ABSTRACT
AIM:To investigate the effect of flavonoids from stem and leaf of Scutellaria baicalonsis Georgi(SSF)on paired helical filament(PHF)abnormality and the regulatory mechanism of protein phosphatase(PP)in rats' brain induced by okadaic acid(OA).METHODS:Male Sprague-Dawley(SD)rats were microinjected with OA(200 ng/kg)by the lateral ventricle to establish a memory impairment model.Morris water maze was used to screen the memory impairment model.The successful model rats were continuous intragastric infusion(ig)SSF for 36 days.The relative pro-tein expression of PHF,PP1,PP2A-Cα,PP2A-Cβ,PP2CA and PP2CB in the rat cerebral cortex and hippocampus were detected by Western blot.GinKgo biloba leaf flavonoids(GLF)were used as positive control drug.RESULTS:Compared with the sham-operated rats ,the relative protein expression of PHF in the cerebral cortex and hippocampus and PP 1 in cor-tex of model rats were significantly increased(P<0.01),and the protein expression of PP2A-Cα,PP2A-Cβin the cere-bral cortex and hippocampus and PP2CB in the hippocampus were decreased(P<0.05),while the relative protein expres-sion of PP2CA and PP2CB in the cortex were significantly increased(P<0.01).SSF reversed the abnormality in the pro-tein expression of PHF,PP2A-Cαand PP2A-Cβin rat cortex and hippocampus and PP1 in rat cortex induced by OA(P<0.01),which had no significant effect on the relative protein expression of PP 2CA and PP2CB.GLF also showed similar results to SSF.CONCLUSION:SSF significantly reduces the abnormal formation of PHF in rats ' brain induced by OA ,which may be related to the regulation of PP 1,PP2A-Cαand PP2A-Cβexpression,but not with PP2CA and PP2CB ex-pression.