[Analysis on changes of purgative biopotency in different processed products of rhubarb].

To determine the difference on purgative biopotency of different processed products of rhubarb and compare rhubarb before and after preparation. The prime biopotency of rhubarb reference substance was determined by comparing with the control substance of sennoside B using rat purgative model. Comparing with calibrated rhubarb reference substance, the bioactivity different processed products of rhubarb was determined by the 2,2',2" method. The purgative biopotency of crude rhubarb was 825.22 U x g(-1). The purgative biopotency of alcohol-processed rhubarb was 699.05 U x g(-1), The purgative biopotency of steamed rhubarb were 459.76 U x g(-1). Carbonized rhubarb cannot be determinate. Crude rhubarb showed a significantly declineing purgative biopotency after being processed, alcohol-processed rhubarb showed less than crude rhubarb and followed by steamed rhubarb. Carbonized rhubarb lost almost all purgative bioactivity.