Osteoporosis In Ovariectomized Rats Research Articles

Anti-osteoporosis activity of red yeast rice extract on ovariectomy-induced bone loss in rats.

Osteoporosis is the most common bone disease, affecting millions of people worldwide and leading to significant morbidity and high costs. Monacolin K, an extract of red yeast rice (RYR, Hongqu), plays important roles in the management of dyslipidemia, coronary heart disease, and diabetes. Our study aimed to investigate the protective effect of monacolin K on ovariectomy-induced bone loss in rats. Fifty female Sprague-Dawley rats were randomly divided into a sham-operated and five ovariectomized (OVX) groups: OVX with vehicle, OVX with fluvastatin, and OVX with RYR extract of three graded doses. Bone mineral density (BMD), biochemical markers, and cell viability were analyzed by dual energy X-ray absorptiometry, enzyme-linked immunosorbent assay, and 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Gene expression was evaluated by real-time polymerase chain reaction amplification and western blot. Our results showed that administration of RYR extract markedly increased the bone mineral density in OVX rats. Moreover, RYR extract decreased the levels of bone turnover markers, including osteocalcin and tartrate resistant acid phosphatase activity. The MMT assay revealed that RYR extract treatment significantly improved the osteoblast viabilities in a dose-dependent manner (P < 0.05). At the molecular level, we further demonstrated that RYR extract enhanced the expression of Bmp2 and Bmp4 both at the mRNA and protein levels. Collectively, these data suggested RYR extract could protect against osteoporosis in ovariectomized rats, most likely through activation of BMP2/4 expression.

Estrogen Deficiency-Associated Bone Loss in the Maxilla: A Methodology to Quantify the Changes in the Maxillary Intra-radicular Alveolar Bone in an Ovariectomized Rat Osteoporosis Model.

The effects of estrogen deficiency on bone characteristics are site-dependent, with the most commonly studied sites being appendicular long bones (proximal femur and tibia) and axial bones (vertebra). The effect on the maxillary and mandibular bones is still inconsistent and requires further investigation. This study was designed to evaluate bone quality in the posterior maxilla of ovariectomized rats to validate this site as an appropriate model to study the effect of osteoporotic changes. Forty-eight 3-month-old female Sprague-Dawley rats were randomly divided into two groups: an ovariectomized (OVX) group (n=24) and Sham-operated (SHAM) group (n=24). Six rats were randomly sacrificed from both groups at time points 8, 12, 16, and 20 weeks. The samples from tibia and maxilla were collected for micro computed tomography (μCT) and histological analysis. For the maxilla, the volume of interest area focused on the furcation areas of the first and second molar. Trabecular bone volume fraction (BV/TV, %), trabecular thickness (Tb.Th.), trabecular number (Tb.N.), trabecular separation (Tb.Sp.), and connectivity density (Conn.Dens) were analyzed after Micro CT scanning. At 8 weeks the indices BV/TV, Tb.Sp., Tb.N., and Conn.Dens showed significant differences (p<0.05) between the OVX and SHAM groups in the tibia. Compared with the tibia, the maxilla developed osteoporosis at a later stage, with significant changes in maxillary bone density only occurring after 12 weeks. Compared with the SHAM group, both the first and second molars of the OVX group showed significantly decreased BV/TV values from 12 weeks, and these changes were sustained through 16 and 20 weeks. For Tb.Sp., there were significant increases in bone values for the OVX group compared with the SHAM group at 12, 16, and 20 weeks. Histological changes were highly consistent with Micro CT results. This study established a method to quantify the changes of intra-radicular alveolar bone in the posterior maxilla in an accepted rat osteoporosis model. The degree of the osteoporotic changes to trabecular bone architecture is site-dependent and at least 3 months are required for the osteoporotic effects to be apparent in the posterior maxilla following rat OVX.

The effects of Cordyceps sinensis phytoestrogen on estrogen deficiency-induced osteoporosis in ovariectomized rats.

