Laxative anthraquinone contents in fresh and cooked Senna siamea leaves.

This study determined the contents of total anthraquinone glycosides in Senna siamea, which are active laxative form, and total anthraquinones in the fresh young leaves, the boiled leaves, and the boiled filtrates by a UV-vis spectrophotometric method. Total anthraquinone glycosides and total anthraquinones, calculated as rhein, in the fresh young leaves were 0.0523 and 0.0910% w/w, respectively. The first and second boiled filtrates contained total anthraquinone glycosides 0.0334 and 0.0031% fresh weight, respectively. The first boiled leaves contained 0.0161% fresh weight and the second boiled leaves contained non-detected amount. Total anthraquinones contents in the first and second filtrates and the first and second boiled leaves were found to be 0.0721, 0.0069, 0.0167% fresh weight and non-detected amount, respectively. The results showed that the process of preparation of khi lek curry by boiling S. siamea young leaves twice with water reduced total anthraquinone glycosides content more than 75%. This confirms the traditional use of khi lek curry as a very mild laxative drug.