Phytochemical analysis and mosquito repellency evaluation of Ocimum sanctum

Abstract

Mosquito-borne diseases, such as dengue fever and zika virus present ongoing public health challenges necessitating the exploration of safer and environmentally sustainable repellent solutions. This research focuses on Ocimum sanctum, commonly known as holy basil, renowned for its pharmacological diversity. The study aims to elucidate its phytochemical composition and evaluate its efficacy as a natural mosquito repellent, specifically targeting Aedes mosquitoes. The objectives encompassed phytochemical screening using methanolic and aqueous extracts, essential oil extraction via hydro-distillation, and formulation of a repellent balm integrating O. sanctum essential oil with beeswax, coconut oil, glycerine, Aloe vera gel, emulsifying oil and preservatives. Plant materials were meticulously collected from Bandaranayake Memorial Ayurvedic Research Institute, Sri Lanka, ensuring authenticity through herbarium sheet preparation and subsequent powdering. Phytochemical screening revealed a complex profile, including alkaloids, glycosides, tannins, flavonoids, phenols, and steroids, highlighting its rich bioactive potential. Essential oil extraction yielded percentages varied between 0.0019-0.0054 v/w%, prompting Thin Layer Chromatography (TLC) for chemical fingerprinting to ensure consistency and quality control. Mosquito repellency was rigorously assessed through cage tests, demonstrating significant efficacy with reductions in mosquito populations ranging from 63.64% to 68.18% in treated areas. This underscores O. sanctum's promise as an effective natural repellent. Despite challenges in optimizing essential oil yield from fresh leaves, the study provides robust evidence supporting O. sanctum's role in sustainable pest management strategies. The study establishes O. sanctum as a promising candidate in the quest for eco-friendly solutions against mosquito-borne diseases, emphasizing its significance in scientific inquiry and practical implementation.