TLR4 and Cerebral ischemia: Therefore, it was indicated that CIRI-induced recruitment of TLR4/NF-kB signaling pathway was probably restrained by meisoindigo (P < 0.05) (Figure 8) It has known that NLRP3 inflammasome acts downstream of TLR4 signaling, and TLR4/NF-κB signaling pathway plays a critical role in the activation of the NLRP3 inflammasome and in the inflammatory reaction after cerebral ischemia (Gao et al., 2009; Vartanian and Stenzel-Poore, 2010).