Effects Of Icariin Research Articles

Effects of icariin on asthma mouse model are associated with regulation of prostaglandin D2 level

BackgroundWe aimed to observe the effect of icariin on an asthma mouse model and explore the potential underlying mechanisms. MethodsThe asthma mouse model was established by ovalbumin (OVA) sensitisation and respiratory syncytial virus (RSV) infection and then treated with icariin. Airway resistance was assessed by whole body plethysmograph. In addition, pathological slides were stained with haematoxylin–eosin, and the peribronchial inflammation was observed microscopically. The concentration of prostaglandin D2 (PGD2) in serum and bronchoalveolar lavage fluid (BALF) was detected by enzyme-linked immuno sorbent assay (ELISA). The relative level of prostaglandin D2 receptor 2 (CRTH2) mRNA was assessed by real-time quantitative PCR. ResultsCompared with the icariin-untreated group, there was a significant reduction of Penh in the treated group. Total leucocyte amount and all sorts of leukocytes were lower in the treated group than in the untreated group. HE staining results revealed that a large number of inflammatory cells infiltrated into the peribronchial tissues of untreated group, and the degree of airway inflammation decreased significantly in the treated group. PGD2 in serum and BALF, as well as CRTH2 mRNA level in lung tissues were lower in the treated group than in the untreated group. ConclusionIcariin is a promising therapeutic strategy for asthma, and PGD2 might be a new target for asthma therapy in OVA-induced and RSV-infected asthma model.

Icariin induces apoptosis in acute promyelocytic leukemia by targeting PIM1.

Acute promyelocytic leukemia (APL) is one type of acute myeloid leukemia (AML) featured by abnormal, heavily granulated promyelocytes. This study aimed to investigate the antitumor activity of icariin in APL cells. APL cell lines (HL-60 and NB4) were used to investigate the effect of icariin in vitro. Cell viability was determined by WST-8 proliferation assay, while cell apoptosis was assessed by flow cytometry. The mRNA and protein expression was determined by quantitative real-time polymerase chain reaction and Western blot, respectively. Moreover, small interfering RNA (siRNA) and overexpressing plasmid were used to manipulate the expression of PIM family kinase 1 (PIM1) to examine the role of PIM1 in icariin-induced apoptosis in APL cells. Icariin could significantly suppress cell growth and induce apoptosis in both model APL cell lines (HL-60 and NB4). It repressed the expression of PIM1 at the molecular level, which was responsible for the antitumor effect of icariin in APL cells. The ectopic overexpression of PIM1 significantly abrogated the inducing effect of icariin on apoptosis. In contrast, the knockdown of PIM1 by siRNA enhanced the antitumor effect of icariin in APL cells. Moreover, the findings indicated that icariin repressed the expression of PIM1 through generating reactive oxygen species and hence modulating the Janus kinase 2(JAK2)/Signal transducer and activator of transcription 3/5 (STAT3/5) signaling pathway. Icariin potently inhibits the cell growth of APL in vitro through inducing caspase-dependent apoptosis. Hence, it can be considered as a promising candidate therapeutic agent for treating APL, although further studies including clinical trials are warranted.

The bisphenol A-enhanced activity of thyroid carcinoma cell line B-CPAP is inhibited by Icarrin

Objective: To investigate the effect of icariin (ICA) on the bisphenol A (BPA)-enhanced proliferation function of thyroid carcinoma cell B-CPAP and underlying mechanism. Methods: The proliferation of Gastric B-CPAP cell line was evaluated by cell counting kit-8 (CCK-8). Apoptosis and ROS expression in B-CPAP cells were detected by flow cytometry. The expression of superoxide dismutase (SOD) and malondialdehyde (MDA) in B-CPAP cells were measured by individual assay kits. The expressions of Bcl-2 and γ-HA2X were detected by Western blot. SPSS 18.0 software was used to analyze the data. Results: B-CPAP cell activity was promoted by treatment with 3×10(-7)mol/L BPA for 48 h, with significant difference in absorbance between BPA and control groups (1.089±0.053 vs 0.935±0.010, P<0.05). The cell activities of BPA+ ICA(25), BPA+ ICA(50), BPA+ ICA(100) and BPA+ ICA(200) groups was 0.780±0.036, 1.007±0.050, 0.958±0.033 and 0.625±0.064, respectively (all P<0.01). The proliferation of B-CPAP cells treated with BPA for 72 hours showed a similar trend to 48 hours. There was no significant difference between all treatment groups in 24 hours. The apoptosis rate was (19.272±0.186)% in BPA-treated cells, and was (22.412±0.238)% in control cells (P<0.05). The apoptosis rates of BPA+ ICA(50) and BPA+ ICA(200) groups were (23.688±0.412)% and (30.270±0.696)%, respectively (P<0.01). The intracellular accumulation of ROS in BPA, BPA+ ICA(50), and BPA+ ICA(200) groups were 806±21, 1 772±37, 2 041±16, respectively (P<0.01). The expressions of anti-apoptotic protein Bcl-2 in control, BPA, BPA+ ICA(50), BPA+ ICA(200) groups were 7 120±151, 9 801±286, 5 902±171 and 4 203±216, respectively (P<0.01). Conclusion: BPA can promote the proliferation of thyroid carcinoma B-CPAP cells and decrease the apoptosis of cells, and this effect can be inhibited by ICA. The possible mechanism is to induce high expression of intracellular ROS and inhibit the expression of antioxidase system, leading to cell oxidative damage, thereby inducing apoptosis.

