Atractylenolide III reduces NLRP3 inflammasome activation and Th1/Th2 imbalances in both in vitro and in vivo models of asthma.

Paediatric asthma is a common inflammatory disease in children. Atractylenolide III is an active component of the Atractylodes rhizome, an herbal medicine that has been used as an asthma treatment. This study aimed to explore the effects and underlying mechanisms of atractylenolide III in IL-4-induced 16HBE cells and ovalbumin-induced asthmatic mice. The results showed that IL-4 stimulation significantly decreased, and atractylenolide III treatment increased, growth and apoptosis of 16HBE cells. In 16HBE cells, administration of atractylenolide III also significantly suppressed the IL-4-induced increases in the expression of cleaved caspase-1; apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC); and nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3). Moreover, the numbers of total leukocytes, neutrophils, eosinophils, and macrophages significantly increased in ovalbumin-induced mice, and then decreased after atractylenolide III treatment. In ovalbumin-induced asthmatic mice, atractylenolide III treatment also significantly inhibited NLRP3 inflammasome activation and restored the Th1/Th2 balance. These results indicate that atractylenolide III reduced NLRP3 inflammasome activation and regulated the Th1/Th2 balance in IL-4 induced 16HBE cells and ovalbumin-induced asthmatic mice, suggesting it has a protective effect that may be useful in the treatment of paediatric asthma.