Effect Of β-cryptoxanthin On Inflammatory Factors In Experimental Periodontitis In Rats

BackgroundPeriodontitis is an inflammatory destructive disease.The etiology of periodontitis is very complex.On the one hand,components of outer membranes of bacteria and its toxic products directly cause the destruction of periodontal tissue after colonization of periodontal pathogens;on the other hand,they can cause excessive host inflammatory status,resulting in or aggravating tissue damage.Interleukin-1β（IL-1β）,tumor necrosis factor-α（TNF-α）,and prostaglandin E₂（PGE₂）are the factors most closely related to periodontitis in host immune response.In addition,the locally produced proinflammatory mediators can be“dumped”into the circulation and can exert and aggravate the inflammatory reaction of systemic or distant.β-cryptoxanthin is a carotenoid derived from citrus,tropical fruits and vegetables.It has anti-inflammatory activity and can inhibit the production of inflammatory factors effectively.Researchers have found thatβ-cryptoxanthin has a protective effect in some systemic inflammatory diseases,and the concentration ofβ-cryptoxanthin in serum is negatively correlated with the prevalence of periodontitis.In addition,studies have shown thatβ-cryptoxanthin can inhibit the production of inflammatory factors in periodontal ligament cells induced by periodontal pathogens.However,studies regarding the effects ofβ-cryptoxanthin on inflammatory factors in periodontitis have not been reported.Therefore,this experiment intended to investigate the changes of inflammatory factors in periodontal tissues and serum of rats after the intervention ofβ-cryptoxanthin,and to explore its effect on periodontitis and its mechanism in vivo.ObjectiveTo study the effect ofβ-cryptoxanthin on inflammatory factors in rats with experimental periodontitis and to explore its mechanism.MethodsThirty male 8-week-old Sprague-Dawley rats were randomly divided into normal group,periodontitis group andβ-cryptoxanthin treatment group,10 rats in each group.Normal group was regarded as control without treatment.The other groups were induced to experimental periodontitis model by ligation of bilateral maxillary second molars cervix and injection with lipopolysaccharide（LPS）（30μl/each）.At the same time,corn oil andβ-cryptoxanthin dissolved in corn oil（12μl/each）was injected in periodontitis group andβ-cryptoxanthin treatment group at the same site respectively.All the rats were treated every 48 hours for three times.Abdominal aorta blood was collected and sacrificed immediately on the 7th day,then the bilateral maxilla were separated.The right part of the tissues（including teeth,alveolar bone and gingival tissue）were used for histological analysis of histomorphology,serum and the left gingival tissue homogenate were detected by ELISA for IL-1β,TNF-αand PGE₂.Results1.Results of histological analysis:compared with normal group,the junctional epithelium migrated apically,the periodontal pockets formed,and massive infiltration of inflammatory cells were seen in the periodontal tissues of periodontitis group.And alveolar bone absorbed irregularly and matured osteoclasts were seen.Compared with periodontitis group,inflammatory cell infiltration in theβ-cryptoxanthin treatment group was significantly reduced,the periodontal fibers were arranged normally,and the alveolar bone loss was slightly.2.The levels of inflammatory factors in gingival tissue and serum:compared with normal group,the levels of IL-1β,TNF-αand PGE₂ in gingival tissue and serum of periodontitis group andβ-cryptoxanthin treatment group were significantly increased（P<0.001）.The levels of these factors ofβ-cryptoxanthin treatment group were significantly lower than those in periodontitis group in both gingival tissue and serum（P<0.001）.Conclusionsβ-cryptoxanthin may reduce the inflammation of periodontal tissues and prevent alveolar bone resorption by inhibiting the production of inflammatory factors in periodontal tissues of periodontitis.Meantime,β-cryptoxanthin can reduce the level of inflammatory factors in serum.