Abstract: OBJECTIVE: To evaluate the anti-apoptotic efficacy of Qingnao Yizhi formula(清脑益智方,QNYZ) in cultured cerebral cortical neuronal cells(CNCs) and the regulation of the NogoA-Nogo receptor(NgR)/Rho-Rho kinase(ROCK) signaling pathway.METHODS: Primary cultured CNCs were randomly divided into the following groups: normal control group(N-C), hypoxia-reoxygenation group(H/R),high-dose QNYZ group(Q-H), low-dose QNYZ group(Q-L) butylphthalide(NBP) group, and Y-27632(a selective ROCK transduction pathway inhibiter) group. Except those in the N-C group, CNCs were placed in hypoxic conditions for 24 h and then in reoxygenation conditions for 24 h. Cell media was changed every 48 h, and various assays were performed on the 7 th day. Cell viability was evaluated by measuring mitochondrial dehydrogenase activity, using a CCK-8 assay, in triplicate. Synapsin(SYN) protein concentrations were evaluated by enzyme-linked immunosorbent assay. NogoA and RhoA protein expression were evaluated through Western blotting. The gene expression of NogoA, NgR, RhoA, and ROCK was evaluated by reverse transcription-polymerase chain reaction. Cell apoptosis was measured using a terminal deoxynucleotidyl transferase biotin-d UTP nick end labeling assay.RESULTS: Compared with the N-C group, the cell viability of the H/R group decreased significantly(P < 0.05). The NogoA and RhoA protein levels and the NogoA, NgR, RhoA, and ROCK m RNA expression levels increased in the H/R group, compared with the N-C group, and decreased significantly in the Q-H and Q-L groups(P < 0.05) and in the Y-27632 group(P < 0.05) compared with the H/R group. The SYN levels in the Q-H, Q-L, and NBP groups significantly increased compared with that in the H/R group(P < 0.05). Compared with the H/R group, the numbers of apoptotic cells in the Q-H,Q-L, and NBP groups significantly decreased(P

Key words: Apoptosis, hypoxia, nogo receptors, rho-associated kinases, signal transduction, neuronal plasticity, Qingnao Yizhi formula