Epimedium-derived phytoestrogen flavonoids exert beneficial effect on preventing bone loss in late postmenopausal women: a 24-month randomized, double-blind and placebo-controlled trial

The beneficial effect of icaritin on osteoporotic bone is dependent on the treatment initiation timing in adult ovariectomized rats

BACKGROUND

Epimedium-derived flavonoids (EFs) have a potential to treat established osteoporosis in postmenopausal women. However, one of the main disadvantages of the compound is the high volume and dosage during long-term administration period. Meanwhile, the beneficial effect of EFs on osteoporotic bone depends greatly on the intervention timing. Whether icaritin (ICT), an active molecular compound from EFs, can exert beneficial effect on osteoporotic bone and whether the beneficial effect is also dependent on the intervention timing remain unknown.

OBJECTIVE

The objective of this study was to evaluate the effect of the early and late ICT treatment on bone turnover markers, trabecular architecture, bone remodeling, biomechanics, colony formation of bone marrow stromal cells and osteoblast, adipocyte and osteoclast-related gene expression in adult ovariectomized rats.

METHODS

Eighty 9-month-old female rats (n=8/group) were sham-operated (Sham) or ovariectomized (OVX). The OVX rats were subjected to ICT treatment initiation at 1 month (early treatment) and 3 months (late treatment) post-operation, respectively. The vehicle-treated Sham and OVX rats starting at month 1 and month 3 post-operation served as the corresponding controls (Sham and OVX controls) for early and late ICT treatment, respectively. Those Sham and OVX rats sacrificed immediately before early and late ICT treatment served as the pretreatment baseline controls. Both ICT and vehicle treatments lasted for 2 months. The bone turnover markers, trabecular architecture, bone remodeling and bone biomechanical properties were analyzed with biochemistry, microCT, histomorphometry and mechanical testing, respectively. The population of bone marrow stromal cells (BMSCs) and osteoblasts were evaluated with colony formation assays, respectively. The expression levels of osteoblast, adipocyte and osteoclast-related genes in bone marrow were assessed by real-time polymerase chain reaction (PCR), respectively.

RESULTS

At the tissue level, early ICT treatment remarkably restored the trabecular bone mass, trabecular architecture and bone biomechanical properties towards pretreatment Sham levels, and significantly increased bone formation from pretreatment OVX level and markedly inhibited bone resorption towards pretreatment Sham level, whereas late ICT treatment failed to have any effect. At the cellular and molecular level, early ICT treatment significantly increased the number of osteoblastic colonies and the level of osteoblast-related gene expression compared to pretreatment OVX levels and remarkably decreased adipocyte and osteoclast-related gene expression towards pretreatment Sham levels. Late ICT treatment failed to have beneficial effect on any of these parameters.

CONCLUSION

ICT can exert anabolic and anti-resorptive effect on osteoporotic bone. The beneficial effect of ICT treatment is dependent on the intervention timing in established osteoporosis induced by estrogen depletion.

Functions and action mechanisms of flavonoids genistein and icariin in regulating bone remodeling

Increasingly natural products particularly flavonoids are being explored for their therapeutic potentials in reducing bone loss and maintaining bone health. This study has reviewed previous studies on the two better known flavonoids, genistein and icariin, their structures, functions, action mechanisms, relative potency, and potential application in regulating bone remodeling and preventing bone loss. Genistein, an isoflavone abundant in soy, has dual functions on bone cells, able to inhibit bone resorption activity of osteoclasts and stimulate osteogenic differentiation and maturation of bone marrow stromal progenitor cells (BMSCs) and osteoblasts. Genistein is an estrogen receptor (ER)-selective binding phytoestrogen, with a greater affinity to ERβ. Genistein inhibits tyrosine kinases and inhibits DNA topoisomerases I and II, and may act as an antioxidant. Genistein enhances osteoblastic differentiation and maturation by activation of ER, p38MAPK-Runx2, and NO/cGMP pathways, and it inhibits osteoclast formation and bone resorption through inducing osteoclastogenic inhibitor osteoprotegerin (OPG) and blocking NF-κB signaling. Icariin, a prenylated flavonol glycoside isolated from Epimedium herb, stimulates osteogenic differentiation of BMSCs and inhibits bone resorption activity of osteoclasts. Icariin, whose metabolites include icariside I, icariside II, icaritin, and desmethylicaritin, has no estrogenic activity. However, icariin is more potent than genistein in promoting osteogenic differentiation and maturation of osteoblasts. The existence of a prenyl group on C-8 of icariin molecular structure has been suggested to be the reason why icariin is more potent than genistein in osteogenic activity. Thus, the prenylflavonoids may represent a class of flavonoids with a higher osteogenic activity.

Icariin from Epimedium brevicornum Maxim promotes the biosynthesis of estrogen by aromatase (CYP19)

ETHNOPHARMACOLOGICAL RELEVANCE

Epimedium brevicornum Maxim 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 five widely used antiosteoporotic medicinal plants (Epimedium 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 a magnetic particle-based enzyme-linked immunosorbent assay (ELISA) kit. Further, the mRNA expression of aromatase was determined by a 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 Epimedium brevicornum was found to significantly promote estrogen biosynthesis in KGN cells. Icariin, the major compound in Epimedium 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 Epimedium brevicornum, and icariin could be utilized for the prevention and treatment of osteoporosis.

Exogenous phytoestrogenic molecule icaritin incorporated into a porous scaffold for enhancing bone defect repair

This study was designed to develop a bioactive scaffold to enhance bone defect repair in steroid-associated osteonecrosis (SAON). Icaritin, a metabolite of the herb Epimedium, has been identified as an angiogenic and osteogenic phytomolecule. Icaritin was homogenized into poly lactic-co-glycolic acid/tricalcium phosphate (PLGA/TCP) to form an icaritin-releasing porous composite scaffold (PLGA/TCP/icaritin) by fine-spinning technology. In vitro, high performance liquid chromatography was used to determine the release of icaritin during degradation of PLGA/TCP/icaritin. The osteogenic effects of PLGA/TCP/icaritin were evaluated using rat bone marrow mesenchymal stem cells (BMSCs). In vivo, the osteogenic effect of PLGA/TCP/icaritin was determined within a bone tunnel after core decompression in SAON rabbits and angiography within scaffolds was examined in rabbit muscle pouch model. In vitro study confirmed the sustainable release of icaritin from PLGA/TCP/icaritin with the bioactive scaffold promoting the proliferation and osteoblastic differentiation of rat BMSCs. In vivo study showed that PLGA/TCP/icaritin significantly promoted new bone formation within the bone defect after core decompression in SAON rabbits and enhanced neovascularization in the rabbit muscle pouch experiment. In conclusion, PLGA/TCP/icaritin is an innovative local delivery system that demonstrates sustainable release of osteogenic phytomolecule icaritin enhancing bone repair in an SAON rabbit model. The supplement of scaffold materials with bioactive phytomolecule(s) might improve treatment efficiency in challenging orthopedic conditions.

