白介素6在甲硝唑羧甲基壳聚糖凝胶治疗大鼠牙周炎中的变化

Changes of interleukin-6 levels in periodontitis rats treated with metronidazole carboxymethyl chitosan gel

目的考察炎性因子白介素6(IL-6)在甲硝唑羧甲基壳聚糖凝胶等制剂局部治疗大鼠牙周炎过程中牙周组织和全血的变化情况。方法采用上颌双侧第一磨牙细丝结扎加接种牙龈卟啉单胞菌制备大鼠牙周炎模型。药物治疗:72只牙周炎SD大鼠,每组18只,MODEL组(阳性对照,不涂布任何药物),M/CMCS组(涂布甲硝唑羧甲基壳聚糖凝胶),PERIO组(涂布盐酸米诺环素软膏),MNZ组(涂布甲硝唑凝胶)。造模成功后每天在结扎丝处分组局部涂药2次。在治疗后的第1周,第3周和第5周,4组分别取6只大鼠,麻醉后采集龈沟液和全血样本,上颌骨及牙周组织块,供ELISA免疫组化实验。结果龈沟液和牙周软组织的IL-6浓度,M/CMCS组、PERIO组和MNZ组在第1周、第3周和第5周较MODEL组同期均明显下降(P<0.05);M/CMCS组和PERIO组在3个时间点均分别比MNZ组低(P<0.05),而在第5周时,M/CMCS组比PERIO组低(P<0.05)。牙槽骨的IL-6浓度,与MODEL组比较,M/CMCS组、PERIO组和MNZ组在第1、3、5周各时间点均降低(P<0.05),M/CMCS组与PERIO组的值在第1、3、5周,均分别较MNZ组低(P<0.05)。血清IL-6浓度,M/CMCS组、PERIO组和MNZ组在第1,3,5周时间点分别较MODEL组降低(P<0.05)。同一组内不同组织样本的IL-6浓度,M/CMCS组、PERIO组和MNZ组,龈沟液、牙周软组织和牙槽骨的IL-6浓度在第3、5周时,均分别低于第1周(P<0.05);比较牙周组织与牙槽骨的IL-6浓度,M/CMCS组3个不同时间点差异无统计学意义(P>0.05),PERIO组牙周组织在第3周和第5周时均分别高于牙槽骨(P<0.05),MNZ组第3周时牙周组织的值高于牙槽骨(P<0.05)。MODEL组的牙周组织毁损严重,牙槽骨严重吸收;M/CMCS组牙龈形态较完整,未见明显牙槽骨吸收;PERIO组和MNZ组存在不同程度的牙周损伤和牙槽骨吸收。牙周组织IL-6平均光密度(MOD)值,M/CMCS组、PERIO组和MNZ组在第1、3、5周各相同时间点均比MODEL组明显下降(P<0.05),在第5周时,M/CMCS组低于MNZ组和PERIO组(P<0.05)。结论甲硝唑羧甲基壳聚糖凝胶可以显著减少牙周炎模型大鼠的相关组织IL-6表达,抑制牙槽骨吸收,其效应可能与M/CMCS能够抑制炎性细胞因子IL-6的分泌有关。

Objective To investigate the changes of interleukin-6(IL-6)in periodontal tissues and whole blood during the local treatment of periodontitis rats with metronidazole carboxymethyl chitosan gel(M/CMCS)and otheRcontrol drugs.Methods The rats were subjected to establish the periodontitis model by orthodontic ligatures fixed around the cervical margins of the bilateral maxillary first molars plus the local infection of Porphyromonas gingivalis.A total of 72 periodontitis SD rats were randomly divided into the MODEL group(positive control,periodontitis rats without the treatment of any drugs),M/CMCS group(periodontitis rats coated with M/CMCS),PERIO group(periodontitis rats coated with minocycline hydrochloride ointment)and MNZ group(coated with metronidazole[MNZ]gel),with 18 rats in each group.AfteRmodeling of periodontitis in rats,drugs were locally coated at the ligation sites twice a day.On weeks 1,3 and 5,six randomly selected rats peRgroup were anesthetized,followed by the collection of gingival creviculaRfluids,whole blood samples,bilateral maxillae,periodontal tissue blocks was performed foRthe enzyme-linked immunosorbent assay(ELISA)and immunohistochemical staining.Results IL-6 concentrations in gingival creviculaRfluid and periodontal soft tissues in M/CMCS group,PERIO group and MNZ group were significantly loweRon weeks 1,3 and 5 than those in MODEL group(P<0.05).IL-6 concentrations in M/CMCS group and PERIO group were significantly loweRthan those in MNZ group at three time points(P<0.05),which,in M/CMCS group were significantly loweRthan those in PERIO group on week 5(P<0.05).Compared with MODEL group,IL-6 concentrations in alveolaRbones of M/CMCS group,PERIO group and MNZ group significantly decreased on weeks 1,3 and 5(P<0.05),which,in M/CMCS group and PERIO group on weeks 1,3 and 5 were significantly loweRthan those in MNZ group(P<0.05).IL-6 concentrations in M/CMCS group,PERIO group and MNZ group were loweRthan those in MODEL group on weeks 1,3 and 5(P<0.05).We also compared IL-6 concentrations in different tissues among groups.IL-6 concentrations in gingival creviculaRfluids,periodontal soft tissues and alveolaRbones in M/CMCS group,PERIO group and MNZ group were loweRthan those on weeks 3 and 5 than those on week 1(P<0.05).There were no significant differences in IL-6 concentrations in periodontal soft tissues and alveolaRbones in M/CMCS group at three different time points(P>0.05),which,in periodontal soft tissues in PERIO group were significantly higheRthan those in alveolaRbones on weeks 3 and 5(P<0.05).IL-6 concentrations in periodontal soft tissues in MNZ group were significantly higheRthan those in alveolaRbones on week 3(P<0.05).The periodontal tissues were severely damaged and alveolaRbones were seriously absorbed in MODEL group,but the gingival morphology in M/CMCS group was relatively complete,and no obvious alveolaRbone absorptions were found.Rats in both the PERIO group and the MNZ group had periodontal injury and alveolaRbone resorptions at varying degrees.The mean optical density(MOD)values of IL-6 in periodontal tissues in M/CMCS group,PERIO group and MNZ group on weeks 1,3 and 5 were significantly loweRthan those in MODEL group(P<0.05).On week 5,MOD values of IL-6 in M/CMCS group were also loweRthan those in MNZ group and PERIO group(P<0.05).Conclusion M/CMCS can significantly reduce IL-6 concentrations in relevant tissues of periodontitis rats,and the effects of resistance to the alveolaRbone resorption may be attributed to the decreased secretion of IL-6.