Larvicidal Potential of Dactyloctenium Aegyptium (L.) Willd. (Poales: Poaceae) Extracts and In Silico Docking of Major Identified Compounds Against Mosquito Vector Proteins.

Abstract

This study evaluated the larvicidal efficacy of the methanol extract of Dactyloctenium aegyptium against Aedes aegypti (L, 1762) (Diptera: Culicidae), Anopheles stephensi Liston, 1901 (Diptera: Culicidae), and Culex quinquefasciatus Say, 1823 (Diptera: Culicidae). The methanol extract exhibited the highest mortality rates, achieving 100% mortality at 250 µg/mL for all species tested, and demonstrated the lowest LC₅₀ values of 94.28 µg/mL for Ae. aegypti, 119.07 µg/mL for An. stephensi, and 103.71 µg/mL for Cx. quinquefasciatus. In contrast, the n-hexane extract was the least effective against Ae. aegypti and Cx. quinquefasciatus, while the chloroform extract showed the least efficacy against An. stephensi. Statistical analysis confirmed the significant impact of extract concentration, type, and mosquito species on mortality rates, with the model explaining 98.4% of the variance. GC-MS analysis of the methanol extract identified several bioactive compounds, with stigmasterol being the most abundant (13.92%), followed by gamma-sitosterol (10.40%) and campesterol (5.31%). Molecular docking studies revealed that campesterol exhibited the highest binding affinity with docking scores of -9.6 kcal/mol for the sterol carrier protein from Ae. aegypti (PDB ID: 1PZ4) and -10.3 kcal/mol for acetylcholinesterase from Anopheles gambiae (PDB ID: 5X61). Additionally, stigmasterol and sitosterol showed significant binding affinities of -9.4 and -9.0 kcal/mol against 1PZ4, and -9.5 and -9.4 kcal/mol against 5X61, respectively. Citrost-7-en-3-ol demonstrated a promising affinity of -9.7 kcal/mol for acetylcholinesterase. Overall, the methanol extract of D. aegyptium shows promise for mosquito control, with specific compounds identified as potential inhibitors of key targets in vector control strategies.