Senna siamea

HABIT: Senna siamea is a tree which has a medium-size, 10-12 m tall, occasionally reaching 20 m. The bole is short; crown dense and rounded at first, later becoming irregular and spreading. The young bark is grey and smooth, and later with longitudinal fissures. The leaves are alternate, 15-30 cm long, compound, with 6-14 leaflets each ending in a tiny bristle. The flowers are bright yellow, in large, up to 60 cm long, upright, with pyramid-shaped panicles. The fruits are flat with indehiscent pod, 5-30 cm long, and constricted between the seeds.

CONSERVATION STATUS: Evaluated as 'Least Concern' by IUCN.

MEDICINAL USES: As C. siamea is a mixture of various groups of chemicals, it is of no surprise that it exhibits different modes of actions. Its major actions include antimalarial, antidiabetic, antitumoral or anticancer , hypotensive, diuretic, antioxidant, laxative, anti-inflammatory, analgesic, antipyretic, anxiolytic,  antidepressant,  sedative, and  antimicrobial activities. Various extracts of leaves, stem bark, and flowers of C. siamea were screened for its antimalarial activity. The potential effects of C. siamea (leaves, roots) on endocrinological system were evaluated by several methods. In research of natural or synthetic products as cancer chemopreventive agents, in vivo and in vitro antitumor activity studies were conducted with various extract of leaves and stem bark of C. siamea. C. siamea (leaves, flowers) is known for its laxative effect in Thailand. Several laxative compounds such as anhydrobarakol, barakol, aloe-emodin, rhein-8- monoglucoside, rhein, chrysophanic acid, anthrone, dianthrone, chrysophanol, sennoside A were identified in this plant.

(Kamagaté, M., Koffi, C., Kouamé, N. M., Akoubet, A., Alain, N., Yao, R., & Die, H. (2014). Ethnobotany, phytochemistry, pharmacology and toxicology profiles of Cassia siamea Lam. The Journal of Phytopharmacology, 3(1), 57-76.)

ETHNOBOTANICAL USES: According to the ethnic differences of populations from localities, the plant is used alone or in combination with other plants or with natural substances for the preparation, especially in decoction. The leaves are the most used parts’ the plant especially by African and Asian population in preparation of the herbal remedies. In Burkina Faso, fresh and dried leaves decoction (boiled for 20 min in 1L of water) is drunk with lemon juice or for body bath throughout the day to treat malaria and liver disorders. In Benin, root decoction is used against fever, constipation, hypertension, and insomnia. In Kenya, the infusion, decoction or maceration of mixture of the roots of S. siamea and those of Zanthoxylum chalybeum are used as antidote for snake bites. In Burkina Faso, flowers decoction is drunk or used in body bath against malaria and liver disorders. This decoction is also effective against insomnia and asthma. In China and Pakistan, the decoction of the leaves and the stems mixture is used as an aperitif, antirheumatic and against swellings. 

(Kamagaté, M., Koffi, C., Kouamé, N. M., Akoubet, A., Alain, N., Yao, R., & Die, H. (2014). Ethnobotany, phytochemistry, pharmacology and toxicology profiles of Cassia siamea Lam. The Journal of Phytopharmacology, 3(1), 57-76.)