柚皮苷抑制PMMA颗粒诱导的破骨细胞形成及骨溶解

目的从体外和体内实验2个方面评价柚皮苷对聚甲基丙烯酸甲酯（PMMA）诱发的破骨细胞性骨溶解的作用。方法培养破骨细胞前体细胞RAW264.7,使用PMMA颗粒刺激细胞,观察柚皮苷的治疗作用。检测抗酒石酸酸性磷酸酶（TRAP）染色、Ca2＋释放实验以及TRAP、组织蛋白酶（CPK）、NF-κB的基因表达。采用小鼠膝关节置钉模型评价柚皮苷对PMMA诱发骨吸收的作用,对实验标本采用生物力学拔出试验进行评价。结果柚皮苷可以有效地抑制破骨细胞的形成并下调骨吸收基因标记物的表达,剂量为10μg/ml时表现出对TRAP活性的最大抑制作用。在颗粒刺激培养液中柚皮苷降低了钙的释放。柚皮苷缓解了膝关节置钉模型中PMMA颗粒刺激所造成的长期的骨吸收,表现为骨体积分数的增加和最大钉拔出力的增加。300 mg/kg的灌胃剂量可达到最好的疗效。结论柚皮苷抑制PMMA诱导的破骨细胞形成,降低PMMA颗粒刺激的钙释放。在观察慢性骨吸收的长期模型中,柚皮苷也有效抑制PMMA诱发的骨吸收,并保留了置入物的稳定性。     

柚皮苷对破骨细胞凋亡的影响

[目的]探讨不同浓度柚皮苷单体对破骨细胞的凋亡的影响及相关机制.[方法]采用100 ng/ml浓度RANKL诱导小鼠单核细胞RAW264.7细胞株获取破骨细胞,之后采用含有不同浓度柚皮苷培养基对破骨细胞进行干预3d.行TRAP染色,扫描电镜观察骨薄片上骨吸收,流式细胞仪检测破骨细胞凋亡,荧光定量PCR检测破骨细胞凋亡基...     

红霉素抑制磨损颗粒诱发体内骨溶解的研究

[目的]通过小鼠体内磨损颗粒颅骨溶解模型研究红霉素(erythromycin,EM)抑制磨损颗粒诱发骨溶解的效果。[方法]24只8周龄的C57BL/J6雄性小鼠随机分为4组:聚甲基丙烯酸甲酯(polymethyl-methacrylate,PM-MA)组接受PMMA30 mg颗粒植入颅顶部,PMMA 2EM组接受30 mg PMMA颗粒植入加每天EM2 mg/kg腹腔内注射,PMMA 10EM组接受PMMA30 mg颗粒植入加每天EM10 mg/kg腹腔内注射,对照组接受假手术。7 d后取出颅骨进行病理学分析。[结果]颅骨破坏面积对照组为0.079 mm2±0.011 mm2,PMMA组0.335 mm2±0.129 mm2,PM-MA 2EM组0.094 mm2±0.019 mm2,PMMA 10EM组0.091 mm2±0.028 mm2。对照组颅骨实验区域内破骨细胞计数为5.3±1.0个,PMMA组为19.2±5.3个,PMMA 2EM组为6.6±1.1个,PMMA 10EM组为6.1±1.9个。与对照组相比,PMMA颗粒可以诱发骨溶解(P<0.001),而EM治疗可以抑制PMMA颗粒诱发的颅骨溶解(P<0.001),及破骨细胞生成(P<0.001)。[结论]EM可以抑制PMMA磨损颗粒诱发的骨溶解。     

