Ethanolic extract of Persea americana Mill. (Lauraceae) seeds induced antiestrogenic effects in young female Wistar rats

OBJECTIVES

The ethanol extract of Persea americana seeds was found to inhibit the development of estrogen-dependent conditions in female Wistar rats, suggesting the ability of its secondary metabolites to interact with estrogen receptors (ERs), either as partial agonists or as antagonists. To test this hypothesis, the abovementioned extract was assessed for its ability to mimic and/or antagonize estradiol effects.

METHODS

Two experiments were conducted in ovariectomized (OVX) rats: (1) animals were treated with estradiol valerate (E2V; 1 mg/kg) or P. americana at doses of 25 and 50 mg/kg; (2) animals were treated with E2V alone (0.75 mg/kg) or in combination with P. americana at the abovementioned doses. Treatments were given orally for 3 days and animals were sacrificed for biochemical and histological analyses of the uterus and vagina.

RESULTS

When administered alone, P. americana did not change the histomorphology of both organs (uterus and vagina). In combination with E2V, P. americana decreased uterine weight [30 % decrease (p<0.001) at 25 mg/kg and 24 % (p<0.01) at 50 mg/kg] and epithelium height (37 % decrease). This was associated with decreased estradiol levels (at least 86 % decrease, p<0.001) in the uterus. Similarly, vagina epithelium height decreased by at least 34 % (p<0.05) when E2V was co-administered with P. americana.

CONCLUSIONS

The seed extract of P. americana contains ER antagonist secondary metabolites accounting for its ability to inhibit the development of estrogen-dependent conditions in female rats.

α-Linolenic Acid Inhibits RANKL-Induced Osteoclastogenesis In Vitro and Prevents Inflammation In Vivo

Inflammation is an important risk factor for bone-destroying diseases. Our preliminary research found that Zanthoxylum bungeanum seed oil (ZBSO) is abundant in unsaturated fatty acids and could inhibit osteoclastogenesis in receptor activator of nuclear factor κB ligand (RANKL)-induced RAW264.7 cells. However, the key constituents in ZBSO in the prevention of osteoclastogenesis and its possible mechanism related to inflammation are still unclear. Therefore, in this study, oleic acid (OA), linoleic acid (LA), palmitoleic acid (PLA), and alpha-linolenic acid (ALA) in ZBSO, havingthe strongest effect on RANKL-induced osteoclastogenesis, were selected by a tartrate-resistant acid phosphatase (TRAP) staining method. Furthermore, the effects of the selected fatty acids on anti-inflammation and anti-osteoclastogenesis in vitro and in vivo were assessed using RT-qPCR. Among the four major unsaturated fatty acids we tested, ALA displayed the strongest inhibitory effect on osteoclastogenesis. The increased expression of free fatty acid receptor 4 (FFAR4) and β-arrestin2 (βarr2), as well as the decreased expression of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), nuclear factor of activated T-cells c1 (NFATc1), and tartrate-resistant acid phosphatase (TRAP) in RAW264.7 cells after ALA treatment were observed. Moreover, in ovariectomized osteoporotic rats with ALA preventive intervention, we found that the expression of TNF-α, interleukin-6 (IL-6), interleukin-1β (IL-1β), NFATc1, and TRAP were decreased, while with the ALA therapeutic intervention, downregulated expression of NF-κB, NFATc1, TRAP, and transforming growth factor beta-activated kinase 1 (TAK1) were noticed. These results indicate that ALA, as the major unsaturated fatty acid in ZBSO, could inhibit RANKL-induced osteoclastogenesis via the FFAR4/βarr2 signaling pathway and could prevent inflammation, suggesting that ZBSO may be a promising potential natural product of unsaturated fatty acids and a dietary supplement for the prevention of osteoclastogenesis and inflammatory diseases.

Investigation of taurine and aqueous garlic extract diet supplementation effect on the healing of rat osteoporotic fractures

BACKGROUND

We have evaluated the effects of taurine and aqueous garlic extract (AGE) as a dietary supplement on osteoporotic fracture (OPF) healing in the ovariectomized rat femur fracture model.

METHODS

In this experimental animal study,twenty-four osteoporosis-remodeled female Wistar albino rats were randomly divided into 3 groups (n: 8) according to their supplemented diet; control, taurine, and AGE groups. Unilateral femur middiaphysis mini-open osteotomy was stabilized with Kirschner wires. Six weeks after osteotomy, the rats were sacrificed before the femurs were harvested and OPF healing was evaluated with biochemical, histologic, microcomputed-tomography, and scintigraphic methods.

RESULTS

As an indicator of the antiosteoporotic effect, the calcium levels of the taurine group were significantly lower than the AGE and control groups in biochemical analyzes (p < 0.01). In histological studies, the new bone diameter and new bone volume values of the taurine group were significantly higher than the control group (p = 0.002 and p = 0.032, respectively), while higher trabecular-compact callus was observed in the taurine and AGE groups, respectively, compared to the control group. In morphological analyses, taurine and AGE groups had significantly higher bone volume/tissue volume, trabecular number, bone surface density, and lower trabecular separation than the control group (p < 0.05). The scintigraphic imaging showed a significant increase in osteoblastic activity of the taurine group compared to the control group (p = 0.005).

DISCUSSION

Taurine and AGE have positive anabolic effects, respectively, on the healing of OPFs, demonstrated by biochemical, histological, morphological, and scintigraphic methods.

Postmenopausal osteoporosis: a bioinformatics-integrated experimental study the pathogenesis

Postmenopausal osteoporosis (PMOP) is a chronic bone metabolic disease, which often causes fractures and various complications, it causes a great social and economic burden, and it is urgent to use modern research techniques to elucidate the pathogenesis of PMOP. At the same time, because of the complex physiological and pathological interaction mechanism between osteoporosis and sarcopenia, the correlation research has become a hot topic. Ovary removal is a commonly used experimental method to study the endocrine system of female animals, and it is also the best animal model to study PMOP. In this study, the preparation of the ovariectomized rat was confirmed through the detection of vaginal smear, the level of bone formation markers, and the analysis of bone tissue morphology. Transcriptome sequencing was used to analyze the molecular mechanism of PMOP in ovariectomized rats, qRT-PCR was used to verify the key targets. Results of Micro-CT and scanning electron microscopy (SEM) showed that the trabecular structure was disorganized and the symptoms of osteoporosis appeared, this indicating that the ovariectomized rats model was successfully prepared. Transcriptional sequencing results of femur tissue showed that 452 differentially expressed genes (DEGs) were screened. Bioinformatics analysis results showed that the osteoporosis caused by ovariectomized rats was mainly related to muscle contraction, calcium signaling pathway, etc. Results of qRT-PCR were consistent with transcriptome analysis. These results reveal the pathogenesis of PMOP in ovariectomized rats and also offer a possibility for elucidating the relevance of action between PMOP and sarcopenia.

Osteogenic Effects of KY-054, a Novel Coumarin Derivative on Femur Cortical Bone in Ovariectomized Female Rats

Osteoporosis is treated with oral and parenteral bone resorption inhibitors such as bisphosphonates, and parenteral osteogenic drugs including parathyroid hormone (PTH) analogues and anti-sclerostin antibodies. In the present study, we synthesized KY-054, a 4,6-substituted coumarin derivative, and found that it potently promoted osteoblast differentiation with an increase in alkaline phosphatase (ALP) activity at 0.01-1 µM in mouse-derived mesenchymal stem cells (ST2 cells) and rat bone marrow-derived mesenchymal stem cells (BMSCs). In the ovariectomized (OVX) rats, KY-054 (10 mg/kg/d, 8 weeks) increased plasma bone-type ALP activity, suggesting in vivo promoting effects on osteoblast differentiation and/or activation. In dual-energy X-ray absorption (DEXA) scanning, KY-054 significantly increased the distal and diaphyseal femurs areal bone mineral density (aBMD) that was decreased by ovariectomy, indicating its beneficial effects on bone mineral contents (BMC) and/or bone volume (BV). In micro-computed tomography (micro-CT) scanning, KY-054 had no effect on metaphysis trabecular bone loss and microarchitecture parameters weakened by ovariectomy, but instead increased metaphysis and diaphysis cortical bone volume (Ct.BV) and cortical BMC (Ct.BMC) without reducing medullary volume (Med.V), resulting in increased bone strength parameters. It is concluded that KY-054 preferentially promotes metaphysis and diaphysis cortical bone osteogenesis with little effect on metaphysis trabecular bone resorption, and is a potential orally active osteogenic anti-osteoporosis drug candidate.

