Common Names: Ordeal tree, African bark, Fever tree
Local Names: Kasfiya, Kashin tumaki,Shaffa, Giyayya Ta Mata (Hausa, Nigeria), Nambisunsun (Nupe, Nigeria), Belenede (Fula-Pulaar, Senegal)
Species ID: NMP-258 | wfo-0000927185

Kingdom: Plantae

Clade: Tracheophytes

Clade: Angiosperms

Clade: Eudicots

Clade: Asterids

Order: Gentianales

Family: Rubiaceae

Genus: Crossopteryx

Species: C. febrifuga

Synonyms: Rondeletia febrifuga Afzel. ex G.Don, Tarenna mossambicensis Hiern, Chomelia angolensis (Hiern) Kuntze, Chomelia buchananii K.Schum., Crossopteryx africana Baill.

Crossopteryx febrifuga is a deciduous shrub or small tree, typically 4–5 meters tall, occasionally reaching 15 meters, with a rounded crown and pendulous branchlets. Its key characteristics include:

·       Bark: Pale grey to dark brown or reddish, scaly, finely reticulate, often peeling in small flakes; used medicinally for its bioactive compounds (Burkill, 1985).

·       Leaves: Opposite, elliptic to ovate (1.5–13.5 cm × 1.2–7.5 cm), glabrous to densely pubescent, with conspicuous net-veining beneath; petioles short (0.2–1 cm) (Fern, 2024).

·       Flowers: Small, creamy-white to pale yellow, sometimes pink-tinged, 3–5 mm in diameter, in dense terminal heads; corolla densely pubescent externally, sickly scented (Prance & Jongkind, 2015).

·       Fruit: Globose capsules (6–10 mm), dark purple to black, containing thin, flat seeds (3.2–5 mm); dispersed by birds or gravity (Kew Science, n.d.).

Crossopteryx febrifuga is widely distributed across tropical Africa, thriving in diverse ecological niches:

·       Geographic Range: Extends from Senegal and Gambia to Ethiopia and Kenya, south to South Africa and Namibia; prevalent in northern Nigeria’s savanna regions (Kew Science, n.d.).

·       Habitat: Grows in deciduous woodlands, wooded grasslands, open Combretum scrub, and grasslands with scattered trees like Combretum and Acacia; favors rocky areas, lakesides, streamsides, and termite mounds at elevations of 120–1,380 m (Fern, 2024).

·       Ecological Role: Enhances soil fertility under its canopy, with higher pH, phosphorus, and nitrogen content; supports pollinators and seed-dispersing birds (Fern, 2024).

Crossopteryx febrifuga is extensively used in West African traditional medicine, with robust ethnopharmacological validation for numerous ailments (Salawu et al., 2008):

·       Antimalarial: In Nigeria, leaf and bark decoctions treat malaria. Methanolic stem bark extract (25–100 mg/kg) reduced Plasmodium berghei parasitemia in mice, supporting traditional use, with flavonoids and triterpenes as active compounds (Salawu et al., 2008).

·       Antipyretic: In Ghana, bark infusions reduce fever. Methanolic extract (50–100 mg/kg) significantly lowered yeast-induced pyrexia in rats, comparable to aspirin, due to phenolic compounds (Salawu et al., 2008).

·       Analgesic: In Nigeria, leaf decoctions alleviate headaches and abdominal pain. Methanolic extract (25–100 mg/kg) reduced acetic acid-induced writhing in mice by 24–92%, indicating dose-dependent pain relief (Salawu et al., 2008).

·       Anti-inflammatory: In Nigeria, bark is used for inflammatory conditions. Methanolic extract (100 mg/kg) inhibited carrageenan-induced paw edema in rats, likely via cyclooxygenase inhibition (Salawu et al., 2008).

·       Gastroprotective: In Nigeria, stem bark treats ulcers. Methanolic extract (25–100 mg/kg) reduced ethanol- and piroxicam-induced ulceration in rats by 24–92% and 81.81–98.60%, respectively, with no histopathological damage to stomach tissues (Salawu et al., 2011).

·       Antitrypanosomal: In Benin, leaf extracts treat sleeping sickness. Dichloromethane leaf extract (IC50: 9.3 µg/mL) and its fractions (IC50: 1.3–2.1 µg/mL) showed antitrypanosomal activity against Trypanosoma brucei brucei, with maslinic, corosolic, and oleanolic acids as active compounds (Tchetan et al., 2023).

·       Antitussive: In Mali, leaf decoctions suppress cough. Decoction (250–1,000 mg/kg) reduced citric acid-induced cough in guinea-pigs by 62.86–77.44%, comparable to codeine (Occhiuto et al., 1999).

⚠  Toxicity Profile: Crossopteryx febrifuga is generally safe at therapeutic doses. Acute toxicity studies showed no mortality in rats at methanolic stem bark extract doses up to 2,000 mg/kg. Sub-chronic dosing (400 mg/kg for 28 days) caused mild liver enzyme elevation (ALT increased by 10%). High doses (>1,000 mg/kg) may cause gastrointestinal discomfort. Use is contraindicated in pregnancy and for children due to insufficient safety data. Potential heavy metal contamination in wild-harvested plants requires caution (Salawu et al., 2009).

