Icariin

Applications

Icariin inhibits the ROS-dependent JNK and p38 pathways.

Description

Icariin is one of the major flavonoids of the herb Epimedium, which has long been used in Tranditional Chinese Medicine to treat bone fracture and prevent osteoporosis. Research has shown that icariin should be an effective component for the bone-strengthening activity of the herb Epimedium, and one of the possible mechanisms for this activity is to stimulate the proliferation and enhance the osteogenic differentiation of marrow stromal cells. Icariin is reported to prevent and treat sexual dysfunction related diseases and improve the use of vasoconstriction. Icariin is used to prepare angiotensin converting enzyme inhibitor medicines, which can be used to treat hypertension-complicated coronary diseases.

References

[1] K. M. Chen, B. F. Ge, H. P. Ma, X. Y. Liu, M. H. Bai, Y, Wang (2005) Icariin, a flavonoid from the herb Epimedium enhances the osteogenic differentiation of rat primary bone marrow stromal cells, 60, 939-942
[2] Patent CN 1199647C “Application of icariin in preparation of medicine for preventing and treating sexual dysfunction”
[3] Patent CN 104739851 A “New application of icariin, or icariin derivatives or icariin salt”

Chemical Properties

Light yellow to yellow solid

Uses

Icariin has been used:

• in the preparation of topical treatment to determine its effects on the improvement of cutaneous wound healing in rats
• to test its analgesic effects on lower back pain (LBP) in rats
• as a potential treatment in osteoporosis condition in rats
• to study its effects on palmitate (PA)-induced insulin resistance in skeletal muscle C2C12 myotubes
• as a neuroprotective agent to study its effects on amyloid-β (Aβ)-induced neuronal insulin resistance in human neuroblastoma SK-N-MC cells

Uses

Icariin has been used as a test material to investigate its, in vitro effect in promoting mouse hair follicle growth, which is assessed by vibrissae hair follicle (VHF) organ-culture model. It is also used as a hepatoprotective.

Definition

ChEBI: Icariin is a member of the class of flavonols that is kaempferol which is substituted at position 8 by a 3-methylbut-2-en-1-yl group and in which the hydroxy groups at positions 3, 4', and 7 have been converted to the corresponding 6-deoxy-alpha-L-mannopyranoside, methyl ether, and beta-D-glucopyranoside, respectively. A phoshphodiesterase-5 inhibitor, it is obtained from several species of plants in the genus Epimedium and is thought to be the main active ingredient of the Chinese herbal medicine Herba Epimedii (yinyanghuo). It has a role as a bone density conservation agent, a phytoestrogen, an EC 3.1.4.35 (3',5'-cyclic-GMP phosphodiesterase) inhibitor and an antioxidant. It is a glycosyloxyflavone and a member of flavonols.

General Description

Icariin is a prenylated flavonol and the major bioactive compound found in Epimedium herb.

Biological Activity

icariin exhibits inhibitory effects on cgmp-specific phosphodiesterase pde5 and camp-specific phosphodiesterase pde4 activities. phosphodiesterase (pde) is a crucial regulator of camp/pka signaling. pdes are encoded by 21 genes which can be sdivided into 11 families according to the substrate specificities and subcellular localization. pdes are widely expressed in neurons. pde5 has been implicated in regulating some physiological processes such as smooth muscle relaxation and neuronal survival. pde4 has been associated with the darpp-32 signaling pathway and dopaminergic neurotransmission [1].

Biochem/physiol Actions

Icariin is a potent neuroprotective agent in neurodegenerative disorders and other disorders affecting the nervous system. It elicits anti-aging properties in unfertilized oocytes against age-related damage. Icariin exerts anti-inflammatory and antifibrotic properties aiding protection in chronic kidney disease (CKD)-associated renal fibrosis in mouse model. It also serves as an excellent antidiabetic and anti-atherosclerotic agent. Icariin is an excellent anti-cancer agent.

Mechanism of action

Icariin is known as an indicative constituent of the Epimedium genus, which has been commonly used in Chinese herbal medicine to enhance treat impotence and improve sexual function, as well as for several other indications for over 2000 years. Icariside II is a intestinal metabolite of icariin. Their inhibition profile are different. Icaritin is a potent inhibitor of UGT1A7 and UGT1A9 but icariside II is a potent inhibitor of UGT1A4, UGT1A7, UGT1A9, and UGT2B7.

in vitro

icariin inhibited the activity of pde5 and pde4 in a dose- andconcentration-dependent manner. the ic50of icariin on pde5 was 0.43 μm and the ic50 on pde4 was 73.50 μm. icariin showed a selective inhibitory effect on cgmp-specific pde5 compared to camp-specific pde4 [2].icariincould also enhance the osteogenic differentiation of rat primary bone marrow stromal cells [3].

in vivo

in castrated rats, a 4-week oral administration of icariinat 1 mg/kg/day and 5 mg/kg/day improved the erectile function and increased nnos and inos expression [4].icariin also showed its effect on stimulating angiogenesis in human endothelial cells [5].

References

nishi a, kuroiwa m, miller d b, et al. distinct roles of pde4 and pde10a in the regulation of camp/pka signaling in the striatum[j]. the journal of neuroscience, 2008, 28(42): 10460-10471.xin z c, kim e k, lin c s, et al. effects of icariin on cgmp-specific pde5 and camp-specific pde4 activities[j]. asian journal of andrology, 2003, 5(1): 15-18.chen k m, ge b f, ma h p, et al. icariin, a flavonoid from the herb epimedium enhances the osteogenic differentiation of rat primary bone marrow stromal cells[j]. die pharmazie-an international journal of pharmaceutical sciences, 2005, 60(12): 939-942.liu w j, xin z c, xin h, et al. effects of icariin on erectile function and expression of nitric oxide synthase isoforms in castrated rats[j]. asian journal of andrology, 2005, 7(4): 381-388.chung b h, kim j d, kim c k, et al. icariin stimulates angiogenesis by activating the mek/erk-and pi3k/akt/enos-dependent signal pathways in human endothelial cells[j]. biochemical and biophysical research communications, 2008, 376(2): 404-408.