Brachystegia eurycoma
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Brachystegia eurycoma Common Names: Achi, Eku, Okwen, Akpakpa, Odukpa,
Bodgei, Tebako, Meblo, Mendou, Ekop-naga Scientific
Classification Kingdom: Plantae Clade: Tracheophytes Clade: Angiosperms Clade: Eudicots Clade: Rosids Order: Fabales Family: Fabaceae Genus: Brachystegia Species: B. eurycoma Synonyms: None
widely documented Morphological Description Brachystegia eurycoma is a large, deciduous tree, typically 20–37 meters tall,
with a broad, flattened crown of twisted, spreading branches. Its key
characteristics include: · Bark: Outer bark rough, brownish-grey, peeling in large flakes;
inner bark red, fibrous, darkening on exposure, exuding yellowish or reddish
gum (Burkill, 1985). · Leaves: Pinnate, 15–30 cm long, with 4–6 pairs of oblong-elliptical
leaflets (3–8 cm × 1–3 cm); basal leaflets smallest, terminal ones largest;
young leaves reddish (Fern, 2024). · Flowers: Small, petal-less, with 10 long stamens and a coiled pistil,
in dense, hairy terminal panicles; creamy-white to pink, blooming before leaf
flush (Prance & Jongkind, 2015). · Fruit: Flattened, dark purplish-brown pods (15–25 cm × 4–6 cm),
containing 4–6 glossy, disc-shaped seeds (2 cm diameter); pods dehisce
explosively September–January (Kew Science, n.d.). Distribution and Habitat Brachystegia eurycoma is native to West Tropical Africa, thriving in specific
ecological niches: · Geographic Range: Southern Nigeria (Cross River, Edo, Delta
states), western Cameroon, possibly Gabon; most abundant in Nigeria’s
rainforest and savanna transition zones (Kew Science, n.d.). · Habitat: Found in riverine forests, miombo woodlands, and open
woodlands; prefers well-drained, loamy soils along stream banks at elevations
up to 1,150 m with 1,200–2,000 mm annual rainfall (Fern, 2024). · Ecological Role: Stabilizes riverbanks; provides canopy cover
and seeds for wildlife; supports soil fertility through nitrogen fixation
(Burkill, 1985). Ethnopharmacology Brachystegia eurycoma, known as Achi in Igbo, is widely used in Nigerian traditional
medicine, with robust ethnopharmacological validation (Irondi et al., 2017): · Antidiabetic: Seed flour treats diabetes in Nigeria. Methanolic seed
extract (100–400 mg/kg) reduced fasting blood glucose in streptozotocin-induced
diabetic rats by 30–50%, inhibiting α-amylase and α-glucosidase, attributed to
flavonoids (catechin, quercetin) and phenolic acids (gallic, caffeic) (Irondi
et al., 2017). · Anticancer: Seeds prevent colon cancer. Dietary inclusion (2.5–10%) in
rats reduced N-methyl-N-nitrosourea-induced colon carcinogenesis by lowering
malondialdehyde and carcinoembryonic antigen, with fiber and polyphenols
limiting oxidative stress (Yusuf et al., 2019). · Anti-inflammatory: Stem bark tinctures reduce inflammation.
Methanolic bark extract (100–700 mg/kg) inhibited carrageenan-induced paw edema
in rats by 40–60%, linked to flavonoids and tannins (Onyeso et al., 2016). · Antimicrobial: Stem bark treats infections. Ethanol bark extract,
containing 4-(4-phenyl-1,4-dihydronaphthalen-1-yl) pentenoic acid,
inhibited Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa (MIC: 0.5–2 mg/mL), supporting use for gonorrhea and wound
healing (Igwe, 2016). · Wound Healing: Seed polysaccharides, combined with snail mucin and honey,
accelerated wound closure in rats within 15 days, preventing bacterial
infection and promoting hair follicle regeneration (Igbe et al., 2018). · Antidiarrheal: Bark extract moderates diarrhea. Methanolic bark extract
(100–700 mg/kg) reduced castor oil-induced diarrhea in rats by 37%, possibly
via muscarinic receptor antagonism or calcium channel modulation (Onyeso et
al., 2016). · Analgesic: Seeds relieve pain. Aqueous seed extract (100 mg/kg) reduced
acetic acid-induced writhing in mice by 50%, with effects partially reversed by
naloxone, suggesting opioid pathway involvement (Edosuyi et al., 2020). ⚠ Toxicity Profile: Brachystegia eurycoma is generally safe at culinary and
therapeutic doses. Acute toxicity studies showed no mortality in rats at
ethanolic leaf extract doses up to 2,000 mg/kg (LD50 > 2,000 mg/kg).
Sub-chronic use may cause mild liver enzyme elevation (ALT increased by 10%).
Antinutrients like tannins and phytates are present in seeds but are reduced by
processing (boiling, roasting). Use is contraindicated in pregnancy and for
children due to insufficient safety data (Onyeso et al., 2016). Phytochemistry The bioactivity of Brachystegia eurycoma is driven by its diverse phytochemical
profile (Irondi et al., 2017): · Flavonoids: Catechin, rutin, quercetin, kaempferol, with antidiabetic
and antioxidant effects (Irondi et al., 2017). · Phenolic Acids: Gallic, caffeic, chlorogenic, ellagic
acids, enhancing anti-inflammatory and anticancer properties (Irondi et al.,
2017). · Alkaloids: Present in seeds and bark, contributing to antimicrobial
activity (Onyeso et al., 2016). · Tannins: High in seeds, providing astringent and antidiarrheal
effects (Onyeso et al., 2016). · Saponins: Found in seeds, aiding wound healing and antimicrobial
activity (Onyeso et al., 2016). · Polysaccharides: Water-soluble, extracted at 44.3% yield
from seeds, used as wound-healing agents (Igbe et al., 2018). Additional Uses · Culinary: Seed flour (Achi) is a staple thickener in Nigerian soups
(e.g., egusi, oha), valued for viscosity without altering flavor; rich in
carbohydrates (53.57%) and fiber (17.2%) (Madubuike et al., 1994). · Timber: Hard heartwood used locally in Nigeria for construction and
furniture, though difficult to work due to splitting (Fern, 2024). · Industrial: Seed polysaccharides used as emulsifiers and stabilizers in
food and pharmaceuticals; gum used like gutta-percha (Fern, 2024). · Ecological: Stabilizes riverbanks; seeds provide food for wildlife;
supports biodiversity in miombo woodlands (Burkill, 1985). References
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| Compounds of Brachystegia eurycoma |
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