Icariin, a Novel Blocker of Sodium and Calcium Channels, Eliminates Early and Delayed Afterdepolarizations, As Well As Triggered Activity, in Rabbit Cardiomyocytes.

Icariin, a flavonoid monomer from Herba Epimedii, has confirmed pharmacological and biological effects. However, its effects on arrhythmias and cardiac electrophysiology remain unclear. Here we investigate the effects of icariin on ion currents and action potentials (APs) in the rabbit myocardium. Furthermore, the effects of icariin on aconitine-induced arrhythmias were assessed in whole rabbits. Ion currents and APs were recorded in voltage-clamp and current-clamp mode in rabbit left ventricular myocytes (LVMs) and left atrial myocytes (LAMs), respectively. Icariin significantly shortened action potential durations (APDs) at 50 and 90% repolarization (APD50 and APD90) and reduced AP amplitude (APA) and the maximum upstroke velocity (Vmax) of APs in LAMs and LVMs; however, icariin had no effect on resting membrane potential (RMP) in these cells. Icariin decreased the rate-dependence of the APD and completely abolished anemonia toxin II (ATX-II)-induced early afterdepolarizations (EADs). Moreover, icariin significantly suppressed delayed afterdepolarizations (DADs) and triggered activities (TAs) elicited by isoproterenol (ISO, 1 μM) and high extracellular calcium concentrations ([Ca2+]o, 3.6 mM) in LVMs. Icariin also decreased INaT in a concentration-dependent manner in LAMs and LVMs, with IC50 values of 12.28 ± 0.29 μM (n = 8 cells/4 rabbits) and 11.83 ± 0.92 μM (n = 10 cells/6 rabbits; p > 0.05 vs. LAMs), respectively, and reversed ATX-II-induced INaL in a concentration-dependent manner in LVMs. Furthermore, icariin attenuated ICaL in a dose-dependent manner in LVMs. The corresponding IC50 value was 4.78 ± 0.89 μM (n = 8 cells/4 rabbits), indicating that the aforementioned current in LVMs was 2.8-fold more sensitive to icariin than ICaL in LAMs (13.43 ± 2.73 μM; n = 9 cells/5 rabbits). Icariin induced leftward shifts in the steady-state inactivation curves of INaT and ICaL in LAMs and LVMs but did not have a significant effect on their activation processes. Moreover, icariin had no effects on IK1 and IKr in LVMs or Ito and IKur in LAMs. These results revealed for the first time that icariin is a multichannel blocker that affects INaT, INaL and ICaL in the myocardium and that the drug had significant inhibitory effects on aconitine-induced arrhythmias in whole rabbits. Therefore, icariin has potential as a class I and IV antiarrhythmic drug.

Icariin stimulates osteogenic differentiation of rat bone marrow stromal stem cells by increasing TAZ expression.