A novel semisynthetic molecule icaritin stimulates osteogenic differentiation and inhibits adipogenesis of mesenchymal stem cells

BACKGROUND

We previously reported that the constitutional flavonoid glycosides derived from herb Epimedium (EF, composed of seven flavonoid compounds with common nuclear stem) exerted beneficial effects on the bone, including promoting bone formation and inhibiting bone marrow fat deposition. Recent in vivo study showed that Icaritin was a common metabolite of these constitutional flavonoid glycosides, indicating that Icaritin is a bioactive compound. The present study was designed to investigate whether Icaritin could promote osteogenic differentiation and suppress adipogenic differentiation of marrow mesenchymal stem cells (MSCs).

METHODS

Primary MSCs were harvested from adult mice and exposed to Icaritin to evaluate whether it could promote osteogenesis and suppress adipogenesis using the following assays: determination of alkaline phosphatase (ALP) activity and mineralization; mRNA expression of osteogenic differentiation marker Runx2; osteocalcin and bone sialoprotein (BSP) by RT-PCR; quantification of adipocyte-like cells by Oil Red O staining assay and mRNA expression for adipogenic differentiation markers peroxisome proliferator-activated receptor gamma (PPARγ); adipocyte fatty acid binding protein (aP2) and lipoprotein lipase (LPL) by RT-PCR. For the underlying mechanism, glycogen synthase kinase-3beta (GSK3β) and β-catenin were also explored by western blotting.

RESULTS

Icaritin promoted osteogenic differentiation and maturation of MSCs as indicated by increased mRNA expression for Runx2, osteocalcin and BSP, and enhanced ALP activity and mineralization; Icaritin inhibited adipogenic differentiation, as indicated by decreased mRNA expression for PPARγ, LPL, aP2, and suppressed formation of adipocyte-like cells; Icaritin inactivated GSK3β and suppressed PPARγ expression when promoting osteogenesis and suppressing adipogenesis of MSCs.

CONCLUSION

This was the first study demonstrating that the novel semisynthetic molecule Icaritin could stimulate osteogenic differentiation and inhibit adipogenesis of MSCs, which was associated with the suppression of GSK3β and PPARγ.

Epimedium-derived flavonoids modulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats via Wnt/β-catenin signal pathway activation

OBJECTIVE

To observe the function of wnt/β-catenin signal pathway on the process that epimedium-derived flavonoids (EFs) regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, and to provide an experimental evidence for the mechanism of EFs on treating postmenopausal osteoporosis.

METHODS

Bone marrow stromal cells from ovariectomized rats were separated and cultivated in the condition of osteoinductive medium or liquid medium for 15 days. Low- (1 μg/mL), medium- (10 μg/mL) and high- (100 μg/mL) dose EFs were administrated correspondingly. Alkaline phosphatase (ALP) staining, ALP activity determination, oil red O staining and realtime polymerese chain reaction (RT-PCR) were used to determine the effect of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats. Moreover, in order to explore the mechanism of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, Dickkopf-related protein 1 (DKK1) was used in the medium group. Enzymelinked immunosorbent assay (ELISA) and RT-PCR were used to determine mRNA levels of β-catenin, low density lipoprotein receptor-related protein 5 (LRP5) and T cell factor (TCF) protein, known as wnt/β-catenin signal pathway related factors.

RESULTS

EFs increased mRNA expression levels of ALP and early osteoblast differentiation factors, such as runt-related transcription factor 2 (Runx2), osteocalcin and collagen I, and decreased mRNA expression levels of fat generation factors, such as peroxisome proliferator activated receptor gamma 2 (PPARγ-2) and CCAAT enhancer-binding protein-α (C/EBPα) in a dose-dependent manner. While osteoblast differentiation factors were down-regulated, fat generation factors were up-regulated when DKK1 was applied. Also EFs up-regulated mRNA expression levels of β-catenin, LRP5 and TCF protein which could be blocked by DKK1.

CONCLUSION

EFs regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats by activating wnt/β-catenin signal pathway, which may be an important molecular mechanism of EFs on treating postmenopausal osteoporosis.

Icariin stimulates the proliferation of rat Sertoli cells in an ERK1/2-dependent manner in vitro

Icariin (ICA), a major constituent of flavonoids from the Chinese medical herb Epimedium brevicornum Maxim, is found to be protective for male reproductive ability, with the underlying mechanism largely unknown. Our study here investigated the effects of ICA on Sertoli cells, which act as nurse cells for the germ cells developing. Icariin was found to stimulate Sertoli cell proliferation in a dose-dependent manner. Further study revealed that Icariin induced an obvious phosphorylation of ERK in Sertoli cells. Inhibition of activation of ERK by the ERK inhibitor U0126 nearly blocked the Icariin-induced proliferation of Sertoli cells. Taken together, our results suggest that Icariin promotes the proliferation of Sertoli cells in vitro by activating the ERK1/2 signal pathway, which might at least partially, explain the protective role of Icariin on male reproductive ability.

Effects of Anhydroicaritin and 2″-Hydroxy-3″-en-Anhydroicaritin on the Proliferation and Differentiation of MC3T3–E1 Osteoblasts

Epimedium brevicornu Maxim., one of the most frequently used traditional Chinese medicines for thousands of years, is prescribed as having “bone strengthening” function and the ability to cure bone diseases. The present study evaluated the osteogenic effects of anhydroicaritin (1) and 2″-hydroxy-3″-en-anhydroicaritin (2) isolated from E. brevicornu by activity-guided assay. Treatment with1 and 2 improved the proliferation of murine osteoblastic MC3T3-E1 cells at doses of 10−7-10−5 mol/L and 10−7-10−6 mol/L, respectively, in the 72-hour culture period. Enzyme linked immunosorbent assay and histochemical staining demonstrated that both of these two prenyl-flavonoids significantly promoted the differentiation of MC3T3-E1 cells by enhancing the level of ALP activity in the cells. Alizarin Red staining and mineralized nodule quantification showed that 1 and 2 had the potential of stimulating the formation of mineralization nodules and further speeding up the formation of bone, indicating that both compounds might be potential candidates for bone regenerative medicine.

