RESUMEN
Objective To study in vitro the inhibitory effects and mechanisms of N-butanol extract of Potentilla anserine L.(NP)against hypoxia-induced nitric oxide(NO)in hippocampus neuron of rats. Methods The models of hippocampus neurons hypoxia injury of Sprague-Dawley(SD)neonatal rats were cultured in vitro. The cultured hippocampus neurons were divided randomly into blank control group, hypoxia injury model group, nimodipine group(2 μmol/L)and NP high(250.0 mg/L),middle(62.5 mg/L),low(15.6 mg/L)dose groups. The activities of hippocampus neurons were examined by methyl thiazolyl tetrazolium(MTT)assay,and meanwhile their contents of nitrogen monoxidum(NO)were detected. Half quantity reverse transcription-polymerase chain reaction(RT-PCR)and Western blotting were used to detect neuronal nitric oxide synthetase(nNOS)mRNA and protein expression levels respectively in each group,immunocytochemistry stain was used to detect protein positive rate. Results Compared with blank control group,the activity of neuron〔absorbance(A)value〕was significantly decreased(0.0826±0.0095 vs. 0.3315±0.0105),content of NO(μmol/g:0.0509±0.0027 vs. 0.0291±0.0032), the expression levels of nNOS mRNA (0.1463±0.0081 vs. 0.0801±0.0058), the positive rate of nNOS〔(74.4238±3.9423)%vs.(28.3714±4.1361)%〕,the expression levels of nNOS protein(A value:1.9130±0.0471 vs. 0.5068±0.0368)were all significantly increased in the hypoxia injury model group(all P0.05). Conclusions NP can ameliorate the injury of rat hippocampus neurons induced by hypoxia in vitro. The possible mechanisms might be related to the effective inhibition of the synthesis of nNOS and NO excessive generation.