Jinxin oral liquid inhibits human respiratory syncytial virus-induced excessive inflammation associated with blockade of the NLRP3/ASC/Caspase-1 pathway

Human respiratory syncytial virus (RSV) is a common virus that causes pneumonia and bronchitis, mostly in infants. Our previous study showed that Jinxin oral liquid (JOL), derived from traditional Chinese medicine, had anti-inflammatory and therapeutic effects on RSV-related pneumonia. However, little is known about the underlying mechanisms of these effects. During a viral infection, including RSV infection, the inflammasome pathway is excessively activated, resulting in an inflammatory reaction and severe tissue damage. Inhibition of the inflammasome pathway has shown good therapeutic effects on lung inflammation. In the present study, we explored the effect of JOL on RSV-induced excessive inflammation in BALB/c mice. Pathological evaluation of lung tissue and measurement of the lung index showed that JOL alleviated lung infection and tissue injury induced by RSV. The enzyme-linked immunosorbent assay showed that JOL reduced the release of inflammatory factors, including interleukin-1β(IL-1β), interleukin-18(IL-18) and interleukin-33(IL-33), in the serum and lung homogenate of RSV-infected mice. Furthermore, the results of real-time PCR, immunohistochemistry, and western blot analyses showed that JOL inhibited the immune inflammatory response of mice infected with RSV through blockade of the NOD-like receptor protein 3(NLRP3)/apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC)/Caspase-1 signalling pathway, as evidenced by the down regulation of the mRNA and protein expression of three key components in the pathway. Collectively, our results showed that JOL inhibited pulmonary inflammation caused by RSV infection. Thus, JOL may be a promising remedy for lung inflammation caused by RSV infection and may help avoid lung tissue damage.