Mutual interactions between flavonoids and enzymatic and transporter elements responsible for flavonoid disposition via phase II metabolic pathways

Flavonoids, existing mainly as glycosides in nature, have multiple "claimed" beneficial effects in humans. Flavonoids are extensively metabolized in enterocytes and hepatocytes by phase II enzymes such as UGTs and SULTs to form glucuronides and sulfates, respectively. These glucuronides and sulfates are subsequently excreted via ABC transporters (e.g., MRP2 or BCRP). Therefore, it is the interplay between phase II enzymes and efflux transporters that affects the disposition of flavonoids and leads to the low bioavailability of flavonoid aglycones. Flavonoids can also serve as chemical regulators that affect the activity or expression levels of phase II enzymes including UGTs, SULTs and GSTs, and transporters including P-gp, MRP2, BCRP, OATP and OAT. In general, flavonoids may exert the inhibitory or inductive effects on the phase II enzymes and transporters via multiple mechanisms that may involve different nuclear receptors. Since flavonoids may affect the metabolic pathways shared by many important clinical drugs, drug-flavonoid interaction is becoming an increasingly important concern. This review article focused on the disposition of flavonoids and effects of flavonoids on relevant enzymes (e.g. UGTs and SULTs) and transporters (e.g. MRP2 and BCRP) involved in the interplay between phase II enzymes and efflux transporters. The effects of flavonoids on other metabolic enzymes (e.g. GSTs) or transporters (e.g. P-gp, OATP and OAT) are also addressed but that is not the emphasis of this review.

Five-year follow-up study of a kidney-tonifying herbal Fufang for prevention of postmenopausal osteoporosis and fragility fractures

To observe the kidney-tonifying herbal Fufangs with phytoestrogenic epimedium for prevention of postmenopausal osteoporosis with both bone mineral density (BMD) and fracture as study endpoints, a 5-year multicenter follow-up study in 194 postmenopausal women (47-70 years old) was conducted in which the subjects were given oral administration of herbal Fufang (10 g/day, twice per day, n = 101) or placebo (n = 93). Both groups were supplemented daily with calcium (600 mg) and vitamin D (400 IU). BMD at distal radius, potential adverse events, and fracture incidence were evaluated at baseline and at 6, 12, 24, 36, 48, and 60 months. At the end of 5 years, 155 subjects had completed the study, with better adherence in the treatment group (13% dropouts, n = 88 at year 5) as compared with the control group (28% dropouts, n = 67 at year 5) (P < 0.05). No notable adverse events were observed in either group. In the treatment group BMD increased significantly from baseline (0.211 ± 0.022 g/cm(2)) to the end of the study (0.284 ± 0.015 g/cm(2)), whereas the control group decreased significantly from baseline (0.212 ± 0.023 g/cm(2)) to 5 years later (0.187 ± 0.022 g/cm(2)) (P < 0.05). The fracture incidence was 2.4 fold lower in the treatment group than in the control group, with a relative risk of 0.57 for the treatment group (95% CI, 0.43-0.70, P < 0.05). In conclusion, in addition to the beneficial effects of oral herbal Fufang on prevention of postmenopausal bone loss, this 5-year multi-center clinical study demonstrated for the first time its potential for reduction in fragility fracture incidence.

Changes in the intestinal absorption mechanism of icariin in the nanocavities of cyclodextrins

Icariin is a bioactive herbal ingredient isolated from Herba epimedii, which has been widely used for the treatment of osteoporosis and male sexual dysfunction in traditional Chinese medicine. The major objective of this work is to investigate the different enhancing effects of β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) on the intestinal absorption of icariin, and to identify the molecular mechanisms of this action. Host-guest-type interactions of icariin with cyclodextrins nanocavities were unambiguously demonstrated by the phase-solubility diagram, ultraviolet spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray powder diffractometry, and two dimensional proton nuclear magnetic resonance rotating-frame Overhauser effect spectroscopy. These results were further supported using molecular modeling studies. The rat single-pass intestinal perfusion model showed that the absorption of icariin was affected by P-glycoprotein (Pgp). The icariin/HP-β-CD inclusion complex provided greater enhancement in the intestinal absorption than the icariin/β-CD inclusion complex. Therefore, the enhancing effect was involved in a solubilizing effect and/or Pgp inhibitory effect. Finally, fluorescence anisotropy measurements and Pgp adenosine triphosphatase (ATPase) assay demonstrated that β-CD exhibited no effect on Pgp, while HP-β-CD showed inhibition by restraining the Pgp ATPase activity rather than changing the fluidity of cell membrane.

Comparative study of osteogenic potential of a composite scaffold incorporating either endogenous bone morphogenetic protein-2 or exogenous phytomolecule icaritin: an in vitro efficacy study

A local delivery system with sustained and efficient release of therapeutic agents from an appropriate carrier is desirable for orthopedic applications. Novel composite scaffolds made of poly (lactic-co-glycolic acid) with tricalcium phosphate (PLGA/TCP) were fabricated by an advanced low-temperature rapid prototyping technique, which incorporated either endogenous bone morphogenetic protein-2 (BMP-2) (PLGA/TCP/BMP-2) or phytomolecule icaritin (ICT) (PLGA/TCP/ICT) at low, middle and high doses. PLGA/TCP served as control. In vitro degradation, osteogenesis and release tests showed statistical differences among PLGA/TCP/ICT, PLGA/TCP and PLGA/TCP/BMP-2 groups, where PLGA/TCP/ICT had the desired slow release of bioactive icaritin in a dose-dependent manner, whereas there was almost no BMP-2 release from the PLGA/TCP/BMP-2 scaffolds. PLGA/TCP/ICT significantly increased more ALP activity, upregulated mRNA expression of osteogenic genes and enhanced calcium deposition and mineralization in rabbit bone marrow stem cells cultured on scaffolds compared with the other two groups. These results indicate the desired degradation rate, osteogenic capability and release property in PLGA/TCP/ICT composite scaffold, as icaritin preserved its bioactivity and structure after incorporation, while PLGA/TCP/BMP-2 did not show an initially expected osteogenic potential, owing to loss of the original bioactivity of BMP-2 during its incorporation and fabrication procedure. The results suggest that PLGA/TCP composite scaffolds incorporating osteogenic ICT might be a promising approach for bone tissue bioengineering and regeneration.

