Icaritin benefit and research
Icaritin is found in horny goat weed herb.
Neuroprotective effects of icaritin against beta amyloid-induced
neurotoxicity in primary cultured rat neuronal cells via estrogen-dependent
pathway.
Neuroscience. 2007 Mar 30;145(3):911-22. Wang Z, Zhang X, Wang H, Qi L, Lou Y.
Institute of Pharmacology & Toxicology and Biochemical Pharmaceutics, College of
Pharmaceutical Sciences, Zhejiang University, Yu-hang-tang Road 388, Hangzhou
310058, China.
Beta-amyloid protein (Abeta) is the hallmark of pathogenic neurotoxins which
contribute greatly to Alzheimer's disease (AD)-associated cascade including
severe neuronal loss. In present study, icaritin, an active natural ingredient
from a Chinese plant, Epimedium sagittatum maxim, was investigated to assess its
neuroprotective effect against the toxicity induced with Abeta(25-35) in primary
cultured rat cortical neuronal cells as well as the underlying mechanisms.
Abeta(25-35) induced neuronal toxicity, characterized by decreased cell
viability, lactate dehydrogenase (LDH) release, and neuronal DNA condensation,
which is associated with both the loss of membrane potential and the alteration
of the expression of Bcl-2 family proteins. The phenotype alternation induced by
Abeta(25-35) could be reversed by icaritin. Furthermore, the neuroprotective
effects of icaritin mentioned above were estrogen receptor dependent due to the
blocking action induced by estrogen receptor antagonist ICI 182,780 and well
matched binding affinity with estrogen receptor by a receptor-ligand docking
experiment. mitogen-activated protein kinase/extracellular signal-regulated
kinase kinase inhibitor PD98059 weakened the protective effects, which implied
mitogen-activated protein kinase/extracellular signal-regulated kinase pathway
may also be involved in and partly contributed to the neuroprotective effects of
icaritin.
Icaritin induces growth inhibition and apoptosis of
human prostatic smooth muscle cells in an estrogen receptor-independent manner.
Amino Acids. 2009 Oct 30. Department of Urology, Xiangya Hospital, Central South
University, 87# Xiangya Road, 410008, Changsha, Hunan, People's Republic of
China.
Icaritin has selective estrogen receptor (ER) modulating activity. ERs are
expressed in the prostate stroma, and estrogens have an important role in the
pathology of benign prostatic hyperplasia (BPH). However, the impact of icaritin
on BPH was not studied. Human prostatic smooth muscle cells (PSMCs) were treated
with 0-100 muM icaritin, also using 10 muM ICI182780 as a specific ER
antagonist. The effects on cell growth and apoptosis were determined by cell
counting and sandwich-enzyme-immunoassay. Western blotting was employed to
illustrate the possible mechanisms. Cell growth was strongly inhibited by
icaritin, and this was accompanied by an augmented apoptosis. Few changes in
icaritin-induced growth inhibition and apoptosis were observed after
pretreatment in the presence of ICI182780. Consistent with growth inhibition and
apoptosis induction, icaritin decreased cyclin D1 and CDK4 expression and
increased Bax/Bcl-2 ratio in human PSMCs. Furthermore, icaritin induced
sustained phosphorylation of extracellular signal-regulated kinase (ERK) in
human PSMCs. PD98059, a specific ERK inhibitor, blocked the activation of ERK by
icaritin and abolished the icaritin-induced growth inhibition and apoptosis. The
results indicate that icaritin reduces growth and induces apoptosis in human
PSMCs via ERK signaling pathway without involvement of ERs.