Icariin, the major ingredient of Herba Epimedii, promotes the osteogenic differentiation of rat bone marrow stromal cells (rBMSCs) and exerts protective effects against bone loss and increases bone regeneration, but the underlying signaling pathway by which icariin affects osteogenic differentiation remain unclear. Transcriptional coactivator with PDZ-binding motif (TAZ) is a transcriptional modulator of the Hippo signaling pathway, which plays an important role in the osteogenic differentiation of BMSCs by activating Runx2 gene during the terminal osteogenic differentiation. In this study, we found that 0.1μM icariin markedly promoted the proliferation, calcium depositions, and osteogenic genes expression of rBMSCs. Icariin (0.1μM) upregulated TAZ, Runx2, β-catenin, Osteopotin, and Dlx5 expression mainly at the early stage of osteogenic differentiation, and increased osteocalcin expression at the late stage. Our result further demonstrated that knockdown TAZ expression by lentivirus-mediated TAZ shRNA inhibited the icariin-induced osteogenic differentiation. Moreover, ICI 182780 (the estrogen receptor alpha inhibitor) or DKK1 (the Wnt/β-catenin pathway inhibitor), inhibited the icariin-induced increase in TAZ expression. Furthermore, icariin stimulated the activation of TAZ as evidenced by increased total TAZ protein and nuclear translocation, but these effects of icariin were blocked by ICI 182780 or DKK1. Taken together, our results demonstrate that icariin promotes the osteogenic differentiation of rBMSCs by increasing TAZ expression, and that the increased TAZ expression induced by icariin is mostly mediated by the ERα and Wnt/β-catenin pathway.

Icariin improves acute kidney injury and proteinuria in a rat model of pregnancy‑induced hypertension.

Icariin has previously been demonstrated to attenuate hyperglycemia-induced renal injury, however the renoprotective effects of icariin in a rat model of pregnancy-induced hypertension (PIH) remain to be elucidated. The present study aimed to investigate the effect of icariin on PIH-induced acute kidney injury (AKI) and proteinuria. Following 18 days of icariin treatment between day 1 and day 18 of gestation, which was combined with NG-nitro-L-arginine methyl ester (L-NAME) treatment between day 12 and day 18 of gestation to induce PIH, the 24 h urine protein level, blood urea nitrogen and serum creatinine were measured by using the Coomassie Brilliant Blue method, a commercial enzymatic kit and the picric acid method, respectively. Renal tissues were collected at day 18 of gestation for hematoxylin and eosin staining and immunohistochemistry. The mRNA expression of AGT and protein expression of angiotensin II (Ang II) in the kidneys of control and PIH rats was investigated by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively, to determine the effect of icariin on components of the renin-angiotensin system. The results demonstrated that L-NAME treatment in pregnant rats resulted in significant increases in systolic blood pressure (SBP) and diastolic blood pressure, in addition to the induction of severe proteinuria. The significant increase in SBP and proteinuria in PIH rats was prevented by icariin. L-NAME-induced AKI resulted in profound renal histological alterations, including mesangial expansion and glomerular lesions. L-NAME administration exerted a marked decrease in the mRNA and protein expression levels of nephrin in the kidneys from PIH rats compared with control group. Furthermore, upregulation of circulating and renal Ang II levels in PIH rats was observed. However, icariin treatment significantly reversed the L-NAME-induced downregulation of nephrin and upregulation of circulating and renal Ang II levels in PIH rats. These results demonstrated that icariin administration improved urinary protein excretion levels and renal tissue damage in PIH rats, and the underlying mechanism was mediated in part, via upregulation of nephrin expression and downregulation of Ang II.

Herb Medicines against Osteoporosis: Active Compounds & Relevant Biological Mechanisms.

Osteoporosis is one of common bone disorders, affecting millions of people worldwide. Treatments of osteoporosis consist of pharmacotherapy and non-pharmacological interventions, such as mineral supplementation, lifestyle changes, and exercise programs. Due to the minimum side effects and favorable cost-effective therapeutic effects, herbal medicine has been widely applied in clinical practices for more than 2,000 years in China. Of the many traditional formulas reported for treating bone diseases, 4 single herbs namely (1) Herba Epimedii, (2) Rhizoma Drynariae, (3) Fructus Psoraleae, and (4) Cortex Eucommiae, are considered as the featured "Kidney-Yang" tonics, and frequently and effectively applied for preventing and treating osteoporosis. With the accruing development of modern chemistry, hundreds of active compounds have been identified and isolated for their anti-osteoporotic effects. This review would first sketch the phytochemistry of these featured "Kidney- Yang" tonics and present the pharmacological characteristics of the most abundant and bioactive compounds derived from the herb Herba Epimedii and Rhizoma Drynariae, including icariin and naringin. Then, the cellular and molecular underpinnings under anti-osteoporotic effects of icariin and naringin are discussed. The concerned structure-function relationships of the featured active herbal compounds would also be reviewed so as to pave the way for future drug design in treating osteoporosis.

