Influence of quercetin on aging of bone marrow mesenchymal stem cells induced by microgravity / 中国药理学通报

Aim To investigate the effect of quercetin on the aging model of bone marrow mesenchymal stem cells established under microgravity. Methods Using 3D gyroscope, a aging model of bone marrow mesenchymal stem cells was constructed, and after receiving quercetin and microgravity treatment, the anti-aging effect of the quercetin was evaluated by detecting related proteins and oxidation indexes. Results Compared to the control group, the expressions of age-related proteins p21, pi6, p53 and RB in the microgravity group significantly increased, while the expressions of cyclin D1 and lamin B1 significantly decreased, with statistical significance (P<0.05). In the microgravity group, mitochondrial membrane potential significantly decreased (P<0.05), ROS accumulation significantly increased (P <0.05), SOD content significantly decreased and MDA content significantly increased (P<0.05). Compared to the microgravity group, the expressions of age-related proteins p21, pi6, p53 and RB in the quercetin group significantly decreased, while the expressions of cyclin D1 and lamin B1 significantly increased, with statistical significance (P<0.05). In the quercetin group, mitochondrial membrane potential significantly increased (P<0.05), ROS accumulation significantly decreased (P<0.05), SOD content significantly increased and MDA content significantly decreased (P<0.05). Conclusions Quercetin can resist oxidation, protect mitochondrial function and normal cell cycle, thus delaying the aging of bone marrow mesenchymal stem cells induced by microgravity.

Effects of isopsoralen on tibial fracture and vascular healing in mice / 中国骨伤

OBJECTIVE@#To explore effects of isopsoralen (ISO) with different doses on fracture and vascular healing in mice.@*METHODS@#Sixty 2-month-old male C57BL/6 mices with body mass of (20±2) g were selected and divided into 4 groups by random number table method:model group (model), low dose group (isopsoralen-low dose, ISO-L), medium dose group (isopsoralen-medium dose, ISO-M) and high dose group (isopsoralen-high dose, ISO-H), with 15 animals in each group. The right tibial fracture model was established. After operation, ISO-L group, ISO-M group and ISO-H group were given ISO concentration of 10 mg·kg-1, 20 mg·kg-1 and 40 mg·kg-1, respectively. Model group was given same volume of normal saline once a day for 28 days. Weighed once a week. X-ray was performed on 7, 14, 21 and 28 days, respectively, and modified I.R. Garrett scoring method was used to evaluate callus growth. After 28 days, the main organs were stripped and weighed, and organ coefficients were calculated. Hematoxylin eosin staining (HE staining) was performed on the organs to observe whether there were pathological structural changes. Micro-computed tomography (Micro-CT) was used to scan fracture area and conduct three-dimensional reconstruction to obtain the effect map, and quantify bone volume fraction (bone volume/total volume, BV/TV). After decalcification, the tibia was embedded in paraffin wax and sectioned. The healing and shape of fracture end were observed by HE staining and ferruxin solid green staining. The right tibia was removed and decalcified after intravascular infusion of Microfil contrast agent. Micro-CT was used to scan the callus microvessels in the fracture area, and the vascular volume fraction and vessel diameter were quantified.@*RESULTS@#After 28 days of administration, there was no significant difference in body mass and organ coefficient among all groups (P>0.05), and no significant pathological changes were found in HE staining of organs. The results of X-ray and improved I.R. Garrett score showed that ISO-M group was higher than that of Model group at 28 days (P<0.05). Scores of ISO-H group at 14, 21 and 28 days were higher than those of the other 3 groups (P<0.05). Micro-CT results showed intracavitary callus in ISO-M group was significantly reduced, which was lower than that in Model group (P<0.05), most of the callus in ISO-H group were subsided, and BV/TV in ISO-H group was lower than that in the other 3 groups (P<0.05). The results of HE staining and ferrubens solid green staining showed fracture area of ISO-H group was closed, continuous laminar bone had appeared, and the fracture healing process was higher than that of other groups. Angiographic results showed vascular volume fraction in ISO-H and ISO-M groups was higher than that in Model and ISO-L groups (P<0.05), and the vascular diameter in ISO-H and ISO-M groups was higher than that in Model and ISO-L groups (P<0.05).@*CONCLUSION@#In the concentration range of 10-40 mg·kg-1, ISO has no obvious toxic and side effects, and could improve bone microstructure, promote formation of callus microvessels, and accelerate healing of fracture ends in a concentration-dependent manner.