Efficacy of Yougui pill combined with Buzhong Yiqi decoction in alleviating the sexual dysfunction in female rats through modulation of the gut microbiota

CONTEXT

Yougui pill combined with Buzhong Yiqi decoction (YPBYD) is used to relieve sexual dysfunction in clinical practice.

OBJECTIVE

To investigate changes in microbial composition caused by sexual dysfunction and identify dominant bacteria related to YPBYD treatment.

MATERIALS AND METHODS

Female Sprague-Dawley rats were randomly divided into four groups (n = 6): one group underwent Sham operation (Sham group), while three groups underwent ovariectomy (one model and two treatment groups). The ovariectomized (OVX) rats received oestradiol benzoate (250 µg/kg/week) or YPBYD (3.6 mL/d) via oral gavage for 4 weeks. Vaginal smear assay was performed; the serum levels of cyclic adenosine monophosphate (cAMP) and oestradiol (E2) were measured, followed by collection of stool samples for 16S rRNA sequencing.

RESULTS

After YPBYD treatment, the levels of E2 and cAMP in OVX rats significantly increased (E2: from 20.45 ± 1.60 ng/L to 24.38 ± 1.70 ng/L; cAMP: from 261.41 ± 9.21 pg/mL to 373.75 ± 17.37 pg/mL). OVX treatment decreased diversity of gut microbiota and YPBYD treatment restored gut microbiota composition. Compared with Sham group, the abundance of Romboutsia significantly increased, while those of Proteobacteria and Staphylococcus markedly decreased in OVX group (all p < 0.05); meanwhile, the abundance of these microbes showed an opposite trend after YPBYD treatment. These microbiotas were involved in tyrosine and tryptophan biosynthesis and fatty acid metabolism.

DISCUSSION AND CONCLUSIONS

These findings are the first to indicate YPBYD can alleviate female sexual dysfunction by modulating gut microbiota in OVX rats, which will help enhance the understanding on potential mechanism of YPBYD against sexual dysfunction.

Estradiol replacement improves high-fat diet-induced insulin resistance in ovariectomized rats

The role of 17β-estradiol (E2) in high-fat diet (HFD)-induced alteration of the protein kinase B (Akt) signaling pathway in ovariectomized (OVX) rats is unclear. Therefore, we examined whether chronic estrogen replacement restores HFD-induced impairment in insulin sensitivity by its effects concomitant with alterations in the Akt isoform 2 (Akt2) and Akt substrate of 160 kDa (AS160) phosphorylation in muscles of OVX rats. Nine-week-old female Wistar rats underwent ovariectomy under anesthesia; after 4 weeks, subcutaneous implantation of either E2 or placebo (PL) pellets was performed, and HFD feeding was initiated. Intravenous glucose tolerance tests were performed to assess insulin sensitivity. Following insulin injection into rats' portal vein, the liver and gastrocnemius muscle were dissected for insulin signaling analysis. We observed that HFD increased energy intake and body weight in the PL group; however, it was temporarily decreased in the E2 group. Adipose tissue accumulation was larger in HFD-fed rats than in normal chow diet (NCD)-fed rats in the PL group; however, this difference was not observed in the E2 group. HFD reduced insulin sensitivity in the PL group only. In vivo insulin stimulation increased Akt2 phosphorylation in the muscles of NCD-fed rats in both groups. In contrast, HFD affected insulin-stimulated phosphorylation of Akt2 and AS160 in the muscles of rats in the PL group but not in the E2 group. Our data suggest that E2 replacement improves HFD-induced insulin resistance, and this effect is accompanied by the alterations in the Akt2 and AS160 phosphorylation in insulin-stimulated muscles of OVX rats.

Identification of the Active Ingredient and Beneficial Effects of Vitex rotundifolia Fruits on Menopausal Symptoms in Ovariectomized Rats

Estrogen replacement therapy is a treatment to relieve the symptoms of menopause. Many studies suggest that natural bioactive ingredients from plants resemble estrogen in structure and biological functions and can relieve symptoms of menopause. The fruit of V. rotundifolia, called "Man HyungJa" in Korean, is a traditional medicine used to treat headache, migraine, eye pain, neuralgia, and premenstrual syndrome in Korea and China. The aim of the present study was to confirm that V. rotundifolia fruit extract (VFE) exerts biological functions similar to those of estrogen in menopausal syndrome. We investigated its in vitro effects on MCF-7 cells and in vivo estrogen-like effects on weight gain and uterine contraction in ovariectomized rats. Using the polar extract, the active constituents of VFE (artemetin, vitexicarpin, hesperidin, luteolin, vitexin, and vanillic acid) with estrogen-like activity were identified in MCF-7 cells. In animal experiments, the efficacy of VFE in ameliorating body weight gain was similar to that of estrogen, as evidenced from improvements in uterine atrophy. Vitexin and vitexicarpin are suggested as the active constituents of V. rotundifolia fruits.

Blackcurrant (Ribes nigrum L.) Extract Exerts Potential Vasculoprotective Effects in Ovariectomized Rats, Including Prevention of Elastin Degradation and Pathological Vascular Remodeling

Estrogen exerts cardioprotective effects in menopausal women. Phytoestrogens are plant-derived substances exhibiting estrogenic activity that could beneficially affect vascular health. We previously demonstrated that blackcurrant (Ribes nigrum L.) extract (BCE) treatment exerted beneficial effects on vascular health via phytoestrogenic activity in ovariectomized (OVX) rats, which are widely used as menopausal animal models. Here, we examined whether BCE treatment reduced elastin degradation and prevented pathological vascular remodeling in OVX rats fed a regular diet (OVX Control) or a 3% BCE-supplemented diet (OVX BCE), compared with sham surgery rats fed a regular diet (Sham) for 3 months. The results indicated a lower staining intensity of elastic fibers, greater elastin fragmentation, and higher α-smooth muscle actin protein expression in OVX Control rats than in OVX BCE and Sham rats. Pathological vascular remodeling was only observed in OVX Control rats. Additionally, we investigated matrix metalloproteinase (MMP)-12 mRNA expression levels to elucidate the mechanism underlying elastin degradation, revealing significantly upregulated MMP-12 mRNA expression in OVX Control rats compared with that in Sham and OVX BCE rats. Together, we identify BCE as exerting a vascular protective effect through reduced MMP-12 expression and vascular smooth muscle cell proliferation. To our knowledge, this is the first report indicating that BCE might protect against elastin degradation and pathological vascular remodeling during menopause.

Collagen Extract Derived from Yeonsan Ogye Chicken Increases Bone Microarchitecture by Suppressing the RANKL/OPG Ratio via the JNK Signaling Pathway

Yeonsan Ogye is a traditional Korean chicken breed (Gallus domesticus, GD), with a dominant gene for fibromelanosis, showing entirely black fluffy head feathers, ear lobes, and pupils. GD collagen extract (78.6 g per 100 g total protein) was derived from the flesh of Yeonsan Ogye. The effects of GD collagen on bone mass, microarchitecture, osteogenic, osteoclastogenic differentiations, and function factor expression were investigated in ovariectomized (OVX) rats. GD collagen stimulated osteogenesis in OVX rats and increased tibial bone strength and calcium content. Micro-computed tomography analysis of tibia cross-sections revealed that GD collagen attenuated the OVX-induced changes in trabecular thickness, spacing, and number. GD collagen stimulated alkaline phosphatase activity, bone-specific matrix proteins (alkaline phosphatase (ALP), osteocalcin, collagen type I (COL-I)) and mineralization by activating bone morphogenetic protein 2 (BMP-2)/mothers against decapentaplegic homolog 5 (SMAD5)/runt-related transcription factor 2 (Runx2). GD collagen inhibited osteoclast differentiation and function gene markers (TRAP, cathepsin K) by interfering with the Wnt signaling, increasing OPG production, and reducing the expression of RANKL, TRAP, and cathepsin K. GD collagen promoted osteogenesis by activating the p38 signal pathway and prevented osteoclastogenesis by lowering the RANKL/OPG ratio and blocking the JNK signaling pathway. Dietary supplementation with GD collagen might inhibit osteoclastogenesis, stimulate osteoblastogenesis, and regulate bone metabolism.

