黄芩苷抑制牙周炎牙槽骨吸收的作用及机理研究
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摘要
牙周炎的破坏过程,是菌斑和宿主之间通过复杂的分子机制相互作用的结果。宿主的防御过程分为非特异性的炎症反应和特异性的免疫应答反应(包括体液免疫、细胞免疫和补体系统)。牙周炎可以说是一种由细菌引起的免疫炎症性疾病,它的发生、发展与免疫细胞及其相关因子的参与有关。
牙槽骨吸收是牙周炎的主要病理变化之一。在牙周炎的治疗中,主要为控制或消除炎症并促进组织再生。应用药物控制炎症、阻断牙槽骨吸收和促进骨再生是不可缺少的一种治疗方法。一些中草药的提取物或单体被证实具有抗炎和直接或间接的抑制破骨细胞分化和功能的作用。
黄芩苷(baicalin)是由唇形科植物黄芩(ScutellariabaicalensiGeorgi)的干燥根中提取的一种黄酮类化合物。黄芩苷是黄芩及其制剂的主要质量控制指标成分。据药理学研究报道,黄芩苷具有显著的抗炎作用,可抑制促进破骨细胞活化和功能的各种因子的产生。一系列的研究提示黄芩苷在牙周病的防治方面具有一定的应用前景。但其在药理作用的机理研究方面尚有很多工作要做。
牙周炎时,T细胞数量、活性增高,导致炎症细胞因子分泌增加,加重牙周炎症和骨吸收。TGF-β可以抑制T细胞的活性和增殖。因而设想黄芩苷的抗炎抗骨吸收的作用可能通过TGF-β起作用,而巨噬细胞是分泌TGF-β的主要来源。故此,我们提出黄芩苷抑制牙周炎牙槽骨吸收的机理可能是:通过促进巨噬细胞分泌TGF-β,从而抑制T细胞的活性、增殖和数量,导致T细胞产生的TNF等炎性因子减少,进一步引起RANKL诱导的破骨细胞形成减少,从而使牙槽骨丧失减缓或停止,牙周炎症减轻。
本实验的目的:①通过动物实验,从Micro-CT和组织学的角度研究黄芩苷对实验性牙周炎牙槽骨吸收的影响;②研究黄芩苷对巨噬细胞分泌TGF-β1的影响;③利用基因干涉技术,将TGF-β基因沉默。研究当TGF-β基因沉默后,黄芩苷是否能够使牙周膜成纤维细胞分泌RANKL/OPG的比值降低。从而证实黄芩苷是否通过TGF-β抑制T细胞的活性、增殖和数量,导致T细胞产生的TNF等炎性因子减少,进一步使牙周膜成纤维细胞分泌RANKL/OPG的比值降低。初步揭示黄芩苷的作用机理,为将黄芩苷应用于牙周病的防治提供理论和实验依据。
一.黄芩苷对实验性牙周炎牙槽骨吸收的影响
建立大鼠牙周炎模型,局部注射黄芩苷,利用micro–CT和组织学检查观察黄芩苷对实验性牙周炎牙槽骨吸收的影响。micro–CT构建出大鼠牙槽骨结构的计算机三维图像数据集,得到良好的视觉效果的同时测定骨小梁的三维结构参数,从而获得黄芩苷抑制大鼠牙周炎牙槽骨吸收的更为直观和确切的证据。结果证实黄芩苷可以有效的抑制LPS诱导的大鼠牙周炎牙槽骨的吸收, 1.0μg/ml的黄芩苷较之0.1μg/ml的黄芩苷具有更好的效果。
二.黄芩苷对巨噬细胞分泌TGF-β1的影响
体外分离培养人巨噬细胞,将不同浓度的黄芩苷加入培养液,48h后用RT-PCR、Western blot技术检测各组细胞TGFβ1表达情况。发现巨噬细胞在不同浓度黄芩苷的作用下, TGFβ1mRNA的表达和蛋白表达均随黄芩苷浓度的增加而增加(P <0.05)。其中, 1.0μg/ml浓度黄芩苷作用最为显著。本实验证实了黄芩苷可以促进巨噬细胞产生TGFβ1。
三. TGF-βⅡR特异性siRNA表达载体的构建及鉴定
根据GeneBank中报道的TGFβⅡR核苷酸序列,参考siRNA的设计原则,按照pSilencer3.1H1载体的设计要求,设计2条siRNA序列。合成的单链寡核苷酸链经退火、磷酸化后形成双链DNA,定向插入pSilencer3.1H1载体,转化感受态细胞增菌后提取质粒。DNA测序证实该重组质粒序列与所设计序列完全一致,表明针对TGF-βⅡR基因的siRNA表达载体已构建成功。为下一步研究工作的开展奠定了良好基础。
四. siRNA转染T细胞并鉴定
用成功构建的2种针对HBV基因的siRNA表达载体pSilencer3.1H1-TGF-βⅡR(1-2)转染稳定表达TGF-βⅡR的T细胞,经潮霉素筛选获得稳定的单克隆细胞株。筛选出的单克隆细胞的流式细胞分析结果和细胞生长曲线显示,细胞周期、增殖指数以及细胞生长速度与对照无显著差异,提示导入TGF-βⅡR特异性siRNA表达载体对T细胞的生长无明显影响。RT-PCR结果证实siRNA能降低TGF-βⅡR mRNA的表达。Western blot结果证实siRNA能抑制T细胞内TGF-βⅡR蛋白的合成。
五.黄芩苷对牙周膜细胞OPG-RANKL表达的影响
将正常牙周膜成纤维细胞与转染和未转染siRNA的T细胞置于加有内毒素和黄芩苷的培养液中,分为6组,观察黄芩苷对正常牙周膜成纤维细胞上OPG– RANKL表达的影响。研究结果证实黄芩苷可以降低PDLC表面RANKL/OPG比值,同时表明TGF-β的信号传导在黄芩苷影响PDLC表面的RANKL/OPG比值的过程中起到重要的作用。分析认为黄芩苷可能通过增强TGF-β对T细胞的抑制作用,引起T细胞活性降低、数量减少,导致T细胞在内毒素作用下分泌的TNF-α等炎症因子减少,降低RANKL/OPG比值,进而降低破骨细胞形成,减少骨丢失,降低牙周炎进展的危险因素。本研究还发现黄芩苷除了通过TGFβ途径外,还可能有其他的通路对PDLC表面的RANKL/OPG进行调控。
结论:黄芩苷可以有效的抑制牙周炎牙槽骨的吸收。其作用机制可能为:黄芩苷促进巨噬细胞分泌TGF-β,从而抑制T细胞的活性、增殖和数量,导致T细胞产生的TNF等炎性因子减少,进一步引起RANKL诱导的破骨细胞形成减少,从而使牙槽骨丧失减缓或停止,牙周炎症减轻。