BackgroundIsoflavones are naturally occurring plant chemicals belonging to the “phytoestrogen” class. The aim of the present study was to examine the effects of isoflavones obtained from Cordyceps sinensis (CSIF) on development of estrogen deficiency-induced osteoporosis in ovariectomized rats.MethodsAfter the rats were treated orally with CSIF, serum alkaline phosphatase (ALP), tartarate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY), C-terminal crosslinked telopeptides of collagen type I (CTX), estradiol and interferonγ (IFN-γ) level were examined. At the same time, the urine calcium, plasma calcium, plasma phosphorus and the mass of uterus, thymus and body were also examined.ResultsThe beneficial effects of CSIF on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, CTX level and IFN-γ level. At the same time, CSIF also increase the OC and estradiol level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary CSIF can prevent bone loss caused by estrogen deficiency.ConclusionThe significant estrogenic activity of CSIF demonstrated that CSIF has significant estrogenic effects in OVX rats.

Effects of nanopowdered eggshell on postmenopausal osteoporosis: a rat study

The preventive effects of nanopowdered eggshell (NPES) on postmenopausal osteoporosis in ovariectomized rats was studied. Rats fed NPES and powdered eggshell (PES) exhibited 6.6 and 2.2% greater bone mineral densities (BMD) than ovariectomized (OVX) rats. NPES administration resulted in greater bone stiffness than PES. Investigation of the trabecular bone in NPES fed rats revealed a 12.4% higher bone volume (BV/TV), 7.5% higher trabecular number (Tb.N.), and 14.5% lower trabecular separation (Tb.Sp.), compared with OVX rats. Serum analysis demonstrated that NPES fed rats showed a significantly (p<0.05) higher (22.4%) osteocalcin level than OVX rats. Urine analyses in NPES fed rats revealed 43.7% lower deoxypyridinoline (DPD) and 87% lower Nteleopeptide levels of type I collagen (NTX) than in OVX rats. NPES attenuated the bone loss induced by ovariectomy in rats.

Rabbiteye blueberry prevents osteoporosis in ovariectomized rats.

ObjectiveIt has been forecasted that the rabbiteye blueberry could inhibit osteoporosis. However, the inhibition and prevention of osteoporosis via rabbiteye blueberry are still elusive. This study was aim to evaluate the anti-osteoporosis effects of rabbiteye blueberry in ovariectomized rats.MethodsThirty rats were randomly divided into three groups of ten rats each as follows: sham-operated group (SG), ovariectomized model control group (OMG), and ovariectomized rabbiteye blueberry treatment group (OBG). The blood mineral levels, the alkaline phosphatase (ALP) activity, and osteoprotegerin (OPG) level were determined. The expression analyses of type I collagen, integrin-β1, and focal adhesion kinase (FAK) were performed. Besides, the bone mineral density (BMD) and bone histomorphometry (BH) were measured.ResultsThe ALP activity in SG and OBG was significantly lower than that in OMG. For the OPG level, the significant increase of OPG level in OBG was indicated compared with the other groups. The mRNA expression levels of type I collagen, integrin-β1, and FAK in OMG were significantly lower than those in other groups. The BMD in OMG were all significantly lower than those in SG and OBG. For BH, blueberry significantly improved the trabecular bone volume fraction, trabecular thickness, mean trabecular bone number, and bone formation rate, and decreased the trabecular separation, the percent of bone resorption perimeter, and mean osteoclast number in OBG compared with OMG.ConclusionsThe rabbiteye blueberries had an effective inhibition in bone resorption, bone loss, and reduction of bone strength of ovariectomized rats and could improve the BMD, osteogenic activity, and trabecular bone structure.

Short-term glucocorticoid treatment causes spinal osteoporosis in ovariectomized rats.