Estradiol Replacement Improves High-Fat Diet-Induced Obesity by Suppressing the Action of Ghrelin in Ovariectomized Rats

This study aims to investigate the effects of estradiol replacement on the orexigenic action of ghrelin in ovariectomized (OVX) obese rats fed with a high-fat diet (HFD). Four weeks after OVX at 9 weeks of age, Wistar rats were subcutaneously implanted with either 17β-estradiol (E2) or placebo (Pla) pellets and started on HFD feeding. After 4 weeks, growth hormone-releasing peptide (GHRP)-6, a growth hormone secretagogue receptor (GHSR) agonist injected intraperitoneally, induced changes in HFD intake, and c-Fos-positive neurons in the hypothalamic arcuate nucleus (ARC) were measured in both groups. The ghrelin protein and mRNA levels, as well as GHSR protein in stomach, were analyzed by Western blotting and real-time PCR. HFD increased energy intake and body weight in the Pla group, while it temporarily reduced these in the E2 group. GHRP-6 enhanced HFD intake and activated neurons in the ARC only in the Pla group. Furthermore, gastric ghrelin and GHSR protein levels were lower in the E2 group than in the Pla group, but plasma acyl ghrelin levels were similar in both groups. Our results suggest that E2 replacement improves obesity by inhibiting the orexigenic action of ghrelin via downregulation of ghrelin and its receptor in stomach in HFD-fed OVX rats.

Effect of Diosgenin on the Circulating MicroRNA Profile of Ovariectomized Rats

The present study aimed to assess the changes in circulating microRNA (miRNA) expression profiles associated with the potential osteoprotective effect of diosgenin (DIO) in ovariectomized (OVX) rats. Wistar rats (female) were subjected to a sham operation (SHAM group) or ovariectomy. OVX rats were treated with DIO (DIO group) or vehicle (OVX group) for 12 weeks. Following treatment, the serum estradiol, bone turnover biomarker levels, and the microarchitecture of tibias were assayed. Based on miRNA microarray and qRT-PCR analyses, differentially expressed (DE) circulating miRNAs were identified between the OVX and SHAM groups (comparison A) and between the DIO and OVX groups (comparison B). Furthermore, putative target genes of shared DE miRNAs with opposite expression trends in the two comparisons were predicted by ingenuity pathway analysis (IPA). Finally, the expression levels of the putative target genes in serum and tibia were validated by qRT-PCR. The micro-CT results demonstrated that DIO had a substantial anti-osteopenic effect on the tibias of OVX rats. In total, we found 5 DE circulating miRNAs (four upregulated and one downregulated) in comparison A and 21 DE circulating miRNAs (15 upregulated and 6 downregulated) in comparison B. However, only one DE circulating miRNA (rno-miR-20a-5p) had opposite expression trends between the two comparisons. Including rno-miR-20a-5p, 7 of the 10 selected DE circulating miRNAs between the two comparisons passed qRT-PCR validation. Specifically, based on qRT-PCR validation, DIO upregulated the expression of rno-miR-20a-5p and downregulated that of three target genes (Tnf, Creb1, and Tgfbr2) of the "osteoclast differentiation" pathway in the tibias of OVX rats. Our results suggested that DIO could change the circulating miRNA profile of OVX rats and inhibited the downregulation of miR-20a-5p in serum and tibia. DIO might exert an anti-osteoclastogenic effect on OVX rats by upregulating the expression of miR-20a-5p in circulation and bone tissue.

Epigallocatechin-3-O-gallate modulates the diversity of gut microbiota in ovariectomized rats

Epigallocatechin-3-O-gallate (EGCG) exists as one of the major active components of green tea and has been studied extensively; however, the relationship between EGCG and the changes in the gut microflora of ovariectomized (OVX) rats as a model of menopause women have not yet been studied. Female Wistar rats were fed on a maintenance material diet and underwent either ovariectomy or SHAM surgery. The ovariectomized rats were divided into OVX group with the treatment of placebo or EGCG group which was treated with EGCG by oral gavage. After 8 weeks of treatment, anxiety-like behaviors were assessed using elevated plus maze test (EMP) and open field test (OFT). The serum estradiol concentration was assayed through ELISA. High-throughput V3-V4 16S rDNA sequencing was conducted to assess the microbial diversity in fecal samples collected from all rats. EGCG, at a concentration of 10 mg/kg, caused behavioral changes in rats similar to anxiety. In EPM, OVX rats spent less time in open arms than SHAM group rats and EGCG group rats (F = 16.043, p < .01). In OFT, the total travelled distance and the number of entries for EGCG group were higher compared with OVX group (F = 30.939, H = 13.107, respectively; p < .01). In addition, the distribution and composition of intestinal microflora in rats changed after ovariectomy. EGCG modulated the diversity of gut microbiota in OVX group at the phylum and the genus levels. Our results suggested that the composition of gut microbiota and anxiety in OVX rats were simultaneously affected by EGCG, and therefore, the two conditions might be strongly related, yet the deeper mechanistic links need further exploration.

Royal jelly attenuates nonalcoholic fatty liver disease by inhibiting oxidative stress and regulating the expression of circadian genes in ovariectomized rats

Nonalcoholic fatty liver disease (NAFLD) has a high incidence in postmenopausal women and is accompanied by insulin resistance, obesity, and dyslipidemia. Royal jelly (RJ), a natural substance derived from hive, possesses numerous health-beneficial properties. Here, we evaluated the effects of RJ (150, 300, and 450 mg kg^-1  day^-1 , 8 weeks) on NAFLD in ovariectomized (OVX) rats. Based on the results, RJ ameliorated the degree of anxiety, improved serum lipid profile, and attenuated the hepatic steatosis and liver injury in OVX rats. Furthermore, the protective effects of RJ could be attributed to its antioxidant properties, which enhance the levels of hepatic antioxidant enzymes. The qRT-PCR results also suggest that RJ improves the disturbances of circadian genes by downregulating their expression, including that of Per1 and Per 2, in the liver of OVX rats. Altogether, our findings suggest that RJ may be a promising agent for the treatment of NAFLD. PRACTICAL APPLICATIONS: Postmenopausal women are at an increased risk of NAFLD. Currently, there are no licensed therapies for NAFLD. Although hormone replacement therapy (HRT) is reported to inhibit the development of NAFLD, it causes unexpected adverse effects. As HRT is controversial, the use of natural supplements to counteract the detrimental effects of menopause has recently attracted more attention. RJ is a natural product secreted from the hypopharyngeal and mandibular glands of worker bees. The present study illustrates the protective effect of the natural product, RJ, and its underlying mechanisms on NAFLD. This is the first study to assess the effect of RJ on NAFLD under estrogen deficiency. Such findings contribute to the further utilization of RJ, which might serve as a promising therapeutic option and natural food for the treatment of NAFLD.

MiR-152 influences osteoporosis through regulation of osteoblast differentiation by targeting RICTOR

Context: Evidence suggests that microRNA (miRNA) regulate gene expression and bone tissue homoeostasis of osteoporosis. MiR-152 has found to be abnormally expressed in osteoporosis, but its role in osteoblast differentiation has not been elucidated. Objective: To understand the potential mechanism of miR-152 in osteoblast differentiation via regulation of RICTOR. Materials and methods: The expression of miR-152 and RICTOR were tested in ovariectomized rat models of osteoporosis. Primary osteoblasts and MC3T -E1 cells were assigned into four groups, namely Control, miR-152 inhibitor, miR-control and miR-152 inhibitor + siRICTOR groups. qRT PCR and Western blot were performed to detect the expressions of miR-152 and RICTOR, respectively. MTT assay was used to evaluate cell viability, and ALP activity determination and mineralization analyses were also conducted. Results: In ovariectomy-induced osteoporotic rats, miR-152 (3.06 ± 0.35) in femoral tissues increased significantly, while RICTOR (0.31 ± 0.04) decreased. Compared with Control group, miR-152 inhibitor group presented appreciable reduction of miR-152 in primary osteoblasts and MC3T3-E1 cells, as well as remarkable increases in RICTOR, p-Akt(s473)/Akt ratio, and osteogenesis-related genes, with enhanced cell viability, ALP activity and mineralization. In comparison with cells in the miR-152 inhibitor group, those in the miR-152 inhibitor + siRICTOR group had no observable difference in miR-152, but were dramatically up-regulated in RICTOR, as well as the corresponding opposite tendencies of other factors. Conclusion: Inhibiting miR-152 promoted osteoblasts differentiation and alleviated osteoporosis by up-regulating RICTOR. Therefore, miR-152 may be an essential mediator of osteoblast differentiation and a new therapeutic strategy for osteoporosis.

