Pseudotargeted Metabolomics And Lipidomics Studies Of Liquiritin In The Treatment Of Depression

Depression had become the main cause of non-fatal loss and more than 322 billion people were suffering from depression.Nevertheless,the unclear pathogeny of depression made the diagnose complicated,the biological indicators absent,the detection ratio low and the therapeutic effect unsatisfactory.It was reported that liquiritin which was extracted from Chinese herbal medicine glycyrrhiza could reduce the depression-related behaviors in rodents.However,the therapeutica mechanism of liquiritin was still confused.Metabolomics and lipidomics were the important means of disease research,in which pseudotargeted profiling was presented recently.Pseudotargeted profiling combined the advantanges of untargeted profiling and targeted profiling,such as high sensitivity,excellent precision and wide lineary range.However,further extension of the analyte coverage and the techniques in pseudotargeted profiling were required.In this work,a pseudotargeted method based on ultra high performance liquid chromatography-segment data dependent acquision-tandem mass spectrometry(UHPLC-SDDA-MS/MS)and a pseudotargeted method based on ultra high performance supercritical fluid chromatography-tandem mass spectrometry(UHPSFC-MS/MS)were developed to investigate the metabolomics and lipidomics studies of liquiritin in the treatment of depression,respectively.The prime contents and results of the work were as follows:1.The rat model of depression was established by chronic unpredictable mild stress method.The appraisals of the animal model were performed by the body weight,the socre in open field test,the preference in sucrose preference test,the score in forced swimming test and the time spent on the open arms in elevated plus maze.All the results showed the success of the construction of the depression model.In addition,both liquiritin and the positive control fluoxetine had antidepression effects on rats to increase the activity of exploration,restore the interest in reward,improve the mental state and alleviate the anxiety of rats.2.A pseudotargeted method based on UHPLC-SDDA-MS/MS was presented and was employed for the metabolite profiles of depressed rats with the treatment of liquiritin.The developed SDDA mode could extend the dwell time for each ion and enhance the detection of co-eluted ions,thereby widening the analyte coverage of pseudotargeted analysis.Compared with the conventional pseudotargeted method based on data dependent acquisition(DDA)mode,both the number of ion pairs and differential variables in the SDDA-based pseudotargeted method were twice those in the former.Compared with the SDDA-based untargeted method,the detection for 99% of the peaks was more sensitive and the percentage(52%)of the peaks with relative standard deviations(RSDs)below 5% was double in the SDDA-based pseudotargeted method.The pesudotargetd method via UHPLC-SDDA-MS/MS was successfully used for the metalomics study of liquiritin in the treatement of depression and 47 differential variables and 5 metabolic pathways were found.3.A pseudotargeted method based on UHPSFC-MS/MS was proposed and was applied to the lipid profiles of depressed rats with the treatment of liquiritin.The developed method provided an environmental friendly way for pseudotargeted lipid profiles.The UHPSFCMS/MS-based pseudotargeted method achieved the separation of lipids in 8 min.The results showed that the linear correlation coefficients(r)were larger than 0.999,the limits of detection in plasma were not more than 1 ng/m L,the RSDs of precision were not more than 12.0% and the recovery ranged from 81.0% to 119.9%,which met the requirement of bioanalytical method validation.Compared with the pseudotargeted method via UHPLC-MS/MS,the UHPSFCMS/MS-based pseudotargeted method used half the analytical time,reduced the peak widths for 84% of the peaks,enhanced the detection sensitivity for 62% of the peaks and performed a better separation for isomers.In addition,the detection of 61% of the peaks in the UHPSFCMS/MS-based pseudotargeted method was 10-times more sensitive than those in the UHPSFCMS-based untargeted method and also better repeatability was observed.The UHPSFCMS/MS-based pseudotargeted method was employed for the lipidomics study of liquiritin in the treatment of depression and 33 differential variables and 3 metabolic pathways were screened.