OBJECTIVETo investigate the mechanism of Modified Xiaoyao Powder (MXP) on electrogastrogram (EGG) and pharmacokinetic characteristics of ferulic acid (FA) in patients with functional dyspepsia (FD) of Gan-qi stagnation with Pi-deficiency syndrome type (FD-GP).

METHODSThe study was conducted following method of pharmacodynamics and pharmacokinetics synchronous determination. The 20 patients with FD-GP and 21 healthy volunteers enrolled were orally administrated with MXP to observe the changes in symptom scores, EGG and pharmacokinetic characteristics of FA in patients using gastrointestinal analyzer and high performance liquid chromatography (HPLC) before and after treatment.

RESULTSAfter treatment, the symptom scores of patients significantly decreased (P < 0.01). EGG showed that the average amplitude of peak and dominant frequency, etc. at the monitoring points, including gastric body, lesser curvature and the near gastric antrum part of greater curvature, etc. were lower than the normal range, the changes were especially obvious and would be worsened after meals (P < 0.01). After treatment by MXP, all the above indexes were improved either before or after meals. The pharmacokinetic parameters of FA in patients of FD-GP before treatment were lower than those in the healthy control group (P < 0.05) and they were insignificant different by MXP comparing with those in the healthy control group.

CONCLUSIONMXP is effective not only in improving clinical symptoms and EGG, but also on pharmacokinetic parameters of FD-GP patients.