Combined virgin coconut oil and tocotrienol-rich fraction protects against bone loss in osteoporotic rat model

Background and Aim:

Both virgin coconut oil (VCO) and tocotrienol-rich fraction (TRF) are rich in antioxidants and may protect the bone against bone loss induced by ovariectomy and high-fat diet. The study aimed to determine the protective effects of combined therapy of VCO and TRF on osteoporosis in ovariectomized (OVX) rat fed with high-fat diet.

Materials and Methods:

Thirty-six female Sprague-Dawley rats were divided into six groups: Sham-operated (SHAM), OVX control, OVX and given Premarin at 64.5 µg/kg (OVX+E2), OVX and given VCO at 4.29 ml/kg (OVX+V), OVX and given TRF at 30 mg/kg (OVX+T), and OVX and given a combination of VCO at 4.29 ml/kg and TRF at 30 mg/kg (OVX+VT). Following 24 weeks of treatments, blood and femora samples were taken for analyses.

Results:

There were no significant differences in serum osteocalcin levels between the groups (p>0.05), while serum C-terminal telopeptide of Type I collagen levels of the OVX+VT group were significantly lower than the other groups (p<0.05). The dynamic bone histomorphometry analysis of the femur showed that the double-labeled surface/bone surface (dLS/BS), mineral apposition rate, and bone formation rate/BS of the OVX+E2, OVX+T, and OVX+VT groups were significantly higher than the rest of the groups (p<0.05).

Conclusion:

A combination of VCO and TRF has the potential as a therapeutic agent to restore bone loss induced by ovariectomy and high-fat diet.

Effect of strontium substituted ß-TCP associated to mesenchymal stem cells from bone marrow and adipose tissue on spinal fusion in healthy and ovariectomized rat

Despite alternatives to autogenous bone graft for spinal fusion have been investigated, it has been shown that osteoconductive materials alone do not give a rate of fusion comparable with autogenous bone. This study analyzed a strontium substituted ß-tricalcium phosphate (Sr-ßTCP) associated with syngeneic, unexpanded, and undifferentiated mesenchymal stem cells from bone marrow (BMSC) or adipose tissue (ADSC) as a new tissue engineering approach for spinal fusion procedures. A posterolateral fusion was performed in 15 ovariectomized (OVX) and 15 sham-operated (SHAM) Inbred rats. Both SHAM and OVX animals were divided into three groups: Sr-ßTCP, Sr-ßTCP + BMCSs, and Sr-ßTCP + ADSCs. Animals were euthanized 8 weeks after surgery and the spines evaluated by manual palpation, micro-CT, and histology. For both SHAM and OVX animals, the fusion tissue in the Sr-ßTCP + BMSCs group was more solid. This effect was significantly higher in OVX animals by comparing the Sr-ßTCP + BMCSs group with Sr-ßTCP + ADSCs. Radiographical score, based on micro-CT 2D image, highlighted that the Sr-ßTCP + BMCSs group presented a similar fusion to Sr-ßTCP and higher than Sr-ßTCP + ADSCs in both SHAM and OVX animals. Micro-CT 3D parameters did not show significant differences among groups. Histological score showed significantly higher fusion in Sr-ßTCP + BMSCs group than Sr-ßTCP and Sr-ßTCP + ADSCs, for both SHAM and OVX animals. In conclusion, our results suggest that addition of BMSCs to a Sr-ßTCP improve bone formation and fusion, both in osteoporotic and nonosteoporotic animal, whereas spinal fusion is not enhanced in rats treated with Sr-ßTCP + ADSCs. Thus, for conducting cells therapy in spinal surgery BMSCs still seems to be a better choice compared with ADSCs.

Blackcurrant Extract with Phytoestrogen Activity Alleviates Hair Loss in Ovariectomized Rats

Ancocyanin-rich blackcurrant extract (BCE) has phytoestrogen activity; however, its effect on hair follicles is unknown. Additionally, hair loss is known to occur during menopause in women owing to decreased estrogen secretion. This study examined whether BCE alleviated female pattern hair loss using a rat model. RNA was extracted and analyzed using a microarray and ingenuity pathway analysis. A quantitative polymerase chain reaction revealed that 1 μg/mL BCE altered many genes downstream of beta-estradiol in human hair dermal papilla cells. Additionally, the expression of the hair follicle stem cell marker keratin 19 was greatly enhanced. In a menopause model, ovariectomized rats were fed a diet containing 3% BCE for three months. An analysis of the number of hair shafts revealed that BCE increased the number of hairs by 0.5 hairs/follicular unit. Moreover, immunostaining revealed that the expression of Ki67 also increased by 19%. Furthermore, fluorescent immunostaining showed that the expression of other stem cell markers, including keratin 15, CD34, and keratin 19, was induced in rat hair follicular cells. In conclusion, these findings suggest that BCE has phytoestrogen activity in hair follicles and contributes to the alleviation of hair loss in a menopausal model in rats.

Estrogen replacement enhances insulin-induced AS160 activation and improves insulin sensitivity in ovariectomized rats

Menopause predisposes women to impaired glucose metabolism, but the role of estrogen remains unclear. In this study, we examined the effects of chronic estrogen replacement on whole body insulin sensitivity and insulin signaling in ovariectomized rats. Female Wistar rats aged 9 wk were ovariectomized under anesthesia. After 4 wk, pellets containing either 17β-estradiol (E₂) or placebo (Pla) were subcutaneously implanted in the rats. After 4 wk of treatment, the intra-abdominal fat accumulation was greater in the Pla group than that in the E₂ group. Hyperinsulinemic-euglycemic clamp analysis and intravenous glucose tolerance test revealed that insulin sensitivity was significantly lower in the Pla group than in the E₂ group. In addition, Western blotting showed that in vivo insulin stimulation increased protein kinase B (Akt) phosphorylation to a similar degree in the gastrocnemius and liver of both groups, but phosphorylated Akt2 Ser⁴⁷⁴ was enhanced in the muscle of the E₂ group compared with the Pla group. Moreover, insulin-stimulated phosphorylation of Akt substrate of 160 kDa (AS160) Thr⁶⁴² was observed only in the E₂ group, resulting in the difference between the two groups. Additionally, AS160 protein and mRNA levels were higher in muscle of the E₂ group than the Pla group. In contrast, E₂ replacement had no effect on glucose transporter 4 protein levels in muscle and glycogen synthase kinase-3β in muscle and liver. These results suggest that estrogen replacement improves insulin sensitivity by activating the Akt2/AS160 pathway in the insulin-stimulated muscle of ovariectomized rats.

Buspirone Nanovesicular Nasal System for Non-Hormonal Hot Flushes Treatment

The aim of this work was to design and characterize a new nanovesicular nasal delivery system (NDS) containing buspirone, and investigate its efficiency in an animal model for the treatment of hot flushes. The presence of multilamellar vesicles with a mean size distribution of 370 nm was evidenced by transition electron microscopy (TEM), cryo-scanning electron microscopy (Cryo-SEM), and dynamic light scattering (DLS) tests. Pharmacodynamic evaluation of the nasal treatment efficacy with the new system was carried out in ovariectomized (OVX) rat—an animal model for hot flushes—and compared with other treatments. We found that the nasal administration of a buspirone NDS resulted in a significant reduction in tail skin temperature (TST). This effect was not observed in the control buspirone-treated groups. Buspirone levels in the plasma and brain of nasally-treated normal rats were quantified and compared with those of rats that had received oral administration by a LC-MS/MS assay. A significantly higher bioavailability was achieved with the new treatment relative to an oral administration of the same drug dose. No pathological changes in the nasal cavity were observed following sub-chronic nasal administration of buspirone NDS. In conclusion, the data of our investigation show that buspirone in the new nanovesicular nasal carrier could be considered for further studies for the development of a treatment for the hot flushes ailment.

Blackcurrant Anthocyanins Increase the Levels of Collagen, Elastin, and Hyaluronic Acid in Human Skin Fibroblasts and Ovariectomized Rats

Blackcurrants (Ribes nigrum L.) contain high levels of anthocyanin polyphenols, which have beneficial effects on health, owing to their antioxidant and anticarcinogenic properties. Phytoestrogens are plant-derived substances with estrogenic activity, which could have beneficial effects on the skin. Estradiol secretion decreases during menopause, reducing extracellular matrix (ECM) component production by skin fibroblasts. Using a normal human female skin fibroblast cell line (TIG113) and ovariectomized rats, the present study investigated whether an anthocyanin-rich blackcurrant extract (BCE) and four blackcurrant anthocyanins have novel phytoestrogenic activities that could benefit the skin in menopausal women. In TIG113 cells, a microarray and the Ingenuity^® Pathway Analysis showed that 1.0 μg/mL of BCE upregulated the expression of many estrogen signaling-related genes. A quantitative RT-PCR analysis confirmed that BCE (1.0 or 10.0 μg/mL) and four types of anthocyanins (10 μM) altered the mRNA expression of ECM proteins and enzymes involved in ECM turnover. Immunofluorescence staining indicated that the anthocyanins stimulated the expression of ECM proteins, such as collagen (types I and III) and elastin. Dietary administration of 3% BCE to ovariectomized rats for 3 months increased skin levels of collagen, elastin, and hyaluronic acid. This is the first study to show that blackcurrant phytoestrogens have beneficial effects on skin experimental models.