Low-frequency pulsed electromagnetic fields promote osteoblast mineralization and maturation of rats through the PC2/sAC/PKA/CREB signaling pathway / 南方医科大学学报

OBJECTIVE@#To explore whether the effect of low-frequency pulsed electromagnetic fields (PEMFs) in promoting osteoblast mineralization and maturation is related to the primary cilia, polycystin2 (PC2) and sAC/PKA/CREB signaling pathway.@*METHODS@#We detected the expression levels of PC2, sAC, PKA, CREB and their phosphorylated proteins in primary rat calvarial osteoblasts exposed to 50 Hz 0.6 mT PEMFs for 0, 5, 15, 30, 60, 90, and 120 min. We blocked PC2 function with amiloride hydrochloride and detected the changes in the activity of sAC/PKA/CREB signal pathway and the mineralization and maturation of the osteoblasts. These examinations were repeated in the osteoblasts after specific knockdown of PC2 via RNA interference and were the co-localization of PC2, sAC, PKA, CREB and their phosphorylated proteins with the primary cilia were using immunofluorescence staining. The expressions of PC2 and the signaling proteins of sAC/PKA/CREB pathway were detected after inhibition of primary ciliation by RNA interference.@*RESULTS@#The expression levels of PC2, sAC, p-PKA and p- CREB were significantly increased in the osteoblasts after exposure to PEMFs for different time lengths (P < 0.01). Blocking PC2 function or PC2 knockdown in the osteoblasts resulted in failure of sAC/PKA/CREB signaling pathway activation and arrest of osteoblast mineralization and maturation. PC2, sAC, p-PKA and p-CREB were localized to the entire primary cilia or its roots, but PKA and CREB were not detected in the primary cilia. After interference of the primary cilia, PEMFs exposure no longer caused increase of PC2 expression and failed to activate the sAC/PKA/CREB signaling pathway or promote osteoblast mineralization and maturation.@*CONCLUSION@#PC2, located on the surface of the primary cilia of osteoblasts, can perceive and transmit the physical signals from PEMFs and promote the mineralization and maturation of osteoblasts by activating the PC2/ sAC/PKA/CREB signaling pathway.

Effects of rosin diglucoside on bone metabolism in young rats / 中国药理学通报

Aim To research the effect of PDG on bone metabolism in young rats. Methods The experimental rats were randomly divided into contro group, PDG-25 group and PDG-50 group. PDG-25 group and PDG-50 group were given PDG at the dose of 25 mg·kg

Different Types of Low-frequency Electromagnetic Fields Resist Bone Loss Caused by Weightlessness / 中国医学科学院学报