In humans, glucocorticoid-induced osteoporosis is the most common cause of medication-induced osteoporosis. Recent clinical data suggest that glucocorticoid therapy increases the risk of vertebral fractures within a short treatment period. Therefore, this study aimed at investigating vertebral bone in a rat model of glucocorticoid-induced postmenopausal osteoporosis. Fifty Sprague-Dawley rats were randomly assigned into three groups: 1) untreated controls, 2) Sham-operated group, and 3) ovariectomized rats treated with glucocorticoid (dexamethasone) for 3 months (3M) after recovery from bilateral ovariectomy. Osteoporotic bone status was determined by means of the gold standard dual energy X-ray absorptiometry (DEXA) scan. Vertebral bodies were examined using µCT, histological analysis, mRNA expression analysis, and biomechanical compression testing. Further systemic effects were studied biochemically using serum marker analysis. Dexamethasone treatment showed at 3M a significantly lower bone mineral density in ovariectomized rats compared to Sham-operated control (p < 0.0001) as analyzed in vivo by DEXA. Furthermore, Z scores reached levels of -5.7 in the spine indicating sever osteoporotic bone status. Biomechanical testing of compression stability indicated a lower functional competence (p < 0.0001) in the spine of treated rats. µCT analysis showed significant reduction of bone volume density (BV/TV%; p < 0.0001), significantly enhanced trabecular spacing (Tb.Sp; p < 0.0001) with less trabecular number (Tb.N; p < 0.001) and complete loss of trabecular structures in glucocorticoid-treated ovariectomized rats. Histological analysis by osteoblast and osteoclast activities reflected a higher bone catabolism reflected by osteoclast counts by TRAP (p < 0.019) and lower bone catabolism indicated by ALP-stained area (p < 0.035).Serum analysis showed a significant increase in osteocalcin (p < 0.0001), osteopontin (p < 0.01) and insulin (p < 0.001) at 3M. Expression analysis of molecular markers in the vertebral body revealed lower expression in tenascin C in the OVX-steroid animals at 3M. Short-term glucocorticoid treatment of ovariectomized rats indicates according to DEXA standards a severe osteoporotic bone status in vertebral bone. Nonetheless, dysfunctional bone anabolism and enhanced bone catabolism are observed. Alterations of bone extracellular matrix proteins that correlate to inferior mechanical stability and affected microstructure were noticed and suggest further investigation. Treatment with dexamethasone was also seen to affect insulin and osteopontin levels and thus osteoblast function and maturation. This described animal model presents a recapitulation of clinically obtained data from early phase glucocorticoid-induced osteoporosis observed in patients.

Effect of Morinda officinalis capsule on osteoporosis in ovariectomized rats

AimTo explore the therapeutic effects of Morinda officinalis capsules (MOP) on osteoporosis in ovariectomized rats. MethodsSix-month-old female Sprague–Dawley rats were induced for postmenopausal osteoporosis (PMOP) by bilateral ovariectomy and divided into seven groups as follows: sham-operated group, ovariectomized (OVX) control group, OVX treated with xianlinggubao (XLGB) (270 mg·kg−1·d−1), OVX treated with alendronate sodium (ALN) (3 mg·kg−1·d−1), and OVX treated with Morinda officinalis capsule (MOP) of graded doses (90, 270 and 810 mg·kg−1·d−1) groups. Oral treatments were administered daily on the 4th week after ovariectomy and lasted for 12 weeks. The bone mineral density was evaluated by dual-energy X-ray absorptiometry. The tartrate-resistant acid phosphatase (TRAP), alkaline phosphatase (AKP), and osteocalcin (OC) levels in the serum and plasma were determined by standard colorimetric and enzyme immunoassays methods. Bone biomechanical properties and morphological parameters were analyzed by three-point bending test and histomorphometry respectively. ResultsMorinda officinalis capsules at all doses were able to significantly prevent the OVX-induced loss of bone mass due to diminishing serum AKP and TRAP levels while elevating OC level in the plasma. Morinda officinalis capsules also enhanced the bone strength and prevented the deterioration of trabecular microarchitecture. ConclusionMorinda officinalis capsules possess potent anti-osteoporotic activity in OVX rats which could be an effective treatment for postmenopausal osteoporosis.

