Sennoside A and B were detected in 21 commercial health tea products surveyed in 2000-2007, but there were 8 products in which the leaves could not be identified as senna because the leaves had become discolored. The results of assay of sennoside levels and TLC chromatograms suggested that processed senna had been used in these products. Next, with reference to tea and health tea manufacturing methods, pharmaceutical senna was roasted or wet-processed experimentally. The results indicated that the discolored leaves contained in commercial health tea were most likely derived from senna leaves. Moreover, sennosides in medicinal doses were detected in some processed senna samples, and were determined to have a cathartic action in mice. Based on morphological confirmation and the results of component analysis, including sennoside, the discolored leaves found in commercial health teas were therefore determined to be senna leaves. There may be possible health risks, including diarrhea.