槲皮苷抑制RANKL诱导的破骨细胞形成及骨吸收

[目的]探讨槲皮苷对核因子κB受体激动剂配体(receptor activator of nuclear factor kappa B ligand,RANKL)诱导的破骨细胞形成及骨吸收功能的影响。[方法]通过CCK-8法观察不同浓度槲皮苷(0~800μmol/L)干预不同时间(48 h、96 h)对RAW 264.7细胞的生存影响,确定合适的体外用药浓度;利用体外RANKL诱导RAW 264.7细胞形成破骨细胞体系,通过抗酒石酸酸性磷酸酶(tartrate resistant acid phosphatase,TRAP)染色计数评价槲皮苷(200、400μmol/L)对破骨细胞形成和生存的影响;通过骨片吸收实验对骨凹陷和骨吸收面积统计分析评价槲皮苷(200、400μmol/L)3 d内对成熟破骨细胞骨吸收功能的影响;釆用实时定量(Real-Time)PCR技术,检测槲皮苷(200、400μmol/L)对RANKL诱导的破骨细胞特异性基因NFATc1、TRAP和c-fos表达水平的影响。[结果]细胞生存实验发现槲皮苷干预96 h后,槲皮苷(0~800μmol/L)对RAW 264.7细胞4 d内生存未发现显著影响;通过TRAP染色发现200、400μmol/L槲皮苷能显著抑制体外RANKL诱导的破骨细胞形成;通过骨片吸收实验发现200、400μmol/L槲皮苷3d内能显著降低骨吸收面积,提示其抑制成熟破骨细胞骨吸收功能;同时,槲皮苷能呈剂量依赖性抑制RANKL诱导活化T细胞核因子(nuclear factor of activated T cells,NFAT)c1、TRAP和c-fos基因表达。[结论]槲皮苷通过抑制NFATc1,TRAP和c-fos的表达,来抑制体外RANKL诱导的破骨细胞形成和骨吸收功能,是一种潜在治疗骨质疏松药物。     

柚皮苷对共培养体系中成骨细胞活性及破骨细胞分化的影响

目的研究在成骨细胞-破骨细胞共培养体系中,柚皮苷对成骨细胞活性和破骨细胞分化的影响。方法将成骨细胞(MC3T3-E1细胞株)和破骨细胞(RAW264.7细胞株)以2∶1的比例分别培养至Transwell小室的上室和下室。根据培养基是否含有柚皮苷分为对照组和柚皮苷(2ng/ml组、20 ng/ml组、200 ng/ml组),培养7 d后对下室破骨细胞进行TRAP染色和骨吸收陷窝鉴定;荧光定量PCR分析成骨细胞骨保护素(osteoprotegerin,OPG)、核因子κB受体活化因子配体(receptor activator for nuclear factor-κB ligand,RANKL)基因和破骨细胞分化基因活化T细胞核因子-1(NFATc-1)、活化T细胞核因子-2(NFATc-2)和核因子κB受体激活蛋白(receptor activator of NF-κB,RANK)的相对表达量。结果与对照组相比,柚皮苷可以促进成骨细胞OPG、RANKL的表达量且可提高OPG/RANKL的比值,差异有统计学意义(P0.05);20 ng/ml柚皮苷TRAP(+)细胞数(5.82±3.37)明显少于对照组(20.56±7.69),差异有统计学意义(P0.05);柚皮苷可抑制破骨细胞NFATc-1、NFATc-2的表达,促进RANK的表达,差异有统计学意义(P0.05)。结论柚皮苷可促进共培养条件体系中成骨细胞OPG和RANKL的表达以及抑制破骨细胞的分化,与上调OPG/RANKL的比值有关。     

小剂量地塞米松对生长期小鼠骨微结构及骨代谢的影响

目的 观察小剂量地塞米松对生长期小鼠骨微结构及骨代谢的影响。方法 24只4周龄雌性小鼠随机分两组（n=12）：地塞米松组（DEX,1mg/kg,肌肉注射,2次/周）,对照组。4w后处死小鼠,检测血清Ⅰ型前胶原N端肽(PINP)和骨Ⅰ型胶原交联C端肽（β-CTX）蛋白的表达水平;检测胫骨干骺端骨保护素（OPG）、核因子-κ B受体活化因子配体（RANKL）表达;抗酒石酸酸性磷酸酶（TRAP）染色方法检测破骨细胞;一侧胫骨行显微CT扫描分析。结果 DEX组小鼠胫表观骨密度和骨体积分数明显高于对照组（P<0.05）,骨小梁数量高于对照组,结构模型指数低于对照组,但无统计学意义。DEX组小鼠血清PINP及β-CTX浓度显著下降（P<0.05）。DEX组小鼠胫骨干骺端OPG表达明显增多,而RANKL表达无明显变化,相对于对照组,OPG/RANKL比值升高。TRAP染色示DEX组小鼠胫骨干骺端破骨细胞数量较对照组减少。结论 小剂量地塞米松间断给药可能通过上调OPG/RANKL比率维持生长期小鼠骨量。     

