Antiplasmodial and antitrypanosomal effects of some plant extracts utilized within Nigerian traditional healing practices

Purpose: To investigate the antiplasmodial and antitrypanosomal properties of extracts from Anthocleista djalonensis A. Chev. (Gentianaceae), Vernonia cinerea Less (Asteraceae), and Pycnanthus angolensis Welw. (Myristicaceae). Methods: Cell growth inhibitory activities were measured using Trypanosoma brucei (10⁶ – 10⁷ parasites/mL in HMI-9 or SDM-79 medium) and Plasmodium falciparum strain 3D7 (0.1 –10 % parasitemia and 10⁸ parasites/mL in culture). An IC50 value less than 10 μg/mL was required for activity. Results: Viability of P. falciparum and T. brucei was significantly reduced when exposed to extracts of A. djalonensis and P. angolensis at 25 μg/mL (p < 0.05), with extract of V. cinerea demonstrating less antiplasmodial activity. Furthermore, crude extracts of A. djalonensis, V. cinerea, and P. angolensis demonstrated strong anti-trypanosomal activity with IC50 values of 0.0036, 2.818, and 4.677 μg/mL,respectively. Conclusion: The study reveals the antiplasmodial and antitrypanosomal properties of A. djalonensis, V. cinerea, and P. angolensis highlighting the need for further investigation of their constituents.