Objective: To explore the protective effect of cerebrospinal fluid (CSF) with the optimized Danggui Shaoyao San (FBD) and its underlying mechanisms. Method: PC12 cells were treated with H2O2/Fe2+ to reproduce the cell injury model. The rabbits were randomly divided into 1 d group and 14 d group and they were given FBD by intragastric administrate. PC12 cells were treated with different concentrations of CSF containing FBD (5%

10%

20%). Cell survival was assessed by Thiazzolyl blue (MTT) assay. The content of maleic diadehyde (MDA) and superoxide dismutase (SOD) activity were determined respectively by thiobarbituric acid and xanthine oxidation enzyme. The Ca2＋content within cell was measured by MTB colorimetry. The protein expression of α7 nicotinic acetylcholine receptor (nAchR) was examined by using immunocytochemical detecting kit

bicinchoninic acid(BCA) protein kit and Dot blot assay. Result: The 20% group for 1 day (1.241±0.117) and 14 days(1.297±0.213) of FBD improved the survival of the PC12. The content of SOD increased from (18.18±0.12) U·mL-1 in the 20% group for 1 d to (19.48±0.34)U·mL-1 and 14 d (19.52±0.33) U·mL-1(P<0.01).In addition

α7nAChR in PC12 cells was significantly up-regulated. The expression of α7nAChR in 20% group for 14 d (0.161±0.024) was significantly higher than that in the group for 1 d(0.132±0.021)(P<0.05).These groups reduced MDA and Ca2＋within cell from (3.26±0.13)mmol·L-1

(74.89±3.66)nmol/105 cell and (2.77±0.05)mmol·L-1

(74.25±2.64)nmol/105 cell to (4.41±0.23)mmol·L-1

(82.42±4.25) nmol/105 cells). Conclusion: The CSF containing FBD can prevent from the neurotoxicity induced by H2O2/Fe2+. It may be related to α7nAchR up-regulation.