磨损颗粒诱导骨溶解的两种动物模型形态学比较研究

目的建立两种磨损颗粒诱导骨溶解模型,比较炎症水平、骨溶解情况以及破骨细胞计数等指标,为骨溶解相关实验动物模型的选择提供依据。方法分别采用小鼠颅骨模型、小鼠气囊植骨模型制备两组磨损颗粒诱导骨溶解模型。通过HE染色法进行形态学观察;利用扫描电子显微镜观察骨溶解情况;采用TRAP染色法进行破骨细胞计数。结果小鼠气囊植骨模型组骨吸收面积为(385.30±5.11)nm2,明显高于小鼠颅骨模型组的(288.60±4.89)nm2(P0.05);小鼠气囊植骨模型组破骨细胞数目为(16.75±0.53)个,明显高于小鼠颅骨模型组的(9.55±0.48)个(P0.05)。结论两种动物模型均构建成功;小鼠气囊植骨模型在炎症水平、骨溶解情况及破骨细胞计数等方面均优于小鼠颅骨模型,因此在模拟磨损颗粒诱导的骨溶解病理过程中小鼠气囊植骨模型模拟度更高。     

植骨气囊在人工关节松动动物模型实验研究中的应用

目的建立一种人工关节无菌性松动的实验动物模型并且定量评价磨损颗粒诱导的骨溶解。方法在8-10周大的近交系BALB/c小鼠背部注射无菌空气形成气囊，后将近交系小鼠颅骨植入气囊。实验组小鼠气囊内注入聚乙烯磨损颗粒，对照组气囊内注入生理盐水，植骨后14d处死小鼠，取出气囊组织和颅骨骨片进行炎性因子（IT-1、TNF、VEGF）和破骨细胞激活相关基因（RANK/RANKL）的分子生物学检测。结果聚乙烯颗粒刺激组气囊炎性反应较对照组明显，炎性细胞渗出增多，气囊囊壁变厚；在颗粒刺激组的囊壁和骨组织界面上可以观察到大量抗酒石酸酸性磷酸酶染色（TRAP）阳性的破骨细胞，HE染色可见骨表明有明显的点状侵蚀，图像软件分析显示两组间差异均有统计学意义（P〈0.05）。ELISA法和RT-PCR法分别测量囊壁组织内炎性因子IL-1，TNF，VEGF含量和RANK的mRNA含量，两组间的差异均有统计学意义（P〈0.05）。结论植骨气囊模型是一种经济、快速、有效的模拟人工关节松动病理过程的实验动物模型。     

应用颅骨-破骨细胞联合培养体系研究先天性成骨不全破骨细胞骨吸收活性

目的 先天性成骨不全(OI)的主要临床表现为骨矿化过程不良,骨量丢失,骨骼畸形和骨折.但是其发病机理,尤其在其骨再建过程中成骨细胞(OB)及破骨细胞(OC)的功能改变尚不清楚.本实验以先天性成骨不全小鼠模型,oim/oim为基础,应用破骨细胞-颅骨联合培养体系研究OB和OC两种细胞在骨再建过程中的功能改变和相互作用.方法 本实验采用小鼠颅骨(CAL)组织培养模型.本模型采用颅骨组织培养,利用颅骨中成骨细胞可以从颅骨片游离出到培养皿及颅骨表面,从而支持培养皿及颅骨表面前体破骨细胞分化成为成熟破骨细胞,并吸收颅骨产生吸收陷窝.本实验中,共2组颅骨-破骨细胞联合培养体系:(1) 对照组(WT)颅骨与对照破骨细胞(WTCAL-WTOC);(2) OI颅骨与OI破骨细胞(OICAL-OIOC).联合培养颅骨及骨髓组织14日后,以TRAP免疫组化染色方法识别破骨细胞,ALP免疫组化染色方法识别成骨细胞,计算OC/OB.破骨细胞骨吸收活性以颅骨表面骨吸收陷窝占颅骨表面百分比并除以培养系统中的破骨细胞数表达.结果 第14日,OICAL-OIOC组的破骨细胞数低于WTCAL-WTOC组(92.50+23.18/mm2 对比 379.00+ 136.53/mm2,P<0.01); OICAL-OIOC组的OC/OB明显低于WTCAL-WTOC组(0.68+0.57对比1.65+0.67,P<0.01);OICAL-OIOC组OI破骨细胞的吸收能力高于WTCAL-WTOC组(27.76+22.81对比7.32+5.09,P<0.001).结论 oim/oim小鼠破骨细胞-颅骨培养体系中破骨细胞的数目明显减少,成骨细胞支持破骨细胞分化能力减低;但其破骨细胞骨吸收活性明显增强,以代偿成骨细胞功能,维持骨再建过程中成骨过程及骨吸收过程的平衡.     