The destruction procedures of periodontitis are the interactive results between bacteria plaque and host through complicate molecule mechanisms. Host defense include nonspecific inflammatory reaction and specific immune response (included that humoral immunity, cell immunity and complement system). Periodontitis disease is an Immune-inflammatory disease caused by bacteria. The occurrence and development of periodontitis are concerned with immunologic cell and correlation factors.
Frontal resorption is one of the main pathological changes of periodontitis. The aims of periodontitis treatment are to control or eliminate inflammation and to encourage reorganization. Drug control is sine qua non method to eliminate inflammation, block up frontal resorption and promote osteanagenesis. Extractive or monomers of some Chinese medicinal herb were confirmed to be equipped with effect ion of anti-inflammatory and direct or indirect inhibition for differentiation and functional of osteoclast.
Baicalin is a flavonoid extracted from the dry root of Labiatae plant Scutellaria. Baicalin is the main indicator component of quality control of Scutellaria and its preparation. According to pharmacological research reports, baicalin has outstanding anti-inflammatory activities and it can inhibit the generation of various kinds factors which encouraged the differentiation and functional of osteoclast. Serial research hint that Baicalin is a promising biological active ingredient for the prevention and cure of periodontitis, but there is still a lot of work on the research of its pharmacological mechanism.
During the procedure of periodontitis, the number and activity of T cell rise, so do many inflammatory cell factors, which aggravate the inflammation of periodontium and bone resorption. TGF-βcan suppress the activity and generation of T cells. Then, it is assumed that the mechanism of baicalin’s anti-inflammatory and anti- frontal resorption activities were related with TGF-β. TGF-βare mainly secreted by macrophage. So, the presumption of the mechanism of baicalin’s anti- frontal resorption activities formed: baicalin may encourage macrophage secret TGF-β, then enhance the inhibition of TGF-βto T cell, causing decrease in the number and activity of T cells, leading to decreased of TNF-αand other inflammatory factors secreted by T-cell under the effect of endotoxin and reduced OPG–RANKL ratio, which further resulted in decreased osteoclast formation and bone loss and the risk factor of periodontitis.
