Glycyrrhetinic acid reduces lung inflammation caused by pneumococcal infection by reducing the toxicity of pneumolysin
Yan Xu,
Ying Ding,
Hongji Wu,
Donglin Li,
Yudi Li,
Yibo Hu,
Haoji Meng
Affiliations
Yan Xu
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China; School of Pediatrics, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China
Ying Ding
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China; School of Pediatrics, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China; Corresponding author. Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China.
Hongji Wu
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China
Donglin Li
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China
Yudi Li
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China
Yibo Hu
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China
Haoji Meng
Department of Pediatrics, The First Affiliated Hospital, Henan University of Chinese Medicine, Zhengzhou, Henan, 450000, China
Objective: In this study, to provide new methods for the treatment of Streptococcus pneumoniae infection, we aimed to describe the anti-inflammatory and antibacterial value of glycyrrhetinic acid on the basis of its inhibitory effect on bacterial growth (without killing the bacteria) and its reduction of the toxicity of S. pneumoniae. Methods: A mouse model was established via intranasal administration of Streptococcus pneumoniae D39, and glycyrrhetinic acid was subcutaneously injected for treatment. The wet‒dry ratio, bacterial flora content and inflammatory factor levels in the mouse lungs were determined. Cell experiments were used to evaluate glycyrrhetinic acid-mediated inhibition of PLY hemolysis and A549 cell death, and WB was used to measure glycyrrhetinic acid-mediated inhibition of PLY oligomerization. Results: Glycyrrhetinic acid reduced the levels of inflammatory factors, the dry‒wet ratio, the abundance of S. pneumoniae in the lungs of infected mice, pneumolysin-mediated A549 cell death, erythrocyte hemolysis and PLY oligoplasia. Conclusion: Glycyrrhetinic acid can reduce the virulence of S. pneumoniae by preventing the oligomerization of PLY.