NF-κB受体激活因子配体抗体防治人工关节无菌性松动的实验研究

目的人工关节无菌性松动与破骨细胞激活后假体周围骨溶解有关,而NF-κB受体激活因子配体(receptor activator of NF-κB ligand,RANKL)/NF-κB受体激活因子(receptor activator of NF-κB,RANK)信号通路是激活破骨细胞的主要途径,通过建立小鼠气囊植骨模型模拟人工关节无菌性松动环境,观察RANKL抗体抑制炎性反应、减轻溶骨反应的作用。方法取8～10周龄雌性BALB/c小鼠60只(体重18～20 g),取其中20只小鼠颅骨制备骨片,作为气囊植骨供体;剩余40只小鼠随机分为阴性对照组(A组)、阳性对照组(B组)、RANKL抗体低剂量组(C组)和RANKL抗体高剂量组(D组),每组10只。于各组小鼠背部制备2 cm×2 cm大小的气囊后植入1片骨片;于植骨后1 d,A组气囊内注射0.5 mL PBS液;B、C、D组注射0.5 mL钛颗粒悬液。钛颗粒悬液注射前2 d,C、D组气囊内分别注射0.1 mL浓度为50μg/mL和500μg/mL的RANKL抗体,每天1次,连续2 d;A、B组注射0.1 mL PBS液。于植骨后14 d处死全部小鼠,取出植入颅骨骨片和周围囊壁组织,进行大体及组织学观察,并行颅骨骨溶解、骨胶原含量及破骨细胞含量分析。结果各组小鼠均存活至实验完成,切口愈合良好。大体观察见A、C、D组小鼠囊壁炎性反应较轻,偶见渗出和新生血管增生;B组炎性反应严重,见渗出以及新生血管增生。组织学观察见A、C、D组小鼠囊壁炎性细胞浸润及增厚不明显,骨胶原丢失量和破骨细胞含量少;B组大量炎性细胞浸润,囊壁增厚,骨胶原丢失量和破骨细胞含量多。B组炎性细胞数、囊壁厚度、骨胶原丢失量以及破骨细胞含量与A、C、D组比较,差异均有统计学意义(P<0.05)。结论 RANKL抗体可阻断小鼠气囊植骨模型的炎症信号传导通路,有效抑制磨损颗粒所致骨溶解。     

Inhibiting wear particles-induced osteolysis with naringin

Purpose

The purpose of this study was to determine the effects of naringin on osteoclastogenesis and osteolysis both in vitro and in vivo.

Methods

In this research osteoclasts were generated from mouse bone marrow monocytes with the receptor activator of NF-КB ligand and the macrophage colony stimulating factor. Naringin, at a concentration of 1, 10, 50, and 100 μg/mL, was respectively added to the medium. Seven days later, the osteoclasts were determined through tartrate-resistant acid phosphatase (TRAP) staining. Mature osteoclasts were isolated from newborn rabbits and cultured for three days on bone slices. Naringin at a concentration of 1, 10, 50, and 100 μg/mL was respectively added to the medium. The resorption bone slices were quantified, and the area was calculated after toluidine blue and Mayer-hematoxylin staining. Polymethyl methacrylate (PMMA) particles were implanted on the calvariae of C57BL/J6 mice. Naringin, at a dose of 50 μg/kg and 100 μg/kg, was respectively given intraperitoneally for seven. Seven days later, the calvariae were removed and processed for pathological analysis.

Results

The result indicated that naringin treatment effectively inhibited in vitro osteoclastogenesis and inhibited mature osteoclasts. In vivo data indicated that naringin strongly inhibited PMMA-induced osteolysis.

