250 nmol NQDI-1 in DMSO is intracerebroventricularly injected following brain insult. Western blotting is performed to determine the expression of ASK1 in the sham, Hypoxia-ischemia (HI), DMSO and NQDI-1 groups and indicate that NQDI-1 markedly inhibits the expression of ASK1 in the brain cortex, compared with the HI and DMSO group. Furthermore, immunofluorescence staining also indicates that the expression of ASK1 is inhibited by NQDI-1 in the brain cortex. The expression of downstream targets of ASK1 is also determined in the present study. The expression levels of p-JNK, p-c-Jun, p53 and caspase 3 are significantly decreased by NQDI-1, compared with the HI and DMSO groups. Low expression of p-JNK in the brain cortex is also observed by immunofluorescence in the NQDI-1-treated group.