正品大黄不同品种间泻下效价强度比较研究

Comparative studies on purgative potency among three spieces of certified rhubarb

目的:考察《中国药典》所载3个品种大黄间泻下效应上的差异及原因,为进一步运用量化指标客观的评价泻下活性奠定基础。方法:以B liss法计算小鼠泻下效应的ED50,比较3个品种间效价强度,测定结肠肠壁细胞Na+-K+-ATP酶活性。利用高效液相色谱法测定大黄中泻下相关组分番泻苷A,结合型大黄素、大黄酚、大黄酸,游离型大黄素、大黄酚、大黄酸的含量。紫外分光光度法测定泻下组分总蒽醌类、结合蒽醌类、游离蒽醌类、总番泻苷类含量。结果:3个品种大黄间泻下效力存在较大的差异,以泻下质反应为指标,唐古特大黄、药用大黄及甘肃产掌叶大黄的泻下ED50分别为0.37,0.99,1.83 g.kg-1。3个品种效价强度比为4.94∶1.85∶1。而对小鼠结肠肠壁细胞膜Na+-K+-ATP酶活性抑制作用,也存在品种差异,唐古特大黄的酶抑制作用强于其他2种。不同品种大黄泻下组分含量差异也较为明显。结论:大黄的3个品种泻下活性与泻下组分存在较大差异,这可能是导致临床处方和成药最终疗效产生差异的重要原因之一。

Objective： To investigate the difference and causes of purgative activity in three species of certified rhubarb, so as to lay steady foundations of further research on assessing purgative activity impersonally by using measurable indexes. Method： The potencies of three species were comparied with purgative EDso of mice as quantitative index which were calculated, and activities of Na^＋ -K ^＋ -ATP ase in mouse colonic epithelial cell membrane were also investigated. The related purgative contents （conjunct and free rhein, chrysophanol, chrysophanic acid, sennoside A） were detected by HPLC and contents （ total anthraquinones, anthraglucosennin; conjunct and free anthraquinones） were detected by UV. Result： There were different purgative activities among three spieces of certi- fied rhubarb. Each purgative EDso of mice was Rheum tangutlcum （ EDso = 0, 37 g·kg^-1 ）, R. officinale （ EDso = 0. 99 g·kg^-1 ） and R. palmatum from Gansu （ EDso = 1.83 g·kg^-1 ）, the ratio of potency of those was 4.94： 1.85： 1. In the meanwhile, the difference of the inhibitory effect on Na^ ＋ -K ^＋ -ATP ase in mouse colonic epithelial cell membrane and relative purgative components also existed in the three species of certified rhubarb. Conclusion： It disclosed that there was notable diference of purgative activity and components a- mong three spieces of certified Rhubarb, which probably resulted in the ultimate diference in clinical prescription and the production of Chinese patent medicines.