Antidepressant-like activity of icariin mediated by group I mGluRs in prenatally stressed offspring

ObjectiveThe present study was performed to identify antidepressant-like activity of icariin in prenatally stressed male rats. MethodsThe effects of icariin on PRS-induced depression were examined using sucrose preference test (SPT) and forced swimming test (FST) in male offspring, and measuring protein and mRNA expressions of group I mGluRs receptors and EAAT2 via western blotting and quantitative real-time PCR assays. ResultsThe results indicated that prenatal restraint stress (PRS) resulted in several behavioral anomalies. Treatment with icariin relieved the elevated protein and mRNA levels of group I mGluR receptors as well as the diminished protein and mRNA levels of EAAT2 in the PRS male offspring. ConclusionsCollectivity, the data support that icariin ameliorates PRS-induced depressive-like behavior via regulating expression of mGluR1, mGluR5 and EAAT2 in the hippocampus.

Effect of Icariin on apoptosis and expression of Fas, Fas ligand, B cell lymphoma, and Bcl-2-associated X protein in CD4 + T lymphocytes from patients with ankylosing spondylitis

ObjectiveTo investigate the effects of icariin on apoptosis and the expression of Fas, Fas ligand (FasL), B cell lymphoma (Bcl-2), and Bcl-2-associated X protein (Bax) in CD4+ T lymphocytes from patients with ankylosing spondylitis. MethodsPrimary cultures of peripheral blood CD4+ T lymphocytes were established and treated with icariin at high, medium, and low doses (0.5, 0.25, and 0.125 mg/mL). Sulfasalazine treated and helthy cells were used as controls. Apoptosis of treated cells was determined by flow cytometry. Reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays were used to determine the effects of icariin on the expression of Fas, FasL, Bcl-2, and Bax. The activity of caspase 8 and caspase 3 was determined by a colorimetric assay. ResultsThe mRNA and protein expression of Fas, and activity of caspase 8 and caspase 3 in CD4 + T lymphocytes were increased by icariin (P < 0.05). Conversely, the mRNA and protein expression of Bcl-2 was decreased (P < 0.05). The expression of FasL and Bax were not significantly different between groups. The proapoptotic effects of icariin were dose-dependent. ConclusionIcariin induces the apoptosis of CD4 + T cells from patients with AS comparing to normal control. Therefore, the induction of apoptosis may be the likely mechanism of action of icariin's antirheumatics activities.

Glucocorticoid-induced leucine zipper may play an important role in icariin by suppressing osteogenesis inhibition induced by glucocorticoids in osteoblasts

Background and purposeIcariin is a potent stimulator of osteogenic differentiation; however, the mechanism underlying its osteogenic effect remains unclear. The osteogenic effect of icariin is related to the upstream glucocorticoid-induced leucine zipper (GILZ) signaling pathway, and antagonism with dexamethasone-induced osteoblast inhibition was noted. MethodsMC3T3-E1 cells were cultured in induced medium treated with icariin with or without dexamethasone. After short interfering RNA (siRNA) were used to silence GILZ expression, the degree of mineralization, proliferation, and GILZ expression as well as the levels of osteogenic (OPG, RANKL, ALP, OC and RUNX2) markers were tested. ResultsDexamethasone inhibited, while icariin increased, osteogenic activity, as indicated by ALP activity and calcium nodules. Meanwhile, dexamethasone dose-dependently (10−6M–10−4M) increased GILZ and RANKL expression and reduced ALP, OPG and OC, but the pattern of mRNA expression was reversed when icariin was added. Furthermore, GILZ (dexamethasone-induced) inhibition caused by icariin or moderately silenced by GILZ siRNA abolished the osteogenesis inhibition effect of dexamethasone, as indicated by the changes in the GILZ, ALP, OPG and RANKL expression levels; ALP activity; and calcium nodule. ConclusionsThese results indicate that the GILZ-mediated osteogenic signal pathway is involved in the osteogenic effect induced by icariin.

Effect of icariin on fracture healing in an ovariectomized rat model of osteoporosis.

