Abstract: ObjectiveTo observe the effect of SSY-B2 on microglial cells in rats after bilateral fornix/fimbria transection.MethodsMale adult SD rats were divided randomly into 6 groups as sham group,model group,positive control agent piracetam group, SSY-B2 low(1.5g crude drug/kg), medium(3g crude drug/kg)and high dosage (6g crude drug/kg)groups. Half to 1 hour before operation, water or drugs were fed introgastrically to each group respectively and continued for 6 weeks.The tissues of brain was gained and the immunoreactive products of BS-I B4 (Isolectin B4 from Bandeiraea Simplifolia, a marker for microglia) in the perilesion area was measured using immunohistochemical methods.ResultsThe number of microglia of the sham and model groups was (30.3±21.8) and (114.5±102.3) respectively, P<0.05. That of three different dosage of SSY-B2 groups was(249.7±149.4), (252.0±191.7)and (244.2±154.9), P<0.05 for each group compared with the model group.ConclusionMicroglia number in the perilesion area can be increased by SSY-B2, which may contribute to the nerve repair and functional improvement after injury.

Key words: traditional Chinese medicine, SSY-B2, microglia, rats