Conclusion

Naringin can effectively inhibit osteoclastogenesis and suppress wear particles-induced osteolysis and might be useful in the treatment or prevention of wear particles-induced osteolysis and aseptic loosening for its effect on osteoclast generation and function.     

Naringin promotes osteoblast differentiation and effectively reverses ovariectomy-associated osteoporosis

Background

Osteoporosis is a common pathological condition that influences 20 % of women over 50 years of age. This condition decreases bone strength and increases the risk of bone fracture. Naringin is a major flavonoid found in grapefruit and an active compound extracted from a Chinese herbal medicine (Rhizoma Drynariae). Studies have shown that naringin possesses many pharmacological effects. The current study evaluated the influence of naringin on osteoblastic cell differentiation and proliferation, and assessed its therapeutic effects on a rat osteoporosis model.

Method

The proliferation, differentiation, and function of rat bone marrow stromal cells (BMSCs) were determined following treatment with various concentrations of naringin. Ovariectomy (OVX)-induced osteoporotic rats were orally administered naringin daily at low, medium, and high dosages, while a control group received PBS for 2 months. Femoral X-ray images and microCT scans were used for bone mineral density (BMD) and BV/TV (bone volume/total volume) analyses, and histological assessments of left tibiae were employed to check for changes in trabecular thickness (Tb.Th) and trabecular space (Tb.Sp) in the groups.

Results

Naringin was effective at enhancing the proliferation and osteogenic differentiation of BMSCs, and a concentration of 10 μg/ml prompted the highest levels of osteocalcin expression among the in vitro study groups. There appeared to be a delayed response pattern of BMSCs to the naringin treatment. Naringin also effectively reversed OVX-induced bone loss via increasing BMD, bone volume, and trabecular thickness. The medium dose (300 mg/kg) appeared to be the optimal dosage for delivering satisfactory therapeutic effects.

Conclusion

Naringin promotes the proliferation and differentiation of BMSCs, and increases osteocalcin expression. Naringin also effectively reverses ovariectomy-induced osteoporosis in rats. The study suggests that naringin administration may represent an effective treatment for osteoporosis.     

Ameliorative effect of naringin in acetaminophen-induced hepatic and renal toxicity in laboratory rats: role of FXR and KIM-1

Context: Acetaminophen (APAP) is an analgesic and antipyretic agent commonly known agent to cause hepatic and renal toxicity at a higher dose. Naringin, a bioflavonoid possesses multiple pharmacological properties such as antioxidant, anti-inflammatory, analgesic and anti-hyperlipidemic activity. Objective: To evaluate the effect of naringin against the APAP-induced hepatic and renal toxicity. Materials and methods: Male Wistar albino rats (180–220?g) were divided into various groups, and toxicity was induced by APAP (700?mg/kg, p.o., 14 days). Naringin (20, 40 and 80?mg/kg, p.o.) or Silymarin (25?mg/kg) was administered to rats 2?h before APAP oral administration. Various biochemical, molecular and histopathological parameter were accessed in hepatic and renal tissue. Results: Naringin pretreatment significantly decreased (p?p?p?p?Conclusion: Naringin exerts its hepato- and nephroprotective effect via modulation of oxido-nitrosative stress, FXR and KIM-1 mRNA expression.     

Naringin ameliorates sodium arsenite-induced renal and hepatic toxicity in rats: decisive role of KIM-1, Caspase-3, TGF-β, and TNF-α

Abstract

Chronic exposure of a naturally occurring metal arsenic leads to renal and hepatic diseases. Naringin, a flavanone glycoside, possesses anti-inflammatory and anti-oxidant potential. The aim of this investigation was to evaluate the protective effect of naringin against arsenic-induced renal and hepatic toxicity in rats. Renal and hepatic toxicity was induced in rats by sodium arsenite (5?mg/kg, p.o.). Rats were treated orally with either vehicle or naringin (20, 40, and 80?mg/kg) or Coenzyme Q10 (10?mg/kg) for 28 days. Various biochemical, histological, and molecular biomarkers were assessed in kidney and liver. Treatment with naringin (40 and 80?mg/kg) significantly and dose-dependently restored (p?<?0.01 and p?<?0.001) altered levels of kidney (serum creatinine, urine creatinine, BUN, uric acid, and creatinine clearance) and liver function test (AST and ALT) induced by sodium arsenite. Elevated levels of oxido-nitrosative stress in renal and hepatic tissue was significantly and dose-dependently decreased (p?<?0.01 and p?<?0.001) by naringin (40 and 80?mg/kg) treatment. It significantly and dose-dependently down-regulated (p?<?0.01 and p?<?0.001) renal KIM-1, Caspase-3, TGF-β, and TNF-α mRNA expression. Histopathological alteration induced in kidney and liver by sodium arsenite was reduced by naringin (40 and 80?mg/kg) treatment. In conclusion, naringin treatment ameliorates arsenic-induced renal and hepatic damage in rats due its antioxidant and anti-inflammatory properties via down-regulation of elevated oxido-nitrosative stress, KIM-1, Caspase-3, TGF-β, and TNF-α levels.     

