Larvicidal activity and chemical compositions of Aloe ferox mill, and Commipora abyssinica (O.Berg) combination against the mosquito vectors Culex pipiens L

Abstract

The aqueous extract was prepared from the Aloe ferox, and Commipora abyssinica combined to develop a botanical mosquito larvicide. The aqueous extract and the solvent fractions obtained using liquid–liquid extraction were tested against Culex pipiens larvae for larvicidal potential. The maximum larvicidal activity was recorded for the ethyl acetate (EtOAc) extract with LC50values of 28.24 µg/mL followed by hexane (104.42 µg/mL), water (140.24 µg/mL), and chloroform (211.41 µg/mL) extract against the Cx. pipiens third instar 24 h post-treatment. In midguts of EtOAc extract-treated larvae, Longitudinal sections showed edema between the degenerated epithelial cells and degraded microvilli. The extract caused a dose‐dependent decrease in the percentage of cell viability of HUVEC cells suing MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The IC50value of the EtOAc extract was 143.6 µg/mL and displayed chromosomal condensation. The total phenolic and flavonoid contents calculated were 15.9 GAE/g (gallic acid equivalentper gram) and 3.69 QurE/g (Qurcetin equivalentper gram), respectively. GC–MS analysis showed that the major chemical components of the EtOAc extract were methyl ester of hexadecanoic acid (28%), 3-benzylbutanoate (9.4%), methyl ester of octadecanoic acid (8.6%), and alpha-muurolene (5.3%). The current investigations revealed the possible use of this botanical combination as a larvicide against Cx. pipienslarvae.