Quercetin Protects Blood-Brain Barrier Integrity via the PI3K/Akt/Erk Signaling Pathway in a Mouse Model of Meningitis Induced by .

() causes serious inflammation and meningitis in piglets. Quercetin has anti-inflammatory and anti-bacterial activities; however, whether quercetin can alleviate brain inflammation and provide protective effects during infection has not been studied. Here, we established a mouse model of infection in vivo and in vitro to investigate transcriptome changes in the mouse cerebrum and determine the protective effects of quercetin on brain inflammation and blood-brain barrier (BBB) integrity during infection. The results showed that induced brain inflammation, destroyed BBB integrity, and suppressed PI3K/Akt/Erk signaling-pathway activation in mice. Quercetin decreased the expression of inflammatory cytokines (, , , and ) and BBB-permeability marker genes (, , , and ), increased the expression of angiogenetic genes ( and ), reduced -induced tight junction disruption, and reactivated -induced suppression of the PI3K/Akt/Erk signaling pathway in vitro. Thus, we concluded that quercetin may protect BBB integrity via the PI3K/Akt/Erk signaling pathway during infection. This was the first attempt to explore the protective effects of quercetin on brain inflammation and BBB integrity in a -infected mouse model. Our findings indicated that quercetin is a promising natural agent for the prevention and treatment of infection.