Osteoporotic Pain is Associated with Increased Transient Receptor Vanilloid 4 Expression in the Dorsal Root Ganglia of Ovariectomized Osteoporotic Rats: A Pilot Basic Study

INTRODUCTION

Osteoporosis can produce a persistent state of pain known as osteoporotic pain. One proposed mechanism of this pathology is increased calcitonin gene-related peptide (CGRP; a marker related to inflammatory pain) expression in the dorsal root ganglia (DRG) innervating osteoporotic vertebrae. Alternatively, a previous study revealed that axial loading caused osteoporotic pain in a rodent model of coccygeal vertebrae compression. Because this compression model is associated with trauma, additional mechanistic studies of osteoporotic pain in the absence of trauma are required. The current study aimedto evaluate the expression and relative distribution of transient receptor potential vanilloid 4 (TRPV4), a pain-related mechanoreceptor, in ovariectomized (OVX) osteoporotic rats.

METHODS

CGRP-immunoreactive (-ir) and TRPV4-ir DRG neurons innervating the L3 vertebrae of Sprague-Dawley rats were labeled with a neurotracer, FluoroGold. Intravertebral pH was also measured during the neurotracer procedure. TRPV4-ir/CGRP-ir FluoroGold-positive DRG neurons were quantified in sham control and OVX rats (n = 10, ea). The threshold for statistical significance was set at P < 0.05.

RESULTS

There was no statistical difference in the number of FluoroGold-positive DRG neurons between groups; however, there were significantly more CGRP-ir/TRPV4-ir FluoroGold-positive DRG neurons in the OVX group compared with the sham control group (P < 0.05) as well as the significantly increased molecular production of each peptide. Intravertebral pH was also lower in the OVX group compared with the sham control group (P < 0.05).

CONCLUSION

Sensory neurons innervating osteoporotic vertebrae exhibited increased expression of co-localized CGRP and TRPV4 in OVX osteoporotic rats. Additionally, intravertebral pH was low in the vicinity osteoporotic vertebrae. Considering that TRPV4 is a mechanosensitive nociceptor that is activated in acidic environments, its upregulation may be associated with the pathology of osteoporotic pain derived from microinflammation involved in osteoporosis.

Effects of combined teriparatide and zoledronic acid on posterior lumbar vertebral fusion in an aged ovariectomized rat model of osteopenia

There has been no study regarding the effect of a combination of teriparatide (TPTD) and zoledronic acid (ZA) on vertebral fusion. In this study, we investigate the effect of single and combined TPTD and ZA treatment on lumbar vertebral fusion in aged ovariectomized (OVX) rats. Sixty two-month-old female Sprague-Dawley rats were ovariectomized and underwent bilateral L4-L5 posterolateral intertransverse fusion after 10 months. The OVX rats received vehicle (control) treatment, or ZA (100 µg/kg, once), or TPTD (60 µg/kg/2 d for 42 d), or ZA + TPTD until they were euthanized at 6 weeks following lumbar vertebral fusion. The lumbar spine was harvested. Bone mineral density (BMD), bone fusion, bone volume (BV), and bone formation rate (BFR)were analyzed by dual-energy X-ray absorptiometry (DXA), radiography, micro-computed tomography, and histomorphometry. Compared with vehicle (control) treatment, ZA and TPTD monotherapy increased bone volume (BV) at fusion site, and ZA + TPTD combined therapy had an additive effect. Treatment with TPTD and ZA + TPTD increased the bone fusion rate when compared with the control group. ZA monotherapy did not alter the rate of bone fusion. The TPTD and ZA + TPTD treatment groups had increased mineral apposition rate (MAR), mineralizing surfaces/bone surface ((MS/BS), and BFR/BS compared with the OVX group. Our experiment confirm that the monotherapy with TPTD and combination therapy with ZA + TPTD in an OVX rat model of osteopenia following lumbar vertebral fusion surgery increased bone fusion mass and bone fusion rate, and ZA + TPTD combined therapy had an additive effect on bone fusion mass. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:937-944, 2018.

Influence of estrogen on individual exercise motivation and bone protection in ovariectomized rats

Bone protection and metabolism are directly linked to estrogen levels, but exercise is also considered to have bone protective effects. Reduced estrogen levels lead to a variety of disorders, for example, bone loss and reduced movement drive. The objective of this study was to investigate the effects of estrogen on individual voluntary exercise motivation and bone protection. We investigated sham operated, ovariectomized, and ovariectomized with estrogen supplemented Wistar rats (20 weeks old) either with or without access to exercise wheels. We selected an experimental approach where we could monitor the individual exercise of group-housed rats with ad libitum access to a running wheel with the help of a subcutaneous chip. In vivo and ex vivo microcomputed tomography analyses of the tibia were performed at two-week intervals from week 0 to week 6. Furthermore, tibial trabecular structure was evaluated based on histomorphometric analyses. We observed a significant bone protective effect of E2. For exercise performance, a substantially high intra-group variability was observed, especially in the E2 group. We presume that dominant behavior occurs within the group-housed rats resulting in a hierarchical access to the running wheel and a high variability of distance run. Exercise did not prevent ovariectomy-induced bone loss. However, lack of estrogen within the ovariectomized rats led to a drastically reduced activity prevented by estrogen supplementation. Our findings are important for future studies working with group-housed rats and exercise. The reason for the high intra-group variability in exercise needs to be investigated in future studies.

Estrogen replacement attenuates stress-induced pressor responses through vasorelaxation via β2-adrenoceptors in peripheral arteries of ovariectomized rats

We examined whether chronic estrogen replacement has an inhibitory effect on stress-induced pressor responses via activation of β₂-adrenoceptor (AR) in peripheral arteries of ovariectomized rats. Female Wistar rats aged 9 wk were ovariectomized. After 4 wk, pellets containing either 17β-estradiol (E₂) or placebo (Pla) were subcutaneously implanted into the rats. After 4 wk of treatment, rats underwent cage-switch stress, and, in a separate experiment, a subset received an infusion of isoproterenol (ISO) with or without pretreatment with the β₁-AR blocker atenolol or the β₂-AR blocker butoxamine. In addition, the isolated mesenteric artery was used to assess the concentration-related relaxing responses to ISO and the β₁- or β₂-AR mRNA level. The cage-switch stress-induced pressor response was significantly attenuated in the E₂-treated group compared with the Pla-treated group. Pretreatment with atenolol reduced blood pressure responses in both groups. However, butoxamine enhanced the pressor response only in the E₂-treated group, resulting in no difference between the two groups. In addition, the intravenous ISO-induced depressor response was significantly enhanced in the E₂-treated group compared with the Pla-treated group. Furthermore, the difference in the depressor response was abolished by pretreatment with butoxamine but not by atenolol. In the isolated mesenteric artery, butoxamine caused a rightward shift in ISO-induced concentration-related relaxation in the E₂-treated group. The β₂-AR mRNA level in the mesenteric artery was higher in the E₂-treated group than in the Pla-treated group. These results suggest that estrogen replacement attenuated the stress-induced pressor response probably by suppressing vasoconstriction via activation of β₂-ARs in peripheral arteries of ovariectomized rats. NEW & NOTEWORTHY In this study, we show, for the first time, that estrogen replacement has an inhibitory effect on the psychological stress-induced pressor response through vasorelaxation via β₂-adrenoceptors, probably due to overexpression of β₂-adrenoceptor mRNA, in peripheral arteries of ovariectomized rats.