Nigella Sativa reverses osteoporosis in ovariectomized rats

BackgroundOsteoporosis poses a significant public health issue. It is a skeletal disorder characterized by compromised bone strength that predisposes to increased risk of fracture. There is a direct relationship between the lack of estrogen after menopause and the development of osteoporosis. About 33% of women over 50 will experience bone fractures as a result of osteoporosis. Nigella Sativa (NS) has been shown to have beneficial effects on bone and joint diseases. The present study was conducted to elucidate the protective effect of Nigella Sativa on osteoporosis produced by ovariectomy in rats.MethodsFemale Wistar rats aged 12–14 months were divided into three groups: sham-operated control (SHAM), ovariectomized (OVX), and ovariectomized supplemented with nigella sativa (OVX-NS) orally for 12 weeks; 4 weeks before ovariectomy and 8 weeks after. After 12 weeks, plasma levels of calcium (Ca+2), phosphorous (Pi), alkaline phosphatase (ALP), amino terminal collagen type 1 telopeptide, malondialdehyde (MDA), nitrates, nitric oxide surrogate, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured. Histological examination of the liver and the tibia was conducted. Histomorphometric analysis of the tibia was also performed.ResultsOVX rats showed significant decrease in plasma Ca+2, accompanied by a significant increase in plasma ALP, amino terminal collagen type 1 telopeptide, MDA, nitrates, TNF-α and IL-6. These changes were reversed by NS supplementation in OVX-NS group to be near SHAM levels. Histological examination of the tibias revealed discontinuous eroded bone trabeculae with widened bone marrow spaces in OVX rats accompanied by a significant decrease in both cortical and trabecular bone thickness compared to Sham rats. These parameters were markedly reversed in OVX-NS rats. Histological examination of the liver showed mononuclear cellular infiltration and congestion of blood vessels at the portal area in OVX rats which were not found in OVX-NS rats.ConclusionNigella sativa reverses osteoporosis in ovariectomized rats, which could be attributed to its high content of unsaturated fatty acids as well as its antioxidant and anti-inflammatory properties.

Effect of diets fortified with Nigella sativa, sesame seeds and high calcium on osteoporosis in ovariectomized rats

Effect of diets fortified with Nigella sativa, sesame seeds and high calcium on osteoporosis in ovariectomized rats

Experimental study on effect of anhydroicaritin phytosomes in preventing and treating bone loss and enhancing bone quality in ovariectomized osteoporosis rats

To explore the effect of anhydroicaritin phytosomes (AIP) in preventing and treating bone loss and enhancing bone quality in ovariectomized osteoporosis rats. Seventy-two SD female rats were randomly divided into 6 groups: the sham group, the model group, the estrogen group and AIP groups (low, middle, high). The sham group was only sham operated, and the remaining five groups were ovariectomized. One week after the ovariectomy, the rats were given 17 beta-estrogen and AIP (15, 30, 60 mg x kg(-1)) for consecutively three months, during which period their serum calcium (s-Ca), serum phosphorus(s-P), alkaline phosphate (ALP), urine calcium (u-Ca), urine phosphorus(u-P), urinary deoxypyridinoline (D-Pyr) and creatinine (Cr) were detected. Subsequently, rats were sacrificed, and their thighbone, second lumbar vertebrate and forth lumbar vertebrate were collected to detect bone mineral density (BMD), bone calcium (b-Ca) and phosphorus (b-P), biomechanical properties and bone histomorphometric parameters. Compared with the sham group, the model group showed a significant increase in serum ALP, u-Ca and D-Pyr /Cr, and reduction in BMD of femur, b-Ca and b-P, biomechanical properties (elastic load, maximum load, break load, stiffness), static parameters (total tissue area, trabecular area, trabecular perimeter) and dynamic parameters (% L Pm, BFR/BV and BFR/ TV), with metratrophia. Compared with the model group, ALP high and middle-dose groups and the estrogen group showed a decrease in serum ALP, u-Ca and D-Pyr/Cr, and growth in BMD of femur, b-Ca and b-P, biomechanical properties of the forth lumbar vertebrae (elastic load, maximum load, break load, stiffness), static parameters (total tissue area, trabecular area, trabecular perimeter) and dynamic parameters (% L Pm, BFR/BV and BFR/TV). The beta-estrogen group showed endometrial hyperplasia, whereas AIP groups showed no hyperplastic change. AIP could inhibit enhanced bone turnover induced by ovariectomy, improve BMD the biomechanical properties of vertebrae, without any stimulation on uterus.

