OBJECTIVETo study the rational daily administration times of rhubarb when it is used to treat experimental jaundice in rats, at the same time, validate the accuracy and feasibility of the method which was previously established to research the rational daily administration times of rhubarb (PD-PK method), and consummate it.

METHODAfter the rats were modeled by 4% ANIT (75 mg x kg(-1)) for two days, rhubarb extraction was drenched 3.6 g x kg(-1) once a day, 1.8 g x kg(-1) twice a day and 1.2 g x kg(-1) three times a day, respectively. Then the total bile and the flow rate of bile were observed. Blood was collected from the veins behind the eye sockets after different intervals and was used to investigate the biochemical indexes of the blood serum, such as TBIL, ALT, ALP, AST and GGT, and to determine the concentration of rheic acid in the blood plasma, then the time-effect curve and time-dose curve were obtained. The rational daily administration times of rhubarb was determined when it was used to treat experimental jaundice based on the comprehend analysis of time-effect and time-concentration relationships.

RESULTCompared with the groups which were administered once a day and three times a day, the total bile within 8 h of the rats which were administered twice a day was 1.56 and 1.7 times higher, respectively, while the TBIL was 23%, 22%, and ALT was 86%, 65% of the other two, ALP was 50%, 71% of the other two, respectively. With administrated twice a day, the blood concentration of rheic acid could maintain a high level for a longer time, which maybe the main reason for its effect.

CONCLUSIONThe method based on pharmacodynamics and pharmacokinetics is scientific and feasible to study the rational daily administration times of traditional Chinese medicine. Rhubarb is better to administrate two times a day to treat jaundice.