Icariin improves cognitive deficits and activates quiescent neural stem cells in aging rats
ABSTRACT Icariin represents an important active component in Herba Epimedii, which is a famous Chinese herbal medicine that is widely used to treat some age-related diseases in oriental countries.
The aim of this work was to investigate the effects of icariin on cognitive function in natural aging rats, and then to explore its mechanism by investigating the activation of quiescent neural stem cells (NSCs) in the hippocampus.
Sprague-Dawley rats that were 18 months of age were divided into two groups including treated rats (i.e., icariin was administered from the age of 18 months to 21 months) and control rats (i.e., only saline was administered). The Morris water maze (MWM) tasks were then employed to measure spatial learning and memory. Subsequently, AraC was infused into the brain with osmotic minipumps in order to destroy proliferative stem cells primarily leaving quiescent NSCs. After seven days of recovery, 5-bromodeoxyuridine (BrdU) was co-labeled with markers for NSC to identify NSCs.
The results from the MWM indicated that icariin has a beneficial effect on cognitive function in aging rats. In addition, by double-labeling BrdU and glial fibrillary acidic protein (GFAP), our findings indicated that NSC activation is markedly increased in the icariin-treated rats compared to control rats. For example, a much greater increase was produced in BrdU and highly polysialylated neural cell adhesion molecule (PSA-NCAM) and BrdU and Olig2 double-labeled cells following icariin treatment.
Our findings suggest that icariin represents a promising candidate for the modulation of aging. Therefore, icariin administration may effectively prevent or delay the onset of age-related cognitive degeneration, and its capability to activate quiescent NSCs may potentially be one of its mechanisms.
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ABSTRACT: The purpose of this systematic review is to assess the efficacy and pharmacological profiles of Herba Epimedii in osteoporosis therapy. Four databases were extensively retrieved that include two Chinese electronic databases (VIP Information and CNKI) and two English electronic databases (CA and MEDLINE). Herba Epimedii has been an important traditional herbal medicine for centuries in China and other Asian countries. Recently, quite a few pharmacological effects of Herba Epimedii, its extracts and active components have been identified that include improving bone health and cardiovascular function, regulating hormone level, modulating immunological function, and inhibiting tumor growth. The anti-osteoporosis activity of Herba Epimedii and its extracts have attracted world-wide attention. The literature search has revealed that a lot of studies have recently been carried out related to the bone-strengthening activity of Herba Epimedii and some of its active compounds, such as total flavonoids and icariin. Pharmacokinetic and toxicity studies have confirmed the efficacy and safety of Herba Epimedii and its most abundant active component icariin, while only a few authors have reviewed the anti-osteoporosis properties of the plants. So we summarize the work of various investigators on the effects of Herba Epimedii, its extracts and active components against osteoporosis. The underlying mechanism of osteoprotective action, derivatives of icariin, animal models and cell lines used in the research were also reviewed in this paper.Pharmazie 09/2013; 68(9):713-22. DOI:10.1691/ph.2013.2900 · 1.00 Impact Factor
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ABSTRACT: ETHNOPHARMACOLOGICAL RELEVANCE: Epimedium brevicornum Maxim (E. brevicornum) has long been used for the treatment of osteoporosis in China and other Asian countries. However, the mechanism behind the antiosteoporotic activity of this medicinal plant is not fully understood. AIM OF THE STUDY: The present study was designed to investigate the effects of 5 widely used antiosteoporotic medicinal plants (E. brevicornum, Cuscuta chinensis, Rhizoma drynariae, Polygonum multiflorum, and Ligustrum lucidum) on the production of estrogen and identify the bioactive compounds responsible for the estrogen biosynthesis-promoting effect. MATERIALS AND METHODS: Human ovarian granulosa-like KGN cells were used to evaluate estrogen biosynthesis, and the production of 17β-estradiol was quantified by magnetic particle-based enzyme-linked immunosorbent assay (ELISA) kit. Further, the mRNA expression of aromatase was determined by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR), and the protein expression of aromatase was detected by western blotting. The activity of alkaline phosphatase (ALP) in rat osteoblastic UMR-106 cells was measured using p-nitrophenyl sodium phosphate assay. RESULTS: Among the 5 antiosteoporotic medicinal plants, the extract of E. brevicornum was found to significantly promote estrogen biosynthesis in KGN cells. Icariin, the major compound in E. brevicornum, was identified to be the active compound for the estrogen biosynthesis-promoting effect. Icariin promoted estrogen biosynthesis in KGN cells in a concentration- and time-dependant manner and enhanced the mRNA and protein expressions of aromatase, which is the only enzyme for the conversion of androgens to estrogens in vertebrates. Further study showed that icariin also promoted estrogen biosynthesis and ALP activity in osteoblastic UMR-106 cells. CONCLUSIONS: These results show that the promotion of estrogen biosynthesis is a novel effect of E. brevicornum, and icariin could be utilized for the prevention and treatment of osteoporosis.Journal of ethnopharmacology 12/2012; 145(3). DOI:10.1016/j.jep.2012.11.031 · 2.94 Impact Factor
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ABSTRACT: Polyphenols are a broad class of compounds. Some are ingested in substantial quantities from nutritional sources, more are produced by medicinal plants, and some of them are taken as drugs. It is becoming clear, that a single polyphenol is impacting several cellular pathways. Thus, a network approach is becoming feasible, describing the interaction of a single polyphenol with cellular networks. Here we have selected icariin to draw a prototypic network of icariin activities. Icariin appears to be a promising drug to treat major age-related diseases, like neurodegeneration, memory and depressive disorders, chronic inflammation, diabetes, and osteoporosis. It interacts with several relevant pathways, like PDE, TGF-ß, MAPK, PPAR, NOS, IGF, Sirtuin, and others. Such networks will be useful to future comparative studies of complex effects of polyphenols.Molecular Nutrition & Food Research 01/2014; 58(1). DOI:10.1002/mnfr.201300409 · 4.91 Impact Factor