Osteoporosis is frequently asymptomatic, presenting a significant clinical and economic burden, particularly following an osteoporosis-associated fracture. Icariin has been reported to inhibit osteoporosis in vitro, and the present study investigated whether icariin also promoted bone fracture healing in ovariectomized osteoporotic (OVX) rats in vivo. A total of 30 female rats were randomly divided into three groups (n=10 per group): i) Sham surgery; ii) OVX; and iii) OVX with icariin (OVX + ICA) groups. At 3 months after the ovariectomy, a unilateral cross-tibia fracture was made at the proximal right tibia. Animals were then sacrificed after 5 weeks of oral treatment. X-rays were taken at 1 week, 3 weeks and 5 weeks of treatment, and dual energy X-ray absorptiometry was used to measure the bone mineral density (BMD). Changes to the osteocalcin (BGLAP), alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) and estradiol levels in blood were measured. Callus formation and bone union were observed, the BMD was significantly higher and the BGLAP, ALP and TRAP levels were reduced, but no significant increase was observed in the blood estradiol level in the OVX + ICA group compared with the OVX group. The present findings indicate that icariin has potential as a novel alternative therapeutic agent for fracture healing in postmenopausal osteoporosis.

Icariin improves the sexual function of male mice through the PI3K/AKT/eNOS/NO signalling pathway.

We aimed to investigate the effect and mechanism of icariin on male sexual function. Forty-eight Crl:CD1(ICR) male mice were randomly divided into control, low-, medium- and high-dose icariin group (intragastric administration of 50, 100 and 200mg/kg/d for 21days). Mating experiment was then performed at a ratio of 1: 3 (male: female). The mating behaviours of male mice were recorded. The genital indexes and serum testosterone, nitric oxide (NO), hypothalamic dopamine (DA) and 5- hydroxy tryptophan (5-HT) concentrations were measured. The expression of endothelial nitric oxide (eNOS), phosphatidylinositol tallow alcohol 3-kinase (PI3K) and phosphorylated protein kinase (p-AKT) in penile tissue was detected by Western blot. All icariin groups exhibited shorter capture latency and ejaculation latency, increased number of capture and ejaculation, higher capture and ejaculation rate, and higher testicular and prostate indexes compared with controls (p<.001). These groups had higher serum testosterone and NO concentrations (p<.001), hypothalamic DA and 5-HT levels, and eNOS, PI3K and phosphorylated AKT expressions in penile tissue (p<.05). The effect of icariin was dose-dependently increased. Our study suggests that icariin improves the sexual function of male mice, which might be associated with the hypothalamic-pituitary-gonadal axis and the PI3K/AKT/eNOS/NO signalling pathway.

Effect of icariin in combination with daily sildenafil on penile atrophy and erectile dysfunction in a rat model of bilateral cavernous nerves injury.

The commonly utilized phosphodiesterase type 5 inhibitors do not lead to satisfactory penile erection after radical prostatectomy mainly because of insufficient nitric oxide drive from the damaged cavernous nerves. The aim of this study was to assess the efficacy and mechanisms of icariin in combination with daily sildenafil on neurogenic erectile dysfunction and penile atrophy in a rat model of bilateral cavernous nerves injury. Sixty male Sprague-Dawley rats injected with 5-ethynyl-2-deoxyuridine (50mg/kg) at postnatal day 1 for the purpose of tracking endogenous stem cells in penis. Forty-eight rats of bilateral cavernous nerves injury were randomized equally into gavage feeding of vehicle, sildenafil (10mg/kg), icariin (1.5mg/kg) and sildenafil+icariin, respectively. Twelve sham-operated rats served as control. The intracavernous pressure and mean arterial pressure was measured and mid-penile cross sections were histologically examined 5weeks after surgery. Western blotting of cavernous tissue protein was also performed. Animals treated with sildenafil+icariin had significantly higher mean intracavernous pressure/mean arterial pressure ratio relative to other rats with bilateral cavernous nerves injury (p<0.05). The circumference and mean cross-sectional area of the paired corpus cavernosum were effectively preserved in the sildenafil+icariin. Treatment with sildenafil+icariin significantly increased the cavernous cyclic guanosine monophosphate concentration compared with the icariin group (p<0.05). In addition, the numbers of neuronal nitric oxide synthase-positive nerves and 5-ethynyl-2-deoxyuridine-positive cells co-expressing S100 in the icariin-treated groups were greater compared with the bilateral cavernous nerves injury control group (p<0.05). These data suggest that the combined use of icariin and daily sildenafil holds promise as a potential therapy for neurogenic erectile dysfunction in the future. The underlying mechanisms appears to involve two aspects: (i) icariin promotes differentiation of endogenous stem cells to Schwann cells, which help to repair the damaged neural pathway for erection; (ii) on this basis, sildenafil can further improve penile engorgement through the cyclic guanosine monophosphate-dependent smooth muscle relaxation.

