Intervention effects and mechanism research of mulberry crude extract on nonylphenol anxiety behavior of SD rats induced by nonylphenol

The aim of this study was toinvestigate the interventioneffects of mulberry crude extract ( MCE) on anxiety behaviors of SD rats exposed to nonylphenol ( NP) .48 SPF rats were randomly divided into 6 goups: normal control group ( corn oil) , MCE control group ( 120 mg/kg) , NP model group ( 270 mg/kg) , and three intervention groups ( 120 mg/kg NP + 30 mg/kg MCE, 120 mg/kg NP + 60 mg/kg MCE, 120 mg/kg NP + 120 mg/kg MCE) .The open field test ( OFT) and elevated plus maze ( EPM) were used to evaluate anxiety behaviors of the rats while the ELISA kitswere used to detect the levels of monoamine neurotransmitter, including serotonin, dopamine, norepinephrine and monoamine oxidase.The distance traveled in the center and entrance frequency to the center of the high-dose intervention groupwere significantly higher thanthe NP group in the OFT.The percentage of open arm entries and time of the high-dose intervention group rats were significantly higher thanthe NP group in the EPM test ( p < 0.05) .Compared with the nonylphenol group, the hypothalamic serotoninand dopamin levels in the high-dose intervention group were significantly lower ( p < 0.05) , the hypothalamus dopamin level was significantly lower in the middledose intervention group ( p < 0.05) and MAO activity of high dose intervention group was significantly increased ( p < 0.05) .Meanwhile as intervention dose increased, norepinephrine levels gradually reduce with no significant difference.Mulberry crude extract can reduce the levels of serotonin, dopamine, norepinephrine in hypothalamus of rats with anxiety caused by nonylphenol and the underlying mechanism may involve up-regulation of MAO activity.