RESUMO
<p><b>OBJECTIVE</b>To investigate the relationship between the laxative potency and anthraquinones content of six kinds of traditional Chinese drugs (TCDs) like Rheum tanguticum, Polygonum cuspidatum, R. palmatum, R. officeinale, Semen Cassiae and Radix Polygoni Multiflori.</p><p><b>METHOD</b>The half effective dose (ED50) was applied to determine the laxative potency and the content of anthraquinones was evaluated by RP-HPLC.</p><p><b>RESULT</b>The ED50 for the six kinds of TCD was 0.458, 0.686, 0.925, 1.004, 1.047, 1.986 g x kg(-1), respectively, and the sequence of laxative potency was R. tanguticum > P. cuspidatum > R. palmatum > R. officeinale > Semen Cassiae > Radix Polygoni Multiflori. In terms of the HPLC quantitative determination, the content of combined anthraquinones was 2.82% ,1.64%, 1.44%, 0.82%, 0.15%, 0.019%, respectively,and the sequence was R. tanguticum > Polygoni cuspidatum > R. palmatum > P. cuspidatum > Semen Cassiae > Radix Polygoni Multiflori.</p><p><b>CONCLUSION</b>There is a great difference in laxative potency between TCDs, and the relationship between laxative potency and the content of combined anthraquinones was found. The bioassay may be utilized to evaluate and control the quality of TCD with the chemical methods.</p>