(K.Schum.) Pierre ex Beille
Pausinystalia johimbe, (Rubiaceae), common name yohimbe, is a plant species native to western and central Africa (Nigeria, Cabinda, Cameroon, Congo-Brazzaville, Gabon, Equatorial Guinea). Extracts from yohimbe have been used in traditional medicine in West Africa as an aphrodisiac and have been marketed in developed countries as dietary supplements.
Yohimbe is one of five Pausinystalia evergreen species growing in West and Central Africa in lowland forests. The tree grows about 30m tall, with a straight bole that is rarely larger than 50–60 cm in diameter. The bark is grey to reddish-brown, with longitudinal fissures, easy to peel and bitter-tasting. The inner bark is pinkish and fibrous. The sapwood is yellowish and the heartwood is ochre-yellow; the wood is fine-grained and relatively dense and moderately hard. The leaves grow in groups of three, with short (about 2 cm) petioles. The blades are oval-shaped, 11–47 cm long and 5 – 17 cm wide. The demand for yohimbe bark has led to over-exploitation, with the possibility of long-term threat to sustainability of the species. Cameroon is the biggest exporter.
Extracts from the bark of yohimbe are used in West African traditional medicine in the belief that it is a herbal tonic and aphrodisiac. Yohimbe bark and extract are used in manufactured dietary supplements, but there is no scientific evidence they have any effect. The levels of yohimbine present in yohimbe bark and manufactured supplements are highly variable.
Although proposed as a potential treatment for erectile dysfunction in humans, there are cautions about its safety or effectiveness. Side effects of using yohimbe, particularly in high doses, may include high blood pressure, increased heart rate, headache, nausea, tremors, and insomnia.
The main phytochemical in the extract is the indoloquinolizidine alkaloid yohimbine. It also contains other alkaloids, such as corynanthine and raubasine, with undefined properties, adding further to concerns about its safety.
Over-exploitation of the tree for its bark has led to concerns that P. johimbe is becoming an endangered species.
Yohimbe bark extract has been declared as insufficiently characterized and possibly unsafe to consume by the European Union and US National Institutes of Health. Yohimbine specifically has so been declared by the European Union, but not by the US National Institutes of Health.[additional citation(s) needed]
- Kew World Checklist of Selected Plant Families, Pausinystalia johimbe
- "Yohimbe". National Center for Complementary and Integrative Health, US National Institutes of Health. July 2012. Retrieved 2016-03-10.
- Beille, P. E. (2013). "Scientific Opinion on the evaluation of the safety in use of Yohimbe (Pausinystalia yohimbe)". EFSA Journal. 11: 1–46. doi:10.2903/j.efsa.2013.3302.
- R.b. Jiofack Tafokou. Pausinystalia johimbe. pp 516-519 in Timbers Volume 2; Volume 7 of Plant Resources of Tropical Africa. Eds. Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A., G.J.H Grubben. PROTA Foundation, 2012. ISBN 9789290814955
- "21 CFR Sec. 522.2670 Yohimbine". US Food and Drug Administration. 2014.
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