Pharmacokinetic Study On Laurolitsine

Laurolitsine is extracted from Litsea glutinosa and belongs to the apophylloid alkaloid compound.In the previous research of our research group,using db/db mice as a model,it was found that Laurolitsine exhibits good anti-diabetic effect and has good value for new drug development.However,the study on its pharmacokinetics in vivo is still blank.Therefore,in this thesis,a large amount of Laurolitsine was extracted from the bark of Litsea glutinosa;its glucose consumption level in vitro and its protective effect on palmitic acid-induced MIN6cells damage were evaluated;a specific and sensitive LC-MS/MS method was established for the determination of Laurolitsine in rat plasma,tissue and excreta.To investigate the pharmacokinetic parameters,tissue distribution and excretion of nematophylline in rats.It provides scientific basis for the further development of Laurolitsine.In this paper,a large amount of Laurolitsine was isolated from the bark of Litsea glutinosa by silica gel column chromatography,gel column chromatography,high performance liquid chromatography and other extraction and separation methods.The purity was more than 95%,which can be used for subsequent cell and pharmacokinetic experiments.The glucose consumption level and the protective ability of islet cells were tested.The results showed that Laurolitsine had a good glucose consumption level and had a protective effect on palmitic acid-induced MIN6 cell damage at a specific concentration.In this paper,we established a LC-MS/MS method for the estimation of Laurolitsine in the plasma of SD rats.After i.g.and i.v.administration,we collected plasma samples from the ophthalmic vein and prepared using the protein precipitation method with methanol.We used C18 column.The mobile phase consisted of water and acetonitrile（containing 0.5‰formic acid）,gradient elution program.The analysis time was 6.5 min and the flow rate was 0.3ml/min.The mass spectrum adopts electrospray ion source（ESI source）,positive ionization mode and multi-reaction monitoring.The quantitative ions of Laurolitsine and internal standard Nuciferine are 314.2→265.1 and 296.3→265.2 respectively.The concentration of Laurolitsine in plasma of SD rats after intragastric administration and intravenous administration was detected by verification method.DAS3.2.8 was used to process the data.Pharmacokinetic results showed that Laurolitsine could be absorbed rapidly in vivo after intragastric administration,T_maxwas 0.47±0.18 h,C_maxwas 14.11±3.30 ng/m L,t_1/2was3.73±2.48 h.C_maxwas 100.05±17.00 ng/m L and t_1/2was 1.67±1.83 h after intravenous administration.In this paper,LC-MS/MS method was established to determine the concentration of Laurolitsine in rat tissues.The drug contents in brain,heart,liver,spleen,lung,kidney,stomach,small intestine,skeletal muscle,body fat and testis tissues were measured at 0.5 h,1 h,2 h,4 h and 6 h after gavage of 10 mg/kg neolitsea alkaloid.The results showed that Laurolitsine could be rapidly distributed in all tissues after intragastric administration,reaching the peak value in30min.Laurolitsine is mainly distributed in stomach,small intestine,liver and lung in rats.A LC-MS/MS method was established to determine the concentration of Laurolitsine in urine and feces of rats.The concentrations of Laurolitsine in urine and feces of rats in different time periods were measured by intragastric administration of 10 mg/kg Laurolitsine.The results showed that the maximum excretion rate of urine was 4-8 h,and that of feces was 8-12h.The cumulative excretion of urine and feces in 36 hours accounted for 0.0325±0.0104%and1.2005±0.5006%of the dosage respectively,indicating that Laurolitsine may exist in the excreta in the form of metabolites.