Icariin inhibits MMP‑1, MMP‑3 and MMP‑13 expression through MAPK pathways in IL‑1β‑stimulated SW1353 chondrosarcoma cells.

Osteoarthritis (OA) is the most common type of arthritis and is a leading cause of disability worldwide, resulting in pain, reduced quality of life and socioeconomic burden. Current therapies for OA focus on mitigating the symptoms of advanced disease, but novel therapeutic agents are needed to inhibit the processes leading to OA. The present study aimed to investigate the effects of Icariin on matrix metalloproteinase (MMP)‑1, MMP‑3 and MMP‑13 expression in interleukin (IL)‑1β‑stimulated human SW1353 chondrosarcoma cells, and to investigate the possible mechanism underlying the chondroprotective effects of Icariin. In the present study, IL‑1β was applied on SW1353 chondrosarcoma cells to mimic the microenvironment of osteoarthritis. The cells were treated with Icariin and mitogen‑activated protein kinase (MAPK) signaling pathway activators or inhibitors. MMP‑1, MMP‑3, MMP‑13, phosphorylated (P)‑p38, P‑c‑Jun N‑terminal kinase (JNK) and P‑extracellular signal‑regulated kinase (ERK) expression was assessed using reverse transcription‑quantitative polymerase chain reaction, ELISA and western blot analysis. The results of the present study demonstrated that Icariin inhibited the expression of MMP‑1, MMP‑3, MMP‑13, P‑p38, P‑ERK and P‑JNK. Furthermore, it was revealed that the inhibition of p38 and ERK contributed to the inhibition of MMP‑1 and MMP‑3 by Icariin, whereas the inhibition of p38 and JNK contributed to the inhibition of MMP‑13. The present results suggested that Icariin may have a chondroprotective effect, exerted through the inhibition of MMP‑1, MMP‑3 and MMP‑13 via MAPK pathways. Therefore, Icariin may have potential as a novel therapeutic strategy for the treatment of osteoarthritis.

Effects of icariin on proliferation, differentiation and mineralization of osteoblasts

Objective To study the effect of icariin the proliferation, differentiation and mineralization of osteoblasts cultured in vitro. Methods The MC3T3-E1 cells were used in the experiment of mice as a source of osteoblast precursor cells, with a final concentration of 0, 10-4, 10-5, 10-6, 10-7, and 10-8 mol/L icariin. The ability of cell proliferation was measured by methyl thiazol tetrazolium (MTT) assay. The cell morphology and the cell growth density were observed by hematoxylin and eosin (HE) staining. Alkaline phosphatase reagent kit was used to test osteoblastic alkaline phosphatase activity for the evaluation of ability of early differentiation of bone cells. The alizarin red staining was used to evaluate the capability of mineralization of osteoblasts. Results The results of MTT showed that the absorbance (A) values in icariin groups (0, 10-4, 10-5, 10-6, 10-7, and 10-8 mol/L) were 0.54±0.04, 0.28±0.04, 0.40±0.02, 0.67±0.03, 0.58±0.01 and 0.55±0.03 respectively, and those in 10-6 mol/L icariin group were significantly higher than those in the rest groups with the difference being statistically significant (P=0.002). HE staining showed that the normal osteoblasts displayed typical spindle, triangular, polygonal and other irregular morphology. As compared with the blank control group, number of cells was greatest, and the cell distribution density was largest in the 10-6 mol/L icariin group. In 10-4 mol/L icarrin group, the expanding osteoblasts were rarely seen. In icariin groups (0, 10-4, 10-5, 10-6, 10-7, and 10-8 mol/L), alkaline phosphatase activity was (1.75±0.11), (0.85±0.35), (1.50±0.21), (2.80±0.12), (2.10±0.36) and (1.80±0.23) U/g prot respectively. Alkaline phosphatase activity was the highest in 10-6 mol/L icariin group (P=0.001), and that in 10-4 mol/L icariin group was the lowest with the difference being statistically significant (P=0.001). The alkaline phosphatase activity in 10-8 mol/L ocariin group was slightly higher than that in the blank group, but the difference was not statistically significant (P=0.292). Alizarin red staining showed that 10-6 mol/L icariin significantly promoted the mineralization of osteoblasts, and a large number of calcium nodules and clusters formed. In 10-4 mol/L icariin group, the epimedium calcium nodules were almost not found. Conclusion Icariin can promote the proliferation, differentiation and mineralization of osteoblasts. Key words: Osteoblast; Icariin; Osteoporosis

Icariin promotes mouse hair follicle growth by increasing insulin-like growth factor 1 expression in dermal papillary cells.