Polymethylmethacrylate particles stimulate bone resorption of mature osteoclasts in vitro

Background?Interaction between wear particle debris and the cells at the implant-bone interface is an important contributory factor to periprosthetic bone loss seen in arthroplasties.

Method?To investigate the effect of this particle-induced response on different stages of osteoclast maturation, polymethylmethacrylate (PMMA) particles were added to a murine osteoclastogenic bone marrow cell culture system at either day 0, day 4, or day 8 of culture, which represented PMMA particle stimulation of precursor osteoclasts, mature osteoclasts, or end-stage osteoclasts, respectively. The number of TRAP-posi-tive multinucleate cells (MNCs) and the degree of bone resorption in culture were measured

Results?Treatment of precursor osteoclasts with PMMA particles resulted in a statistically significant increase in TRAP-positive MNCs that persisted for 4 days, but there was no significant increase in bone resorption. Addition of particles to mature osteoclasts resulted in a significant increase in the number of TRAP-positive MNCs that lasted for 8 days, and also a significant increase in bone resorption. Treatment of end-stage osteoclasts with PMMA particles did not result in an increased number of TRAP-positive MNCs and there was no increase in bone resorption.

Interpretation?Treatment of mature osteoclasts with PMMA particles resulted in an elevated number of TRAP-positive cells. This persisted over a longer period of time than at the other stages of osteoclast development, and there was also a greater increase in bone resorption.     

铁死亡在肝缺血—再灌注损伤大鼠肠损伤中的作用

目的 探究铁死亡在肝缺血-再灌注损伤(HIR)大鼠肠损伤中的作用。方法 选择健康清洁级雄性SD大鼠40只,周龄8～10周,体重220～260 g。采用随机数字表法将大鼠分成四组：假手术组(S组)、铁死亡抑制剂Ferrostatin-1+假手术组(SF组)、HIR模型组(IR组)和铁死亡抑制剂Ferrostatin-1+HIR模型组(IF组),每组10只。S组腹腔注射等容量0.02%DMSO,30 min后行假手术,仅进行开腹、分离第一肝门和关腹处理。SF组腹腔注射Ferrostatin-1(溶于0.02%DMSO)5 mg/kg, 30 min后行假手术。IR组腹腔注射等容量0.02%DMSO,30 min后制备HIR模型。IF组腹腔注射Ferrostatin-1(溶于0.02%DMSO)5 mg/kg, 30 min后制备HIR模型。于再灌注后8 h处死大鼠,取小肠组织,采用ELISA法检测肠组织丙二醛(MDA)、谷胱甘肽(GSH)和铁(Fe²⁺)浓度;采用速率法检测血清中ALT和AST活性;采用Western blot法检测谷胱甘肽过氧化物酶4(GPX4)、铁...     

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

BackgroundBased on a rat model of human relatively high exposure to cigarette smoke, this study aimed to estimate whether Epimedium pubescen flavonoid (EPF) may prevent a smoke-induced decrease in bone mineral density (BMD) and weakening of the biomechanical properties of bone.MethodsFifty male Wistar rats were randomized into five groups: controls, passively smoking groups and passively smoking rats administered EPF at three dosage levels (75, 150 or 300 mg/kg/day) in drinking water for 4 months. A rat model of passive cigarette smoking was prepared by breeding male rats in a cigarette-smoking box for 4 months. Bone metabolic makers, BMD and biomechanical properties of the femoral distal end and femoral diaphysis were examined.ResultsExposure to cigarette smoke decreased the BMD, affected bone turnover (inhibited bone formation and stimulated its resorption) and weakened the biomechanical properties of the femur at its distal end and diaphysis. EPF supplementation during cigarette smoke exposure prevented the decrease in BMD, accelerated bone turnover and weakened the biomechanical properties of bone.ConclusionOur data suggest that EPF supplementation can prevent the adverse effects of smoke exposure on BMD and biomechanical properties by inhibiting bone turnover and preventing bone resorption, and in this way it can decrease the risk of bone fractures.     