Objective To compare the effects of 50-Hz 0.6-mT low-frequency pulsed electromagnetic fields(PEMFs) and 50-Hz 1.8-mT sinusoidal alternating electromagnetic fields(SEMFs) in preventing bone loss in tail-suspended rats,with an attempt to improve the prevention and treatment of bone loss caused by weightlessness.Methods Tail-suspension rat models were used to simulate microgravity on the ground. Forty rats were randomly divided into four groups[control group,hindlimb-suspended(HLS) group,HLS+PEMFs group,and HLS+SEMFs group],with 10 rats in each group. In the PEMFs treatment group and SEMFs treatment group,the intervention was 90 min per day. Rats were sacrificed after four weeks. Bone mineral density(BMD) of femur and vertebra was measured by dual-energy X-ray absorptiometry and biomechanical strength by AG-IS biomechanical instrument. Serum osteocalcin(OC),tartrate-resistant acid phosphatase 5b(Tracp 5b),parathyroid hormone(PTH),and cyclic adenosine monophosphate(cAMP) were detected by ELISA. The microstructure of bone tissue was observed by Micro-CT and HE staining.Results The BMD of the femur(P=0.000) and vertebrae(P=0.001) in the HLS group was significantly lower than in the control group;the BMD of the femurs(P=0.001) and vertebrae(P=0.039) in the HLS+PEMFs group was significantly higher than in the HLS group;the BMD of the femurs in the HLS+SEMFs group was significantly higher than in the HLS group(P=0.003),but the BMD of the vertebrae showed no significant difference(P=0.130). There was no significant difference in the BMD of the femur(P=0.818) and vertebrae(P=0.614) between the HLS+PEMFs group and the HLS+SEMFs group. The maximum load(P=0.000,P=0.009) and elastic modulus(P=0.015,P=0.009) of the femurs and vertebrae in the HLS group were significantly lower than those in the control group;the maximum load of the femur(P=0.038) and vertebrae(P=0.087) in the HLS+PEMFs group was significantly higher than that in the HLS group,but the elastic modulus was not significantly different from that in the HLS group(P=0.324,P=0.091). The maximum load(P=0.190,P=0.222) and elastic modulus(P=0.512,P=0.437) of femurs and vertebrae in the HLS+SEMFs group were not significantly different from those in the HLS group. There were no significant differences in the maximum load and elastic modulus of femurs(P=0.585,P=0.948) and vertebrae(P=0.668,P=0.349) between the HLS+PEMFs group and the HLS+SEMFs group. The serum OC level in the HLS group was significantly lower than that in the control group(P=0.000),and the OC level in HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.006) were significantly higher than that in the HLS group. The serum Tracp 5b concentration in the HLS group was significantly higher than that in the control group(P=0.011). There was no significant difference between the HLS+PEMFs group(P=0.459) and the HLS+SEMFs group(P=0.469) compared with the control group.Serum Tracp 5b concentrations in the HLS+PEMFs group(P=0.056) and the HLS+SEMFs group(P=0.054) were not significantly different from those in the HLS group. The PTH(P=0.000) and cAMP concentrations(P=0.000) in the HLS group were significantly lower than those in the control group. The PTH(P=0.000,P=0.000) and cAMP concentrations(P=0.000,P=0.000) in the HLS+PEMFs group and the HLS+SEMFs group were significantly higher than in the HLS group. The femoral cancellous bone of the HLS group was very sparse and small compared with the control group. The density and volume of the cancellous bone were similar among the control group,HLS+PEMFs group,and HLS+SEMFs group. Compared with the control group,the HLS group had lower BMD(P=0.000),bone volume (BV)/tissue volume(TV)(P=0.000),number of trabecular bone (Tb.N)(P=0.000),and trabecular thickness(Tb.Th)(P=0.000) and higher trabecular bone dispersion(Tb.Sp)(P=0.000) and bone surface area(BS)/BV(P=0.000). Compared with the HLS group,the HLS+PEMFs group and the HLS+SEMFs group had significantly lower Tb.Sp(P=0.000,P=0.000) and BS/BV(P=0.000,P=0.000) and significantly increased BMD(P=0.000,P=0.000),BV/TV(P=0.001,P=0.004),Tb.Th(P=0.000,P=0.001),and Tb.N(P=0.000,P=0.001). The trabecular thickness significantly differed between the HLS+PEMFs group and the HLS+SEMFs group(P=0.024). The HLS group(P=0.000),HLS+PEMFs group(P=0.000),and HLS+SEMFs group(P=0.000) had the significantly lower osteoblast density on the trabecular bone surface than the control group;however,it was significantly higher in the HLS+SEMFs group(P=0.000) and the HLS+PEMFs group(P=0.000) than in the HLS group. The HLS group had significantly lower density of osteoblasts in the endothelium than the control group(P=0.000);however,the density of osteoblasts was significantly higher in HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.000) than HLS group and was significantly higher in HLS+PEMFs group than in HLS+SEMFs group(P=0.041). Compared with the control group,a large number of fatty cavities were produced in the bone marrow cavity in the HLS group,but the fat globules remarkably decreased in the treatment groups,showing no significant difference from the control group. The number of adipose cells per mm bone marrow in the HLS group was 4 times that of the control group(P=0.000);it was significantly smaller in the HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.000) than in the HLS group,whereas the difference between the HLS+PEMFs group and the HLS+SEMFs group was not statistically significant(P=0.086). Conclusions 50-Hz 0.6-mT PEMFs and 50-Hz 1.8-mT SEMFs can effectively increase bone mineral density and biomechanical values in tail-suspended rats,increase the concentration of bone formation markers in rat blood,activate the cAMP pathway by affecting PTH levels,and thus further increase the content of osteoblasts to prevent the deterioration of bone micro-structure. In particular,PEMFs can prevent the reduction of bone mineral density and maximum load value by about 50% and increase the bone mass of tail-suspended rats by promoting bone formation.

