Combined effect of methanolic extracts of Senna occidentalis (Fabaceae) and Khaya senegalensis (Meliaceae) collected in the far-north region (Cameroon) on adults of Anopheles gambiae senso stricto GILES 1902

Background and objectives: Malaria remains a significant public health burden in sub-Saharan Africa, primarily due to the presence of its primary vector, Anopheles gambiae. The increasing resistance to synthetic insecticides has necessitated the exploration of environmentally friendly alternatives,...

Full description

Saved in:
Bibliographic Details
Main Authors: Ngatarang Celestine, Nanga Woulsou Maurice, Saotoing Pierre, Ndjonka Dieudonné
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Parasite Epidemiology and Control
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2405673125000431
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Background and objectives: Malaria remains a significant public health burden in sub-Saharan Africa, primarily due to the presence of its primary vector, Anopheles gambiae. The increasing resistance to synthetic insecticides has necessitated the exploration of environmentally friendly alternatives, such as plant-derived bioactive compounds. This study investigated the adulticidal activity of methanolic extracts from the leaves of Senna occidentalis (Fabaceae) and Khaya senegalensis (Meliaceae) against A. gambiae, a primary malaria vector, in a laboratory experiment conducted from January to February 2020 at the Entomology Laboratory, University of Ngaoundéré, Adamaoua Region, Cameroon. Methodology and results: The extraction yields were 17.8 % for S. occidentalis and 14.9 % for K. senegalensis. Phytochemical analysis revealed that S. occidentalis leaves contained 21.55 mg gallic acid equivalent (GAE)/100 g of polyphenols and 24.88 mg quercetin equivalent (QE)/100 g of flavonoids, whereas K. senegalensis leaves contained 18.34 mg GAE/100 g of polyphenols, 34.34 mg QE/100 g of flavonoids, and 27.56 mg catechin equivalent (CE)/100 g of tannins. Bioassays conducted according to World Health Organization (WHO) protocols demonstrated synergistic insecticidal effects between the extracts against A. gambiae. The lethal concentration (LC50) values were 0.87 g/L for S. occidentalis and 1.07 g/L for K. senegalensis, with half-lethal time (HL50) values of 2 h 48 min and 2 h 14 min, respectively. The most effective combination (S. occidentalis [75 %] + K. senegalensis [25 %]) achieved an LC50 of 0.98 g/L and HL50 of 1 h 45 min. Conclusion and application: These results highlight the potential of S. occidentalis and K. senegalensis extracts as sustainable biocides for controlling A. gambiae ss populations. Their synergistic efficacy and high phytochemical content support further development into eco-friendly vector control tools, aligning with global efforts to combat insecticide resistance.
ISSN:2405-6731