| Through extensive pharmacological studies on TGP (Total glucosides of paeony,TGP), it is found that TGP has effect not only in anti-inflammatory, but also in protecting acute chemical and immunologic hepatic injury. TGP can improve the activity of antioxidant enzyme and have the actions of anti-free radicals, immuno-regulation, and inhibition of the proliferation of stellate cells in liver promoted by Kupffer cells in vitro rats with hepatic injury and so on. Its mechanism has something to do with that above.The topic studied on the pharmacokinetics distinction of TGP in acute hepatic injury induced by CCl4 and in normal rats by HPLC method. The kinetics parameters and absorption parameters were determined and compared at different mass concentration in rats. The intestines in rats were cannulated for in situ recirculation. Plasma protein binding rate was determined in liver injury rats induced by CCl4, and contrast with normal Rats. The bioactive constituents and possible metabolic products were presumed by serum fingerprintings, which were established foundation to research internal bioactive constituents of TGP and metabolic process. As follow:Part one Pharmacokinetics of TGP in liver injury rats induced by CCl4Objective: Study the Pharmacokinetics of TGP on acute hepatic injury of rats induced by CCl4, and compared with normal rats. Meanwhile, considered the influence of kinetic parameter at different mass concentration.Methods: After the rats oral administrationed of TGP, the concentration of Paeoniflorin and Albiflorin in biological samples were determined by HPLC at different time. Results: In model rats, t1/2 of Paeoniflorin and Albiflorin at high, medium, low dose were 300. 97, 271.37, 294.46min; 313.34, 302.33, 302.76 min. Ke(×10-3) were 2.35, 2.62, 2.52 mL/min; 2.24, 2.40, 2.34mL/min. Cmax were 22.54, 14.52, 5.49μg/mL; 9.02, 5.04, 2.34μg/mL. AUC0-t were 8792.9, 5048.3, 1897.2μg·min/mL; 3393.7, 1930.6, 809.0μg·min/mL, Tmax of Paeoniflorin and Albiflorin at different concentration were all 2h. In normal rats, t1/2 of Paeoniflorin and Albiflorin at high, medium, low dose were 236.85, 221.10, 237.10 min; 224.12, 238.77, 227.71 min. Ke(×10-3) were 3.07, 3.26, 3.28mL/min; 3.13, 2.92, 3.12mL/min. Cmax were 19.16, 1.60, 4.38μg/mL; 7.16, 4.00, 1.93μg/mL. AUC0-t were 6975.6, 4064.1, 1500.6μg·min/mL; 2701.9,1635.4, 635.1μg·min/mL. Tmax of Paeoniflorin and Albiflorin at different concentration were all 2.5h.Conclusion: Compared with normal rats, Cmax and AUC0-t of model rats increased remarkably. t1/2 extended and Tmax were shorter obviously. Tmax and t1/2 not effected by dose of TGP, but as dose increased, Cmax and AUC0-t increased with a linear correlation.Part two Study on plasma protein binding rates of TGP on acute hepatic injury of rats induced by CCl4Objective: To determine the plasma protein binding rates of Total Glucosides of Paeony (TGP) in liver injury rats induced by CCl4 and in normal rats in vitro. Meanwhile two groups were compared.Methods: The equilibrium dialysis method was employed to determine the plasma protein binding rates of Paeoniflorin and Albiflorin in TGP on acute hepatic injury of rats induced by CCl4 and normal rats. The concentration of Paeoniflorin and Albiflorin in plasma was measured by HPLC. Using SPSS11.5, the plasma protein binding rates of high, middle and low were compared within and between groups.Results: At the concentration of 50, 100, 200μg·mL-1 of TGP, the plasma protein binding rates of Albiflorin and Paeoniflorin with liver injury rats pl -asma were (12.4±1.5)%, (13.2±1.6)%, (20.2±2.1)%; (15.5±0.4)%, (16.5±1.4)%, (27.9±1.6)%. And normal rats were (8.1±0.9)%, (9.7±2.3)%, (14.7±1.4)%; (12.7±1.6)%, (13.5±0.8)%, (15.6±0.2)%.Conclusions: The protein binding capacities of TGP is low in the plasma of rats with liver injury. Moreover, the binding rates may proportionally depend on the plasma concentration; compared with the normal rats, the binding rates had increased in liver injury rats induced by CCl4.Part three Studies on the absorption kinetics of TGP in rats stomach and intestineObjective: To investigate the absorption kinetics of active components of TGP in rat stomach and intestine.Methods: The absorption parameters of TGP at different concentration were determined by HPLC, and the intestine in rats was cannulated for in situ recirculation.Results: The absorbed doses of Paeoniflorin and Albiflorin were (45.22±7.81), (86.41±13.67), (153.77±12.38)μg·h-1; (18.04±2.89), (34.95±4.08), (61.36±9.11)μg·h-1, which were determined after two hours of TGP oral admin -istrationed at 1, 2, 4 mg/mL.The recirculated fluid of TGP with the concentration of Paeoniflorin at 40, 80, 120mg/mL had recirculated two hours. The absorption rates (Ka)of Paeoniflorin had no marked difference at40, 80, 120mg/mL. so was Albiflorin. The recirculated fluid of TGP had recirculated two hours in different segments with the same concentration. The absorption rates(Ka) of Paeoniflorin were evidently higher in duodenum than ileum and colon, and Jejunum was higher than colon. The absorption rates(Ka) of Albiflorin were evidently higher in duodenum and Jejunum than the others.Conclutions: TGP can be absorbed in whole intestinal segments and stomach, and the duodenum was the highest absorption part. TGP concentration and absorbed doses were with a linear correlation in rats stomach and intestine, but the absorption rates (Ka) in different concentration had no obvious difference. Part four Preliminary study on serum fingerprinting of TGPObjective: To explore the serum fingerprinting of TGP at different time, and lay the foundation for the researching the bioactive constituents of TGP.Metheds: The blood migrating constituents of TGP were determined by HPLC, Through compared and analyzed fingerprintings of TGP, blank sera and drug contained sera at 15min, 1 h, 3 h, 6 h and the blood migrating constituents were decided.Results: Paeoniflorin and Albiflorin which change low and high follow -ing time were measured in the serum fingerprintings. The peak area of Paeoni -florin and Albiflorin are largest in 3 h.Conclution: This topic got the serum fingerprinting at different time by HPLC. The blood migrating constituents were presumed. Paeoniflorin and Albiflorin were supposed to be the material base of pharmacodynamic action in TGP.In summary, the study found that Cmax and AUC0-t of model rats increased remarkably compared with normal rats. t1/2 extended and Tmax were shorter obviously. Tmax and t1/2 not effected by dose of TGP, but as dose increased, Cmax and AUC0-t increased with a linear correlation. The protein binding capacities of TGP is low in the plasma of rats with liver injury. Moreover, the binding rates may proportionally depend on the plasma concentration; compared with the normal rats, the binding rates had increased in model group. TGP can be absorbed in whole intestinal segments and stomach, and the duodenum was the highest absorption part. TGP concentration and absorbed doses were with a linear correlation in rats stomach and intestine, but the absorption rates (Ka) in different concentration had no obvious difference, which suggested that TGP diffused in body maybe with the passive diffusion mechanism. Paeoniflorin and Albiflorin were supposed to be the material base of pharmacodynamic action in TGP.
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