The beneficial effect of Icariin on bone is diminished in osteoprotegerin-deficient mice

BACKGROUND

Osteoprogeterin (OPG) plays an important role in regulating bone homeostasis by inhibiting osteoclastogenesis and bone resorption. Icariin is the major ingredient of Herba Epimedii, which exerts anabolic and anti-resorptive effects on bone, but the mechanism remains unknown. In this study, we evaluated the role of OPG in Icariin-mediated beneficial effects on bone.

MATERIALS AND METHODS

Twelve-week-old Opg knockout (KO) male mice and their wild type (WT) littermates were orally administered with Icariin (0.3 mg/g) everyday for 8 weeks. Bone mass and microstructure in the right proximal tibiae were analyzed with micro-computed tomography (μCT). Bone remodeling was evaluated with serum biochemical analyses and bone histomorphometry. The colonies of fibroblast and osteoblast from bone marrow derived cells were quantified. The mRNA expressions of osteoblast and osteoclast related genes in trabecular bone from the femora were analyzed by real-time PCR.

RESULTS

Icariin treatment led to greater trabecular bone volume and trabecular number compared with vehicle treatment in WT mice. Icariin treatment increased bone formation parameters while it decreased bone resorption parameters in WT mice; however, the anabolic response of trabecular bone to Icariin treatment was diminished in KO mice. At cellular and molecular levels, Icariin significantly increased the formation of osteoblast colonies from bone marrow derived cells and the Opg gene expression in trabecular bone of WT mice.

CONCLUSIONS

These data suggest that Icariin treatment exerted anabolic and anti-resorptive effects on trabecular bone of WT mice, in which the effects were diminished in KO mice. The effects of Icariin treatment on bone are dependent on up-regulation of Opg, therefore, OPG plays an essential role in Icariin-mediated beneficial effects on trabecular bone.

Effect of epimedium pubescen flavonoid on bone mineral status and bone turnover in male rats chronically exposed to cigarette smoke

Background

Epimedii herba is one of the most frequently used herbs in formulas that are prescribed for the treatment of osteoporosis in China and its main constituent is Epimedium pubescen flavonoid (EPF). However, it is unclear whether EPF during chronic exposure to cigarette smoke may have a protective influence on the skeleton. The present study investigated the effect of EPF on bone mineral status and bone turnover in a rat model of human relatively high exposure to cigarette smoke.

Methods

Fifty male Wistar rats were randomized into five groups: controls, passive smoking groups and passive smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day) in drinking water for 4 months. A rat model of passive smoking was prepared by breeding male rats in a cigarette-smoking box. Bone mineral content (BMC), bone mineral density (BMD), bone turnover markers, bone histomorphometric parameters and biomechanical properties were examined.

Results

Smoke exposure decreased BMC and BMD, increased bone turnover (inhibited bone formation and stimulated its resorption), affected bone histomorphometry (increased trabecular separation and osteoclast surface per bone surface; decreased trabecular bone volume, trabecular thickness, trabecular number, cortical thickness, bone formation rate and osteoblast surface per bone surface), and reduced mechanical properties. EPF supplementation during cigarette smoke exposure prevented smoke-induced changes in bone mineral status and bone turnover.

Conclusion

The results suggest that EPF can prevent the adverse effects of smoke exposure on bone by stimulating bone formation and inhibiting bone turnover and bone resorption.

Effect of Epimedium pubescen flavonoid on bone mineral density and biomechanical properties of femoral distal end and femoral diaphysis of passively smoking male rats

BACKGROUND

Based on a rat model of human relatively high exposure to cigarette smoke, this study aimed to estimate whether Epimedium pubescen flavonoid (EPF) may prevent a smoke-induced decrease in bone mineral density (BMD) and weakening of the biomechanical properties of bone.

METHODS

Fifty male Wistar rats were randomized into five groups: controls, passively smoking groups and passively smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day) in drinking water for 4 months. A rat model of passive cigarette smoking was prepared by breeding male rats in a cigarette-smoking box for 4 months. Bone metabolic makers, BMD and biomechanical properties of the femoral distal end and femoral diaphysis were examined.

RESULTS

Exposure to cigarette smoke decreased the BMD, affected bone turnover (inhibited bone formation and stimulated its resorption) and weakened the biomechanical properties of the femur at its distal end and diaphysis. EPF supplementation during cigarette smoke exposure prevented the decrease in BMD, accelerated bone turnover and weakened the biomechanical properties of bone.

CONCLUSION

Our data suggest that EPF supplementation can prevent the adverse effects of smoke exposure on BMD and biomechanical properties by inhibiting bone turnover and preventing bone resorption, and in this way it can decrease the risk of bone fractures.

The first multicenter and randomized clinical trial of herbal Fufang for treatment of postmenopausal osteoporosis

This multicenter and randomized clinical trial showed that daily oral herbal formula Xian Ling Gu Bao (XLGB) was safe in postmenopausal women over a 1-year treatment. Those patients (n ∼ 50) treated with XLGB at the conventional dose demonstrated a statistically significant increase in dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) at lumbar spine at 6 months and a numerically increased BMD at 12 months.

INTRODUCTION

The aim of this study was to examine the safety and efficacy of a herbal formula XLGB in postmenopausal women (ChiCTR-TRC-00000347).

METHODS

One hundred eighty healthy postmenopausal women (≥60 years old) with BMD T-score ≤ -2.0 (lumbar spine or femoral neck) were recruited from four clinical centers to receive low-dose (conventional dose) XLGB (L-XLGB group, 3 g/day, n = 61) or high-dose XLGB (H-XLGB group, 6 g/day, n = 58) or placebo (CON group, n = 61). Women received daily calcium (500 mg) and vitamin D (200 IU) supplementation. Primary endpoints were lumbar spine BMD and safety; secondary endpoints were femoral neck BMD and bone turnover markers measured at baseline and at 6 and 12 months.

RESULTS

Of 180 women recruited, 148 completed the study. The compliance in each group was comparable. Prominent adverse events were not observed in either group. In the L-XLGB group at 6 months, lumbar spine BMD by DXA increased significantly from baseline (+2.11% versus CON +0.58%, p < 0.05), but femoral neck BMD did not; at 12 months, BMD in the L-XLGB group decreased from 6-month levels yet remained higher than baseline, but without difference from the CON group. There was no dose-dependent response. Bone turnover marker levels declined during the first 6 months after XLGB treatment. There was no significant difference in the overall incidence of side effects among treatment and control groups.

