As a medicinal plant, indigo has been used as an emetic. The Chinese use Indigofera tinctoria L. to clean the liver, detoxify the blood, reduce inflammation, alleviate pain, and reduce fever (11.1-10). The powdered root of Indigofera cf. patens is used in South Africa to alleviate toothache (11.1-96). Indigofera spirata is known as a plant teratogen because of the presence of indospicine (11.1-96). Indigofera endecaphylla plant, creeping indigo, is poisonous and has been responsible for livestock death (11.1-96). Indigofera arrecta Hochst. ex A. Rich and Indigofera caroliniana Mill. are used as dye plants (9.1-5).
Source: Simon, J.E., A.F. Chadwick and L.E. Craker. 1984. Herbs: An Indexed Bibliography. 1971-1980. The Scientific Literature on Selected Herbs, and Aromatic and Medicinal Plants of the Temperate Zone. Archon Books, 770 pp., Hamden, CT.