Study On Pharmacokinetics And Biotransformation Of Aesculin And Aesculetin From Cichorium

Objective:1. Aesculin and aesculetin in rat plasma were determined by UPLC, simultaneously. Their pharmacokinetics in rat plasma were studied.2. To establish determination method of aesculin and aesculetin in rat urine. Their pharmacokinetics in rat urine were studied, too.3. Biotransformation of aesculin and aesculetin in rat were studied by HPLC-MS. Methods:1. Hypersil BDS C18column was adopted, mobile phase consisted of methanol-0.2%formic acid (12:88) at a flow rate of1.2ml·min-1, the column temperature was35℃, the detection wavelength was339nm. Tinidazole was as an internal standard. Rat plasma samples were pretreated by methanol-acetonitrile (2:3). Aesculin and aesculetin contents in rat plasma and their pharmacokinetic parameters were calculated.2. Tinidazole internal standard was added to urine, urine samples were pretreated by Solid Phase Extraction (SPE) columns and determined by HPLC. Shim-pack VP-ODS column (250mm×4.6mm,5μm) was adopted, mobile phase consisted of methanol-0.2%formic acid (13:87) at a flow rate of1.0ml·min-1, column temperature was35℃, the detection wavelength was339nm.3. Rat urine purified by SPE columns were analyzed by HPLC-MS, Metabolites and metabolic pathway of aesculin and aesculetin were presumed. Results:1. After oral administration of aesculin and aesculetin, aesculin disposition was described as the two-compartment model with a weight of1/C2, while aesculetin was described as the two-compartment model with a weight of1/C. Aesculin and aesculetin were absorpted rapidly after oral administration, and reached peak concentrations rapidly. Two drugs were eliminated fast in vivo, the retention time of aesculin was1.2803h and aesculetin was3.3969h, respectively.2. Cumulative urine concentrations of rat in different time periods after gavaging aesculin and aesculetin were detected, Cumulative urinary excretion of aesculetin in48h was larger than aesculin, combined with blood data shows that aesculetin absorption rate was larger than aesculin. Small portion of the prototype drugs were eliminated by the renal, and renal clearance of aesculetin was less than aesculin, drug metabolites was mainly eliminated which was predicted by data of original drug renal clearance. Total urine drug excretion of prototype aesculin was0.578%, k=0.0631h-1,t1/2=10.983h, and prototype aesculetin was0.355%, k=0.0640h"1, t1/2=10.8281h, respectively.3. Five metabolites in rat urine were elucidated, the metabolism pathway of aesculin and aesculetin were hydrolysis, reduction and sulfation. Conclusion:In this study, pharmacokinetics and biotransformation in rat of aesculin and aesculetin were studied. The process and metabolites of them were clarified. The results provided the parameters for hepatoprotective effect of Cichorium glandulosum.