Senna--an old drug in modern research.

Senna was introduced in therapy in the 9th century by the Arabs. In the second half of the 19th century chemical investigation of the drug was undertaken, but only a century later the sennosides were isolated. Pharmacological research on senna started at the beginning of this century. During the last 25 years interest in the pharmacology of synthetic and natural laxatives steadily increased. Senna, containing only dianthrones as active substances, is still in the center of scientific research and merits this special attention.