New insight into the epidemiological trends of respiratory syncytial virus infection and the underlying anti-respiratory syncytial virus mechanisms of andrographolide: integrating Global Burden of Disease database, network pharmacological analysis, and in vitro experiments.

Respiratory syncytial virus (RSV) infection causes severe burdens and harms worldwide every year, lacking specific therapeutic drugs. Andrographolide is a marketed agent, whose antiviral mechanisms between RSV and the host remain unknown. In this report, we first uncover the global disease burdens caused by RSV infection via Global Burden of Disease database analysis to raise public awareness. Results showed that the overall RSV infection mortality and trends decreased globally during 1990-2021, but children and the elderly remained high-risk populations, and the disease burdens are still severe. Then, an in vitro experiment was performed to reveal the effects of andrographolide, a promising anti-RSV strategy, on the RSV lifecycle and key processes. Meanwhile, molecular docking, cellular heat migration assays (cellular thermal shift assay [CETSA]), and immunoblotting were integrated to screen and identify the efficacy of andrographolide on key RSV adsorption receptors. Notably, the inhibition of andrographolide on RSV viral adsorption was found to be better than ribavirin, and the corresponding key adsorption receptor was further identified as CX3CR1. Subsequently, downstream targets and signaling pathways were unveiled via network pharmacological analysis. Finally, andrographolide was validated to significantly inhibit the expression of reactive oxygen species (ROS), TNF-α, IL-6, and IL-1β after RSV infection via the regulation of the ROS/TXNIP/NF-κB pathway. Our findings highlight that the disease burdens caused by RSV infection are still grim, deserving attention. Andrographolide, a promising anti-RSV drug, was first identified as suppressing RSV adsorption to host cells by affecting CX3CR1 and inhibiting the ROS/TXNIP/NF-κB pathway, thereby reducing oxidative stress and inflammatory responses.IMPORTANCEThe respiratory syncytial virus (RSV) is the leading pathogen responsible for acute lower respiratory tract infections globally in infants, children, the elderly, and immunocompromised individuals, warranting widespread attention. Due to its complex pathogenic mechanism, there are currently no specific drugs available. Andrographolide, a marketed drug, has long been known for its efficacy against viral infections and is frequently prescribed in China for the treatment of upper respiratory tract infections; however, the precise mechanisms of its anti-RSV action remain unclear. Our study aimed to unveil the new global epidemiological trends and burdens caused by RSV to attract attention and elucidate the antiviral mechanisms of andrographolide against the RSV, presenting data that support its unique potential as a therapeutic agent capable of flexibly adapting to treat RSV infection. These findings pave the way for developing andrographolide as a new anti-RSV drug and expanding clinical therapeutic options.