Increase Libido - PDE5 was isolated from the human platelet and PDE4 from the rat liver tissue using the FPLC system (Pharmacia, Milton Keynes, UK) and the Mono Q column. The inhibitory effects of icariin on PDE5 and PDE4 activities were investigated by the two-step radioisotope procedure with [(3)H]-cGMP/[(3)H]-cAMP. Papaverine served as the control drug.

Icariin is a cGMP-specific PDE5 inhibitor that may be developed into an oral effective agent for the treatment of Erectile Dysfunction.

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Antioxidant - The objective in this work is to determine the antioxidant capacity and effectiveness of icariin (2-(4‘-methoxylphenyl)-3-rhamnosido-5-hydroxyl-7-glucosido-8-(3‘-methyl-2-butylenyl)-4-chromanone), the major component in herba epimedii being used widely in traditional Chinese medicine for the treatment of artherosclerosis and neuropathy, in which 2,2‘-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced peroxidation of linoleic acid (LH) in sodium dodecyl sulfate (SDS) acts as the experimental system.

By the view of kinetics, icariin is an antioxidant with much higher effectiveness. In addition, the antioxidant capacities of icariin used together with other antioxidants have been determined and the results indicate that the n of icariin decreases markedly while the n values of Trolox and TOH increase, even if the n of icariin is a negative value in the presence of VC-12.

These findings implicate that the evaluation of antioxidant activity should not only focus on an n value, a thermodynamic possibility, but k_inh and the charge property of the micelle should be also taken into account. To some extent, the latter factors are more important than the thermodynamic possibility.

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Anti-Cancer - The aims of the present study were to determine the estrogenic activities of icariin (ICA) and its derivatives and their structure–estrogenic activity relationship. Therefore, icaritin (ICT) and desmethylicaritin (DICT) were derived from ICA. The estrogenic activities of ICA, ICT and DICT were examined by cell proliferation and progestogen receptor mRNA expression of estrogen-receptor-positive MCF-7 cells.

Cell proliferation induced by ICT and DICT was completely antagonized by ICI182,780. ICT and DICT increased progestogen receptor (PR) at mRNA levels at 48 h after treatment, although the effects were not as prominent as 17β">-estradiol (E₂).

These phenomena were not observed with ICA. Results demonstrate that ICT and DICT (nonconjugated forms) possess estrogen-like activity; however, ICA appears to have no estrogenicity in the MCF-7 cell line model in vitro.

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Boosts Nitric Oxide- Icariin, a flavonoid isolated from Epimedii herba, is considered to be the major therapeutical constituent of E. herba. The aim of this study was to investigate the possible protective effects and to clarify the mechanism of icariin on endothelial cells in vitro. Incubation of human umbilical vein endothelial cells (HUVEC) derived EA. hy926 cells with icariin(0.1, 1, 10 μmol l− 1) from 6 h to 72 h, then the production of NO was measured to evaluate the protective effects of icariin. RT-PCR was employed to confirm the mRNA expression of endothelial nitric oxide synthase (eNOS).

Western blotting was used to evaluate the protein expression of eNOS. NO production was enhanced in a time- and concentration-dependent manner (P < 0.05), which was well matched with the expression of eNOS mRNA (up to 2.4-fold) and protein (up to 2.5-fold) after long-term incubation with icariin in endothelial cells (P < 0.05). Moreover, activated NF-κB was increased in EA. hy926 cells incubated with icariin for 24 h, in association with an increase in the expression of eNOS gene. In addition to its long-term effects on eNOS expression, icariin also enhanced the production of bioactive NO in the short-term (after a 5 min incubation, P < 0.05). In concert with other effects, the protective effects of icariin on endothelial cells may contribute to the cardiovascular protective effects.

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