The purposes of this study were:①through animal experiment, to study the effect of baicalin on alveolar bone resorption by micro-CT and histological.②To study the effect of baicalin on TGFβ1 in macrophage.③Through RNA interference, RNA of TGFβ1 was silenced. Then, the effects of baicalin on the ratio of RANKL/OPG in HPDL cells were studied. It was confirmed that baicalin diminished the ratio of RANKL/OPG in HPDL cells through TGF-β. Baicalin inhibit the activity, quantity and generation of T cells through TGF-βand then, inflammatory factors secreted by T cell were diminished, further, the ratio of RANKL/OPG in HPDL cells step down. It was revealed the action mechanism of baicalin initially and provided the base in theory and experiment for the prevention and cure of periodontal disease.
1. Influence of baicalin on alveolar bone absorption in rats with periodontitis
Establishing the animal model of periodontitis firstly, baicalin were injected repeat at the same time, then, the effects of baicalin on alveolar bone resorption were studied by micro-CT and histological. In this study, by performing ultrahigh-resolution micro-CT scans of alveolar bone, it was confirmed that baicalin could inhibit the alveolar bone absorption induced by Lipopolysaccharide (LPS). Compared with baicalin solution of 0.1μg / ml, baicalin solution of 1.0μg / ml had stronger inhibition.
2. Effect of baicalin on TGFβ1 in macrophage
Macrophages were cultivated in vitro firstly. Then, under different concentration of baicalin, expression of TGFβ2 in macrophages was detected with RT-PCR and Western-blot. The results showed that baicalin could promote the expression of TGFβ1 in macrophage and the expression of TGFβ2 increased with the rising of baicalin concentration (P <0.05). Baicalin of 1.0μg / ml had the more significant effect.
3. Establishment of siRNA Eukaryotic Expression Vectors of Recombinant Targeting Gene TGF-βⅡR
Referring to the design principles of siRNA , two siRNA sequences were designed according to the TGF-βRⅡnucleotide sequence reported in GeneBank, and the design requirements of pSilencer3.1H1 vector(Ambion,Inc). TGF-βRⅡ siRNA transcription template was synthesized. Annealing products were connected directly with pSilencer3.1H1 vector which had been digested by BamHⅠand HindⅢbefore. Then, DH5αcompetent cells were transformed by the connected products. The sequencing results are exactly the same as the designed sequence, which means that the siRNA expression vector targeted TGF-βRⅡhas been constructed successfully.
4. T cells transfection and identification
T cells that express TGF-βⅡR stablely were transfected by pSilencer3.1H1-TGF-βⅡR(1-2). Unicellular suspension was prepared with monoclonal cell strain of stably transfected siRNA1 and siRNA2. The growth rate of T cells that transfected with siRNA1 and siRNA2 stably are similar to that of normal T cells’in control group, the differences between each group have no statistics significance (P> 0.05). Both the results of RT-PCR and Western blot have shown that the belt of TGF-βRⅡin T cells transfected with siRNA1 is obviously darker than the control zone, while the belt of TGF-βRⅡin T cells transfected with siRNA2 has no significant changes compared with the control group. It illustrates that the expression of TGF-βRⅡin T cells transfected with siRNA1 has been inhibited significantly, which means that the degradation effect of siRNA1 on TGF-βRⅡmRNA in T cells are characteristic and high performance.
5. Effect of baicalin on RANKL/OPG in HPDL cells
T cells transfected siRNA1or not together with HPDL cells were place in the medium that had been added with baicalin and LPS. They were divided into six groups and cultured for 48 hours. RT-PCR was used to detect the expression of RANKL and OPG in HPDL cells and observe whether baicalin could affect expression of RANKL-OPG in HPDL cells with and without TGFβsignal transduction. It demonstrated that TGF-βsignaling transduction played an important role in the effect of baicalin on RANKL / OPG ratio in HPDL cells. This study supported that baicalin may enhance the inhibition of TGF-βto T cell, decrease the number or activity of T cells and decreas TNF-αand other inflammatory factors, which are secreted by T-cell under the effect of LPS, then reduced OPG–RANKL ratio, which further resulted in decreasing of osteoclast formation and bone loss. The study also found that baicalin not only act through TGFβto regulate RANKL / OPG ratio in HPDL cells, but also act through other pathway.