Icariin is a major flavonoid isolated from Epimedium spp. leaves (Epimedium Herba), and has multiple pharmacological functions, including anti-angiogenesis, anti-oxidant, anti-inflammatory and immunoprotective effects. To investigate whether icariin can stimulate growth of hair follicles in mice and the underlying mechanism. In vitro, the effect of icariin on hair growth was assessed by using a vibrissae hair follicle (VHF) organ-culture model. The proliferation of hair matrix keratinocytes and the expression of insulin-like growth factor (IGF)-1 in follicles were examined by double immunostaining for 5-bromo-2'-deoxyuridine and IGF-1, in the presence or absence of icariin. Dermal papilla cells (DPCs) were cultured and IGF-1 level was measured by reverse transcription-PCR and ELISA after icariin treatment. In vivo, the effect of icariin on hair growth was examined by gavage feeding of icariin to mice whose backs had been depilated, and the conversion of telogen to anagen hair was observed. Treatment with icariin promoted hair shaft elongation, prolonged the hair cycle growth phase (anagen) in cultured VHFs, and accelerated transition of hair cycle from telogen to anagen phase in the dorsal skin of mice. There was significant proliferation of matrix keratinocytes and an increased level of IGF-1 in cultured VHFs. Moreover, icariin treatment upregulated IGF-1 mRNA expression in DPCs and increased IGF-1 protein content in the conditioned medium of DPCs. These results suggest that icariin can promote mouse hair follicle growth via stimulation of IGF-1 expression in DPCs.

Icariin Inhibits AMPK-Dependent Autophagy and Adipogenesis in Adipocytes In vitro and in a Model of Graves' Orbitopathy In vivo

Graves' orbitopathy (GO), an extrathyroidal manifestation of Graves' disease, is an inflammatory autoimmune disorder of the orbit that involves the differentiation of precursor cells into mature adipocytes and retro-orbital adipose tissue accumulation. Here, we examined the involvement of autophagy in adipogenesis and explored the effects of icariin, a flavonoid isolated from the genus Epimedium with a wide range of biological and pharmacological effects, on autophagy and adipogenesis in 3T3-L1 preadipocytes and in a mouse model of GO. Microscopic examination of autophagosome formation and lipid droplet accumulation by Oil Red O staining, and western blot assessment of autophagic markers in the presence of the autophagy inhibitors Asn and 3-MA showed that autophagy is essential for adipogenesis. Icariin inhibited the differentiation of preadipocytes into mature adipocytes by suppressing autophagy, and these effects were mediated by the inhibition of AMPK/mTOR pathway activation. In a mouse model of thyroid stimulating hormone receptor induced GO, icariin reduced orbital muscle adipose tissue expansion and lipid droplet accumulation by inhibiting AMPK/mTOR mediated autophagy. Collectively, these results reveal a potential mechanism underlying the protective effects of icariin against autophagy induced adipogenesis and suggest that icariin could be developed as a new therapeutic candidate for the prevention and treatment of GO.

Icariin influences adipogenic differentiation of stem cells affected by osteoblast-osteoclast co-culture and clinical research adipogenic.

To build mouse osteoblast MC3T3-E1 and mouse osteoclast RAW264.7 co-culture system and to study the effect of icariin on the activity of osteoblasts and osteoclasts in the co-culture system. In vitro acquisition and cultivation of mouse osteoblasts MC3T3-E1 and mouse RAW264.7 cells were conducted. Osteoblast and osteoclast activities of cells were detected by CCK-8 staining experiment, alizarin red staining and tartaric-resistant acid phosphatase (TRAP) staining. We used different concentrations of icariin to interfere in osteoblast-osteoclast co-culture system. The effects of icariin on various genes were detected by PCR and Western blot methods The correction between the expression of PPARγ and BMD was analyzed in patients with osteoporosis. Mouse osteoblast-osteoclast co-culture system was built, and the osteogenic differentiation effect was enhanced. Icariin can improve the MC3T3-E1 osteogenic differentiation activity, enhance the expression of OPG and RANKL gene protein, reduce the NF-κb gene and protein expression, increase of ALP, TGF-b1 and RANKL gene expression level and reduce RANK gene expression. Icariin can act on MC3T3-E1 cells-RAW264.7 cells co-culture system, and promote the osteogenic activity of MC3T3-E1 cells, inhibit the osteoclast activity of RAW264.7 cells and reduce the level of BMSCs adipogenic differentiation. The expression level of PPAR-γ gene was negatively correlated with the level of BMD. Mouse MC3T3-E1 cells and mouse RAW264.7 cells could be co-cultured in vitro, and icariin could improve the osteogenic activity of MC3T3 cells-RAW264.7 cells and decrease the osteoclast activity. Icariin could inhibit adipogenic differentiation of BMSCs in the osteoblast-osteoclast co-culture, promoting osteogenic differentiation and inhibiting osteoclast differentiation.