CONCLUSION

XLGB over 1-year treatment at the conventional dose demonstrated safe and only a statistically significant increase in BMD at lumbar spine at 6 months in postmenopausal women.

Dynamic expression of DKK1 protein in the process whereby Epimedium-derived flavonoids up-regulate osteogenic and down-regulate adipogenic differentiation of bone marrow stromal cells in ovariectomized rats

OBJECTIVE

To observe the dynamic expression of DKK1 protein in the process whereby Epimedium-derived flavonoids (EFs) regulate the balance between osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats, and to provide experimental evidence for the mechanism of EFs in the treatment of postmenopausal osteoporosis.

METHODS

  Bone marrow stromal cells from ovariectomized rats were separated and cultivated in osteoinductive or liquid medium for 15 days in vitro. EFs (10 µg/mL) were applied to both cultures. Alkaline phosphatase (ALP) staining, ALP activity determination, Oil Red O staining and fluorescence quantitative polymerase chain reaction were used to determine the influence of EFs on osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats. Moreover, in order to explore the exact mechanism of EFs on osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats, enzyme linked immunosorbent assay was used to determine the dynamic expression of DKK1 protein in this process.

RESULTS

EFs increased activity of ALP and mRNA expression of Runx2 (early osteoblast differentiation factor) and decreased mRNA expression of PPARγ-2 (key factor of fat generation). Importantly, EFs down-regulated expression of DKK1 protein in an osteogenic induction medium and inhibited up-regulation of DKK1 protein in an adipogenic induction medium.

CONCLUSION

  EFs regulate the balance between osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats by down-regulating expression of DKK1 protein. This may be an important molecular mechanism of EFs in the context of treatment of postmenopausal osteoporosis.

Prevention of bone resorption by intake of phytoestrogens in postmenopausal women: a meta-analysis

Phytoestrogens as selective estrogen receptor modulators like compounds may consider as a therapeutic option in osteoporosis. In this regard, the effect of phytoestrogens on bone biomarkers was examined in several trials which their results are controversial. We aimed this meta-analysis to evaluate the net effect of phytoestrogens on bone markers. A thorough search was conducted from 2000 to 2010 in English articles. All randomized clinical trials were reviewed, and finally, 11 eligible randomized clinical trials were selected for meta-analysis. Totally 1,252 postmenopausal women were enrolled in the study by considering the changes of pyridinoline (Pyd), desoxypyridinoline (Dpyd), bone alkaline phosphatase, and osteocalcin concentrations in urine and serum after phytoestrogens consumption. The urine Pyd and Dpyd levels decreased significantly in phytoestrogens consumers. Effect size and effect size for weighted mean difference of urine Pyd levels showed -1.229171 (95% confidence interval (CI) = -1.927639 to -0.530703) and -9.780623 (95% CI = -14.240401 to -5.320845), respectively, a significant results in comparison to control group and significant results for Dpyd -0.520132 (95% CI = -0.871988 to -0.168275) and -0.818582 (95% CI = -1.247758 to -0.389407), respectively. Meta-analysis indicates that phytoestrogens intake can prevent bone resorption, but its benefits on bone formation are not significant. This favorable effect was observed in low doses and in at least 3 weeks of phytoestrogens intake.

Classic yin and yang tonic formula for osteopenia: study protocol for a randomized controlled trial

Background

Osteoporosis is a growing worldwide problem, with the greatest burden resulting from fractures. Nevertheless, the majority of fractures in adults occur in those with "osteopenia" (bone mineral density (BMD) only moderately lower than young normal individuals). Since long-term drug therapy is an expensive option with uncertain consequences and side effects, natural herbal therapy offers an attractive alternative. The purpose of this study is to evaluate the effect on BMD and safety of the Classic Yin and Yang Tonic Formula for treatment of osteopenia and to investigate the mechanism by which this efficacy is achieved.

Methods/design

We propose a multicenter double-blind randomized placebo-controlled trial to evaluate the efficacy and safety of the Classic Yin and Yang Tonic Formula for the treatment of osteopenia. Participants aged 55 to 75 with low bone mineral density (T-score between -1 and -2.5) and kidney deficiency in TCM will be included and randomly allocated into two groups: treatment group and control group. Participants in the treatment group will be treated with Classic Yin and Yang Tonic Granule, while the controlled group will receive placebo. Primary outcome measure will be BMD of the lumbar spine and proximal femur using dual-energy X-ray absorptiometry. Secondary outcomes will include pain intensity measured with visual analogue scales, quality of life, serum markers of bone metabolism, indices of Neuro-endocrino-immune network and safety.

Discussion

If the Classic Yin and Yang Tonic Formula can increase bone mass without adverse effects, it may be a novel strategy for the treatment of osteoporosis. Furthermore, the mechanism of the Chinese medical formula for osteoporosis will be partially elucidated.

Trial registration

This study is registered at ClinicalTrials.gov, NCT01271647.

Osteogenic effects of flavonoid aglycones from an osteoprotective fraction of Drynaria fortunei--an in vitro efficacy study

Drynaria fortunei (Kunze) J. Sm. is a traditional Chinese herb used for the treatment of osteoporosis and other bone metabolic disorders. Previous studies demonstrated that "small polar active fraction in Drynaria fortunei (SDF)"exerted osteoprotective effects in ovariectomized (OVX) mice. This study aims to investigate the constituents in SDF and systemically evaluate their osteogenic effects in vitro. Five flavonoid aglycones, naringenin, kurarinone, kushennol F, xanthogalenol, and sophoraflavanone G were identified in SDF. All the compounds did not show effects on proliferation of osteoblastic UMR 106 cells at the concentrations of 0.1-1000 nM, but significantly increased the ALP activity of the cells at most of the concentrations from 10 nm to 1000 nM. Xanthogalenol at the concentration of 100 nM significantly increased concentration of acid-solubilized calcium. ICI 182,780, antagonist of estrogen receptor (ER), diminished the effect of kushennol F on ALP activity and the effect of xanthogalenol on acid-solubilized calcium. In conclusion, flavonoid aglycones in SDF could promote differentiation and mineralization of osteoblastic UMR 106 cells in vitro, which was explained by activation of ER signaling pathway. This study provides scientific evidences for the conduction of in vivo experiments to confirm potential effects of flavonoid aglycones on preventing OVX-induced osteoporosis.

