Icariins research studies

Epimedium species (aka horny goat weed) have been utilized for the treatment of erectile dysfunction in Traditional Chinese Medicine for many years. Icariin is the active moiety of Epimedium species.

What is the difference between the ingredients icariins and icariin in horny goat weed extract? Why is the one with icariin more expensive?
   A. Icariins contains 2 or 3 chemical substances, which include icariin. The manufacturing process of icariin is much more difficult, thus the raw material cost of icariin is higher than the cost of Icariins.

Effects of icariin on cGMP-specific PDE5 and cAMP-specific PDE4 activities.
Department of Urology, the 1st Hospital, Peking University, 8 Xishiku Street, Xicheng District, Beijing 100034, China.
To clarify the mechanism of the therapeutic action of icariin on erectile dysfunction. PDE5 was isolated from the human platelet and PDE4 from the rat liver tissue. Icariin and papaverine showed dose-dependent inhibitory effects on PDE5 and PDE4 activities. The potencies of selectivity of icariin and papaverine on PDE5 (PDE4/PDE5 of IC(50)) were 167 times and 4.5 times, respectively. Icariin is a cGMP-specific PDE5 inhibitor that may be developed into an oral effective agent for the treatment of erectile dysfunction.

Icariin protects against bone loss induced by oestrogen deficiency and activates oestrogen receptor-dependent osteoblastic functions in UMR 106 cells.
Br J Pharmacol. 2010 Jan 27. Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China.
Icariin may be the active ingredient in Herba Epimedii, a Chinese herb commonly used for treatment of osteoporosis. The present study aims to delineate the mechanism(s) by which icariin prevents bone loss after ovariectomy (OVX) in vivo and stimulates osteoblastic functions in vitro. Experimental approach: Ovariectomized or sham-operated C57BL/6 mice were treated with vehicle, 17beta-oestradiol or icariin for 6 weeks. Total and trabecular bome mineral density (BMD) as well as polar stress-strain index of distal femur were measured by peripheral computed tomography. The mRNA expressions of OPG and RANKL in tibia were studied by RT-PCR. Interactions between the oestrogen receptor (ER) antagonist ICI182,780 and icariin were studied in UMR 106 cells. The functional transactivation of ERalpha and ERbeta as well as ERalpha phosphorylation by icariin were also assessed. Icariin suppressed the loss of bone mass and strength in distal femur and increased the mRNA expression ratio of OPG/RANKL in tibia, following OVX. Icariin increased ER-dependent cell proliferation, alkaline phosphatase (ALP) activity, gene expression of OPG and the OPG/RANKL ratio in UMR 106 cells. Our results indicate that icariin exerts anabolic effects in bone possibly by activating ER in a ligand-independent manner. Its ability to prevent OVX-induced bone loss without inducing uterotrophic effects supports its use as an alternative regimen for management of postmenopausal osteoporosis.