Role of recombinant plasmid pEGFP-N1-IGF-1 transfection in alleviating osteoporosis in ovariectomized rats

Decreased levels of serum insulin-like growth factor-1 (IGF-1) have been proven to cause osteoporosis. Gene transfer of IGF-1 offers an attractive technology to treat skeletal metabolic disorders including osteoporosis, but the viral vectors are limited by their high antigenicity and immune response. Our purpose was to investigate the expression of a non-invasive vector, recombinant plasmid enhanced green fluorescent protein-N1 (pEGFP-N1) that transferred IGF-1 gene into ovariectomized (OVX) rats in vivo and evaluate the effect of this therapy on osteoporosis. OVX or sham operations were performed in 60 female, 7-month-old unmated SD rats. 12 weeks after OVX operation, the vectors were transfected to the 10-month-old rats and experimental data were detected from 48 h to 7 week after transfection. Our results showed that remarkable expression of fluorescence and serum IGF-1 was observed in the rats transfected by recombinant plasmids, indicating that IGF-1 gene was successfully transferred to OVX rats by injecting the vector through hydrodynamic method via the tail vein. The bone metabolism index including serum alkaline phosphatase, the histomorphometric parameters of lumbar vertebra including trabecular area percentage, trabecular thickness, trabecular number and trabecular separation, and the bone mineral density (BMD) and biomechanical parameters of lumbar vertebra including BMD, maximum condensing force, crushing strength in OVX rats transfected by pEGFP-N1-IGF-1 were improved remarkably compared with OVX+pEGFP-N1 rats, indicating that the transfection of recombinant plasmid pEGFP-N1-IGF-1 played a significant role in alleviating osteoporosis in rats induced by OVX. This encouraged a potential approach of IGF-1 gene therapy to the treatment of osteoporosis.

Alleviating anastrozole induced bone toxicity by selenium nanoparticles in SD rats

Aromatase inhibitors like anastrozole play an undisputed key role in the treatment of breast cancer, but on the other hand, various side effects like osteoporosis and increased risk of bone fracture accompany the chronic administration of these drugs. Here we show for the first time that selenium nanoparticles, when given in conjugation to anastrozole, lower the bone toxicity caused by anastrozole and thus reduce the probable damage to the bone. Selenium nanoparticles at a dose of 5μg/ml significantly reduced the cell death caused by anastrozole (1μM) in HOS (human osteoblast) cells. In addition, our results also highlighted that in female SD rat model, SeNPs (0.25, 0.5, 1mg/kg/day) significantly prevented the decrease in bone density and increase in biochemical markers of bone resorption induced by anastrozole (0.2mg/kg/day) treatment. Histopathological examination of the femurs of SeNP treated group revealed ossification, mineralization, calcified cartilaginous deposits and a marginal osteoclastic activity, all of which indicate a marked restorative action, suggesting the protective action of the SeNPs. Interestingly, SeNPs (1mg/kg/day) also exhibited protective effect in ovariectomized rat model, by preventing osteoporosis, which signifies that bone loss due to estrogen deficiency can be effectively overcome by using SeNPs.

Effects of different extracts of kanggushu (抗骨疏) on osteoporosis in model rats and the underlying mechanisms

