Alexandrina senna is now one of the most important herbal exports of Sudan, thanks to its fame as an antidote against constipation and other disorders.
The herb is also known by its first name "senna" and the Arabic compound "sana makka".
It is a shrubby plant that reaches 0.5-1, rarely two, metres in height with a branched, pale-green erect stem and long spreading branches bearing four or five pairs of leaves. The flowers are yellow.
It grows wild in rural Khartoum and elsewhere around Sudan. Due to the high demand for the herb, farmers have tended to grow it on a commercial scale.
The City of Omdurman is an important marketing center of the senna, where it is shipped to drug manufacturers worldwide.
Senna is viewed as one of the most important laxative plants in the World. It is also useful in other disorders of the digestive system and enters into the formulations of drugs that help with weight loss, formulations of blood purification drugs, and drugs for the elimination of viruses and fungus.
Pharmacy plants give it leverage over other laxatives because its work starts from the colon where it is decomposed by the colon bacteria and then it takes effect. Its effect on the stomach and the small intestines is negligent and accordingly it does not affect food assimilation as do other laxatives. Another advantage of senna is that it is not followed with constipation as in the case of some other laxatives. It also does not cause stomach contractions.
In Sudan the locals often take it raw. They either munch its fruit or soak it in water and then drink the emulsion.
They also use it as a fermented food called "kawal" which is prepared by fermenting leaves of the senna. The leaves will be put in a pot made of mud and buried under the ground for some time because the fermenting bacteria do not work in an open air. Kawal is very nutritious. The protein it contains is higher than that of beef. Also, it is rich in essential amino acids and calcium. According to an interview conducted by Sudanow with Professor Mona Ahmed Agab Arbab, a former director of the technical department of the Sudanese Standards and Metrology Organization (SSMO) and a former scientist in the Food Research Center, they have a British colleague who has been keen to maintain sufficient stock of kawal powder with him all the time.
The Senna is an old medical plant. Research has revealed that it was used during the times of the old Nubian kingdoms and the times of the pharos.
It is referred to in the literature of the old Islamic medicine in the treatment of some skin diseases, hemorrhoids (piles) and backbone pains.