Investigation Of The Effects Of Squalene And Squalene Epoxides On The Homeostasis Of CoQ10 In Rats By UPLC-MS

Objective:In this paper,a highly sensitive method for the determination of coenzyme Q10(CoQ10)in rat plasma was established by using ultra-high performance liquid chromatography-high resolution Obitrap mass spectrometry(UPLC-MS).The effect of squalene and the squalene oxides on the homeostasis of coenzyme Q10 in rats were studied.Methods:First,a UPLC-MS method for the determination of CoQ10 in rat plasmas was established by selecting CoQ9 as the internal standard.Rats were given two different doses of squalene(100?L and 50?L)by intragastric administration.Blood samples were collected at different time points after intragastric administration.The established UPLC-MS method was used to determine the concentration of CoQ10 in plasmas,and QC verification was conducted to investigate whether the gavage of squalene could affect the balance of CoQ10 in rats.The oxidation products of squalene were isolated,purified and detected.Rats were given two different doses of oxidized squalene(100?L and 50?L)by intragastric administration,and the plasmas concentration of CoQ10 was determined to investigate the effect of different epoxidation squalene on the synthesis of CoQ10.Results:By analyzing the plasma samples at different time points after gavage of squalene in rats,the experimental results obtained by different treatment methods were compared.Use of Thermo company Obitrap high-resolution mass spectrometer,in the optimization of sheath gas,auxiliary gas,capillary temperature,spray capillary tube voltage,voltage and tube after lens mass spectrum parameters such as voltage,standard curve of CoQ10 were determined,respectively with[M-H]~-(m/z 862)for target material to obtain the correlation coefficient of standard curve conforms to the requirements,according to the standard curve,the linear range of CoQ10 is 1~1000 ng/mL.After gavage of squalene and two kinds of oxidized squalene,the CoQ10 balance in rats was affected by the established UPLC-MS detection method.Conclusion:In this study,a highly sensitive and rapid method based on UPLC-MS combined with the precipitation protein method was established for the quantification of CoQ10 in rat plasmas.Two kinds of squalene epoxides were successfully isolated by column chromatography.The effects of different doses of squalene and squalene oxide on the CoQ10 level in rats were studied.Results both squalene and its oxide promoted the synthesis of CoQ10 in rats.There was no significant difference between the high and low dose groups,and the low dose squalene and squalene oxide were enough to promote the synthesis of CoQ10.This study provides new information for understanding the interaction of squalene and squalene oxide with CoQ10 in vivo,which is helpful for the treatment of CoQ10 deficiency in humans.