Icariin inhibits osteoclast differentiation and bone resorption by suppression of MAPKs/NF-κB regulated HIF-1α and PGE(2) synthesis

Icariin has been reported to enhance bone healing and treat osteoporosis. In this study, we examined the detail molecular mechanisms of icariin on lipopolysaccharide (LPS)-induced osteolysis. Our hypothesis is that icariin can inhibit osteoclast differentiation and bone resorption by suppressing MAPKs/NF-κB regulated HIF-1α and PGE(2) synthesis. After treatment with icariin, the activity of osteoclasts differentiation maker, tatrate resistances acid phosphatease (TRAP), significantly decreased at the concentration of 10(-8)M. Icariin (10(-8)M) reduced the size of LPS-induced osteoclasts formation, and diminished their TRAP and acid phosphatease (ACP) activity without inhibition of cell viability. Icariin also inhibited LPS-induced bone resorption and interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) expression. The gene expression of osteoprotegerin (OPG) was up-regulated, while receptor activator of NF-κB ligand (RANKL) was down-regulated. Icariin also inhibited the synthesis of cyclo-oxygenase type-2 (COX-2) and prostaglandin E(2) (PGE(2)). In addition, icariin had a dominant repression effect on LPS-induced hypoxia inducible factor-1α (HIF-1α) expression of osteoclasts. On osteoclasts, icariin suppresses LPS-mediated activation of the p38 and JNK; while on the osteoblasts, icariin reduced the LPS-induced activation of ERK1/2 and I-kappa-B-alpha (IκBα), but increased the activation of p38. In conclusion, we demonstrated that icariin has an in vitro inhibitory effects on osteoclasts differentiation that can prevent inflammatory bone loss. Icariin inhibited LPS-induced osteoclastogenesis program by suppressing activation of the p38 and JNK pathway.

Herba Epimedii: anti-oxidative properties and its medical implications

Herba Epimedii is a Chinese herbal medicine with proven efficacy in treating cardiovascular diseases and osteoporosis, and in improving sexual and neurological functions. This efficacy is found to be related to the potent anti-oxidative ability of Herba Epimedii and its flavonoid components, with icarrin as the main effective constituent, along with polysaccharides and vitamin C. These ingredients have been proven to be effective against oxidative-stress related pathologies (cardiovascular diseases, Alzheimer’s disease and inflammation) in animal rodent models and in vitro studies. Their anti-oxidative properties are found to be related to an inductive effect on endogenous free-radical scavenging enzymes such as catalase and glutathione peroxidase and the inherent electron-donating ability of flavonoids.

Total flavonoid fraction of the Herba epimedii extract suppresses urinary calcium excretion and improves bone properties in ovariectomised mice

Flavonoids are the active components of Herba epimedii (HEP), a commonly used herb for the management of osteoporosis in China over the centuries. The present study aims to characterise the in vivo effects of its total flavonoid (TF) fraction on bone properties and mineral metabolism as well as to study the mechanism involved in achieving its protective effects against ovariectomy (OVX)-induced bone loss. TF suppressed OVX-induced increase in urinary Ca excretion as well as loss of bone mass and strength at the distal femur in mice in a dose-dependent manner. The changes in urinary Ca excretion were inversely correlated with the expressions of renal Ca transport protein (CaBP-28K) and vitamin D receptor mRNA in OVX mice. TF (100 μg/g) treatment prevented the deterioration of trabecular bone microarchitecture induced by OVX in mice. In addition, TF treatment increased the expression of type I collagen and osteocalcin mRNA and the ratio of osteoprotegerin/receptor activator of NF-κB ligand mRNA, and suppressed the increase in IL-6 mRNA induced by OVX in the femur of mice. The present results indicate that the optimal dosage of the TF fraction of HEP for the improvement of bone properties and mineral metabolism in OVX mice was between 50 and 100 μg/g. Mechanistic studies indicated that TF might increase renal Ca reabsorption, stimulate the process of osteoblast formation as well as suppress the process of osteoclastogenesis in OVX mice.

Icariin isolated from Epimedium pubescens regulates osteoblasts anabolism through BMP-2, SMAD4, and Cbfa1 expression

Epimedii herba is one of the most frequently used herbs in formulas prescribed for the treatment of osteoporosis in China. The main active flavonoid glucoside extracted from Epimedium pubescens is Icariin, which has been reported to enhance bone healing and reduce osteoporosis occurrence. However, the detailed molecular mechanisms remain unclear. In this present study, we examine the molecular mechanisms of icariin by using primary osteoblast cell cultures obtained from adult mice. The osteoblast cells were harvested from 8-month old female Imprinting Control Region (ICR) mice. The effects of icariin stimulation on the proliferation, differentiation and maturation of osteoblasts were examined. The production of nitric oxide (NO) and caspase-3 were analyzed, along with the gene expressions of bone morphogenetic protein-2 (BMP-2), SMAD4, Cbfa1/Runx2, OPG, and RANKL. The viability of the osteoblasts reached its maximum at 10(-8)M icariin. At this concentration, icariin increased the proliferation and matrix mineralization of osteoblasts and promoted NO synthesis. With icariin treatment, the BMP-2, SMAD4, Cbfa1/Runx2, and OPG gene expressions were up-regulated; the RANKL gene expression was however down-regulated. Concurrent treatment involving the BMP antagonist (Noggin) or the NOS inhibitor (L-NAME) diminished the icariin-induced cell proliferation, ALP activity, NO production, as well as the BMP-2, SMAD4, Cbfa1/Runx2, OPG, RANKL gene expressions. In this study, we demonstrate that in vitro icariin is a bone anabolic agent that may exert its osteogenic effects through the induction of BMP-2 and NO synthesis, subsequently regulating Cbfa1/Runx2, OPG, and RANKL gene expressions. This effect may contribute to its action on the induction of osteoblasts proliferation and differentiation, resulting in bone formation.