Mechanisms underlying alterations in norepinephrine levels in the locus coeruleus of ovariectomized rats: Modulation by estradiol valerate and black cohosh

Hot flushes are common in menopause. Norepinephrine (NE), primarily synthesized in the locus coeruleus (LC), plays a major role in central thermoregulation. Furthermore, we previously observed decreased dopamine beta hydroxylase (DβH), a key enzyme in NE synthesis, in LC neurons following ovariectomy. In this study, we explore the mechanisms underlying decreased NE levels in the LC (LC-NE) in ovariectomized (OVX) rats, and the modulating effects of estradiol valerate (E2) and black cohosh (ICR). We used high-performance liquid chromatography to detect LC-NE in SHAM, OVX, OVX-E2, and OVX-ICR groups. Western blotting and immunohistochemistry were performed to investigate the expression of NE metabolic enzymes, the NE reuptake transporter (NET), and estrogen receptors (ERs) in the LC. We observed significant LC-NE decreases in the OVX group. E2 and ICR enhanced LC-NE but did not restore them to SHAM levels. Ovariectomy affected NE synthesis, degradation, and reuptake. Levels of NE catabolic enzymes monoamine oxidase A (MAOA) and catechol-O-methyltransferase (COMT) decreased, while NET expression increased. E2 restored MAOA and COMT to SHAM levels but had no effect on NET. ICR restored COMT and NET to SHAM levels but had no effect on MAOA. Moreover, the OVX group also exhibited decreased expression of ERα and ERβ. E2 enhanced the expression of ERα and ERβ, while ICR only enhanced ERβexpression. Taken together, reduced NE in OVX rats resulted from reduced synthesis and increased degradation and reuptake. E2 and ICR may regulate these processes in different ways through various ERs.

Effects of 17β-estradiol on leptin signaling in anterior pituitary of ovariectomized rats

Leptin is secreted predominantly by adipocytes and exerts its role mainly by interaction with the long form of leptin receptor (LEPR_V2). It has been identified that LEPR_V2 is widely distributed in various tissues, including the anterior pituitary. Cross-talk between leptin and estrogens has been indentified. Estrogen is known to modulate the tissue-specific expression of LEPR_V2 and leptin in ovariectomized (OVX) rats, a model of postmenopausal condition. Our previous data showed that 17β-estradiol (E₂) up-regulated the expression of LEPR_V2 protein and mRNA in rat dorsal root ganglion (DRG) in an estrogen receptor alpha (ERα)-dependent manner. But it is still unclear whether estrogen can regulate leptin signalling in the pituitary of OVX rats. In the present study, we found that ovariectomy decreased the expressions of LEPR_V2. Administration of E₂ increased the expressions of LEPR_V2 in a dose-dependent manner. In addition, E₂ improved LEPR_V2, STAT3, and SOCS3 protein levels in OVX rats. The effects of exogenous E₂ were attenuated by ICI 182,780, a specific estrogen receptors antagonist. However, E₂ did not change the Lepr_v1, a type of short form of leptin receptor (LEPR), or leptin mRNA levels. Thus, E₂ plays a crucial role in regulating pituitary sensitivity to leptin in OVX rats. Our findings implied that exogenous E₂ had potential roles in modification of the function of pituitary in postmenopausal women.

Effects of Administration of Amlodipine and Lacidipine on Inflammation-Induced Bone Loss in the Ovariectomized Rat

This study was performed to evaluate the possible protective effect of two calcium channel blocker's "lacidipine (LAC) and amlodipine (AML)" on bone metabolism in an experimental ovariectomized and inflammation-induced osteoporosis rat model (OVXinf). For the purpose of this study, the rats were divided into eight groups, each containing eight rats: sham-operated control (group 1, SH), sham + inflammation (group 2, SHinf), ovariectomy (group 3, OVX), ovariectomy + inflammation (group 4, OVXinf), ovariectomy + LAC 4 mg/kg (group 5, OVX + LAC), ovariectomy + inflammation + LAC 4 mg/kg (group 6, OVXinf + LAC), ovariectomy + AML 5 mg/kg (group 7, OVX + AML), ovariectomy + inflammation + AML 5 mg/kg (group 8, OVXinf + AML). The levels of osteocalcin and osteopontin decreased in OVXinf + LAC and OVXinf + AML groups. The serum levels of TNF-α, IL-1β, and IL-6 were increased significantly in the OVXinf rats compared with the SH group. Gene expression levels of the osteogenic factor runt-related transcription factor 2 (Runx2) and type I collagen 1A1 (Col1A1) significantly decreased in the OVXinf group, when compared with the control group. AML or LAC administrations increased the levels of Runx2 and Col1A1. These results suggest that amlodipine and lacidipine may be a novel therapeutic target for radical osteoporosis treatment in hypertensive patients.

Improvement of neurological disorders in postmenopausal model rats by administration of royal jelly

OBJECTIVE

Royal jelly (RJ) from honeybees (Apis mellifera) has estrogenic activity. Estrogen deficiency after menopause leads to a high risk of memory impairment and depression as well as metabolic syndrome and osteoporosis. We here investigated the effect of RJ on memory impairment and depression-like behaviors in ovariectomized (OVX) rats.

METHODS

OVX rats were administered with RJ for 82 days. Hippocampus-dependent spatial memory and depression-like behaviors were assessed by the Morris water maze test and the forced swimming test, respectively. The weights of body, brain and uterus and the contents of protein and myelin galactolipids including galactosylceramide and sulfatide were measured.

RESULTS

Memory impairment and depression-like behaviors in OVX rats were recovered to the levels of sham-operated rats by RJ administration. Increased body weight and decreased uterine weight in OVX rats were recovered to the levels of sham-operated rats by 17β-estradiol (E2) administration but not by RJ administration. In contrast, brain weight was slightly increased by RJ administration but not by E2 administration. The contents of protein and myelin galactolipids were higher in the brains of RJ-administered OVX rats than in the brains of E2-administered OVX rats.

CONCLUSION

The results suggest that RJ has a beneficial effect on neurological symptoms of a menopausal disorder.

The Natural Substance MS-10 Improves and Prevents Menopausal Symptoms, Including Colpoxerosis, in Clinical Research

Many natural substances were screened to develop nutraceuticals that reduce menopausal symptoms. A complex of Cirsium japonicum var. maackii and Thymus vulgaris extracts, named MS-10, had significant positive effects. Under a low concentration of estrogen, which represents postmenopausal physiological conditions, MS-10 had beneficial effects on estrogen receptor-expressing MCF-7 cells by reversibly enhancing estrogen activity. In addition, in the ovariectomized rat model, changes in bone-specific alkaline phosphatase activity and osteocalcin, as well as low-density lipoprotein cholesterol and triglyceride levels were significantly decreased by MS-10. These results show that MS-10 protected bone health and reduced metabolic disturbances. Furthermore, in a clinical study, all menopausal symptoms, including hot flushes, parenthesis, insomnia, nervousness, melancholia, vertigo, fatigue, rheumatic pain, palpitations, formication, and headache, as well as colpoxerosis, were significantly improved by taking MS-10 for 90 days. Therefore, the evidence supports that MS-10 is an effective natural substance that can safely improve menopausal symptoms, including colpoxerosis.

Electroacupuncture at the governor vessel and bladder meridian acupoints improves postmenopausal osteoporosis through osteoprotegerin/RANKL/RANK and Wnt/β-catenin signaling pathways

Previous studies have demonstrated that pretreatment with electroacupuncture (EA) at the zusanli/ST36 and sanyinjiao/SP6 acupoints prevents ovariectomy-induced osteoporosis in rats; however, the therapeutic effects of EA at the governor vessel (GV) and bladder meridian (BL) acupoints remain unclear. In the present study, the effects of EA at the GV4, GV6, BL20 and BL23 acupoints on the bones of ovariectomized (OVX) rats were investigated to identify the pathways that mediate the action of EA on the bones. A postmenopausal osteoporosis model was established by performing an ovariectomy in six-month-old female Sprague Dawley rats. Following the ovariectomy, EA treatment was administered once per day for 90 days, with an interval of 5 days per 10 days. The changes in the serum levels of estradiol (E2) and the bone turnover markers, osteocalcin (OC) and tartrate-resistant acid phosphatase 5b (TRACP 5b), were determined, while the bone mineral density (BMD) of the lumbar vertebra and the histomorphology of the femur were observed. Furthermore, the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL), which are involved in the OPG/RANKL pathway, were detected by ELISA. In addition, the protein expression levels of low-density lipoprotein receptor-related protein (LRP) 5, β-catenin and runt-related transcription factor (Runx) 2, which are involved in the Wnt/β-catenin signaling pathway, were detected by western blot analysis. The results revealed that the GV and BL EA treatment groups significantly increased the serum levels of E2 and OC, decreased the serum levels of TRACP 5b and increased the BMD of the lumbar vertebra when compared with the OVX group. With regard to the histomorphology of the bone tissue, an ordered arrangement and a slight thinning of the trabeculae, with no evident hairline fractures, was observed in the femurs following EA treatment in the OVX rats. Furthermore, histomorphological analysis revealed that EA treatment significantly increased the values of the bone histomorphometry indices, trabecular area percentage, trabecular thickness and trabecular number, and reduced the value of trabecular separation, as compared with the OVX group. In addition, the ratio of OPG/RANKL expression was significantly upregulated, and the expression levels of LRP5, β-catenin and Runx2 were significantly upregulated in the EA treatment groups. Therefore, these results demonstrated that long-term stimulation with EA treatment at the GV and BL acupoints was able to alleviate osteoporosis induced by an ovariectomy through regulating the OPG/RANKL and Wnt/β-catenin signaling pathways.