Preventive effect and mechanism of puerarin on rat models of disuse osteoporosis / 中国中药杂志

To investigate the preventive effect and possible mechanism of puerarin(Pur) in rat model of disuse osteoporosis(DOP),thirty healthy Wistar female rats of 2 months old were randomly divided into control group(Control), hindlimb suspension group(HLS), and puerarin group(HLS+Pur) in hindlimb suspension, with 10 rats in each group. A disuse osteoporosis model was established by tail suspension method, and 15.4 mg·kg~(-1) puerarin suspension was administered to HLS+Pur group every day, and the same volume of distilled water was administered to Control group and HLS group respectively. After 28 days, the rats were sacrificed by abdominal aorta blood collection, the main organs of the rats were removed, and the bone tissues of the rats were dissected. The organ index of the rats was calculated and the histopathology of the organs was observed under microscope. Bone mineral density test and bone biomechanical experiment were performed. Bone histomorphometry results were observed after bone tissue sectioning, and serum biochemical markers of bone metabolism were determined. There was no significant difference in organ index between the groups. There was no obvious abnormality in the pathological examination of the organs. The results of bone mineral density showed that puerarin could significantly increase the bone density of the tibia and vertebrae caused by hindlimb suspension. The mechanical parameters experiments showed that puerarin could effectively increase the maximum load and elastic modulus of the tibia and vertebrae. Fluorescence labeling showed that the fluorosis interval increased and the bone formation increased during puerarin treatment. The VG staining results showed that compared with the HLS group, in the puerarin group, the number of trabecular bone increased, the thickness of the trabecular bone became thicker, and the bone separation became smaller, which greatly improved the bone microstructure after hindlinb suspension. In addition, serum biochemical indicators showed that puerarin could promote bone formation index bone calcium. The content of osteocalcin(OC) increased and inhibited the formation of tartrate-resistant acid phosphatase 5 b(TRACP 5 b). Puerarin has a preventive effect in the rat model of disuse osteoporosis and its effect is good, and its mechanism may be related to promoting bone formation and inhibiting bone resorption.

Effect of Compound Medicine of Tanshinone 2A and Resveratrol on Peak Bone Mass in Growing Rats / 中国医学科学院学报

