Efficiency of Datura stramonium metabolites as a promising insecticide against the vector-borne diseases Culex pipiens and Aedes aegypti.

Abstract

Mosquitoes, one of the deadliest animals on the planet, cause millions of fatalities each year by transmitting several human illnesses. Therefore, it was necessary to use many synthetic pesticides to prevent the spread of diseases, which led to an increase in the effective use of synthetic pesticides to protect humans. The extensive use of pesticides caused serious health problems for humans, environmental damage, and mosquito resistance to synthetic insecticides. This study aimed to evaluate the larvicidal efficacy of Datura stramonium extracts (methanol, ethyl acetate, n-hexane, and aqueous) against larvae and adults of Culex pipiens and Aedes aegypti with phytochemical profiles. Bioassays were conducted under laboratory conditions, and lethal concentrations (LC₅₀ and LC₉₀) were calculated after 24 and 48 h. Methanol and ethyl acetate extracts showed the strongest ability to kill larvae, with LC₅₀ values of 40.19 ppm for Cx. pipiens and 71.46 ppm for Ae. aegypti. In adulticidal assays, aqueous and ethyl acetate extracts induced the highest mortality rates (up to 88 %) at 100 ppm. The methanol extract exhibited strong antimicrobial activity, recording the largest inhibition zone (27 mm) against Klebsiella pneumoniae, followed by Staphylococcus aureus (25 mm) and Candida albicans (22 mm). highlighting its potential as a dual-function natural agent with both insecticidal and antimicrobial properties. UPLC/MS analysis identified several bioactive phytochemicals, including alkaloids withanolides, alkaloids, phenolic acids, cinnamic acid derivatives and flavonoids, that may contribute to the observed effects. The n-hexane extract revealed twelve volatile components from the mono-, di-, and sesquiterpenoid classes, along with volatile alkaloids such as nicotine and scopolamine. Antimicrobial tests also revealed moderate to high inhibition against selected bacterial and fungal pathogens. Quantitative real-time PCR revealed that the genes Apismin, Defincin 1, SFCYP1, SFCYP4, SFCYP5, and SFRYR were significantly increased, while SFCYP3 was consistently decreased in both Datura and pesticide. However, SFCYP2 is believed to increase in pesticide and decreased in Datura. These findings highlight Datura stramonium as an available, eco-friendly, and promising natural alternative to synthetic insecticides for vector control.