Reciprocal regulation of adipocyte and osteoblast differentiation of mesenchymal stem cells by Eupatorium japonicum prevents bone loss and adiposity increase in osteoporotic rats

Pathological increases in adipogenic potential with decreases in osteogenic differentiation occur in osteoporotic bone marrow cells. Previous studies have shown that bioactive materials isolated from natural products can reciprocally regulate adipogenic and osteogenic fates of bone marrow cells. In this study, we showed that Eupatorium japonicum stem extracts (EJE) suppressed lipid accumulation and inhibited the expression of adipocyte markers in multipotent C3H10T1/2 and primary bone marrow cells. Conversely, EJE stimulated alkaline phosphatase activity and induced the expression of osteoblast markers in C3H10T1/2 and primary bone marrow cells. Daily oral administration of 50 mg/kg of EJE for 6 weeks to ovariectomized rats prevented body weight increase and bone mineral density decrease. Finally, activity-guided fractionation led to the identification of coumaric acid and coumaric acid methyl ester as bioactive anti-adipogenic and pro-osteogenic components in EJE. Taken together, our data indicate a promising possibility of E. japonicum as a functional food and as a therapeutic intervention for preventing osteoporosis and bone fractures.

The effects of different exercise modes for preventing endothelial dysfunction of arteries and bone loss in ovariectomized rats

[Purpose]

Several epidemiological studies have demonstrated that there are positive correlations between vascular disorders and bone loss in postmenopausal women. The aim of the present study was to examine the effect of different types of exercise (e.g., climbing and swimming) for preventing endothelial dysfunction of arteries and bone loss in ovariectomized rats.

[Methods]

Twenty Sprague-Dawley female rats were randomly divided into three groups: ovariectomy (OVX) plus treatment with vitamin D₃ and nicotine (VDN) (control rats [Con], n = 7), which is an animal model for endothelial dysfunction and bone loss; voluntary climbing resistance exercise with OVX plus VDN (climbing rats [Clim], n = 6), and swimming exercise with OVX plus VDN (swimming rats [Swim], n = 7). The period of exercise training was 8 weeks.

[Results]

The endothelin-1 (ET-1) protein levels were significantly lower in the Clim and Swim groups than in the Con. The endothelial nitric oxide synthase protein levels were significantly higher in the Swim group than in the Con, but they did not differ between the Clim and Con groups. The cortical bone mineral density in the tibia and breaking energy of the femur were significantly higher in the Clim group than in the Con, but this positive effect was not seen in the Swim group.

[Conclusion]

Voluntary climbing exercise decreased arterial ET-1 protein levels and prevented bone loss in a postmenopause-model rat combining OVX and VDN. Conversely, swimming suppressed endothelial dysfunction of the arteries but did not prevent bone loss. Thus, the type of exercise should be cautiously chosen for enhancing vascular function and bone status, especially in females after menopause.

17β-Estradiol alters the response of subfornical organ neurons that project to supraoptic nucleus to plasma angiotensin II and hypernatremia

This study was done in urethane anesthetized, ovariectomized (OVX) female rats that were either implanted or not implanted with silastic capsules containing17β-estradiol (E2) to investigate the effect of systemic changes in E2 on the discharge rate of subfornical organ (SFO) neurons that projected to supraoptic nucleus (SON) and responded to changes in plasma levels of angiotensin II (ANG II) or hypernatremia. Extracellular single unit recordings were made from 146 histologically verified single units in SFO. Intra-carotid infusions of ANG II excited ~57% of these neurons, whereas ~23% were excited by hypertonic NaCl. Basal discharge rate of neurons excited by ANG II or hypertonic NaCl was significantly lower in OVX+E2 rats compared to OVX only animals. The response of SFO neurons antidromically activated by SON stimulation to intra-carotid injections of ANG II or hypertonic NaCl was greater in the OVX only compared to the OVX+E2 rats. Intra-carotid injections of E2 in either group attenuated not only the basal discharge of these neurons, but also their response to ANG II or hypertonic NaCl. In all cases this inhibitory effect of E2 was blocked by an intra-carotid injection of the E2 receptor antagonist ICI-182780, although ICI-182780 did not alter the neuron's response to ANG II or hypertonic NaCl. Additionally, ICI-182780 in the OVX+E2 animals significantly raised the basal discharge of SFO neurons and their response to ANG II or hypertonic NaCl. These data indicate that E2 alters the response of SFO neurons to ANG II or NaCl that project to SON, and suggest that E2 functions in the female to regulate neurohypophyseal function in response to circulating ANG II and plasma hypernatremia.

Identification of a vibration regime favorable for bone healing and muscle in estrogen-deficient rats

Numerous whole-body vibration (WBV) devices of various forces are available on the market, although their influence on the musculoskeletal system is not yet understood. The effect of different WBVs on bone healing and muscle function was evaluated in rats ovariectomized at 3 months of age. 2 months after ovariectomy, bilateral metaphyseal tibia osteotomy and T-plate osteosynthesis were performed. Rats were divided into groups: intact, OVX, and OVX exposed to vertical WBVs of 35, 50, 70, or 90 Hz (experiment 1) or horizontal WBVs of 30, 50, 70, or 90 Hz (experiment 2) 5 days after osteotomy (0.5 mm, 15 min/day for 30 days). The tibia and gastrocnemius and soleus muscles were collected. Vertical vibrations (>35 Hz) improved cortical and callus densities, enlarged callus area and width, suppressed the tartrate-resistant acid phosphatase gene, enhanced citrate synthase activity, accelerated osteotomy bridging (35 and 50 Hz), upregulated the osteocalcin (Oc) gene (70 Hz), and increased relative muscle weight (50 Hz). Horizontal vibrations reduced cortical width (<90 Hz) and callus density (30 Hz), enhanced alkaline phosphatase (Alp) gene expression (50 Hz), decreased the size of oxidative fibers (35 and 70 Hz), and increased capillary density (70, 90 Hz). Biomechanical data; serum Oc, Alp, and creatine kinase activities; body weight; and food intake did not change after WBVs. Vertical WBVs of 35 and 50 Hz produced more favorable results than the higher frequencies. Horizontal WBV showed no positive or negative effects. Further studies are needed to elucidate the effects of WBV on different physiological systems, and precautions must be taken when implementing WBV in the treatment of patients.

Increased variability of bone tissue mineral density resulting from estrogen deficiency influences creep behavior in a rat vertebral body

Progressive vertebral deformation increases the fracture risk of a vertebral body in the postmenopausal patient. Many studies have observed that bone can demonstrate creep behavior, defined as continued time-dependent deformation even when mechanical loading is held constant. Creep is a characteristic of viscoelastic behavior, which is common in biological materials. We hypothesized that estrogen deficiency-dependent alteration of the mineral distribution of bone at the tissue level could influence the progressive postmenopausal vertebral deformity that is observed as the creep response at the organ level. The objective of this study was thus to examine whether the creep behavior of vertebral bone is changed by estrogen deficiency, and to determine which bone property parameters are responsible for the creep response of vertebral bone at physiological loading levels using an ovariectomized (OVX) rat model. Correlations of creep parameters with bone mineral density (BMD), tissue mineral density (TMD) and architectural parameters of both OVX and sham surgery vertebral bone were tested. As the vertebral creep was not fully recovered during the post-creep unloading period, there was substantial residual displacement for both the sham and OVX groups. A strong positive correlation between loading creep and residual displacement was found (r=0.868, p<0.001). Of the various parameters studied, TMD variability was the parameter that best predicted the creep behavior of the OVX group (p<0.038). The current results indicated that creep caused progressive, permanent reduction in vertebral height for both the sham and OVX groups. In addition, estrogen deficiency-induced active bone remodeling increased variability of trabecular TMD in the OVX group. Taken together, these results suggest that increased variability of trabecular TMD resulting from high bone turnover influences creep behavior of the OVX vertebrae.