Conclusion: Baicalin can inhibit alveolar bone absorption effectively. The mechanism of action may be that: baicalin could promote the expression of TGFβ1 in macrophage and then, enhance the inhibition of TGF-βto T cell, decrease the number or activity of T cells and decreas TNF-αand other inflammatory factors (which are secreted by T-cell under the effect of LPS) then reduced OPG–RANKL ratio, which further resulted in decreasing of osteoclast formation and bone loss.
牙槽骨吸收是牙周炎的主要病理变化之一。在牙周炎的治疗中,主要为控制或消除炎症并促进组织再生。应用药物控制炎症、阻断牙槽骨吸收和促进骨再生是不可缺少的一种治疗方法。一些中草药的提取物或单体被证实具有抗炎和直接或间接的抑制破骨细胞分化和功能的作用。
黄芩苷(baicalin)是由唇形科植物黄芩(ScutellariabaicalensiGeorgi)的干燥根中提取的一种黄酮类化合物。黄芩苷是黄芩及其制剂的主要质量控制指标成分。据药理学研究报道,黄芩苷具有显著的抗炎作用,可抑制促进破骨细胞活化和功能的各种因子的产生。一系列的研究提示黄芩苷在牙周病的防治方面具有一定的应用前景。但其在药理作用的机理研究方面尚有很多工作要做。
牙周炎时,T细胞数量、活性增高,导致炎症细胞因子分泌增加,加重牙周炎症和骨吸收。TGF-β可以抑制T细胞的活性和增殖。因而设想黄芩苷的抗炎抗骨吸收的作用可能通过TGF-β起作用,而巨噬细胞是分泌TGF-β的主要来源。故此,我们提出黄芩苷抑制牙周炎牙槽骨吸收的机理可能是:通过促进巨噬细胞分泌TGF-β,从而抑制T细胞的活性、增殖和数量,导致T细胞产生的TNF等炎性因子减少,进一步引起RANKL诱导的破骨细胞形成减少,从而使牙槽骨丧失减缓或停止,牙周炎症减轻。
本实验的目的:①通过动物实验,从Micro-CT和组织学的角度研究黄芩苷对实验性牙周炎牙槽骨吸收的影响;②研究黄芩苷对巨噬细胞分泌TGF-β1的影响;③利用基因干涉技术,将TGF-β基因沉默。研究当TGF-β基因沉默后,黄芩苷是否能够使牙周膜成纤维细胞分泌RANKL/OPG的比值降低。从而证实黄芩苷是否通过TGF-β抑制T细胞的活性、增殖和数量,导致T细胞产生的TNF等炎性因子减少,进一步使牙周膜成纤维细胞分泌RANKL/OPG的比值降低。初步揭示黄芩苷的作用机理,为将黄芩苷应用于牙周病的防治提供理论和实验依据。
一.黄芩苷对实验性牙周炎牙槽骨吸收的影响
建立大鼠牙周炎模型,局部注射黄芩苷,利用micro–CT和组织学检查观察黄芩苷对实验性牙周炎牙槽骨吸收的影响。micro–CT构建出大鼠牙槽骨结构的计算机三维图像数据集,得到良好的视觉效果的同时测定骨小梁的三维结构参数,从而获得黄芩苷抑制大鼠牙周炎牙槽骨吸收的更为直观和确切的证据。结果证实黄芩苷可以有效的抑制LPS诱导的大鼠牙周炎牙槽骨的吸收, 1.0μg/ml的黄芩苷较之0.1μg/ml的黄芩苷具有更好的效果。
二.黄芩苷对巨噬细胞分泌TGF-β1的影响
体外分离培养人巨噬细胞,将不同浓度的黄芩苷加入培养液,48h后用RT-PCR、Western blot技术检测各组细胞TGFβ1表达情况。发现巨噬细胞在不同浓度黄芩苷的作用下, TGFβ1mRNA的表达和蛋白表达均随黄芩苷浓度的增加而增加(P <0.05)。其中, 1.0μg/ml浓度黄芩苷作用最为显著。本实验证实了黄芩苷可以促进巨噬细胞产生TGFβ1。
三. TGF-βⅡR特异性siRNA表达载体的构建及鉴定
根据GeneBank中报道的TGFβⅡR核苷酸序列,参考siRNA的设计原则,按照pSilencer3.1H1载体的设计要求,设计2条siRNA序列。合成的单链寡核苷酸链经退火、磷酸化后形成双链DNA,定向插入pSilencer3.1H1载体,转化感受态细胞增菌后提取质粒。DNA测序证实该重组质粒序列与所设计序列完全一致,表明针对TGF-βⅡR基因的siRNA表达载体已构建成功。为下一步研究工作的开展奠定了良好基础。
四. siRNA转染T细胞并鉴定
用成功构建的2种针对HBV基因的siRNA表达载体pSilencer3.1H1-TGF-βⅡR(1-2)转染稳定表达TGF-βⅡR的T细胞,经潮霉素筛选获得稳定的单克隆细胞株。筛选出的单克隆细胞的流式细胞分析结果和细胞生长曲线显示,细胞周期、增殖指数以及细胞生长速度与对照无显著差异,提示导入TGF-βⅡR特异性siRNA表达载体对T细胞的生长无明显影响。RT-PCR结果证实siRNA能降低TGF-βⅡR mRNA的表达。Western blot结果证实siRNA能抑制T细胞内TGF-βⅡR蛋白的合成。
五.黄芩苷对牙周膜细胞OPG-RANKL表达的影响
将正常牙周膜成纤维细胞与转染和未转染siRNA的T细胞置于加有内毒素和黄芩苷的培养液中,分为6组,观察黄芩苷对正常牙周膜成纤维细胞上OPG– RANKL表达的影响。研究结果证实黄芩苷可以降低PDLC表面RANKL/OPG比值,同时表明TGF-β的信号传导在黄芩苷影响PDLC表面的RANKL/OPG比值的过程中起到重要的作用。分析认为黄芩苷可能通过增强TGF-β对T细胞的抑制作用,引起T细胞活性降低、数量减少,导致T细胞在内毒素作用下分泌的TNF-α等炎症因子减少,降低RANKL/OPG比值,进而降低破骨细胞形成,减少骨丢失,降低牙周炎进展的危险因素。本研究还发现黄芩苷除了通过TGFβ途径外,还可能有其他的通路对PDLC表面的RANKL/OPG进行调控。
