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

Objective: To determine the difference on purgative biopotency of different processed products of rhubarb and compare rhubarb before and after preparation.

Method: 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.

Result: 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.

Conclusion: 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.