Icariin protects murine chondrocytes from lipopolysaccharide-induced inflammatory responses and extracellular matrix degradation

Septic arthritis is an inflammatory arthropathy characterized by degeneration of articular cartilage. Icariin, the main active flavonoid glucoside isolated from Epimedium pubescens, is used as antirheumatics (or antiinflammatory), tonics, and aphrodisiacs in traditional Chinese medicine. In this study, we used lipopolysaccharide (LPS) to simulate the in vitro inflammatory response of chondrocytes during septic arthritis. Our hypothesis is that the icariin can protect chondrocytes from LPS-induced inflammation and extracellular matrix degradation. The inflammation of neonatal mice chondrocytes was induced by LPS and the antiinflammatory effects were examined. The synthesis of nitric oxide was analyzed, whereas the titer of glycosaminoglycan and total collagen were measured and the gene expressions (including inducible nitric oxide synthase [iNOS], matrix metalloproteinase [MMP]-1, MMP-3, and MMP-13) were evaluated. The results showed that the viability of chondrocytes, extracellular matrix synthesis, was significantly decreased, whereas nitric oxide synthesis was significantly increased in the presence of 10(-5) g/mL LPS. Icariin pretreatment can partially reverse these effects. The up-regulated expressions of MMP-1, 3, 13, cyclooxygenase-2 (COX-2), and iNOS genes by LPS treatment were also significantly down-regulated by the pretreatment of icariin to 1.8%, 0.056%, 7.7%, 3.1%, and 5.3% of the LPS-positive control sample, respectively. Our results demonstrate that icariin is a safe anabolic agent of chondrocytes. Icariin may exert its protective effects through inhibition of nitric oxide and MMP synthesis, and may then reduce the extracellular matrix destruction.

Icariin protects against bone loss induced by oestrogen deficiency and activates oestrogen receptor-dependent osteoblastic functions in UMR 106 cells

BACKGROUND AND PURPOSE

Icariin may be the active ingredient in Herba Epimedii, a Chinese herb commonly used for treatment of osteoporosis. The present study aims to delineate the mechanism(s) by which icariin prevents bone loss after ovariectomy (OVX) in vivo and stimulates osteoblastic functions in vitro.

EXPERIMENTAL APPROACH

Ovariectomized or sham-operated C57BL/6 mice were treated with vehicle, 17beta-oestradiol or icariin for 6 weeks. Total and trabecular bome mineral density (BMD) as well as polar stress-strain index of distal femur were measured by peripheral computed tomography. The mRNA expressions of OPG and RANKL in tibia were studied by RT-PCR. Interactions between the oestrogen receptor (ER) antagonist ICI182,780 and icariin were studied in UMR 106 cells. The functional transactivation of ERalpha and ERbeta as well as ERalpha phosphorylation by icariin were also assessed.

KEY RESULTS

Icariin suppressed the loss of bone mass and strength in distal femur and increased the mRNA expression ratio of OPG/RANKL in tibia, following OVX. Icariin increased ER-dependent cell proliferation, alkaline phosphatase (ALP) activity, gene expression of OPG and the OPG/RANKL ratio in UMR 106 cells. Icariin did not activate ERE-luciferase activity in UMR 106 cells, via the ERalpha or the ERbeta-mediated pathway, but it did increase ERalpha phosphorylation at Ser118.

CONCLUSIONS AND IMPLICATIONS

Our results indicate that icariin exerts anabolic effects in bone possibly by activating ER in a ligand-independent manner. Its ability to prevent OVX-induced bone loss without inducing uterotrophic effects supports its use as an alternative regimen for management of postmenopausal osteoporosis.

Side effects of phytoestrogens: a meta-analysis of randomized trials

BACKGROUND

Phytoestrogens are widely used by postmenopausal women for the treatment of the climacteric syndrome. The risk of adverse effects of this treatment, however, is unknown.

METHODS

Using a fixed-effects model, we performed a meta-analysis of side effects comparing phytoestrogen treatment with placebo or no treatment in randomized controlled trials.

RESULTS

We identified 174 randomized controlled trials. Side effects were reported in 92/174 randomized controlled trials with 9629 participants. The overall incidence of side effects in the phytoestrogen and control groups was 2019/5502 (36.7%) and 1824/4806 (38.0%), respectively (P=.2; incidence rate ratio [IRR] 1.01; 95% confidence interval [CI], 0.95-1.08). Comparing various side effect categories, we found significantly higher rates of gastrointestinal side effects among phytoestrogen users (P=.003; IRR 1.28; 95% CI, 1.08-1.50). Gynecological (IRR 0.94; 95% CI, 0.74-1.20), musculoskeletal (IRR 1.20; 95% CI, 0.94-1.53), neurological (IRR 0.91; 95% CI, 0.70-1.19), and unspecific side effects (IRR 0.95; 95% CI, 0.88-1.03) were not significantly different between groups. Within side effect categories, we found no significantly higher rates of side effects in women using phytoestrogens. Specifically, the rates of hormone-related side effects such as endometrial hyperplasia, endometrial cancer, and breast cancer were not significantly different between groups.

CONCLUSIONS

Based on the available evidence, phytoestrogen supplements have a safe side-effect profile with moderately elevated rates of gastrointestinal side effects. Rates of vaginal bleeding, endometrial hyperplasia, endometrial cancer, and breast cancer were not significantly increased among phytoestrogen users in the investigated studies.

Epimedium-derived flavonoids promote osteoblastogenesis and suppress adipogenesis in bone marrow stromal cells while exerting an anabolic effect on osteoporotic bone

BACKGROUND

Epimedium-derived flavonoids (EFs) have been reported to prevent bone loss in ovariectomized (OVX) rats and late postmenopausal women but the underlying mechanism of the anabolic effect is unknown.

OBJECTIVE

This study aimed to investigate the effect of EFs on osteoporotic bone using histomorphometry and on osteoblastogenesis/adipogenesis of bone marrow stromal cells (BMSCs).

METHODS

11-month-old female Wistar rats were divided into Sham, OVX, Sham+soluble vehicle (Sham+SV), OVX+SV and OVX+EFs (10 mg/kg/day) groups. 3 months after surgery, rats from the first two groups were euthanized to verify the establishment of OVX-induced osteoporosis. Other groups were orally treated with either daily SV or EFs for 4 months. At sacrifice, serum was analyzed for the levels of osteocalcin and TRACP 5b, BMD in the proximal femur was measured by pQCT. Static and dynamic bone histomorphometry was performed in proximal tibiae with microCT and undecalcified sections, respectively. The effect of EF treatment on differentiation of rat BMSCs was assessed by colony formation assays and gene expression analysis, respectively. Gene expression, ALP activity and adipocyte numbers were determined in differentiating human BMSCs after exposure to conditioned serum from SV- or EFs-treated OVX rats.