结论:黄芩苷可以有效的抑制牙周炎牙槽骨的吸收。其作用机制可能为:黄芩苷促进巨噬细胞分泌TGF-β,从而抑制T细胞的活性、增殖和数量,导致T细胞产生的TNF等炎性因子减少,进一步引起RANKL诱导的破骨细胞形成减少,从而使牙槽骨丧失减缓或停止,牙周炎症减轻。
The destruction procedures of periodontitis are the interactive results between bacteria plaque and host through complicate molecule mechanisms. Host defense include nonspecific inflammatory reaction and specific immune response (included that humoral immunity, cell immunity and complement system). Periodontitis disease is an Immune-inflammatory disease caused by bacteria. The occurrence and development of periodontitis are concerned with immunologic cell and correlation factors.
Frontal resorption is one of the main pathological changes of periodontitis. The aims of periodontitis treatment are to control or eliminate inflammation and to encourage reorganization. Drug control is sine qua non method to eliminate inflammation, block up frontal resorption and promote osteanagenesis. Extractive or monomers of some Chinese medicinal herb were confirmed to be equipped with effect ion of anti-inflammatory and direct or indirect inhibition for differentiation and functional of osteoclast.
Baicalin is a flavonoid extracted from the dry root of Labiatae plant Scutellaria. Baicalin is the main indicator component of quality control of Scutellaria and its preparation. According to pharmacological research reports, baicalin has outstanding anti-inflammatory activities and it can inhibit the generation of various kinds factors which encouraged the differentiation and functional of osteoclast. Serial research hint that Baicalin is a promising biological active ingredient for the prevention and cure of periodontitis, but there is still a lot of work on the research of its pharmacological mechanism.
During the procedure of periodontitis, the number and activity of T cell rise, so do many inflammatory cell factors, which aggravate the inflammation of periodontium and bone resorption. TGF-βcan suppress the activity and generation of T cells. Then, it is assumed that the mechanism of baicalin’s anti-inflammatory and anti- frontal resorption activities were related with TGF-β. TGF-βare mainly secreted by macrophage. So, the presumption of the mechanism of baicalin’s anti- frontal resorption activities formed: baicalin may encourage macrophage secret TGF-β, then enhance the inhibition of TGF-βto T cell, causing decrease in the number and activity of T cells, leading to decreased of TNF-αand other inflammatory factors secreted by T-cell under the effect of endotoxin and reduced OPG–RANKL ratio, which further resulted in decreased osteoclast formation and bone loss and the risk factor of periodontitis.