Objective To study the effect of the compound medicine of tanshinone 2A and resveratrol on peak bone mass in growing rats and to explore its possible mechanism,so as to explore anti-osteoporosis mechanisms of new traditional Chinese medicine (TCM) drugs. Methods Totally 40 1-month-old female Wistar rats were randomly divided into tanshinone 2A group,resveratrol group,compound group (tanshinone 2A and resveratrol),and normal control group,with 10 rats in each group. Body weight was measured once every two weeks,and the whole body bone mineral density was measured with dual-energy X-ray monthly. When the whole-body bone mineral density became statistically significant between medication groups and control group,all animals were sacrificed to determine the bone mineral density of vertebrae and right femoral bone. The biomechanical properties of femur and vertebrae were measured by AGS-X series universal test,then the bone morphology was analyzed with Fuchsin picric acid staining. Finally,the levels of tartrate-resistant acid phosphatase 5b and osteocalcin were measured with enzyme-linked immunosorbent assay.Results The body weights were not statistically significant among all groups (P>0.05). The whole-body bone mineral density showed no significant difference (P>0.05) after feeding for 1 month;however,two months later,it was significantly different between medication groups and control group;in particular,the whole-body (P=0.016),femoral (P=0.001),and vertebral bone mineral density (P=0.034),bone trabecular number (P=0.024),thickness (P=0.040),and area (P=0.038) were significantly increased in the compound group,along with the significantly decreased trabecular separation degree (P=0.032). Compared with the control group,the compound group had significantly increased osteocalcin (P=0.033) and tartrate-resistant acid phosphatase 5b (P=0.028) levels in serum.Conclusion The compound of tanshinone 2 A and resveratrol can improve the bone density and bone quality in rats,and such effect is higher than either tanshinone 2 A monomer or resveratrolmonomer.

Resveratrol and puerarin on peak bone mass in young rats / 中国骨伤

<p><b>OBJECTIVE</b>To compare effects of resveratrol, puerarin and the compounds on peak bone mass in rats.</p><p><b>METHODS</b>Forty SPF Wistar rats weighed 109.45 g to 119.44 g with an average of 115.87 g were selected. After 3 days' adaption, rats were divided into control group (the same volume of distilled water per day), puerarin group(15.4 mg/kg puerarin daily), resveratrol group (8.4 mg/kg resveratrol daily), compound drug group (daily dose of 8.4 resveratrol added 15.4 mg/kg of puerarin) and 10 in each group. The body weight of the rats was monitored at every 7 days and body bone density was measured at every month. All rats were sacrificed after 3 months. The bone mineral density of femur and vertebrae was detected by dual energy X-ray absorptiometry; bone biomechanics, VG staining was used to analyze bone histomorphometry;ELISA was used to detect serum bone metabolic index and microstructure of femur were scanned with Micro-CT scanner.</p><p><b>RESULTS</b>There were no significant differences in body weight among groups during exoeriment. Bone mineral density results showed BMD of femur and vertebrae in the other three groups were significantly increased, and R+P group was significantly higher than PR group and RES group(<0.05) by compared with CON group;three-point bending and compression test results showed compared with CON group, other three groups of femoral and vertebral maximum load values were significantly increased, and P+R group was higher than PR group and RES group, but elastic modulus was not statistically significant. Bone histomorphometry showed that number of trabecular bone in other three groups were significantly increased compared with CON group, separation of trabecular bone were significantly reduced, continuity was improved, and R+P group was significantly better than RES and PR group. The results of Micro-CT scan showed that separation of trabecular bone were significantly reduced, continuity were improved in other three groups, and R+P group was significantly better than RES and PR group. The numbers of trabecular bone (Tb.N), trabecular bone thickness (Tb.Th), volume of trabecular bone (BV/TV) in PR group, RES group and R+P group were significantly higher than CON group, but trabecular bone separation (Tb.Sp) was significantly reduced. Serum levels results showed, level of OC in the other three groups were higher than control group(<0.05), content of TRACP 5b decreased, and level of OC in P+R group was significantly higher than PR group and RES group, content of TRACP 5b was no significant change.</p><p><b>CONCLUSIONS</b>Compound of puerarin and resveratrol assigned in a 1:1 ratio could improve bone mineral density and bone mass in young rats, enhance biomechanical properties of bone, promote mineralization and maturation of osteoblasts, inhibit osteoblastic bone resorption, and is better than the role of their respective monomers. The paper showed that traditional Chinese medicine compound medicine will be used as a new way to prevent and treat osteoporosis.</p>

Effect of 50 Hz 1.8 mT sinusoidal electromagnetic fields on bone mineral density in growing rats / 中国骨伤

