Common Names: Yohimbe, Yohimbe bark, Burantashi
Local Names: Idagbon (Yoruba, Nigeria), Nikiba (Edo, Nigeria)
Species ID: NMP-257 | wfo-0000925772 | NCBI_Taxonomy ID: 170026

Kingdom: Plantae

Clade: Tracheophytes

Clade: Angiosperms

Clade: Eudicots

Clade: Asterids

Order: Gentianales

Family: Rubiaceae

Genus: Corynanthe

Species: C. johimbe

Synonyms: Pausinystalia johimbe (K.Schum.) Pierre, Pausinystalia zenkeri W.Brandt, Pseudocinchona johimbe (K.Schum.) A.Chev., Pausinystalia trillesii Beille

Corynanthe johimbe is an evergreen tree, typically growing 15–30 meters tall, with a straight bole rarely exceeding 50–60 cm in diameter. Its key characteristics include:

·       Bark: Grey to reddish-brown, with longitudinal fissures, bitter-tasting; inner bark pinkish, fibrous, rich in alkaloids (Burkill, 1985).

·       Leaves: Arranged in whorls of three, oval-shaped (11–47 cm × 5–17 cm), glossy green, with short petioles (0.5–1 cm); veins prominent (Fern, 2024).

·       Flowers: Small, yellowish-white, in axillary or terminal panicles; 5-petaled, fragrant, blooming seasonally (Prance & Jongkind, 2015).

·       Fruit: Capsules, small (1–2 cm), dark brown, containing winged seeds; dispersed by wind (Kew Science, n.d.).

Corynanthe johimbe is native to western and central Africa, thriving in specific ecological niches:

·       Geographic Range: Found in Nigeria, Cameroon, Gabon, Equatorial Guinea, Congo-Brazzaville, and DR Congo; prevalent in Nigeria’s Atlantic evergreen forests (Kew Science, n.d.).

·       Habitat: Grows in lowland rainforests, closed-canopy forests, and coastal forests; prefers well-drained, loamy soils (pH 5.5–6.5) with annual rainfall of 1,500–2,500 mm; occurs at elevations up to 1,000 m (Fern, 2024).

·       Ecological Role: Supports pollinators like bees; contributes to forest biodiversity; over-exploitation threatens local populations (Burkill, 1985).

Corynanthe johimbe is a cornerstone of West African traditional medicine, with pharmacological studies validating several applications (Iwu, 2014):

·       Aphrodisiac: In Nigeria, bark decoctions are used to enhance libido. Yohimbine, an α2-adrenergic receptor antagonist, increases blood flow and nerve impulses to sexual organs, supporting its use for erectile dysfunction (ED) in animal studies, though human efficacy is inconsistent (Tam et al., 2001).

·       Stimulant: In Cameroon, bark is chewed to combat fatigue. Yohimbine’s CNS stimulation enhances alertness, with mild monoamine oxidase inhibitor (MAOI) properties (De Smet, 1997).

·       Antimalarial: In Nigeria, leaf infusions treat malaria. While direct studies on C. johimbe are limited, corynanthe alkaloids show antiplasmodial activity in related species, suggesting potential (Rosales et al., 2020).

·       Analgesic: In Ghana, bark extracts alleviate pain. Yohimbine’s opioid receptor binding provides analgesic effects, though less potent than morphine (Takayama, 2004).

·       Antidepressant Potential: In Nigeria, bark is used for mood enhancement. Yohimbine’s sympathomimetic activity may boost mood, but clinical evidence is lacking (Cimolai & Cimolai, 2011).

⚠  Toxicity Profile: Corynanthe johimbe can be toxic, especially at high doses. Yohimbine (6% in bark) causes severe side effects, including hypertension, tachycardia, anxiety, nausea, tremors, and insomnia. Acute intravenous toxic dose for dogs is 0.55 mg/kg; human intoxications report hypotension, abdominal distress, and CNS paralysis. Chronic use may lead to kidney or liver damage. Combining yohimbine with MAOIs, antidepressants, or tyramine-rich foods is contraindicated due to hypertensive risks. Use is banned in several countries and requires medical supervision (De Smet, 1997; Cimolai & Cimolai, 2011).

