TLR4 and the downstream target, NF-κB are found to facilitate the inflammatory reaction in cerebral ischemia and infarction (Zheng et al., 2017) We test whether TLR4/NF-κB is involved in the inhibitory effect of meisoindigo on NLRP3 inflammasome activation and microglia/macrophage polarization, and firstly find that meisoindigo obviously decreases the stroke-induced upregulation of TLR4/NF-kB pathway proteins and IL-1β in concentration-dependent manners, which has no statistic difference by comparing with treatment of TAK-242, a specific inhibitor of TLR4. The gene discussed is NLRP3; the disease is brain ischemia.