Background:::Respiratory syncytial virus (RSV), which is the predominant viral pathogen
responsible for causing acute lower respiratory tract infections in children, currently lacks
specific therapeutic drugs. Despite andrographolide's demonstrated effectiveness against various
viral infections, its effects on RSV infection remain unclear.
Methods:::In this study, RSV infection and andrographolide-intervened A549 cell lines were
used. The virus load of RSV and the levels of IL-6 and IL-8 in the cell supernatant were quantified.
The potential targets of andrographolide in the treatment of RSV-infected airway epithelial
cells were analyzed using the Gene Expression Omnibus (GEO) database and the PharmMapper
Database, and the changes in mRNA expression of these target genes were measured. To further
illustrate the effect of andrographolide on the death pattern of RSV-infected airway epithelial
cells, Annexin V-FITC/PI apoptosis assays and Western blotting were conducted.
Results:::Andrographolide decreased the viral load and attenuated IL-6 and IL-8 levels in cell supernatant
post-RSV infection. A total of 25 potential targets of andrographolide in the treatment
of RSV-infected airway epithelial cells were discovered, and CASP1, CCL5, JAK2, and STAT1
were identified as significant players. Andrographolide noticeably suppressed the increased
mRNA expressions of these genes post-RSV infection as well as IL-1β. The flow cytometry
analysis demonstrated that andrographolide alleviated apoptosis in RSV-infected cells. Additionally,
RSV infection decreased the protein levels of caspase-1, cleaved caspase-1, cleaved IL-1β,
N-terminal of GSDMD, and Bcl-2. Conversely, andrographolide increased their levels.
Conclusion:::These results suggest that andrographolide may reduce RSV-induced inflammation by
suppressing apoptosis and promoting pyroptosis in epithelial cells, leading to effective viral clearance.