Effects of 1,8-cineole on inflammatory response in a rat model of experimental periodontitis
BACKGROUND:Previous studies have shown that 1,8-cineole has anti-inflammatory,antioxidation,antibacterial and anti-tumor effects.It has good anti-inflammatory effects in many diseases.OBJECTIVE:To investigate the effect of 1,8-cineole on inflammatory response in a rat model of experimental periodontitis.METHODS:Thirty Sprague-Dawley rats were assigned into normal control group,periodontitis control group and 1,8-cineole group with ten rats in each group according to the completely randomized digital table method.Except for the normal control group,rats in the other groups were induced into experimental periodontitis.The periodontitis model was constructed by the orthodontic ligature wire method.Eight weeks after modeling,in the 1,8-cineole group,1,8-cineole was placed into periodontal pockets,twice per day for 4 weeks.In the normal control group and the periodontitis control group,the same amount of normal saline was placed into periodontal pockets,twice per day for 4 weeks.After administration,general observation and periodontal clinical indicators were performed.Hematoxylin-eosin staining was used for periodontal histological evaluation.The expressions of inflammatory factors in the serum and gingiva at mRNA and protein levels were detected.RESULTS AND CONCLUSION:(1)Compared with the normal control group,rats in the periodontitis control group showed increased gingival bleeding index and periodontal probing depth(P<0.05),increased serum levels of interleukin 1β,tumor necrosis factor α,and interleukin 6(P<0.05),decreased serum level of interleukin 10(P<0.05),increased mRNA and protein levels of interleukin 1β,tumor necrosis factor α,and interleukin 6 in gingival tissue(P<0.05),and decreased mRNA and protein level of interleukin 10 in gingival tissue(P<0.05).Hematoxylin-eosin staining of periodontal tissues showed that compared with the normal control group,periodontal inflammation was obvious in the periodontitis control group.(2)Compared with the periodontitis control group,rats in the 1,8-cineole group showed decreased gingival bleeding index and periodontal probing depth(P<0.05),decreased serum levels of interleukin 1β,tumor necrosis factor α,and interleukin 6(P<0.05),increased serum level of interleukin 10(P<0.05),decreased mRNA and protein levels of interleukin 1β,tumor necrosis factor α,and interleukin 6 in gingival tissue(P<0.05),and increased mRNA and protein level of interleukin 10 in gingival tissue(P<0.05).Hematoxylin-eosin staining of periodontal tissues showed that compared with the periodontitis control group,periodontal inflammation was remarkably alleviated in the 1,8-cineole group.To conclude,1,8-cineole can attenuate the inflammatory response in the rat model of experimental periodontitis.