RESULTS

The serum level of osteocalcin was higher and TRACP 5b was lower in EFs versus SV-treated OVX rats. BMD, BV/TV, Tb.N and Conn.D in EFs-treated OVX rats were significantly greater than those of SV-treated OVX rats. Bone histomorphometric parameters OS/BS, MAR, and BFR/BS were significantly higher in EFs versus SV-treated OVX rats. EFs significantly increased osteogenesis and decreased adipogenesis of BMSCs, as evidenced by CFU-ALP and CFU-Adipo assays, respectively. The mRNA level of Runx2 and bone sailoprotein was significantly higher while PPARgamma2 was significantly lower in BMSCs from EFs-treated versus SV-treated OVX rats. ALP activity and Runx2 mRNA was significantly higher while adipocyte number and PPARgamma2 mRNA was significantly lower in human BMSCs after exposure to conditioned serum from EFs versus SV-treated OVX rats.

CONCLUSION

EFs exerted anabolic effect on osteoporotic bone by concomitantly promoting osteogenic and suppressing adipogenic differentiation of BMSCs.

Shockwave exerts osteogenic effect on osteoporotic bone in an ovariectomized goat model

Our recent in vitro study showed that extracorporeal shock wave (ESW) stimulated calcium deposition in human periosteal cells. In this study, we hypothesized that the use of ESW could induce new bone formation in osteoporotic bone. Using our established osteoporotic goat model, the calcaneus, distal radius and femoral condyle of the left limb were treated with ESW once per month; the contralateral side served as the control. Bone mineral density (BMD), microarchitecture and dynamic histomorphometric index were evaluated after 9 months. Trabecular BMD of the calcaneus increased significantly by 2.90%. This finding was substantiated by micro-computed tomography findings showing that trabecular bone volume fraction and trabecular thickness of the treated calcaneus were enhanced compared with the contralateral control. However, significant difference could not be detected in the other two weight-bearing skeletal sites. Mineral apposition rates of all ESW-treated regions were also consistently higher than those of the control. These findings suggest that ESW treatment could enhance local BMD by inducing new bone formation, yet the effect was more apparent in non-weight-bearing sites.

Chemical markers for the quality control of herbal medicines: an overview

Selection of chemical markers is crucial for the quality control of herbal medicines, including authentication of genuine species, harvesting the best quality raw materials, evaluation of post-harvesting handling, assessment of intermediates and finished products, and detection of harmful or toxic ingredients. Ideal chemical markers should be the therapeutic components of herbal medicines. However, for most herbal medicines, the therapeutic components have not been fully elucidated or easily monitored. Bioactive, characteristic, main, synergistic, correlative, toxic and general components may be selected. This article reviews the effective use of chemical markers in the quality control of herbal medicines including the selection criteria considering the roles and physicochemical factors which may affect the effective use of chemical markers.

Metabonomic study on ageing: NMR-based investigation into rat urinary metabolites and the effect of the total flavone of Epimedium

The aim of this work was to investigate the effects of ageing on rat urinary metabolites and to evaluate the anti-ageing effects of the total flavone of Epimedium (TFE). Proton nuclear magnetic resonance based metabonomic analyses was performed on urine from rats aged 4, 10, 18 and 24 months, and rats administered with TFE. By multivariate analysis, 26 characteristic resonances were found to be highly related with the age of rats, and ten of them were structurally postulated as creatinine, lactate, alanine, acetate, acetone, succinate, allantoin, methylamine, dimethylamine and trimethylamine-N-oxide; these metabolites involve creatinine metabolites, aliphatic amines metabolites and some important intermediates or end products of energy metabolism. Principal components analysis revealed that the metabolic profiles of 24-month-old rats treated with TFE closely resembled those of rats aged 18 months. In addition, most of these characteristic resonances were reset to younger levels by TFE intervention. The result suggests that TFE administration can markedly influence the ageing process and shows anti-ageing effects, which might due to the melioration of pyruyate metabolism and oxidative phosphorylation.

LC–MS/MS method for the simultaneous determination of icariin and its major metabolites in rat plasma

A rapid and sensitive method using liquid chromatography-tandem mass spectroscopy (LC-MS/MS) was developed and validated for the simultaneous quantitative determination of icariin and its two major metabolites, icariside I and icariside II in rat plasma. The analytes were extracted by liquid-liquid extraction with ethyl acetate after internal standard (daidzein) spiked. The separation was performed by a ZORBAX SB-C(18) column (3.5 microm, 2.1 mm x 100 mm) and a C(18) guard column (5 microm, 4.0 mm x 2.0mm) with an isocratic mobile phase consisting of acetonitrile-water-formic acid (50:50:0.05, v/v/v) at a flow rate of 0.25 mL/min. The Agilent G6410A triple quadrupole LC-MS system was operated under the multiple reaction monitoring (MRM) mode using the electrospray ionization technique in positive mode. The nominal retention times for icariin, icariside I, icariside II and daidzein were 1.21, 1.88, 2.34 and 1.35 min, respectively. The lower limits of quantification (LLOQ) of icariin, icariside I and icariside II of the method were 1.0, 0.5 and 0.5 ng/mL, respectively. The method was linear for icariin and its metabolites with correlation coefficients >0.995 for all analytes. The intra-day and inter-day accuracy and precision of the assay were less than 12.5%. This method has been applied successfully to a pharmacokinetic study involving the intragastric administration of icariin to rats.

Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium

The Chinese medicinal herb, Epimedium, used traditionally for bone health exerts estrogenic activity (EA) in vitro. A genetically characterized Epimedium brevicornum (EB) extract induced biphasic responses in the mRNA and protein expression of the estrogen-regulated progesterone receptor gene in breast cancer (MCF-7) cells. These changes were mirrored changes in estrogenic receptor (ERalpha) content. In male Sprague-Dawley rats, administration of the estrogenic prodrug, estradiol valerate increased area-under-curve of serum effects for ERalpha (AUC difference: 18,900EA(ERalpha) min; 95% CI: 0-37,800; p = 0.05) and breast cancer cell (MCF-7) growth (AUC difference: 30,200EA(MCF-7) min; 95% CI: 24,200-36,200; p<0.001), compared to placebo. Oral administration of Epimedium brevicornum increased ERalpha activity (1320EA(ERalpha) min, p<0.01). Our data indicate that estrogen-responsive bioassays can measure the pharmacokinetic/pharmacodynamics of estrogenic activity in serum. Epimedium brevicornum extract increases estrogenic activity in serum and human studies are required to evaluate whether Epimedium extracts have utility for estrogen replacement therapy.