To investigate the preventive effects and possible underlying mechanism of different extracts of Kanggushu () on osteoporosis in ovariectomized rats. One hundred and sixtyfive female SD rats were divided into 11 groups: control, sham, model, Xianling Gubao Capsule (), nilestriol, Kanggushu aqueous extract high-, medium-, and low-dose and suet extract high-, medium-, and low-dose groups. The osteoporosis model was made by ovariectomizing the rats. The latter 8 groups were administered intragastricly with Xianling Gubao Capsule, nilestriol, Kanggushu aqueous extract and suet extract for 12 weeks, respectively, while the other 3 groups were administered orally saline. The whole body bone mineral density, bone mineral content, organ coefficient of uterus, serum estradiol and alkaline phosphatase contents, blood calcium, phosphorus, interleukin 6 and bone Gla-protein levels after treatment were monitored. Additionally, three-point bending test of femur, HE staining, and scanning electron microscope were performed to explore the pharmacodynamics and underlying mechanisms. In comparison with ovariectomized rats of model group, Kanggushu aqueous extract high-dose resulted in an increased bone mineral density, bone mineral content and organ coefficient of uterus, improved estradiol level, and improved maximum load and structural stiffness (P<0.05 or P<0.01). Two-dimensional and three-dimensional trabecular structure was also observed under HE staining and scanning electron microscopy, and the number and thickness of trabecular bone in Kanggushu aqueous extract high-dose group was significantly increased compared to the model group, while the lipid droplets in bone marrow cavity were significantly less. However, there were no significant differences in blood calcium, total serum alkaline phosphatase and bone Gla protein among different treatment groups. Overall, the osteoprotective effects of Kanggushu aqueous extract were comparable to those of nilestriol and were significantly more effective than those of Xianling Gubao Capsule. The preventive effects of Kanggushu aqueous extract might be partly due to the increased estradiol level, accelerated restoration of bone trabecular reticulate structure, and accordingly increased bone mineral density in osteoporosis rats.

Effects of fermented black soybean pulp on lipid and bone metabolism in ovariectomized rats

To investigate the effect of fermented black soybean pulp on serum lipid metabolism and osteoporosis in ovariectomized rats, Sprague-Dawley rats were divided into 4 groups: sham-operated control group, ovariectomized control group, ovariectomized group treated with black soybean pulp (BSP), and ovariectomized group treated with fermented black soybean pulp (FBSP). Rats were fed experimental diets for 8 weeks after ovariectomy. Compared to the control, FBSP supplemen-tation led to the improving effect for femur weight, abdominal fat, alanine aminotransferase, aspartate aminotransferase activity, hepatic lipid levels, and thiobarbituric acid reactive substances. Also, serum HDL-cholesterol, estradiol levels, serum alkaline phosphatase activity, and osteocalcin levels in the FBSP group were significantly lower than in the control group (p<0.05). These results suggest that FBSP is effective in improving lipid metabolism and preventing osteoporosis in ovariectomized rats.

The effects of long‐term exposure to extremely low‐frequency magnetic fields on bone formation in ovariectomized rats

The effects of long-term extremely low-frequency magnetic field (ELF-MF) exposure on bone formation and biochemical markers were investigated in ovariectomized rats. Sixty mature female Sprague-Dawley rats were randomly divided into four different groups (n = 15): (i) unexposed control (CTL); (ii) ovariectomized only (OVX); (iii) non-ovariectomized, exposed (SHAM + ELF-MF); and (iv) ovariectomized, exposed (OVX + ELF-MF). The third and fourth groups were exposed to 1.5 mT ELF-MF for 4 h a day for 6 months. Bone mineral density (BMD) was determined using dual energy X-ray absorption (DEXA) measurements. The formation and resorption of bone were evaluated using bone-specific alkaline phosphatase (BAP), osteocalcin, osteoprotogerin, and N-telopeptide. After 6 months of ELF-MF therapy, BMD values were significantly lower in the OVX group and higher in the OVX + ELF-MF and SHAM + ELF-MF groups than they were before therapy (P < 0.001). Although there was no significant difference in BMD values among the groups before therapy, the BMD values increased significantly after 6 months in the OVX + ELF-MF and SHAM + ELF-MF groups and were reduced in the OVX group compared to the CTL group (P < 0.001). The concentrations of BAP, osteocalcin, osteoprotogerin, and N-telopeptide in the three experimental groups also changed in a significant way compared to the CTL group. The results of the present study suggest that osteoporosis can be inhibited by ELF-MF stimulation treatments. It was also concluded that ELF-MF may be useful in the prevention of osteoporosis in ovariectomized rats.