The effects of icariin on the expression of HIF-1α, HSP-60 and HSP-70 in PC12 cells suffered from oxygen–glucose deprivation-induced injury

Context: The effects of icariin, a chief constituent of flavonoids from Epimedium brevicornum Maxim (Berberidaceae), on the levels of HIF-1α, HSP-60 and HSP-70 remain unknown. Objective: To explore the effects of icariin on the levels of HSP-60, HIF-1α and HSP-70 neuron-specific enolase (NSE) and cell viability. Materials and methods: PC12 cells were treated with icariin (10−7, 10−6 or 10−5 mol/L) for 3 h (1 h before oxygen–glucose deprivation (OGD) plus 2 h OGD). HSP-60, HIF-1α, HSP-70 and NSE were measured using enzyme-linked immunosorbent assay (ELISA). Cell viability was determined by metabolic 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: After 2 h OGD, levels of HIF-1α, HSP-60, HSP-70 and NSE were increased significantly (HIF-1α: 33.3 ± 1.9 ng/L, HSP-60: 199 ± 16 ng/L, HSP-70: 195 ± 17 ng/L, NSE: 1487 ± 125 ng/L), and cell viability was significantly decreased (0.26 ± 0.03), while icariin (10−7, 10−6, or 10−5 mol/L) significantly reduced the contents of HIF-1α, HSP-60, HSP-70 and NSE (HIF-1α: 14.1 ± 1.4, 22.6 ± 1.8, 15.7 ± 2.1, HSP-60: 100 ± 12, 89 ± 6, 113 ± 11, HSP-70: 139 ± 9, 118 ± 7, 95 ± 9 and NSE: 1121 ± 80, 1019 ± 52, 731 ± 88), and improved cell viability (0.36 ± 0.03, 0.38 ± 0.04, 0.37 ± 0.03) in OGD-treated PC12 cells. Discussion and conclusion: These results indicate that the protective mechanisms of icariin against OGD-induced injury may be related to down-regulating the expression of HIF-1α, HSP-60 and HSP-70.

Use of an Osteoblast Overload Damage Model to Probe the Effect of Icariin on the Proliferation, Differentiation and Mineralization of MC3T3-E1 Cells through the Wnt/β-Catenin Signalling Pathway

Background/Aims: Mechanical loading plays an important role in the regulation of bone mass. However, bone cells are not always under physiological stress. In some cases, bone tissue is subjected to an overloaded mechanical environment. For example, a person who is weight training and a stevedore often experience bone pain, inflammation and other bone fatigue damage symptoms. Icariin is the major ingredient of Herba epimedii, which has been widely used for the treatment of bone injury in traditional Chinese medicine, but its mechanism remains unknown. The aim of this study was to probe the effect of icariin on the proliferation and differentiation of osteoblasts exposed to overload and to determine whether the Wnt/β-catenin signalling pathway is involved in the drug response in osteoblasts. Methods: Mouse MC3T3-E1 cells were exposed to mechanical tensile strain using a four- point bending device to create an overload damage model. An MTT assay was performed to determine the effects of icariin on MC3T3-E1 cell proliferation. The mRNA and protein levels of ALP, COL-I, OCN, RUNX2 and β-catenin were assessed using RT-PCR and immunoblotting. The protein levels of β-catenin in the MC3T3-E1 cells were also determined using fluorescence microscopy. The mineralization of osteoblasts was assessed using Alizarin Red S staining. Results: We found that icariin enhanced the proliferation of osteoblasts exposed to overload and promoted MC3T3-E1 cell differentiation and mineralization. Furthermore, the gene and protein expression levels of β-catenin and RUNX2 all increased with icariin treatment compared with those in the damage group. Conclusion: Our study suggested that icariin promotes proliferation and differentiation in osteoblasts exposed to overload. The effect of icariin on osteoblastic differentiation acted by activating the RUNX2 promoter and the Wnt/β- catenin pathway.