Studies On Pharmacokinetic Characteristics Of Pedanculosid And Ilexolic Acid In Maodongqing Capsules

Maodongqing capsules belong to Chinese drugs pharmaceutics, what are extracted from the plant of Aquifoliaceae, and the medicinal parts are maodongqing’s dried root. The capsules have good effect, be widely used for the treatment of coronary atherosclerotic heart disease、angina pectoris、thrombosis angiitis obliterans,etc. Triterpenoid saponins are main active ingredients of Maodongqing capsules, ilexolic acid is one of the main metabolites of them in body.Currently,the studies are mainly in ilexsaponin A、B1、B2 and ilexgenin A, and throughout the literature,we can find the research is mainly in School of Chinese Herbal Medicine of Guangzhou University of TCM. Standards of tests are made in their own laboratory.We choose research subjects from the active ingredients of Maodongqing in literatures,and we must take the question where we can buy choosed ingredients into accunt.This topic’s research subjiects are pedanculosid and ilexolic acid.At present, Maodongqing capsules take rutin as quality control gredient which they don’t contain,it is unreasonable and not scientific.The article attempts to study metabolic properties of Maodongqing capsules’s two gredients on the basis of existing studies, in order to provide important information for manufactures’s quality control,clinical treatment and follow-up researches.Use HPLC To find a method for the tset of pedanculosid and ilexolic acid in Maodongqing capsules. The separation was carried out at 40℃ on an Agilent Zorbax SB-C18 (4.6 mm×150 mm,5 μm) column with and 0.2% phosphoric acid as a mobile phase in a gradient elution. The flow rate was 1.0 mL·min-1 and the injection volume was 20 μL. detecting target compound at 215 nm. Pedunculoside showed a good linear relationship at the range of 1.22～521.1 μg · mL-1 (r= 0.9995),The average recovery was 99.24% with RSD 0.68%. Ilexolic acid showed a good linear relationship at the range of 1.23～289.6μg · mL-1(r= 0.9991),the average recovery was 99.53% with RSD 0.85%. The way is easy, accurate with good reproducibility and can be used for quality control of Maodongqing capsules.To create a method for testing the concentration of pedunculoside and ilexolic acid in rats plasma, and to testing the binding rate. HPLC and equilibrium dialysis were used to tested binding level of pedunculoside and ilexolic acid in vitro. The protein binding ratios of pedunculoside with Low, moderate and high concentration in vitro were 39.72%±2.68%,52.05%±3.35% and 52.32%±0.76%, respectively; The protein binding ratios of ilexolic acid in vitro were 55.18%±3.66%,60.79%±2.20% and 47.00%±1.59%, respectively. The HPLC method used to separate pedunculoside and ilexolic acid in rats plasma was simple and convenient. The binding of pedunculoside and ilexolic acid with plasma of rats was moderate and protein binding ratio did not affect the drug concentration.To study the Pharmacokinetic characteristics of Pedanculosid in rat plasma after Tail vein injection. A liquid chromatograph-mass spectrometer(LC-MS) assay of Pedanculosid in rat plasma was established and used to determine the plasma concentration of Pedanculosid after Tail vein injection by 2.86 mg per rat. DAS Ver 1.0 software was used for statistics analysis of its pharmacokinetic parameters. Pedanculosid showed two-compartment model distribution in vitro, the main pharmacokinetic parameters were half-life time(5.20 h)、clearance(51.07 L·h-1)、the maximum concentration (22.68μg·L-1)and apparent volume of distribution(2355.69 L). The method had high sensitivity, could be used to detect the concentration of Pedanculosid in rat plasma and analyze its pharmacokinetic parameters.To study the influence of Maodongqing Capsule on metabolic activity of CYP1A2, CYP3A2, CYP2C6, CYP2D1, CYP2D2 and CYP2E1 by Cocktail probe drug in rats. Use theophylline, midazolam, tolbutamide, omeprazole, dextromethorphan and chlorzoxazone as the probe drug of cytochrome P450。The rats were randomly divided into three groups:control group, low group and high group。Maodongqing capsule was orally given to the low and high groups once a day with the dose of 0.45g and 0.9g per rat, respectively。The control group and the experimental group administered equal volume of saline, each group was once a day, for 14 days。Cocktail probe drugs in each group were given in the 15th day, the plasma was taken at different time before and after Maodongqing capsule, The plasma concentration of probe drugs were determined by LC-MS/MS and their corresponding pharmacokinetic parameters were calculated。the Cmax, AUC0-t of theophylline low group had significant differences(P≤0.01); The AUC0-t of tolbutamide high group had significant differences(P≤0.01); the AUC0-t of chlorzoxazone low group had significant differences(P≤0.05); while had no significant differences on the activities of other probes in rats。Maodongqing capsule had a significant induction to CYP2C6 and CYP1A2 in rats,and had a moderate induction to CYP2E1 in rats, while no significant influence in other subtypes.