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Damiana - is a small shrub that grows 1-2 m high and bears
aromatic, serrate leaves that are 10-25 cm long. Small yellow flowers bloom in
early to late summer which are followed by small fruits with a sweet smell and
fig-like flavor. The medicinal part of the plant is its leaves, which are
harvested during the flowering season. Damiana is found throughout Mexico,
Central America, and the West Indies, as well as in parts of South America.
Turnera diffusa and T. aphrodisiaca are generally regarded as the same plant in
herbal commerce. A closely-related species, T. ulmifolia, is similar in
appearance, but it has different traditional medicinal uses. The botanical Latin
name of the plant, Turnera aphrodisiaca, describes its ancient use as an
aphrodisiac.
TRIBAL AND HERBAL MEDICINE USES
Damiana was recorded to be used as an aphrodisiac in the
ancient Mayan civilization, as well as for "giddiness and loss of balance." A
Spanish missionary first reported that the Mexican Indians made a drink from the
damiana leaves, added sugar, and drank it for its purported power to enhance
lovemaking.
Damiana has a long history of use in traditional herbal
medicine throughout the world. It is thought to act as an aphrodisiac,
antidepressant, tonic, diuretic, cough-suppressant, and mild laxative. It has
been used for such conditions as depression, anxiety, sexual inadequacy,
debilitation, bed-wetting, menstrual irregularities, gastric ulcers, and
constipation. In Mexico, the plant also is used for asthma, bronchitis,
neurosis, diabetes, dysentery, dyspepsia, headaches, paralysis, nephrosis,
spermatorrhea, stomachache, and syphilis. Damiana first was recorded with
aphrodisiac effects in scientific literature over 100 years ago.
From 1888 to 1947 damiana leaf and damiana elixirs were
listed in the National Formulary in the United States. For more than a century
damiana's use has been associated with improving sexual function in both males
and females. Dr. James Balch reports in his book Prescription for Nutritional
Healing that damiana "relieves headaches, controls bed-wetting, and stimulates
muscular contractions of the intestinal tract. . . ." The leaves are used in
Germany to relieve excess mental activity and nervous debility, and as a tonic
for the hormonal and central nervous systems. E. F. Steinmetz states that in
Holland, damiana is renowned for its sexual-enhancing qualities and its positive
effects on the reproductive organs. The British Herbal Pharmacopoeia cites
indications for the use of damiana for "anxiety neurosis with a predominant
sexual factor, depression, nervous dyspepsia, atonic constipation, and coital
inadequacy."
PLANT CHEMICALS
Damiana's chemical composition is complex and its
components have not been identified completely. The leaves contain up to 1%
volatile oil that is comprised of at least 20 constituents (including
1,8-cineole, p-cymene, alpha- and beta-pinene, thymol, alpha-copaene, and
calamene). Damiana leaves also contain tannins, flavonoids, beta-sitosterol,
damianin (a brown, bitter substance), and the glycosides gonzalitosin, arbutin,
and tetraphyllin B. Damiana has been reported to be non-toxic in humans and
animals.
The main constituents of damiana include: Albuminoids,
alpha-copaene, alpha-pinene, arbutin, barterin, beta-pinene, beta-sitosterol,
calamenene, caoutchouc, chlorophyll, 1,8-cineole, cymene, cymol, damianin,
essential oil, gamma-cadinene, gonzalitosin-i, hexacosanol-1, luteolin,
quinovopyranosides, tannins, tetraphyllin b, thymol, triacontane, and
trimethoxyflavones.
BIOLOGICAL ACTIVITIES AND CLINICAL RESEARCH
Only one clinical study has been conducted to validate
the traditional use of the plant for sexual dysfunction and impotence. In 1999,
a group of researchers in Italy administered damiana to both sexually potent and
sexually sluggish (or impotent) rats. The extract had no effect on sexually
potent rats but, in the others, it increased the percentage of rats achieving
ejaculation and made them more sexually active. A U.S. patent was awarded in
2002 for a combination of herbs, including damiana, to "overcome natural
inhibitors of human sexual response and allow for improved response and
psychological effects." Another U.S. patent was awarded for an herbal
combination for females, with inventors reporting that damiana could ". . .
relieve anxiety, depression, headaches during menstruation, and exhaustion.
Damiana also helps to balance female hormone levels and control hot flashes." A
1998 in vitro clinical study reported that components in damiana bound to
progesterone receptors in cultured human breast cancer cells, leading
researchers to surmise that it had a neutral or anti-estrogenic activity.
Central nervous system depressant activity has been
attributed to damiana and verified by research. Damiana also has been used in
combination with other plants for its thermogenic activity. Two U.S. patents
have been filed on oral appetite suppressants containing damiana, citing its
inclusion as an anti-anxiety and thermogenic substance.
Damiana's traditional use for diabetes has been studied
by scientists as well. In 1984, Mexican researchers reported the hypoglycemic
activity of the plant when a leaf infusion was given to diabetic mice. This
effect was re-verified in Mexico when the plant was prepared in the traditional
manner (as an infusion) and given orally to hyperglycemic rats. This study
reported that damiana reduced blood glucose levels as well. A more recent (2002)
study however, reported that an ethanol extract of damiana evidenced no
hypoglycemic activity. These conflicting studies suggest that the active
"hypoglycemic" chemicals in damiana may be extracted in the traditional (hot
water) process, and are lost or not extracted in alcohol.
CURRENT PRACTICAL USES
With such an ancient history of traditional uses
worldwide, it's not unusual that the plant appears in many books on herbal
remedies published world wide. Damiana is also widely available in most health
food and natural product stores in a variety of forms - from tea blends,
capsules and tablets to liquid tinctures and extracts. Most herbalists prefer to
use damiana in combination with other medicinal plants; therefore, it can be
found in quite a few herbal combination formulas for sexual potency, weight
loss, depression, hormonal balancing, and overall tonics. Most of the damiana
sold in herbal commerce today originates from Mexican and Latin American
cultivation projects.
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