<p><b>OBJECTIVE</b>To study effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields (SEMFs) on bone mineral density (BMD) in SD rats.</p><p><b>METHODS</b>Thirty SD rats weighted(110±10) and aged 1 month were randomly divided into control group and electromagnetic field group, 15 in each group. Normal control group of 50 Hz 0 mT density and sinusoidal electromagnetic field group of 50 Hz 1.8 mT were performed respectively with 1.5 h/d and weighted weight once a week, and observed food-intake. Rats were anesthesia by intraperitoneal injection and dual energy X-ray absorptiometry were used to detect bone density of whole body, and detected bone density of femur and vertebral body. Osteocalcin and tartrate-resistant acid phosphatase 5b were detected by ELSA; weighted liver, kidney and uterus to calculate purtenance index, then detected pathologic results by HE.</p><p><b>RESULTS</b>Compared with control group, there was no significant change in weight every week, food-intake every day; no obvious change of bone density of whole body at 2 and 4 weeks, however bone density of whole body, bone density of excised femur and vertebra were increased at 6 weeks. Expression of OC was increased, and TRACP 5b expression was decreased. No change of HE has been observed in liver, kidney and uterus and organic index.</p><p><b>CONCLUSIONS</b>50 Hz 1.8 mT sinusoidal electromagnetic fields could improve bone formation to decrease relevant factors of bone absorbs, to improve peak bone density of young rats, in further provide a basis for clinical research electromagnetic fields preventing osteoporosis foundation.</p>

Inhibition of osthole for resorption of rats femur tissue in vitro / 中国骨伤

<p><b>OBJECTIVE</b>To investigate osthole effect on femoral tissue resorption activity of rat in vitro.</p><p><b>METHODS</b>Six SD rats weighted (80 ± 5) g were used to isolate and culture femoral tissue (diaphyses and metaphysis) in vitro. The cultured tissue were devided into control group, estradiol group and osthole group. The femoral tissue was treated with final concentration of 1 x 10(-5) mol/L osthole and 1 x 10(-8) mol/L estradiol culture in vitro at 48 hours after cultured. Tartrate-resistant acid phosphatase (StrACP) activity, glucose and Lactic acid content, StrACP, MCSF (Macrophage colony stimulating factor) and CTSK (Cathepsin K) mRNA was detected by Real-Time RT-PCR were detected.</p><p><b>RESULTS</b>Concetration of Alkaline phosphatase activity were 2226 and 2498 in 1 x 10(-5) mol/L osthole and 1 x 10(-8) mol/L estradiol respectively. As compared with control group, the activity of StrACP of 1 x 10(-5) mol/L osthole and 1 x 10(-8) mol/L estradiol were inhibited at 6, 9, 12 days (P < 0.05); under treatment of in l x 10(-5) mol/L osthole, the content of Lactic acid were increased and the content of glucose were decreased at 3, 6, 9 days (P < 0.05); StrACP, MCSF and CTSK mRNA expression level were inhibited at 6, 9 days (P < 0.05).</p><p><b>CONCLUSION</b>Osthole can inhibit bone resorption and raise the level of nutrition metabolism of femurs tissue.</p>

Icariin enhances differentiation and maturation of rat calvarial osteoblasts in collagen hydrogel three-dimensional culture / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of icariin on the differentiation and maturation of rat calvarial osteoblasts(ROB) in collagen hydrogel three-dimensional culture.</p><p><b>METHODS</b>ROB were obtained by enzyme digestion from the segregated neonatal SD rats skull and were embedded in 2 mg/mL rat tail collagen for three-dimensional culture. The growth state of ROB was observed by FDA/PI staining, HE staining and scanning electron microscopy. ROB were treated with icariin at the concentration of 1 × 10⁻⁴, 1 × 10⁻⁵, 1 × 10⁻⁶ and 1 × 10⁻⁷ mol/L respectively. The activity of alkaline phosphatase(ALP) was detected after 3, 6, 9 d of icariin treatment. Three-dimensional cultured ROB were treated with optimal concentration icariin for 12, 24, 36, 48 h and total RNA was extracted and the mRNA expressions of bone morphogenetic protein-2 (BMP-2), Runt-related transcription factor 2 (RUNX-2) and Osterix were detected by real time RT-PCR. The protein expression of BMP-2, RUNX-2 and Osterix were examined by Western-blotting.</p><p><b>RESULTS</b>ROB were cultured in collagen hydrogel successfully. FDA/PI staining, HE staining, and scanning electron microscopy showed that ROB adhered with collagen tightly and distributed homogeneously. Icariin at final concentration of 1 × 10⁻⁵, 1 × 10⁻⁶ and 1×10⁻⁷ mol/L all enhanced the activity of ALP of collagen hydrogel three-dimensional cultured ROB, and 1 × 10⁻⁶ mol/L was the optimal concentration. Besides, icariin (1 × 10⁻⁶ mol/L) increased mRNA and protein expression of BMP-2、RUNX-2 and Osterix compared to control group.</p><p><b>CONCLUSION</b>Icariin can enhance the expression of osteogenic markers of ROB in collagen hydrogel three-dimensional culture significantly.</p>

