LABORATORY EVALUATION OF ETHANOLIC EXTRACT OF OCIMUM GRATISSIMUM

This study conducted a comprehensive laboratory evaluation of the ethanolic extract of Ocimum gratissimum (scent leaf), a plant renowned for its ethnopharmacological applications in tropical regions. The research aimed to characterize its bioactive phytochemical constituents and assess its toxicological effect on the stored-product pest, Acanthoscelides obtectus (beans weevil). Fresh leaves were collected, dried, and pulverized before undergoing ethanolic extraction (70% v/v) using a 1:10 plant-to-solvent ratio, resulting in a crude extract. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of the extract revealed a complex profile of twenty bioactive compounds. Major identified constituents included eugenol (a phenolic compound), caryophyllene (a sesquiterpene), n-Hexadecanoic acid (palmitic acid), squalene (a triterpene), 11-Octadecenoic acid methyl ester, Isopropyl stearate, and phytosterols (β-Sitosterol and Campesterol). These compounds are collectively associated with a wide range of pharmacological properties, providing a scientific basis for the plant's traditional uses. The observed antimicrobial, antiinflammatory, antioxidant, and analgesic activities are attributed to the synergistic interactions among these constituents rather than a single compound. In a contact toxicity bioassay, the ethanolic extract demonstrated an exceptionally rapid and potent insecticidal effect against Acanthoscelides obtectus. The results showed a remarkable 100% mortality rate within the first minute of exposure, a finding that signifies an extraordinarily fast-acting mechanism, likely neurotoxic or asphyxiant in nature, mediated by the volatile and bioactive compounds present. This study successfully delineated the phytochemical composition of O. gratissimum ethanolic extract, validating its traditional medicinal uses through the identification of compounds with significant therapeutic potential. Furthermore, the extract exhibited profound and immediate insecticidal activity against a major agricultural pest. These findings position O. gratissimum not only as a valuable source of lead compounds for nutraceutical and pharmaceutical development but also as a highly promising candidate for formulation into a natural, eco-friendly botanical insecticide for the protection of stored legumes. It is recommended that future research focuses on toxicity profiling in nontarget organisms, elucidating the precise mode of insecticidal action, and conducting clinical trials to establish safe dosage regimens for human therapeutic applications.