Study On PK And PD In Irritable Bowel Syndrome With Syndrome Of Liver Invading The Spleen Of Extract From Citrus Aurantium

ObjectiveThe purpose of our study was to explore the effect of extract from Citrus aurantium on IBS rat with syndrome of liver invading the spleen induced by acetic acid and restraint stress. Our study was divided into three parts:(1)To study the changes of pharmacodynamics caused by extract from citrus aurantium;(2) A comparative study was designed and conducted to compare the pharmacokinetic difference of naringin, hesperidin, neohesperidin, naringenin and hesperetin of citrus aurantium in control and IBS model rat fecal flora.(3)To explore the relationship between PK and PD for three flavonoid glycosides in normal and IBS rat.Methods1、Pharmacological experimentAnimals were assigned into4groups (n=8for each group):IBS group(both instillation with acetic acid and restraint stress);Control group; ZSZHT group (IBS rats were cured by extract from citrus aurantium); Dicetel group (IBS rats were cured by Dicetel drugs). Briefly, the IBS rats were filled with4%acetic acid (1mL) by their anus.7d later, the rats fasting for24h were anesthetized with ether and tied for1h(from their regaining consciousness) each day. The modeling lasted3week. Rats were treated by relative drugs through gastric perfusion method for one week. Behavior performance and biochemical indexes were measured in different experimental phase among all groups.2、The hydrolysis of flavanone glycosides by rat fecal floraHigh-performance liquid chromatography was used to determine the flavanone glycosides and their corresponding aglycones in rat fecal flora. The DAS2.1pharmacokinetic program were used to calculate the pharmacokinetic parameters. Statistical analysis comparison of the pharmacokinetic parameters between control and IBS groups were possessed by SPSS16.0. At the same time, we used an LC-MS/MS technique to detect new metabolites from citrus aurantium by rat fecal flora.3、The study of PK-PD modelEstablished the LC-MS/MS method for determining the concentration of three f lavanone glycosides (naringin, hesperidin, neohesperidin) in normal and IBS rat plasma at different time points. Meanwhile, the concentration of NO in plasma were measured as pharmacodynamics index. At last, relevant data of PK-PD modeling were performed with WinNonlin4.0.1.Results1、After modeling, the consumption of sucrose water、weight、 the number of fecal pellets expelled and visceral sensitivity in IBS were significantly different with normal rats. Behavior performance in IBS rats was obviously improved and visceral sensitivity in IBS rats was significantly reduced after oral administration of extract from citrus aurantium and Dicetel. Besides, the concentration of NO was increased and the number of MC was reduced in IBS rats after curing with above drugs.2、Compared to normal rat fecal flora, three flavanone glycosides (naringin, hesperidin, neohesperidin) were more quickly hydrolyzed and generated the corresponding aglycones in IBS rat fecal flora. Significant differences existed in the pharmacokinetic parameters between these two groups. Meanwhile, six new metabolites from citrus aurantium were determined in rat fecal flora by the LC-MS/MS method.3、A remarkable decrease (P<0.05) in the value of AUC and Cmaxfor naringin, hesperidin, and neohesperidin and increase (P<0.05) of CL_F and elimination rate (A) for naringin and hesperidin were observed in IBS group after oral administration of extract from citrus aurantium compared to normal group. Besides, the time to peak was earlier in IBS group than normal group. Pharmacokinetic-pharmacodynamic (PK-PD) model were best described by a Sigmod-Emax model. The value of Emax、Ec50、Keo and S were obviously altered in IBS group, though there were no significant differences between two groups.ConclusionFlavanone glycosides from citrus aurantium has evident therapeutic effect on model rat suffering from irritable bowel syndrome with syndrome of liver invading the spleen, which implements its mechanism by adjusting the concentration of NO and the number of MC. In addition, we presume that the alteration in pharmacokinetics of flavanone glycosides from citrus aurantium due to the imbalance of gastrointestinal microbiota in IBS rat gut will increase the affinity between flavanone glycosides and NO, which increase effectiveness of citrus aurantium.