The purposes of this study were:①through animal experiment, to study the effect of baicalin on alveolar bone resorption by micro-CT and histological.②To study the effect of baicalin on TGFβ1 in macrophage.③Through RNA interference, RNA of TGFβ1 was silenced. Then, the effects of baicalin on the ratio of RANKL/OPG in HPDL cells were studied. It was confirmed that baicalin diminished the ratio of RANKL/OPG in HPDL cells through TGF-β. Baicalin inhibit the activity, quantity and generation of T cells through TGF-βand then, inflammatory factors secreted by T cell were diminished, further, the ratio of RANKL/OPG in HPDL cells step down. It was revealed the action mechanism of baicalin initially and provided the base in theory and experiment for the prevention and cure of periodontal disease.
1. Influence of baicalin on alveolar bone absorption in rats with periodontitis
Establishing the animal model of periodontitis firstly, baicalin were injected repeat at the same time, then, the effects of baicalin on alveolar bone resorption were studied by micro-CT and histological. In this study, by performing ultrahigh-resolution micro-CT scans of alveolar bone, it was confirmed that baicalin could inhibit the alveolar bone absorption induced by Lipopolysaccharide (LPS). Compared with baicalin solution of 0.1μg / ml, baicalin solution of 1.0μg / ml had stronger inhibition.
2. Effect of baicalin on TGFβ1 in macrophage
Macrophages were cultivated in vitro firstly. Then, under different concentration of baicalin, expression of TGFβ2 in macrophages was detected with RT-PCR and Western-blot. The results showed that baicalin could promote the expression of TGFβ1 in macrophage and the expression of TGFβ2 increased with the rising of baicalin concentration (P <0.05). Baicalin of 1.0μg / ml had the more significant effect.
3. Establishment of siRNA Eukaryotic Expression Vectors of Recombinant Targeting Gene TGF-βⅡR
Referring to the design principles of siRNA , two siRNA sequences were designed according to the TGF-βRⅡnucleotide sequence reported in GeneBank, and the design requirements of pSilencer3.1H1 vector(Ambion,Inc). TGF-βRⅡ siRNA transcription template was synthesized. Annealing products were connected directly with pSilencer3.1H1 vector which had been digested by BamHⅠand HindⅢbefore. Then, DH5αcompetent cells were transformed by the connected products. The sequencing results are exactly the same as the designed sequence, which means that the siRNA expression vector targeted TGF-βRⅡhas been constructed successfully.
4. T cells transfection and identification
T cells that express TGF-βⅡR stablely were transfected by pSilencer3.1H1-TGF-βⅡR(1-2). Unicellular suspension was prepared with monoclonal cell strain of stably transfected siRNA1 and siRNA2. The growth rate of T cells that transfected with siRNA1 and siRNA2 stably are similar to that of normal T cells’in control group, the differences between each group have no statistics significance (P> 0.05). Both the results of RT-PCR and Western blot have shown that the belt of TGF-βRⅡin T cells transfected with siRNA1 is obviously darker than the control zone, while the belt of TGF-βRⅡin T cells transfected with siRNA2 has no significant changes compared with the control group. It illustrates that the expression of TGF-βRⅡin T cells transfected with siRNA1 has been inhibited significantly, which means that the degradation effect of siRNA1 on TGF-βRⅡmRNA in T cells are characteristic and high performance.
5. Effect of baicalin on RANKL/OPG in HPDL cells
T cells transfected siRNA1or not together with HPDL cells were place in the medium that had been added with baicalin and LPS. They were divided into six groups and cultured for 48 hours. RT-PCR was used to detect the expression of RANKL and OPG in HPDL cells and observe whether baicalin could affect expression of RANKL-OPG in HPDL cells with and without TGFβsignal transduction. It demonstrated that TGF-βsignaling transduction played an important role in the effect of baicalin on RANKL / OPG ratio in HPDL cells. This study supported that baicalin may enhance the inhibition of TGF-βto T cell, decrease the number or activity of T cells and decreas TNF-αand other inflammatory factors, which are secreted by T-cell under the effect of LPS, then reduced OPG–RANKL ratio, which further resulted in decreasing of osteoclast formation and bone loss. The study also found that baicalin not only act through TGFβto regulate RANKL / OPG ratio in HPDL cells, but also act through other pathway.
Conclusion: Baicalin can inhibit alveolar bone absorption effectively. The mechanism of action may be that: baicalin could promote the expression of TGFβ1 in macrophage and then, enhance the inhibition of TGF-βto T cell, decrease the number or activity of T cells and decreas TNF-αand other inflammatory factors (which are secreted by T-cell under the effect of LPS) then reduced OPG–RANKL ratio, which further resulted in decreasing of osteoclast formation and bone loss.
引文
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