Musculoskeletal response to whole-body vibration during fracture healing in intact and ovariectomized rats

This study investigated the effect of vibration on bone healing and muscle in intact and ovariectomized rats. Thirty ovariectomized (at 3 months of age) and 30 intact 5-month old female Sprague-Dawley rats underwent bilateral metaphyseal osteotomy of tibia. Five days later, half of the ovariectomized and of the intact rats were exposed to whole-body vertical vibration (90 Hz, 0.5 mm, 4 x g acceleration) for 15 min twice a day during 30 days. The other animals did not undergo vibration. After decapitation of rats, one tibia was used for computed tomographic, biomechanical, and histological analyses; the other was used for gene expression analyses of alkaline phosphatase (Alp), osteocalcin (Oc), tartrate-resistant acid phosphatase 1, and insulinlike growth factor 1. Serum Alp and Oc were measured. Mitochondrial activity, fiber area and distribution, and capillary densities were analyzed in M. gastrocnemius and M. longissimus. We found that vibration had no effect on body weight and food intake, but it improved cortical and callus densities (97 vs. 99%, 72 vs. 81%), trabecular structure (9 vs. 14 trabecular nodes), blood supply (1.7 vs. 2.1 capillaries/fiber), and oxidative metabolism (17 vs. 23 pmol O(2)/s/mg) in ovariectomized rats. Vibration generally increased muscle fiber size. Tibia biomechanical properties were diminished after vibration. Oc gene expression was higher in vibrated rats. Serum Alp was increased in ovariectomized rats. In ovariectomized rats, vibration resulted in an earlier bridging; in intact rats, callus bridging occurred later after vibration. The chosen vibration regimen (90 Hz, 0.5 mm, 4 x g acceleration, 15 min twice a day) was effective in improving musculoskeletal tissues in ovariectomized rats but was not optimal for fracture healing.

Curcuma comosa improves learning and memory function on ovariectomized rats in a long-term Morris water maze test

AIM OF THE STUDY

Curcuma comosa extract and some purified compounds from this plant have been reported to have estrogenic-like effects, and estrogen improves learning in some animals and potentially in postmenopausal women; therefore, this study tested the hypothesis that Curcuma comosa and estrogen have similar beneficial effects on spatial learning and memory.

MATERIALS AND METHODS

Curcuma comosa hexane extract, containing 0.165 mg of (4E,6E)-1,7-diphenylhepta-4,6-dien-3-one per mg of the crude extract, was orally administered to ovariectomized Wistar rats at the doses of 250 or 500 mg/kg body weight. 17beta-estradiol (10 microg/kg body weight, subcutaneously) was used as a positive control. Thirty days after the initiation of treatment, animals were tested in a Morris water maze for spatial learning and memory. They were re-tested every 30 days and a final probe trial was run on day 119.

RESULTS

Compared to control rats, OVX rats displayed significant memory impairment for locating the platform in the water maze from day 67 after the surgery, onward. In contrast, OVX rats treated with either Curcuma comosa or estrogen were significantly protected from this decline in cognitive function. Further, the protection of cognitive effects by Curcuma comosa was larger at higher dose.

CONCLUSIONS

These results suggest that long-term treatment with Curcuma comosa has beneficial effects on learning and memory function in rats.

Role of 5-HT(1A) receptors in fluoxetine-induced lordosis inhibition

The selective serotonin reuptake inhibitor (SSRI), fluoxetine (Prozac(R)), is an effective antidepressant that is also prescribed for other disorders (e.g. anorexia, bulimia, and premenstrual dysphoria) that are prevalent in females. However, fluoxetine also produces sexual side effects that may lead patients to discontinue treatment. The current studies were designed to evaluate several predictions arising from the hypothesis that serotonin 1A (5-HT(1A)) receptors contribute to fluoxetine-induced sexual dysfunction. In rodent models, 5-HT(1A) receptors are potent negative modulators of female rat sexual behavior. Three distinct experiments were designed to evaluate the contribution of 5-HT(1A) receptors to the effects of fluoxetine. In the first experiment, the ability of the 5-HT(1A) receptor antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY100635), to prevent fluoxetine-induced lordosis inhibition was examined. In the second experiment, the effects of prior treatment with fluoxetine on the lordosis inhibitory effect of the 5-HT(1A) receptor agonist, (+/-)-8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT), were studied. In the third experiment, the ability of progesterone to reduce the acute response to fluoxetine was evaluated. WAY100635 attenuated the effect of fluoxetine; prior treatment with fluoxetine decreased 8-OH-DPAT's potency in reducing lordosis behavior; and progesterone shifted fluoxetine's dose-response curve to the right. These findings are consistent with the hypothesis that 5-HT(1A) receptors contribute to fluoxetine-induced sexual side effects.

In vitro and in vivo effect of parathyroid hormone analogue (1-14) containing -amino-iso-butyric acid residue (Aib)1,3

Firstly, parathyroid hormone (1-14) [PTH (1-14)] analogue containing various -amino-iso-butyric acid residue (Aib) was synthesized by exchanging the 1st and 3rd Ala residues of alpha carbon of PTH (1-14). This analogue revealed to have the quite tight and stable -helical structure using the nuclear magnetic resonance (NMR) analysis. The biological activities of these analogues were examined using a cAMP- generating assay in LLC-PK1 cell lines stably transfected with the wild- type human PTH1 receptor. Only the PTH analogue substituted with methyl moiety without acetylation showed significant cAMP generating action with 15.0 +/- 3.414 of EC50. Then, we used an ovariectomized rat model system to compare the in vivo effects of parathyroid hormone analogue with that of PTH (1-84). Daily subcutaneous administration of the unacetylated Aib1,3PTH (1-14) for 5 weeks in 30 nM/kg subcutaneously with positive control group receiving PTH (1-84) with 8 nM/ kg were performed. However, there was no significant change in spinal or femoral bone mineral density assessed by dual x-ray absorptiometry (DXA) in the Aib1,3PTH (1-14) group where definite increase of these parameters shown in the PTH (1-84) group (p < 0.001). Assessment of bone strength was evaluated with no significant differences among all groups. It was quite disappointing to see the actual discrepancies between the result of significant pharmacokinetic potency and the in vivo clinical effect of the Aib1,3PTH (1-14). However, there are several limitations to mention, such as the short duration of treatment, matter of dosage, and insufficient effect of tight -helical structures with absence of C-terminus. In conclusion, our findings suggest that unacetylated Aib1,3PTH (1-14) did not exhibit any anabolic effects at the bones of ovariectomized rats.

The osteoprotective effect of Herba epimedii (HEP) extract in vivo and in vitro

Herba epimedii (HEP) is one of the most frequently used herbs prescribed for treatment of osteoporosis in China. In the present study, the in vivo effects of HEP extract on bone metabolism were evaluated using 4-month-old ovariectomized (OVX) or sham-operated (Sham) female Sprague-Dawley rats orally administered with HEP extract (110 mg kgd), 17ss-estrogen (2 mg kgd) or its vehicle for 3 months. HEP extract significantly decreased urinary calcium excretion, suppressed serum alkaline phosphatase (ALP) activity and urinary deoxypyridinoline levels in OVX rats (P < 0.05 versus vehicle-treated OVX rats). Histomorphometric analysis indicated that HEP extract could prevent OVX-induced bone loss by increasing tibial trabecular bone area and decreasing trabecular separation in OVX rats (P < 0.05 versus vehicle-treated OVX group). The in vitro effects of HEP extract were also studied using rat osteoblast-like UMR 106 cells. HEP extract significantly stimulated cell proliferation in a dose-dependent manner (P < 0.01 versus vehicle-treated) and increased ALP activity at 200 microgml (P < 0.01 versus vehicle-treated) in UMR 106 cells. It modulated osteoclastogenesis by increasing osteoprotegrin (OPG) mRNA and decreasing receptor activator of NF-kappaB ligand (RANKL) mRNA expression, resulting in a dose-dependent increase in OPG/RANKL mRNA ratio (P < 0.01 versus vehicle-treated). Taken together, HEP treatment can effectively suppress the OVX-induced increase in bone turnover possibly by both an increase in osteoblastic activities and a decrease in osteoclastogenesis. The present study provides the evidence that HEP can be considered as a complementary and alternative medicine for treatment of post-menopausal osteoporosis.