Potential application of andrographolide in vital pulp therapy by inducing expression of human β defensin 4

Abstract Aim This study aimed to investigate the ability of andrographolide to induce human β defensin 4 (HBD4) expression in dental pulp stem cells and its effect on inflammatory pulp tissue in rats in vivo. Methods The expression of HBD4 in andrographolide‐induced dental pulp stem cells was examined using quantitative polymerase chain reaction and immunofluorescence staining. High‐throughput analysis of protein acetylation was conducted to screen the mechanism of andrographolide‐induced HBD4 expression. Colony‐forming unit methods were used to study the antimicrobial ability of andrographolide‐induced HBD4 on Porphyromonas gingivalis . Finally, the ability of andrographolide to preserve vital pulp was examined using Wistar rats with irreversible pulpitis. Results HBD4 expression level increased after andrographolide stimulation, which was related to histone acetylation modification, as revealed by acetylome analyses. Antibacterial testing confirmed that andrographolide‐induced HBD4 was sensitive to P. gingivalis . Furthermore, andrographolide controlled pulp inflammation in a Wistar rat irreversible pulpitis model and induced the restorative dentin formation. Conclusion We concluded that andrographolide induced the expression of HBD4 in dental pulp stem cells through histone acetylation modification and exerted inhibitory effects on pulp tissue inflammation in vivo.