The bioactivity of Corynanthe johimbe is driven by its rich alkaloid profile (Rosales et al., 2020):

·       Indole Alkaloids: Yohimbine (indoloquinolizidine), the primary compound, with α2-adrenergic antagonist properties (De Smet, 1997).

·       Other Alkaloids: Corynanthine, raubasine, and rauwolscine, with undefined pharmacological effects, contributing to safety concerns (Fern, 2024).

·       Tannins: Present in bark, providing astringent properties (Burkill, 1985).

·       Phenolics: Trace amounts, supporting antioxidant activity (Iwu, 2014).

·       Cultural: In Yoruba culture, bark is used in rituals for fertility and vitality, often called “burantashi” (Iwu, 2014).

·       Construction: Wood is used for firewood and small-scale construction in Nigeria (Fern, 2024).

·       Commercial: Bark extracts are marketed globally as dietary supplements, though efficacy is unproven (Kew Science, n.d.).

·       Conservation: Over-exploitation for bark has led to concerns about endangerment, necessitating sustainable harvesting practices (Fern, 2024).

• Burkill, H. M. (1985). The useful plants of West Tropical Africa (Vol. 1). Royal Botanic Gardens, Kew.

• Cimolai, N., & Cimolai, T. (2011). Yohimbine use for physical enhancement and its potential toxicity. Journal of Dietary Supplements, 8(4), 346–354.

• De Smet, P. A. G. M. (1997). Yohimbe alkaloids – Corynanthe species. In P. A. G. M. De Smet, K. Keller, R. Hänsel, & R. F. Chandler (Eds.), Adverse effects of herbal drugs (Vol. 3, pp. 1–10). Springer.

• Fern, K. (2024). Pausinystalia johimbe. Useful Tropical Plants Database. https://tropical.theferns.info/viewtropical.php?id=Pausinystalia+johimbe

• Iwu, M. M. (2014). Handbook of African medicinal plants (2nd ed.). CRC Press.

• Kew Science. (n.d.). Corynanthe johimbe K.Schum. Plants of the World Online. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:747599-1

• McGaw, L. J., Rabe, T., Sparg, S. G., Jäger, A. K., Eloff, J. N., & van Staden, J. (2001). An investigation on the biological activity of Combretum species. Journal of Ethnopharmacology, 75(1), 45–50.

• Rosales, P. F., Bordin, G. S., Gower, A. E., & Moura, S. (2020). Indole alkaloids: 2012 until now, highlighting the new chemical structures and biological activities. Fitoterapia, 143, 104558.

• Takayama, H. (2004). Chemistry and pharmacology of analgesic indole alkaloids from the Rubiaceous plant, Mitragyna speciosa. Chemical and Pharmaceutical Bulletin, 52(8), 916–928.

• Tam, S. W., Worcel, M., & Wyllie, M. (2001). Yohimbine: A clinical review. Pharmacology & Therapeutics, 91(3), 215–243.

• EU Food Safety - Yohimbe Report

• World Agroforestry - Pausinystalia johimbe

• Health - Yohimbe Benefits

• Octadecanoic acid
• Palmitic Acid
• Methyl palmitate
• 9, 12-Octadecadienoic acid (Z, Z)-
• 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-
• 2-Methylene-11-hexadecynoic acid
• 2,4-Dimethyl-1,3-dioxane

Igwe, K. K., Madubuike, A. J., Ikenga, C., Otuokere, I. E., & Amaku, F. J. (2016). Studies of the medicinal plant Pausinystalia yohimbe ethanol leaf extract phytocomponents by GCMS analysis. International Journal of Scientific Research and Management, 4(5), 4116-4122.