| Depression,as a psychiatric disorder,has a high incidence and a large number of patients are disabled and die due to suicide,which has seriously damaged human health and become a heavy burden for China and even the world.The specific pathogenesis of depression is complex and the cause is unclear.It is presumed to be caused by a variety of factors such as psychological,physiological and social factors..Most of the antidepressants commonly used in clinical practice are designed to give the monoamine neurotransmitter hypothesis.With the increase of clinical applications,the drawbacks of the drugs such as slow onset of action,large individual differences,and significant adverse effects are gradually exposed.It has also been reported that the commonly used first-line antidepressant venlafaxine has insufficient intracerebral uptake to adequately meet clinical needs.In the preliminary work,a series of esters were designed and synthesized based on the structure of desmethylvenlafaxine,the active metabolite of venlafaxine,on the basis of ODV,among which O-19 showed good brain uptake properties and potential pharmacodynamic value by pharmacokinetic studies.Piperonyl acid was introduced to the phenolic hydroxyl group of ODV to synthesize the corresponding piperonyl esters,and this modification significantly enhanced the lipid solubility of the drug making it significantly more orally bioavailable and blood-brain barrier permeable,focusing on the target-enriched hypothalamic metabolic transformation to release ODV with piperonyl acid and improve targeting.Purpose:Based on the results of pharmacokinetic assay of O-19,it was hypothesized that it has obvious antidepressant effect,therefore,the antidepressant pharmacological effects of O-19 were investigated in order to solve the drawbacks of traditional antidepressant drugs such as low brain uptake,poor targeting and poor efficacy in some patients,and to provide experimental basis for the subsequent development of O-19 into a new clinical antidepressant.Methods:Antidepressant primary screening:Suspension tail assay and forced swimming assay were conducted to derive the latency and total immobility time,and then the antidepressant effect of O-19 was initially assessed.A model of acute depression induced by reserpine was established by body temperature,eyelid closure and motor inability,and the inhibitory effect of O-19 on monoamine neurotransmitter reuptake was initially explored.Establishment of a chronic mild unpredictable stress model to evaluate the antidepressant behavioral effects of O-19:60 male Kunming mice were randomly divided into the following six groups:blank control group,model group,O-19 low dose group（26.2 mg/kg）,O-19 medium dose group（52.4 mg/kg）,O-19 high dose group（104.8 mg/kg）and VEN group（positive control group,40 mg/kg）.Except for the blank control group,all groups of mice were subjected to chronic mild unpredictable stress modeling.The antidepressant behavioral effects of O-19 were evaluated by（1）weighing to examine the effect of O-19 on body weight in CUMS model mice;（2）measuring the sugarwater preference rate to assess the effect of O-19 on the symptoms of pleasure deficit in CUMS model mice;（3）assessing the effect of O-19 on behavioral despair in CUMS model mice by forced swimming and tail suspension experiments;（4）conducting the absentee field experiment to evaluate the effect of O-19 on the activity exploration ability of CUMS model mice;（5）conducting Morris water maze experiment,dark avoidance and jumping platform experiment to evaluate the effect of O-19 on the learning memory ability of CUMS model mice.Establishment of a chronic mild unpredictable stress model to evaluate the mechanism of antidepressant effect of O-19:The levels of 5-HT,NE and DA in mouse hippocampal homogenates were detected to evaluate the effects of O-19 on monoamine neurotransmitters in CUMS model mice;the levels of SOD,MDA and GSH-Px in mouse hippocampus were detected to evaluate the effects of O-19 on oxidative stress in CUMS model mice;the levels of TNF-α and IL-1β in mouse serum were detected to evaluate the effects of O-19 on inflammatory response in CUMS model mice;the levels of TNF-α and IL-1β in mouse serum were detected to evaluate the effects of O-19 on inflammatory response in CUMS model mice.The effect of O-19 on the inflammatory response of CUMS mice was evaluated by HE staining and calculation of hippocampal coefficients;the effect of O-19 on the apoptosis of hippocampal cells in CUMS mice was evaluated by detecting the expression of Bax,Bcl-2 and Caspase-3 by immunohistochemistry.The effect of O-19 on hippocampal BDNF level in CUMS model mice was evaluated by detecting hippocampal BDNF expression by immunohistochemistry.Preliminary safety evaluation:After CUMS was continuously modeled and simultaneously administered for 36 days,the organ coefficients of heart,liver,spleen,lung and kidney of each group of mice were weighed and calculated for a simple preliminary evaluation of the safety of O-19.Results:（1）In the forced swimming and tail suspension experiments,the low,medium and high dose groups of O-19 significantly prolonged the latency period and shortened the total immobility experiment in different degrees compared with the model group.And compared with the VEN group,the medium and high doses of O-19 were better than the VEN group in some indexes.（2）In the acute model induced by reserpine,all three dose groups of O-19,low,medium and high,could significantly reduce the decrease of body temperature caused by reserpine.the middle and high dose groups of O-19 could not significantly inhibit the eyelid closure and movement caused by reserpine.（3）In the CUMS model,each dose group of O-19 had different degrees of significant inhibitory effects on behavioral abnormalities caused by CUMS.The incubation period and total immobile time of forced swimming and tail suspension tests,upright times of mice in open field experiment,times of crossing platform in water maze experiment and time spend in target quadrant and platform area,the inhibition of abnormal behavior in the middle and high dose groups of O-19 was stronger than that in the VEN group.（4）In the CUMS model,each dose group of O-19 had different degrees of significant inhibition on the abnormal biochemical indexes caused by CUMS.Among them,the inhibition of 5-HT,NE,SOD and MDA in hippocampal homogenate,IL-1βin serum,Bcl-2 and BDNF expression in immunohistochemistry was stronger in the middle and high dose groups of O-19 than in the VEN group.Conclusion:O-19 showed strong antidepressant effects,and its mechanism of action may be related to the inhibition of reuptake of monoamine neurotransmitters（5-HT,NE,DA）,anti-oxidative stress,anti-inflammatory response,and protection of hippocampal neurons.And the experimental results showed that there was no significant difference between O-19 low-dose group and VEN group（P>0.05）,and O-19 medium-dose group showed better efficacy than VEN group in some experimental results.Therefore,O-19 has good efficacy and is expected to have good application prospects with lower dose administration. |
PDF Full Text Request