The leaves and seedpods are used as a laxative, diuretic and anti parasitic. The seeds have been soaked in water until they are mucilaginous and then swallowed as a treatment for sore throats. The root is cardiac and febrifuge. An infusion has been used in the treatment of fevers and heart problems. A poultice of the root has been used in treating sores. The Cherokee and other peoples use the root of the plant to treat high fevers, a worm remedy, treat fainting spells and pneumonia.
Senna is in the legume family and fixes nitrogen in the soil.
As for using any medicinal wild plants, do your research!