Herman Parfait Awono- Ambene*;
Metoh Theresia Njuabe; Soh Desire;
Introduction: Anopheles mosquitoes transmit malaria which is a life-threatening disease in Cameroon and in Africa. As an alternative strategy to control mosquitoes, we assessed the larvicidal activity of Momordica foetida, Gnidia glauca and Vepris soyauxii, extracts on Anopheles gambiae s.l., and evaluated their acute oral toxicity.
Method: The whole plant except the fruits of M. foetida, fresh leaves of G. glauca, and stem barks of V. soyauxii crude extracts were obtained by solvent extraction and then bio-assayed against third-instar larvae of Anopheles gambiae s.l. with concentrations ranging from 100 to 450 ppm for 24h and 48h respectively. Wistar rats were used to evaluate the acute oral toxicity of the plant’s methanolic extracts.
Results: Methanolic extracts had higher larvicidal activity as compared to aqueous extracts where V. soyauxii methanolic extract showed the highest larvicidal activity of LC50 and LC90 values of 203.92 and 241.459 ppm respectively followed by G. glauca and finally M. foetida methanolic extracts on An. gambiae ss. Similarly, in An. coluzzii, V. soyauxii still had the highest larvicidal activity with values of LC50 being 215.007 and 270.866 ppm for LC90, M. foetida followed and finally G. glauca, methanolic extracts. As for the toxicity, the highest concentration of 2260.7 mg/kg did not show any symptoms of toxicity or death on the Wistar rats.
Conclusion: V. soyauxii, G. glauca and M. foetida methanolic extracts showed promising biological responses against malaria vector species, Anopheles gambiae and Anopheles coluzzii, and may serve as a potential alternative and eco-friendly tool for larval control in African endemic countries.
Study impact: The investigated plant extracts are promising as larvicides against An. gambiae s.l. mosquitoes and are useful leads in the search for new biodegradable larvicides.
Keywords: Larviciding, Malaria, Anopheles gambiae