Research The Interaction Between Emodin And The Rat Intestinal Mucosa P-glycoprotein?MRP2 By Ussing Chamber

ObjectiveTo establish Ussing chamber experimental models on interaction of oral drugs with P-glycoprotein and MRP2 at intestinal mucosa.Using this model to study absorption of emodin came from Radix Polygoni Multiflori at rats different intestine segments.Exploration the relationship between emodin and efflux-type transportprotein of P-glycoprotein and MRP2 in rats intestine tissue.Methods1.To establish Ussing chamber experimental models.(1)This models was selected to evaluated the impact of p-glycoprotein inhibitor verapamil on digoxin in both absorption(M-S)and secretion(S-M)direction at each intestine segment by cumulative permeation amounts(Q),apparent permeability coefficients(Papp)and efflux transport rate(Er).If Papp increased in M-S or decreased in S-M and Er decreased after adding inhibitor,the model was established successfully.(2)This model was selected to evaluate the impact of MRP2 inhibitor ciclosporin A on pravastatin in both M-S and S-M direction at duodenum,jejunum and ileum by Papp and Er.If Papp increased in M-S or decreased in S-M and Er decreased after adding inhibitor,the model was established successfully.2.Selected the models to study infiltration of emodin in different concentration at rats different intestine segments in absorption and secretion direction,by determining Q,Papp and Er.3.Study the Papp in both M-S and S-M and Er variation of emodin at jejunum after using verapamil at the mucosal side of intestinal tissue.Then compared with the control group to study the impact of P-gp on the drug absorption and inspect whether emodin is the substrate of P-gp.4.Study the Papp in both M-S and S-M and Er variation of emodin at jejunum after using cyclosporine A at the mucosal side of the intestinal tissue.Then compared with the control group to study the impact of MRP2 on the drug absorption and inspect whether emodin is the substrate of MRP2.5.Study the Papp in both M-S and S-M and Er variation of digoxin at jejunum after using different concentrations of emodin at the mucosal side of intestinal tissue.Then compared with blank group to study the impact of drug on the adsorption of digoxin and inspect whether emodin is inhibitor or inducer of P-gp.6.Study the Papp in both M-S and S-M and Er variation of Pravastatin at jejunum after using different concentrations of emodin at the mucosal side of intestinal tissue.Then compared with blank group to study the impact of drug on the adsorption of Pravastatin and inspect whether emodin is inhibitor or inducer to MRP2.Results1.(1)In control group,Er of digoxin at duodenum,jejunum,ileum and colon is 3.23±0.73,4.78±0.52,5.18±0.81,2.77±0.20 respectively.Verapamil with concentration of 100?g · ml-1 can diminish Er of digoxin at different intestine segments,statistical difference were shown at jejunum(0.73±0.10)and ileum(1.38±0.38)but not at colon.Statistical difference was shown at colon(1.28 ± 0.30)when the concentration of Verapamil is 200?u g·ml-1.(2)Compared with control group,Papp in S-M of pravastatin was decreased in each intestine segment with significant differences.Cyclosporine A at 50?g · ml-1 could decrease Er of pravastatin at jejunum and ileum with significant differences.Cyclosporine A at 100?g · ml-1 reduced the Er of pravastatin at duodenum,jejunum and ileum with significant differences.2.Q at duodenum,jejunum,ileum and colon were increased rapidly in 30 min,but Q had not been increased remarkably during 30 min to 120 min.Papp in S-M always greater than it in M-S under different concentration of Emodin,and significant difference was shown in high concentration group(P<0.01).Er of emodin was increased with the raising of concentration given.3.When combined with verapamil,different concentration of emodin has different parameters.At jejunum,in low concentration group,Papp was increased in M-S and decreased in S-M with the diminishment of Er.No significant difference was shown.For middle concentration group,Papp in M-S was not increased,Papp in S-M and Er was not decreased.For high concentration group,Papp in M-S was not increased,Papp in S-M and Er was reduced.Both in S-M and M-S there was no statistical difference.4.When combined with cyclosporine A,different concentration of emodin has different parameters.At jejunum,in low concentration group,Papp in M-S was increased(P<0.01)and Papp in S-M was decreased,Er also diminished(P<0.05).For middle concentration group,Papp in M-S was increased(P<0.05),Papp in S-M(P<0.01)and Er(P<0.01)was decreased with statistical difference.For high concentration group,Papp in M-S was increased(P<0.05),Papp in S-M and Er was reduced.5.At jejunum for digoxin,when different concentration of emodin was added,Papp in M-S was not increased,Papp in S-M and Er were not reduced,compared with control group.6.At jejunum for Pravastatin,when different concentration of emodin was added,Papp in M-S was not increased,Papp in S-M and Er were not reduced,compared with control group.ConclusionExperimental models on interaction of drugs with P-glycoprotein and MRP2 were established by Ussing chamber,shows that results are reliable.The results indicate that the absorption and transport of emodin was affected by exclusive transport protein.Emodin was not affected by P-gp but by MRP2 in absorption process,which displays that emodin maybe the substrate of MRP2.This research also shows that emodin is neither inhibitor nor inducer for P-gp and MRP2.