Unveiling the Potential of Citrus Maxima Leaf Extract for use in the Control of Dengue Fever Mosquito Aedes Aegypti

Abstract

Dengue fever transmitted by Aedes aegypti remains a major public health problem in India with year-round transmission. The present study was aimed to evaluate the phytochemical constituents and larvicidal potential of Citrus maxima leaf extracts against Aedes aegypti. Leaves were extracted with water and ethanol and subjected to phytochemical screening, FTIR, GC-MS, larvicidal and anti-bacterial studies. Phytochemical screening showed presence of alkaloid, carboxylic acid, flavonoids, protein, saponins and cardiac glycosides in aqueous extract, while ethanol extract contained flavonoids, phenol, quinones, saponins, tannins, cardiac glycosides and carbohydrates. Flavonoids, saponins and cardiac glycosides were common in both. FTIR of aqueous extract showed O-H stretch at 3408.11 cm⁻¹ and C=O at 1638.81 cm⁻¹. Ethanol extract showed more diverse peaks at 2980, 2902 and strong C-O-C at 1081.33 cm⁻¹ indicating terpenoids and flavonoid glycosides. Larvicidal bioassay was carried out at 100, 150 and 200 ppm for 24 and 48 hrs. Aqueous extract caused 40-80% mortality while ethanol extract caused 50-100%. Complete 100% mortality was observed with ethanol at 200 ppm after 48 hrs, indicating higher potency with LC50 near 100 ppm. Anti-bacterial activity showed 14 mm zone against E. coli in both extracts and 18 mm against Bacillus cereus in aqueous extract. GC-MS of ethanol extract, selected due to higher activity, revealed 8 major compounds including 7-Hydroxy coumarin, 2-Ethylacridine (highest peak at 16.743 min), Benzoquinoline, phenol derivative and Trilaurin, which are known for repellent and neurotoxic action. The study concludes that Citrus maxima leaf ethanol extract possesses significant larvicidal potential and can be developed as eco-friendly botanical larvicide for dengue vector control.