Effect of Baizhu(Rhizoma Atractylodis Macrocephalae)extract on intestinal absorption of brucine and strychnine in vitro and in situ

OBJECTIVE:To investigate the antagonistic effect of the extract of Baizhu(Rhizoma Atractylodis Macrocephalae)(RAM)on the intestinal absorption of brucine and strychnine in Strychnos nux-vomica(NUX)and propose the mechanism of these effects.METHODS:The apparent permeability value(Papp)and absorption rate constant(Ka)were chosen as indices.The everted intestinal sac model and in situ single-pass intestinal perfusion model were used to study the effects of the RAM extract on the absorption of brucine and strychnine.To confirm the results,the brucine and strychnine concentrations in hepatic portal venous blood were determined.Western blotting was used to study P-glycoprotein(P-gp)expression in the Caco-2 cell line.RESULTS:Papp and Ka of brucine and strychnine were significantly increased in the presence of a P-gp inhibitor,but no significant increase was noted in the presence of a tight junction regulator.The RAM extract inhibited the absorption of brucine and strychnine and enhanced P-gp expression.CONCLUSION:The primary absorption mechanism for brucine and strychnine is passive transport,which is affected by P-gp.

Analysis of the influence of processing of bran stir-baking on the main components of Paeoniae Radix Alba-Atractylodis Macrocephalae Rhizoma herbal pair by high-performance liquid chromatography

The crude and processed Paeoniae Radix Alba-Atractylodis Macrocephalae Rhizoma herbal pairs, originated from Bai-zhu-shao-yao-san, are used to treat different diseases clinically. In order to evaluate the crude and processed Paeoniae Radix-Atractylodis Macrocephalae Rhizoma herbal pairs, a simple, easy, and sensitive high-performance liquid chromatography coupled with diode array detectors was developed for simultaneous determination of nine bioactive components in the herbal pairs. The calibration curve exhibited good linearity（r2≥0.9992）. The LODs and LOQs were ≤7.30 and 11.53 μg/m L, respectively. The intra-, inter-day and repeatability RSD values of the nine compounds were less than 3.86%, 2.71%, and 4.29%, respectively. The RSD stability values were less than 3.64%. The recovery of the method was in the range of 96.70%–102.10%, with RSD values less than 3.52%. The developed method can be applied to the intrinsic quality control of crude and processed Paeoniae Radix-Atractylodis Macrocephalae Rhizoma herbal pairs.