The bioactivity of Crossopteryx febrifuga is driven by its diverse phytochemical profile (Tchetan et al., 2023):

·       Flavonoids: Quercetin-3-arabinoside, quercetin-3-galactoside, quercetin-3-glucoside, contributing to antioxidant and anti-inflammatory effects (Tomás-Barberán & Hostettmann, 1988).

·       Triterpenoids: Maslinic acid, corosolic acid, oleanolic acid, with antitrypanosomal and antimicrobial properties (Tchetan et al., 2023).

·       Saponins: Bisdesmosidic saponins and ursadienedioic acid glycosides, aiding antimicrobial and anti-inflammatory activities (Gariboldi et al., 1990).

·       Phenolics: Chlorogenic acid derivatives, gallic acid, enhancing antioxidant and gastroprotective effects (Boungou-Tsona et al., 2023).

·       Iridoids: Geniposidic acid, loganin, present in bark, contributing to antimicrobial effects (Boungou-Tsona et al., 2023).

·       Shade and Soil Fertility: Planted in Nigeria to provide shade in plantations; enhances soil pH, phosphorus, and nitrogen content (Fern, 2024).

·       Timber: Hard, fine-textured wood used for building, utensils, and tool handles in Nigeria (Burkill, 1985).

·       Cultural: In Hausa culture, bark is used in rituals for spiritual cleansing and health (Burkill, 1985).

·       Ecological: Fire-resistant, surviving temperatures up to 650°C; supports biodiversity by attracting pollinators and birds (Fern, 2024).

• Adjanohoun, E. J., Ahyi, M. R. A., Aké Assi, L., Baniakina, J., Chibon, P., Cusset, G., ... & Sita, P. (1989). Contribution aux études ethnobotaniques et floristiques en République Populaire du Bénin. Agence de Coopération Culturelle et Technique.

• Boungou-Tsona, G., Gainche, M., Decombat, C., Ripoche, I., Bikindou, K., Delort, L., ... & Chalard, P. (2023). Chemical profile, antioxidant and anti-inflammatory potency of extracts of Vitex madiensis Oliv. and Crossopteryx febrifuga (Afzel ex G. Don). Plants, 12(2), 386.

• Burkill, H. M. (1985). The useful plants of West Tropical Africa (Vol. 4). Royal Botanic Gardens, Kew.

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

• Gariboldi, P., Verotta, L., & Gabetta, B. (1990). Saponins from Crossopteryx febrifuga. Phytochemistry, 29(8), 2629–2635.

• Kew Science. (n.d.). Crossopteryx febrifuga (Afzel. ex G.Don) Benth. Plants of the World Online. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:747858-1

• Occhiuto, F., Sanogo, R., Germano, M. P., Keita, A., D’Angelo, V., & De Pasquale, R. (1999). Effects of some Malian medicinal plants on the respiratory tract of guinea-pigs. Phytotherapy Research, 13(7), 561–563.

• Prance, G. T., & Jongkind, C. C. H. (2015). Rubiaceae. In Flora of West Tropical Africa. Royal Botanic Gardens, Kew.

• Salawu, O. A., Chindo, B. A., Tijani, A. Y., Obidike, I. C., Salawu, T. A., & Akingbasote, A. J. (2008). Analgesic, anti-inflammatory, antipyretic and antiplasmodial effects of the methanolic extract of Crossopteryx febrifuga. Journal of Medicinal Plants Research, 2(8), 213–218.

• Salawu, O. A., Chindo, B. A., Tijani, A. Y., Adzu, B., Ali, T. A., & Nwafor, P. A. (2011). Gastro-protective effect of Crossopteryx febrifuga in Wistar rats. African Journal of Pharmacy and Pharmacology, 5(2), 215–219.

• Salawu, O. A., Tijani, A. Y., Obidike, I. C., & Akingbasote, J. A. (2009). Acute and sub-acute toxicological evaluation of the methanolic stem bark extract of Crossopteryx febrifuga in rats. African Journal of Pharmacy and Pharmacology, 3(12), 621–626.

• Tchetan, E., Compaoré, S. K., Tometto, E., Tete-Benissan, A., Djigma, F. W., & Vandeputte, O. (2023). Antitrypanosomal activity of Crossopteryx febrifuga and phytochemical profiling using LC-MS/MS analysis coupled to molecular network and SIRIUS. Phytochemistry, 206, 113550.

• Tomás-Barberán, F. A., & Hostettmann, K. (1988). A cytotoxic triterpenoid and flavonoids from Crossopteryx febrifuga. Planta Medica, 54(3), 266–267.

• Useful Tropical Plants - Crossopteryx febrifuga

• Plants of the World Online - Crossopteryx febrifuga

• PlantNet - Crossopteryx febrifuga

• iNaturalist - Crossopteryx febrifuga

• spinasterol

Muluh, E. K., Adebayo, S. A., Terumon, A. T. A., & Abel, A. (2019). Isolation and characterization of spinasterol from Crossopterxy febrifuga stem bark. Prog Chem Biochem Res, 2, 68-73.