Description:
Epimedium is a genus of
twenty-one related plant species. The Chinese refer to epimedium as "yin
yang huo", which has been loosely translated by some as "licentious goat
plant" and explains why Western supplement companies have adopted the
titillating name by which it is known in the U.S: (horny goat weed).
Epimedium is grown as an ornamental herb in Asia and the Mediterranean
region, and various species are used for medicinal purposes, including
Epimedium sagittatum, Epimedium brevicornum, Epimedium wushanense,
Epimedium koreanum, and Epimedium
pubescens.
Claims:
Because of the traditional use of
epimedium for treating fatigue and boosting sex drive, the majority of
the claims for Western dietary supplements center around sex drive: ·
Boosts libido (sex drive) · Increases energy levels · Enhances recovery
from exercise (via cortisol-control) · Makes you more sexy (not really,
but this is what the ads would suggest)
Theory:
The use
of epimedium as a medicinal herb dates back to at least 400 A.D., where
it has been used as a tonic for the reproductive system (boosting libido
and treating impotence) and as a rejuvenating tonic (to relieve
fatigue). Epimedium is thought to work via modulation of cortisol levels
(the primary stress hormone). Under conditions of high stress, the
increased cortisol levels are known to cause fatigue and depress sex
drive - so bringing cortisol levels back into normal ranges is also
thought to help restore normal metabolism, energy levels and
libido.
Scientific Support:
Animal studies have shown
that epimedium may function a bit like an adaptogen (such as cordyceps,
rhodiola, ashwagandha, and ginseng) by increasing levels of epinephrine,
norepinephrine, serotonin, and dopamine when they are low (an
energy-promoting effect), but reducing cortisol levels when they are
elevated (an anti-stress effect). There is also evidence that epimedium
can restore low levels of both testosterone and thyroid hormone
(bringing low levels back to their normal levels) - which may account
for some of the benefits of epimedium in improving libido (sex drive).
Animal studies using epimedium have shown a reduction in bone breakdown,
an increase in muscle mass, and a loss of body fat-each of which may be
linked to the observed return of abnormal cortisol levels back to normal
values (and rhythm). In a series of studies conducted in humans and
animals by Chinese researchers, immune-system function was directly
suppressed and bone loss was accelerated, by using high-dose synthetic
cortisol (glucocorticoid drugs). Subsequent administration of epimedium
extract reduced blood levels of cortisol and improved immune
immune-system function (in the humans) and slowed bone loss and
strengthened bones (in the animals).
Safety:
It is
interesting to note that although at least 15 fifteen active compounds
have been identified in epimedium extracts, (luteolin, icariin,
quercetin, and various epimedins), many supplement companies currently
use alcohol extracts standardized only for high levels of icariin. The
traditional use of epimedium, however, is as a hot-water decoction
(tea), which would result in a very different profile of active
constituents when compared to the high-icariin alcohol extracts that are
more commonly used in commercial products. Although at least one test
test-tube study has shown icariin to protect liver cells from damage
with by various toxic compounds, other feeding studies (in rodents) have
suggested that high-dose icariin may be associated with kidney and liver
toxicity. There have been no reports of adverse side effects associated
with the traditional preparation of epimedium (water-extracted) at the
suggested dosage (250 to 1,000mg per day).
Dosage: Because
all of the existing scientific evidence for the anti-stress and
cortisol-controlling effect of epimedium has been demonstrated for
water-extracted epimedium (that is, as a tea), and because this form of
extraction may result in a safer form of epimedium (compared to the
high-icariin alcohol extract), it may be prudent to select supplements
that specifically use a more traditional formulation. There have been no
reports of adverse side effects associated with the traditional
preparation of epimedium (water-extracted) at the suggested dosage
(250-1,000mg/day in 2-3 divided doses).
References:
1.
Cai D, Shen S, Chen X. Clinical and experimental research of Epimedium
brevicornum in relieving neuroendocrino-immunological effect inhibited
by exogenous glucocorticoid. Zhongguo Zhong Xi Yi Jie He Za Zhi. 1998
Jan;18(1):4-7.
2. Chen MD, Kuang AK, Chen JL. Influence of
yang-restoring herb medicines upon metabolism of thyroid hormone in
normal rats and a drug administration schedule. Zhong Xi Yi Jie He Za
Zhi. 1989 Feb;9(2):93-5, 70.
3. Gau S, Fu D, Zhang H. Advances in the
study on the treatment of osteoporosis with Epimedium brevicornum and
its compound prescription. Zhongguo Zhong Yao Za Zhi. 1999
Apr;24(4):249-51.
4. Gu Y, Meng G. Preparation conditions for
decoction of Epimedium grandiflorum Morr. Zhongguo Zhong Yao Za Zhi.
1990 Jul;15(7):412-3, 446.
5. Kuang AK, Chen JL, Chen MD. Effects of
yang-restoring herb medicines on the levels of plasma corticosterone,
testosterone and triiodothyronine. Zhong Xi Yi Jie He Za Zhi. 1989
Dec;9(12):737-8, 710.
6. Lee MK, Choi YJ, Sung SH, Shin DI, Kim JW,
Kim YC. Antihepatotoxic activity of icariin, a major constituent of
Epimedium koreanum. Planta Med. 1995 Dec;61(6):523-6.
7. Liang HR,
Vuorela P, Vuorela H, Hiltunen R. Isolation and immunomodulatory effect
of flavonol glycosides from Epimedium hunanense. Planta Med. 1997
Aug;63(4):316-9.
8. Liu ZY, Yang YG, Zheng B. Effect of improving
memory and inhibiting acetylcholinesterase activity by invigorating-qi
and warming-yang recipe. Zhongguo Zhong Xi Yi Jie He Za Zhi. 1993
Nov;13(11):675-6, 646.
9. Peng G, Fu M, Zhang D. The experimental
study about the relations between Chinese herb-epimedium leptorrhizum
stearn (CH-ELS) and endogenous cAMP in alveolar bone of orthodontic
tooth in rats. Zhonghua Kou Qiang Yi Xue Za Zhi. 1997
Jan;32(1):40-2.
10. Wu T, Cui L, Zhang Z, Chen Z, Li Q, Liao J, Huang
L. Experimental study on antagonizing action of herba Epimedii on side
effects induced by glucocorticoids. Zhongguo Zhong Yao Za Zhi. 1996
Dec;21(12):748-51, 763.
11. Yu S, Chen K, Li S, Zhang K. In vitro and
in vivo studies of the effect of a Chinese herb medicine on osteoclastic
bone resorption. Chin J Dent Res. 1999 Feb;2(1):7-11.
Copyright
2001, SupplementWatch, Inc. - http://www.supplementwatch.com/
