Properties for sourcing Nigerian larvicidal plants.

Aedes aegypti is the primary vector of chikungunya, yellow and dengue fevers. Dengue fever is the major cause of child morbidity and hospitalisation in some Asian and African countries, while yellow fever is prevalent in Nigeria. The development of resistance to the available insecticides has necessitated the continued search for safer ones from plants. Eighteen plant extracts with ethnomedical claims of or demonstrated febrifuge, antimalarial, insecticidal and insect repellent biological activities were tested for activity against the fourth instar larvae of Aedes aegypti. About 61% of the eighteen extracts demonstrated high to moderate larvicidal activity. Extracts of Piper nigrum and Abrus precatorius seeds were the most active and the larvicidal constituent(s) of the latter should be determined.

In-vitro evaluation of anti-trichomonal activities of Eugenia uniflora leaf.

Eugenia uniflora, used ethnomedically in some tropical countries as an anti-infective, has shown anti-malarial and anti-trypanocidal activities. Therefore using bioactivity guided fractionation, anti-trichomonal activity of E. uniflora leaf was investigated. Anti-trichomonal activities of leaf methanol extract and its fractions against Trichomonas gallinae as well as their cytotoxicities using an in vitro haemaglutination assay were determined. Anti-trichomonacidal activities of the extract improved on purification up to a stage. Subfractions E(2-5) had LC(50) and LC(90) values of 4.77 - 5.28, 18.49 - 25.00 and 4.53 - 5.18, 18.32 - 19.07 µg/ml at 24 and 48 hrs, respectively that were better than those of metronidazole. Further purification of E(2-5) led to loss of activity suggesting that the active components were probably working synergistically and additively. Demonstration of low haemaglutination titre values of 0.00 - 5.33 by methanolic extract and its partition fractions suggested their low toxicity profile. The established safety of the leaf indicated that its anti-trichomonal activity was not due to non-specific cytotoxicity, hence could be used in ethnomedicine as an anti-trichomonal agent.