gymnema sylvestre extract
given to healthy volunteers does not
produce any blood sugar-lowering, or
hypoglycemic, effects.
