Chemical,Pharmacokinetics,and Metabolism Study On The Constituents From Dichloromethane Fraction Of Cortex Dictamni

Cortex Dictamni has been used as traditional Chinese herbal medicine for the treatment of cancer,urticaria,eczema,and jaundice.Alkaloids,limonids and sesquiterpenes are the major types of compounds been reported in Cortex Dictamni.Modern pharmacology studies have shown that some of the constituents in Cortex Dictamni have arterial vasodilation,anti-cancer,anti-fungal,and other activities.So far,most attention was paid on the chemical compositions study for its significant efficacy.However,there is still no comprehensive reports about the absorption,distribution,metabolism,and excretion of the constituents in Cortex Dictamni have been published.Thus,figure out the effective chemicals and conduct systemic pharmacokinetics and metabolism study are of essential for drug development from Cortex Dictamni,and also important for its rational use in clinicalAnticancer activity screening of the fractions made from Cortex DictamniThe Cortex Dictamni extract was extracted with 95%aqueous ethanol,than the extract was partitioned with petroleum ether,dichloromethane,n-butanol,and water to get the petroleum ether,dichloromethane,n-butanol,and water fraction,respectively.Human lung cancer cell line A549 and NCI-H460 were selected as the anticancer activity screening model.The the results turned out that the dichloromethane fraction of Cortex Dictamni has the strongest anti-proliferation effect on the two cancer cell lines mentioned above.Chemical study of the dichloromethane fraction made from Cortex DictamniA Ultra-high performance liquid chromatography-electrospray ionization linear ion trap mass spectrometry method was developed for the qualitative identification of the chemicals in the dichloromethane fraction of Cortex Dictamni,a quantification methods based on HPLC-UV was developed first for the determination of the concentrations of limonin,dictamnine,obacunone,and fraxinellone in the dichloromethane fraction of Cortex Dictamni.by comparing with the retention time and mass fragmentation pathway of the standards,7 compounds were identified as isodictamnine,limonin,robustine,dictamnine,obacunone,fraxinellone,and prekimmianine.Another four constituents were also identified as isopteleine,5-hydroxy-4,8-dimethoxy-furoquinoline,?-fagarine,and 5-methoxydictamnine based on their tandem mass.From the results above,we found that most of the constituents in dichloromethane fraction of Cortex Dictamni belong to the limonoids and furoquinoline alkaloids.The amont of the limonin,dictamnine,obacunone,and fraxinellone in the dichloromethane fraction of Cortex Dictamni was quantified.Pharmcokinetics study of multi-constituents in Cortex Dictamni after oral admistration of the dichloromethane fraction of Cortex Dictamni.A quantification method based on the Ultra-high performance liquid mass spectrometry was developed for the determination of the concentrations of limonin,dictamnine,obacunone,and fraxinellone in rat plasma,and was applied for a pharmacokinetics study.After oral administion of the dichloromethane fraction of Cortex Dictamni,the Cmax and AUC0-t of dictamnine was very significantly high than that of the other three compounds after dosage adjustment.Limonoids showed poor oral absorption characteristics,take fraxinellone for example,the oral bioavailability of fraxinellone was only 5%after oral admistration of fraxinellone suspension.Thus,we speculate that the oral bioavailability of furan quinoline alkaloids are signigicantly higher than limonoids.Absorption,distribution,and excretion study of dictimnine in rat.A quantification method was developed for the determination of the concentration of dictaminie in rat plasma,urine,bile and feces,the concentration-curve of dictamnine in rat plasma after oral administration of 5 mg·kg-1 dictamnine and after tail vein injection of a mg·kg-1 dictamnine were obtained,and the absolute oral bioavailability of dictmnine in rat was calculated out as 47.9%.The tissue distribution study found that the dictmnine in rat liver,small intestine and lung were relatively higher than other tissues.And in brain tissue,the dictamnine can also be detected,means that the dictamnine can be transport through the blood-brain barrier.Excretion study found the 0.153%,0.017%,and 0.027%of the dictamine was excreted through the urine,bile,and feces,respectively.From the excretion results,we arrived at the conclusion that Dictamnine was mainly excreted in its metabolte form in rats.Dictamnine which did not absorbed in the intestine may be metabolized by intestinal bacteria,and then excreted with feces in its metabolite form.Metabolism of dictamnine in liver microsomes animal and humanA method based on high performance liquid chromatography-electrospray ionization linear ion trap mass spectrometry was developed of the characterization of the metabolites profiles of dictamnine after incubated with liver microsomes from mouse,rat,beagle dog,monkey and human.Nine metabolites were detected,and 8 of them were identified.The effects of non-specific and specific inhibitors on the formation the metabolites of dictamnine in human liver microsomes were investigated.We found that most of the metabolites were mediated by the CYP450 enzymes,and the predominant metabolite of dictamnine,M7,was mainly catalyzed by CYP3A4.