Effect of different-intensity SEMFs on bone mineral density and histomorphometry in SD rats / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the effects of different-intensity sinusoidal electromagnetic fields (SEMFs) on bone mineral density (BMD) and histomorphometry in SD rats.</p><p><b>METHODS</b>Thirty female SD rats were randomly divided into three groups: group A (a control group), group B (0.1 mT group) and group C (0.6 mT group). The rats in group B and C were exposed to 50 Hz SEMFs 3 hours each day. However,the magnetic intensity was different between group B and group C:0.1 mT for group B and 0.6 mT for group C. After 8 weeks, all the animals were killed. Changes of BMD and histomorphometric properties were observed.</p><p><b>RESULTS</b>Compared with group A, the BMD of whole body, femur and vertebrae of rats in group B increased significantly; the area percentage, number and width of bone trabeculae in vertebrae and femur of rats in group B were larger than those of group A; but the resolution of bone trabeculae of rats in group B was lower than that of group A. The trabecular number in group C rats were significantly decreased, compared with that in group A rats. The outcome of double fluorescence labeling in group B was found to be significantly different with that in group A. But the difference between rats in group A and C was not significant.</p><p><b>CONCLUSION</b>This study demonstrates that 50 Hz 0.1 mT SEMFs can increase BMD, improve bone tissue microstructure and, promote bone formation.</p>

Effect of sinusoidal electromagnetic field on bone mineral density and histomorphometry of rats at different time points / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of 50 Hz 0.1 mT sinusoidal electromagnetic field at different time points on bone mineral density(BMD)and histomorphometry in rats.</p><p><b>METHODS</b>Totally 50 6-week-old female SD rats were equally randomized into 5 groups: control group,45-minute group,90-minute group,180-minute group,and 270-minute group. Except for the control group,the other four groups were given magnetic intervention in the 50-Hz 0.1-mT sinusoidal electromagnetic field for 45 minutes,90 minutes,180 minutes,or 270 minutes,respectively,on a daily basis. After 8 weeks,the total body BMD,femur BMD,and vertebral BMD were measured by dual-energy X-ray absorptiometry. The left tibia and the fifth lumbar vertebrae were separated for bone tissue static and dynamic analyses.</p><p><b>RESULTS</b>Compared with control group,the 90-minute group and the 180-minute group had significantly different total body BMD(P<0.01,P<0.05),while no such significant difference was seen in the 45-minute group and 270-minute group (P>0.05). The femur,vertebral BMD,serum biochemical markers,and the static parameters of the fifth lumbar vertebrae tissue showed significant differences in the 90-minute group,180-minute group,and 270-minute group(P<0.01),but not in the 45-minute group (P>0.05). As shown by double fluorescent labeling,the distance was sorted in an order of 90-minute group>180-minutes group>270-minute group>45-minutes group>control group.</p><p><b>CONCLUSION</b>The 50-Hz 0.1-mT sinusoidal electromagnetic field can effectively increase bone mineral density and improve bone morphology;however,the intervention effectiveness differs at different time points,with the best effectiveness seen at 90 minutes.</p>

