Abstract: Objective To explore the effect of baicalein on alveolar bone resorption in rats with periodontitis and its regulation of nucleotide-binding oligomerization domain-like receptor protein 3 / cysteine aspartate protease 1 (NLRP3 / Caspase-1) pathway. Methods A total of 40 rats with periodontitis were randomly divided into model group, baicalein group, activator group and baicalein + activator group, another 10 rats without any treatment were taken as the control group. The distance from the cemento-enamel junction to aleolar crest (CEJ-AC) of the rats were measured. The expressions of interleukin-6 ( IL-6) and transforming growth factor-β ( TGF-β) in the serum and the periodontal tissues were detected. The pathological changes in periodontal tissues were observed. The expression levels of NLRP3 and Caspase-1 proteins were detected. Results The CEJ-AC distance, the expression levels of IL-6 and TGF-β in the serum, the positive rates of IL-6 and TGF-β expression in the periodontal tissues, and the expression levels of NLRP3 and Caspase-1 proteins were all increased in the model group (P< 0. 05). After the intervention with baicalein, all those indexes above were decreased (P< 0. 05). The treatment of activator significantly attenuated the effect of baicalein on above indexes. Conclusion Baicalein reduces the inflammation response, and controls alveolar bone resorption by inhibition of NLRP3 / Caspase-1 pathway. 

Key words: baicalein, periodontitis rats, NLRP3/ Caspase-1 pathway, alveolar bone resorption