Interferon-gamma production changes in parallel with bacterial lipopolysaccharide induced bone resorption in mice: an immunohistometrical study

It has been reported that bacterial lipopolysaccharide (LPS) induces alveolar bone resorption and that the host immune system, especially activated T cells, plays a crucial role in osteoclastogenesis. On the other hand, interferon-gamma (IFN-g), which is produced by activated T cells, suppresses bone resorption both in vitro and in vivo. Thus, the question arises as to whether or not IFN-g production increases with increasing bone resorption. We previously demonstrated that repeated injections of Escherichia coli LPS into mouse gingiva causes osteoclast formation in alveolar bone. In the present study we observed changes in the IFN-g production of infiltrating cells in concurrence with bone resorption. Mice were repeatedly injected with 5 mg LPS 26 times every 48 hours. After the 16th injection, when the alveolar bone resorption reached a plateau, the concentration of LPS was altered (25 mg LPS or PBS alone). The level of bone resorption became significantly elevated, and the number of IFN-g- and interleukin-1 beta (IL-1b)-bearing cells also increased significantly in relation to bone resorption within the 25 mg LPS-injected group. On the other hand, few tartrate-resistant acid phosphatase positive cells, or IFN-g- and IL-1b-bearing cells, were seen in the PBS-injected group. These results suggest that alteration in IFN-g-bearing cells might play a role in counterbalancing LPS-induced bone resorption resulting from osteoclast activating cytokines such as IL-1b.     

Effects of acetylsalicylic acid and naproxen on bone resorption and formation in rats

Summary The influence of acetylsalicylic acid (ASA) (150mg/kg/12h) and naproxen (20mg/kg/12h) on bone metabolism in young male rats has been studied. The doses were chosen to provide serum concentrations comparable with ordinary anti-inflammatory steady-state levels in humans. After the rats had been prelabeled with collagen- and mineral-tracing radioisotopes the rats received the drugs by gavage twice a day for 9 and 18 days. Bone resorption was measured as loss of carbon-labeled hydroxyproline (collagen) and strontium-85 (minerals). At 9 days ASA had retarded both collagen and mineral resorption in the femur by about 10% compared with controls. The resorption of both collagen and minerals was inhibited. After 18 days' treatment there were no differences regarding bone resorption, but bone formation had decreased by about 10% in the ASA-treated animals, as measured by net increases of collagen and calcium in the femur. Naproxen did not influence bone resorption or formation significantly. The results indicate an inhibitory effect of ASA on bone resorption and formation in growing rats, whereas the effect of naproxen seems negligible.

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Zusammenfassung Es wird über die Wirkung von Azetylsalizylsaure (ASS) in einer Dosis von 150mg/kg/12 Std bzw. Naproxen (20 mg/kg/12 Std) auf den Knochenstoffwechsel junger mdnnlicher Ratten berichtet. Die erreichten Serumkonzentrationen entsprachen dem antiinflammatorischen Niveau, das in der Humanmedizin erstrebt wird. Nach Isotopenmarkierung des Knochenkollagens and -minerals erhielten die Ratten 2mal täglich fiir die Dauer von 9 and 18 Tagen ASS bzw. Naproxen. Gemessen an der Abnahme der Kollagen- and Mineralisotope zeigten die mit ASS behandelten Ratten eine Herabsetzung der Knochenresorption nach 9, aber nicht nach 18 Tagen. Beurteilt nach Kollagen- and Calziumgehalt, wurde statt dessen nach diesem Zeitraum eine Verminderung des Knochenneubaus gefunden. Naproxen führte zu keiner Beeinflussung dieser Werte. Mit dieser Untersuchung konnte gezeigt werden, daß die Umbauvorgange des wachsenden Knochens durch ASS, aber nicht durch Naproxen beeinfluBt werden.