Effect of osthole on bone metabolism in rat femoral tissues in vitro / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of osthole on bone metabolism in rat femoral tissues in vitro.</p><p><b>METHODS</b>The rat femoral tissues were isolated in vitro. The optimal concentrations of ostehole (1×10(-5) mol/L) and estradiol (1×10(-8) mol/L) (the positive control) were selected by alkaline phosphatase activity (ALP). The ALP and calcium levels were detected by commmerical regents, and the expressions of osteoprotegerin, receptor activator of nuclear factor-κB ligand, runx-related gene 2, and bone morphogenetic protein-2 mRNA were determined by real-time reverse transcription-polymerase chain reaction.</p><p><b>RESULT</b>The osthole (1×10(-5) mol/L) significantly increased the activity of ALP, calcium level as well as the expressions of osteoprotegerin, receptor activator of nuclear factor-κB ligand, runx-related gene-2 and bone morphogenetic protein-2 mRNA in rat femoral tissues in vitro.</p><p><b>CONCLUSION</b>Osthole can improve calcium level and ALP activity and regulate the bone metabolism-related genes in rat femoral tissues.</p>

Mechanisms of icariin in regulating bone formation of osteoblasts and bone resorption of osteoclasts / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the molecular mechanisms of icariin (ICA) in regulating the bone formation of osteoblasts and the bone resorption of osteoclasts.</p><p><b>METHODS</b>Primary osteoblast cell cultures were obtained from newborn rat calvarial. Calcified nodules were stained by alizarin red. The mRNA levels of osterix (OSX), runt-related transcription factor 2 (Runx-2), alkaline phosphatase (ALP), Collagen1, osteoprotegerin (OPG), and receptor activator of nuclear factor-ΚB ligand (RANKL) were analyzed by quantitative real-time RT-PCR, the protein levels of OPG, RANKL, and Collagen1 were examined by Western blotting, and the intracellular Ca(2+) concentration of osteoblasts was measured on a flow cytometer using the Cellquest program.</p><p><b>RESULTS</b>Compared with control group, ICA markedly promoted bone formation by significant up-regulating the gene expressions of OSX, Runx-2,ALP, and Collagen1, the protein expression of Collagen1(all P<0.01), and the Ca(2+) concentration. Furthermore, ICA remarkably inhibited bone resorption by significant up-regulating the mRNA and protein expressions of OPG as well as the OPG/RANKL ratio.</p><p><b>CONCLUSIONS</b>ICA could promote bone formation of osteoblasts through inducting the gene expressions of OSX,Runx-2, ALP and Collagen1, and the protein expressions of Collagen1, and by increasing the Ca (2+) concentration. Moreover, ICA could inhibit bone resorption of osteoclasts through regulating OPG/RANKL signal pathway.</p>

Comparison between icariin and genistein in osteogenic activity of marrow stromal cells / 中国中药杂志

<p><b>OBJECTIVE</b>To compare the effect of icariin and genistein in the osteogenic differentiation of rat bone marrow stromal cells (rBMSC).</p><p><b>METHOD</b>Rat marrow stromal cells were seperated in vitro, and the optimal concentration of genisten and icriin were screened. Genistein and icariin with the concentration of 1 x 10(-5) mol x L(-1) were adopted to intereven rBMSCs cultured in vitro. Alkaline phosphatase (ALP) was determined at 3, 6, 9, 12,15 d after intervention; calcified nodule was detected with alizarin red staining at 12 d; OXS, Runx-2, bone morphogenetic protein (BMP-2) and Collagen-I mRNA expression were observed with Real-time RT-PCR at 12, 24, 48, 72, 96 h.</p><p><b>RESULT</b>Genistein and icariin with the concentration of 1 x 10(-5) mol x L(-1) could increase the activity of ALP and the content of Ca, regulate OXS, BMP-2, Runx-2 and Collagen-I mRNA expression.</p><p><b>CONCLUSION</b>Icariin showed a stronger effect in improving the osteogenic differentiation of rat bone marrow stromal cells than genistein.</p>