| BackgroundPeriodontitis is a chronic inflammatory disease characterized by the destruction of periodontal supporting tissue.It is a prevalent oral infectious diseases,affecting more than 80%～96%of the adults’s population in China with the new epidemiological adjustment,and the trend is increasing year by year.It’s an urgent time to deal with periodontitis as it has become the primary cause of tooth loss in adults.Periodontitis is caused by accumulation of profuse amounts of dental plaque.At present,more and more studies have found that the damage of periodontal supporting tissue is also mainly caused by the excessive immune response of the organism to eliminate the pathogenic microorganisms.It is the key to control plaque microbes and regulate host overimmune response of successful treatment of periodontitis.But systemic use of antibiotics can interfere with normal body systems and may cause several side effects,such as drug resistance.Chinese herbal medicine as its small side effects has become a hot spot for the treatment of periodontitis.Several compounds extracted from spices and herbs exhibit anti-inflammatory effects and immunomodulatory activity,which suggest potential pharmacological uses.It can prevent the release of many kinds of inflammatory factors,such as TNF-a and IL-1β,inhibit the differentiation and function of osteoclasts,and regulate the host immune activity.It has become one of the ways to develop new drugs for the treatment of periodontitisCurcumin is a traditional Chinese medicine with the properties of immunomodulatory,anti-inflammatory and anti-oxidation activities.It can regulat the transduction of immune molecules,inflammatory factors,oxidation-active enzymes and related signaling pathways.Curcumin exhibits anti-inflammatory effects and has been suggested as a treatment for inflammatory diseases.But the anti-inflammatory effects of curcumin on periodontitis and the molecular mechanisms remain unclear.The aim of this study was to investigate the effects of curcumin on the lipopolysaccharide(LPS)induced inflammatory response in rat gingival fibroblasts in vitro and ligation-induced experimental periodontitis in vivo,and to speculate the possible anti-inflammatory mechanism of curcumin.The study will provide a theoretical basis for the curcumin in the treatment of periodontal disease.Methods1.In vitro experiment:The gingival fibroblasts were incubated with different concentrations of curcumin in the absence or presence of LPS.The effect of curcumin on cell activity was detected by MTT;Concentrations of interleukin-1 β(IL-1β),tumor necrosis factor-a(TNF-a),osteoprotegerin(OPG)and soluble receptor activator of nuclear factor kappa-B ligand(RANKL)culture supernatants of rat gingival fibroblasts were determined by enzyme linked immunosorbent assay;The nuclear fraction of rat gingival fibroblasts was extracted and nuclear factor kappa-B(NF-κB)activation was assessed by western blotting to elucidate related mechanisms.2.In vivo experiment:Wistar rats were divided into three groups randomly:a ligation-only(L)group,a ligation group treated with 30 mg/kg body weight curcumin(L+C30),and a ligation group treated with 100 mg/kg body weight curcumin(L+ C100);Curcumin was given every days by oral gavage(1 times/day for 30days).The gingival inflammation between the first and second molars were observed by hematoxylin and eosin staining.Collagen fibers were observed by picro-sirius red staining;The radioimmunoassay was used to examine the concentrations of TNF-α and IL-1β in the gingival tissue;Alveolar bone loss was assessed by micro-CT with the analysis of bone biological parameters.Results1.There was no difference among groups of cell viability,and curcumin had no cytotoxicity.Curcumin attenuated the production of IL-1β and TNF-α in rat gingival fibroblasts stimulated by LPS,and inhibited the LPS-induced decrease in OPG/sRANKL ratio and NF-κB activation.There were statistical differences among different concentrations of curcumin.2.The silk thread tightly entangle the orthodontic ligature,which could be firmly ligated to the neck of the first mandibular molars during the experimental period.Few seriously collagen fiber destructions were found in the curcumin group compared to the control group.The expression of TNF-α and IL-1β in gingival tissue decreased significantIy.Micro-CT showed that the distance from the enamel cementum to the top of alveolar ridge could reduce with the high dose curcumin.Furthermore,Curcumin can alleviate trabecular bone breakdown in the bone specific parameters,including percent bone area,trabecular thickness and bone mineral density.There was statistical difference between different doses of curcumin.ConclusionsCurcumin plays a protective role in periodontal lesions by inhibiting the activation of NF-κ B signaling pathway and the expression of inflammatory factors of TNF-a and IL-1 β... |
PDF Full Text Request