Pharmacokinetic-pharmacodynamic Study On Antipyretic Effects And Anti-inflammatory Of Coptisine On Endotoxin-induced Pyrexia Of Rats

Background and Purpose Pharmacokinetic-pharmacodynamic(PK-PD)modeling was a hot topic in modern drug research methods.In the area of drug research,coptisine is an isoquinoline alkaloid found in Chinese medicine Coptis chinensis,which has many pharmacological activities such as sterilization and anti-inflammation.Our previous in vitro anti-inflammatory results demonstrated that coptisine inhibited the endotoxin-induced inflammatory response in a dose-dependent manner,in order to further clarify the dose-effect relationship and time course of its anti-inflammatory effects in the whole animal pop?Lation.It is proposed that body temperature be a macro-inflammation index of inflammation,and a series of microscopic inflammatory factors such as NO,TNF-?,i NOS,and other PD indicators were tested,and a PK-PD model based on the mechanism of PD indicators was established to evaluate coptisine antipyretic,anti-inflammatory effects.Moreover,Comparing the biological differences and the significance of the model parameters obtained between the microscopic and macroscopic indicators,to provide the basis for the clinical research of anti-inflammatory and antipyretic activity of coptisine.Experimental Approach(1)Method for establishing rat blank plasma and lung tissue First,lung tissue and plasma samples were prepared and then acetonitrile(A)-0.1% aqueous formic acid solution(B)was used as the mobile phase to inject into the liquid phase system.Agilent Eclipse Plus C8(3.0 mm × 150 mm,1.8 ?m)column,flow rate: 1 m L·min-1,UV detection at 345 nm,column temperature 40°C,gradient elution: 0~10 min,90% B~ 60%B;10~20 min,60%B;20~25 min,90%B.(2)Study on Antipyretic Effect of Coptisine on Endotoxin in Rats by PK-PD Nine healthy male Sprague-Dawley(SD)rats were randomly divided into three groups,each with three.The rats in first group were injected intravenously with lipopolysaccharide(LPS,100 ?g·kg-1)alone.The second and third group rats were given coptisine high-dose(3.87 mg·kg-1)and coptisine low-dose(1.93 mg·kg-1)by tail vein injection at 30 min after LPS given,respectively.Body temperature was measured at different time points,and blood samples from tail vein were collected simultaneously.The blood concentration of coptisine was determined by ultra performance liquid chromatography.We use Monolix software to model PK-PD of coptisine mean plasma concentration and temperature effects,by population computation with non-covariates.Besides,we select the best goodness of fit model to evaluate coptisine antipyretic effect.(3)PK-PD study of the inhibitory effect of coptisine based on NO?TNF-? and other inflammatory factors Plasma and lung coptisine concentrations,plasma and lung TNF-? concentrations,plasma NO concentrations,lung i NOS expression after intravenous injection of three doses of coptisine in LPS-stimulated rats were measured.Based on these data,pop?Lation PK-PD model evaluation was performed on the plasma concentration of coptisine and efficacy indexes such as NO and i NOS,etc.Key Results(1)Under this chromatographic condition,berberine and berberine can be completely separated in rat plasma and lung tissue,and no endogenous substances in the biological sample interfere with the determination of the analyte,indicating specificity;the peak area has a good linear relationship,but Biological sample pretreatment methods have poor recovery.(2)Finally,Coptisine can significantly inhibit body temperature of endotoxin-induced fever in rats.two-compartment linear elimination model was used to describe the final PK model.Gaussian function,an input function of body temperature changes,which was used to depict PD model,the Emax model was used to link PK and PD.At last,the final model was fitted better,the fitting res?Lts indicated that the EC50 of antipyretic effect of coptisine was 89.7 ?g·L-1,the Emax was 1.88?.(3)The build model makes a well quantitative description of the TNF-? generation in plasma at first(1 h),and then diffusion from plasma to lung(2 h)causing i NOS overexpression(7 h),lung i NOS distributing to blood followed by elevation of plasma NO(8 h).Coptisine suppressed plasma TNF-? generation in a linear method,and decreased the area under the curve(AUC0-12h)level of plasma TNF-? 57.27%.The inhibitory effect of coptisine on early TNF-? production res?Lted in the cascade inhibition of i NOS and NO.Conclusion and Implications Coptisine has strong anti-pyretic effect on endotoxin-induced pyrexia of rats and its potency is highly,the distribution in vivo is small and the eliminate is quickly.Moreover,TNF-? responding to stim?Lation in the early-term is a key factor in later inflammatory cascade.Linear inhibitory effect of coptisine on TNF-? generation caused the concatenation inhibition of i NOS and NO.This comprehensive PK-PD model provided a good explanation of the lag time of TNF-?,i NOS,NO production,and quantitatively evaluated the inhibition of TNF-? production by coptisine.