Prevention of disuse osteoporosis in rats by Cordyceps sinensis extract

Cordyceps sinensis has been known as a traditional medicine in China, and C. sinensis plus strontium could prevent osteoporosis in ovariectomized rats. The present study shows that daily oral administration of C. sinensis at higher doses in adult hind limb suspension rats can prevent disuse-induced bone loss and deterioration of trabecular microarchitecture. Cordyceps sinensis induces estradiol production and prevents osteoporosis in ovariectomized rats. This study was to examine whether C. sinensis can prevent disuse-induced osteoporosis. Rats were randomly divided into six groups, and five groups were treated with hind limb suspension (HLS). One HLS group received alendronate (2.0mg/kg/day) orally, and to the three other HLS groups to each group, a different amount of C. sinensis (100, 300, and 500mg/kg/day) was orally administered for 8weeks before and after HLS. The remaining HLS group was set as a control without treatment. Each group consisted of 10 males and females. The body weights, biochemical parameters in serum and urine, bone mineral density (BMD), bone mineral content (BMC), mechanical testing, and bone microarchitecture were examined. Treatments with higher C. sinensis dosage (300 and 500mg/kg/day) or alendronate had a positive effect on body weights, mechanical strength, BMD, and BMC compared to the other HLS groups. C. sinensis decreased markers of bone turnover dose dependently and increased the osteocalcin levels in HLS rats. The result of micro-CT analysis from the L4 vertebra showed that C. sinensis (500mg/kg) significantly prevented the reduction of the bone volume fraction, connectivity density, trabeculae number, and thickness as well as improved the trabeculae separation and structure model index in HLS rats. The present study demonstrates that administration of C. sinensis at higher doses over an 8-week period can prevent the disuse osteoporosis in rats. It implies that C. sinensis might be an alternative therapy for prevention of disuse-induced osteoporosis also in humans.

Effects of Cheonnyuncho (Opuntia humifusa) seeds treatment on the mass, quality, and the turnover of bone in ovariectomized rats

Cheonnyuncho (Opuntia humifusa), rich in polyphenols and flavonoids, is known to have medicinal benefits in the treatment of arteriosclerosis and inflammation. This study was undertaken to evaluate the effects of cheonnyuncho seed powder (OHS) on postmenopausal osteoporosis in ovariectomized rats. OHS treatment prevented an ovariectomy (OVX)-induced decrease in biomechanical quality of femurs. OHS also dose-dependently inhibited bone mineral density (BMD) decreases in femurs, which were accompanied by a significant decrease in skeletal remodeling, as evidenced by decreased levels of the bone turnover markers osteocalcin, alkaline phosphatase (ALP) activity, and serum and urinary Ca excretion. Micro-CT analysis of femoral metaphysics showed that OHS prevented the OVX-induced decrease in bone volume/tissue volume, trabecular thickness, and trabecular number. Concluded, the treatment with OHS improves bone biomechanical quality through modification of BMD and trabecular microarchitecture without hyperplastic effects on the uterus. For these reasons, OHS may be suitable as an alternative treatment of postmenopausal osteoporosis.

Symbol effects of optimal dose of estradiol combined with puerarin on bone in ovariectomized rats

Low dose of puerarin combined with estradiol shows similar effects to high dose of puerarin or estradiol on treatment of osteoporosis in rats. To search the optimal doses for estradiol and puerarin for treatment of type I osteoporosis. Sixty-four healthy female rats were randomly divided into eight experimental groups (n = 8): sham-operated, ovariectomized, puerarin-50, estradiol-200, puerarin+estradiol-5, 50, 10, 150. All rats were subjected to ovariectomy except those in the sham-operated group. Rats in the puerarin-50 group were subcutaneously injected with 50 mk/kg puerarin, once a day. Rats in the estradiol-200 group were subcutaneously injected with 200 μg/kg estradiol, twice a week. Rats in the puerarin+ estradiol-5, 50, 10, 150 groups were subcutaneously injected with 25 mg/kg puerarin, once a day and simultaneously injected with 5, 50, 10, 150 μg/kg estradiol, twice a week. Compared with sham-operated group, bone mineral density, bone calcium, and bone phosphorous of rats were significantly lower in the ovariectomized group (P < 0.05), and bone tissue presented with the pathological change of osteoporosis. After treatment with puerarin and/or estradiol for 10 and 20 weeks, bone mineral density, bone calcium, and bone phosphorous levels were significantly increased (P < 0.05), and puerarin+estradiol-100 group acquired the most obvious curative effects on osteoporosis. The results showed that 25 mg/kg puerarin (once a day) and 100 μg/kg estradiol (twice a day) is the best dose for treatment of osteoporosis in ovariectomized rats.

