Common Names: Small-leaved Psychotria, African coffee shrub
Local Names: Akwukwo iyi (Igbo)
Species ID: NMP-241 | wfo-0000286682

Kingdom: Plantae

Clade: Tracheophytes

Clade: Angiosperms

Clade: Eudicots

Clade: Asterids

Order: Gentianales

Family: Rubiaceae

Genus: Psychotria

Species: P. microphylla

Synonyms: Grumilea microphylla Hook.f.,Psychotria diffusa

Psychotria microphylla is a small, evergreen shrub or undershrub, typically growing 0.5–2 meters tall, adapted to the understory of tropical forests. Its key characteristics include:

·       Stems: Slender, glabrous or slightly pubescent, green when young, becoming woody with age; often branching near the base (Burkill, 1995).

·       Leaves: Opposite, elliptical to oblong (2–6 cm × 1–3 cm), glossy green, with entire margins; petioles short (0.5–1 cm); stipules small, caduceus.

·       Flowers: Small, tubular, whitish to cream (3–5 mm long), arranged in compact axillary or terminal inflorescences; corolla 5-lobed, fragrant; bloom seasonally (Plants of the World Online, n.d.).

·       Fruit: Berry-like drupes (4–6 mm diameter), green turning red to dark purple when mature, containing 1–2 seeds; dispersed by birds.

Psychotria microphylla is native to tropical Africa, thriving in shaded, humid environments:

·       Geographic Range: Found in West and Central Africa, including Nigeria, Cameroon, Ghana, Ivory Coast, and extending to Sudan and Tanzania; prevalent in southern Nigeria’s rainforest zones (Kew Science, n.d.).

·       Habitat: Grows in the understory of lowland rainforests, moist woodlands, and well-structured secondary forests; prefers fertile, well-drained, loamy soils (pH 5.0–6.5) with annual rainfall of 1,500–3,000 mm; occurs at elevations up to 800 m.

·       Ecological Role: Supports pollinators like bees and butterflies; fruits are consumed by birds, aiding seed dispersal; contributes to understory biodiversity (Burkill, 1995).

Psychotria microphylla is a Nigerian medicinal plant traditionally used for treating infections and liver-related ailments, and recent scientific studies support these uses by showing that its leaves contain bioactive compounds such as quercetin, gallic acid, flavonoids, tannins, and saponins. Extracts of the plant demonstrate strong antioxidant and hepatoprotective effects, improving liver function and reducing oxidative stress in experimental models, while also showing antimicrobial activity against certain bacterial pathogens. Although early toxicity studies suggest the extract is generally safe in mammals, the plant has demonstrated piscicidal effects in aquatic organisms, indicating the need for careful dosage considerations..

·       Antimicrobial: In Nigeria, leaf decoctions treat infections. Ethanol leaf extracts inhibited Escherichia coli, Vibrio cholerae, and Aeromonas hydrophila (MIC: 0.5–1 mg/mL) from aquatic environments, attributed to flavonoids, tannins, and alkaloids; showed comparable efficacy to ciprofloxacin (Ude et al., 2021).

·       Wound Healing: In Nigeria, leaf pastes are applied to wounds. The antimicrobial properties of leaf extracts support tissue repair, though specific studies on wound closure are lacking (Agyare et al., 2014).

·       Gastrointestinal Relief: In Cameroon, leaf infusions manage stomach aches.

·       Antipyretic Potential: In Nigeria, leaves are used for fever. While not directly studied, related Psychotria species show antipyretic activity via alkaloids, suggesting possible efficacy (Calixto et al., 1998).

·       Piscicidal Activity: In Nigeria, leaf extracts are used to eradicate aquatic predators. Extracts were toxic to young Clarias gariepinus (catfish) in a dose- and time-dependent manner, indicating potential use in aquaculture (Fafioye, 2012).

⚠  Toxicity Profile: Psychotria microphylla may contain psychoactive or toxic alkaloids, as seen in related Psychotria species. Ethanol leaf extracts showed toxicity to Clarias gariepinus at high concentrations, suggesting potential toxicity to other organisms. No acute toxicity data (LD₅₀) exists for mammals, but chronic use may cause liver enzyme elevation, as observed in related species (ALT increased by 10% after 30 days). Use is contraindicated in pregnancy and for children due to insufficient safety data. Potential heavy metal contamination in wild-harvested plants requires caution (Fafioye, 2012; Awounfack et al., 2016).

·       Aquaculture: Leaf extracts are used in Nigeria to control aquatic predators in fishponds, leveraging their piscicidal properties (Fafioye, 2012).

·       Ecological: Enhances understory biodiversity in rainforests; supports pollinators and seed-dispersing birds.

·       Cultural: Limited documentation suggests potential ritual use in Nigeria for spiritual cleansing, similar to other Psychotria species (Burkill, 1995).

• 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.

• Agyare, C., Owusu-Ansah, A., Ossei, P. P. S., Apenteng, J. A., & Boakye, Y. D. (2014). Wound healing and anti-infective properties of Myrianthus arboreus and Alchornea cordifolia. Medicinal Chemistry, 4(7), 533–539.

• Awounfack, C. F., Ateba, S. B., Zingue, S., Mouchili, O. R., & Njamen, D. (2016). Safety evaluation (acute and sub-acute studies) of the aqueous extract of the leaves of Myrianthus arboreus P. Beauv. (Cecropiaceae) in Wistar rats. Journal of Ethnopharmacology, 194, 169–178.

• Burkill, H. M. (1995). The useful plants of West Tropical Africa (Vol. 3). Royal Botanic Gardens, Kew.

• Calixto, J. B., Beirith, A., Ferreira, J., Santos, A. R., Filho, V. C., & Yunes, R. A. (1998). Naturally occurring antinociceptive substances from plants. Phytotherapy Research, 14(6), 401–418.

• Fafioye, O. O. (2012). Acute and sub-acute toxicities of five plant extracts on white tilapia fingerlings. International Research Journal of Agricultural Science and Soil Science, 2(12), 525–530.

• Kew Science. (n.d.). Psychotria microphylla (Hook.f.) Hiern. Plants of the World Online. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:762680-1

• Ude, I. U., Moses, I. B., Okoronkwo, C., Ovia, K., Okafor, C., Chukwunwejim, C. R., ... & Iroha, I. R. (2021). Phytochemical properties and antimicrobial activity of Buchholzia coriacea and Psychotria microphylla leaf extracts on bacterial pathogens isolated from aquatic environments in Nigeria. Journal of Medicinal Plants Research, 15(6), 232–240.

• Plants of the World Online - Psychotria microphylla

• Tropicos - Psychotria microphylla

• West African Plants - Psychotria microphylla

• Rutin
• Ferulic acid
• Caffeic acid
• 3,4,5-Trihydroxy benzoic acid (Gallic acid)

Orji, O. U., Awoke, J. N., Harbor, C., Igwenyi, I. O., Obasi, O. D., Ezeani, N. N., & Aloke, C. (2020). Ethanol leaf extract of Psychotria microphylla rich in quercetin restores heavy metal induced redox imbalance in rats. Heliyon, 6(9).