Protective effect of folic acid on osteoporosis in ovariectomized rats

Objective To investigate the protective effect of folic acid(FA) on osteoporosis in ovariectomized(OVX) rats.Methods Forty three-month-old female SD Rats were divided into 5 groups, sham operation group, OVX group, diethylstilbestrol group(0.03mg·kg-1·d-1),low dose FA Group (5 mg·kg-1·d-1),and high dose FA group (20 mg·kg-1·d-1).Gastric gavage in each group was started from one week after being ovariectomized and lasted 10 weeks. Sham operation group and OVX group were treated with solvent. The rats were sacrificed at the end of 10th week after treatment. The total homocysteine(tHcy) in plasma, alkaline phosphatase(ALP), and tartrate-resistant acid phosphatase(TRACP) activity of bone homogenates were measured. The bone mineral density(BMD) and bone biomechanics were determined using L5 vertebrae and right femur. The bone tissue slices were made with L6 vertebrae and left femur and HE stained, and then the histomorphology was observed. Results Compared with sham operation group, plasma tHcy level was significantly increased(P＜0.01), BMD of lumbar vertebrae and femur was remarkedly decreased in OVX group(all P＜0.01). Plasma tHcy concentration was negatively correlated with lumbar BMD(r=-0.359, P=0.040). Plasma tHcy level in both groups treated with folic acid was significantly reduced(all P＜0.01). The ALP concentration in bone homogenates was higher, the TRACP concentration in bone homogenates was lower, and BMD and bone biomechanics of lumbar vertebrae and femur were increased in high dose FA group than those in OVX group(all P ＜0.01). Conclusions In OVX rats hyperhomocysteinemia existed and was involved in the development of osteoporosis. Folic acid could protect OVX rats from osteoporosis, due probably to improved homocysteine metabolism. Key words: Folic acid; Homocysteine; Osteoporosis; Ovariectomized; Rat

Ethinylestradiol liposome preparation and its effects on ovariectomized rats’ osteoporosis

Ethinylestradiol liposome (EEL) was prepared by thin film evaporation–extrusion technique and its effects on ovariectomized rat osteoporosis were investigated. The liposomes were characterized with clear homogeneous lamellar vesicles and had the average size of 200 ± 1.5 nm. The long term stability of liposome formulations were tested over a 28-day period at 4°C and ethinylestradiol retention was approximately 80% up to 28 day. Release data of ethinylestradiol was tested in PBS pH 7.4 at 37°C using a dialysis method and its release profiles were biphasic, showing a relatively large burst effect over the first four hours, followed by a slower release phase. Ovariectomized rat model was used to investigate EEL effects on osteoporosis. After three months post-surgery, the rats were divided into two groups and injected intraperitoneally (IP) with 2 μg per kilogram per day of either free ethinylestradiol (EE) or encapsulated ethinlyestradiol (EEL). At termination of one month IP injection, the rats were killed and the bone mineral density (BMD) and alkaline phosphatase (ALP) were measured. BMD value in free EE group increased by 20.3 %, while it increased by 37.8 % in EEL group. According to ALP value, the two treatment groups increased by 28.6 % and 42.0 %, respectively. These data indicated that ethinlyetradiol liposome had better effect than that of free ethinylestradiol did in treatment of the ovariectomized rats’ osteoporosis. But the metabolites and biodistribution of ethinylestradiol liposome in vivo need to investigate in the further research work.