QUALITATIVE PHYTOCHEMICAL SCREENING AND LARVICIDAL ACTIVITY OF OCIMUM AMERICANUM LEAVES METHANOL EXTRACT AGAINST MOSQUITO LARVAE

Author (s) : Ms. S.Kalaivani,

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Abstract :
Mosquito-borne diseases pose significant health threats worldwide, necessitating effective control measures to combat the spread of these diseases. In this study, we investigated the phytochemical constituents and larvicidal activity of the methanol extract derived from Ocimum americanum (commonly known as American Basil) leaves against mosquito larvae. The qualitative phytochemical screening of the O. americanum leaves methanol extract was conducted using standard procedures to identify various secondary metabolites present in the extract. The tests included the detection of alkaloids, flavonoids, phenolics, terpenoids, saponins, and tannins, which are known to possess diverse bioactive properties. For the larvicidal activity assessment, the methanol extract was evaluated against the larvae of Aedes aegypti, an important vector responsible for transmitting diseases like dengue, chikungunya, and Zika virus. The World Health Organization (WHO) larval bioassay protocol was employed to determine the larvicidal efficacy of the extract. Various concentrations of the extract were prepared, and mortality rates of mosquito larvae were recorded after 24 and 48 hours of exposure.The qualitative phytochemical screening revealed the presence of alkaloids, flavonoids, phenolics, terpenoids, saponins, and tannins in the O. americanum leaves methanol extract. These phytochemicals have been previously reported for their insecticidal properties, suggesting their potential role in the observed larvicidal activity. The larvicidal bioassays demonstrated a concentration-dependent larval mortality. The O. americanum extract exhibited significant larvicidal activity against A. aegypti larvae, with higher mortality rates observed after 48 hours of exposure compared to 24 hours. This finding suggests that the extract might have a delayed toxic effect on mosquito larvae. The results of this study indicate that O. americanum leaves methanol extract holds promise as a natural larvicide against mosquito larvae, particularly A. aegypti. Further research is warranted to isolate and identify the active compounds responsible for the observed larvicidal activity. The development of eco-friendly and sustainable mosquito control agents from botanical sources, such as O. americanum, could provide a valuable contribution to combat mosquito-borne diseases and reduce the reliance on synthetic chemical insecticides.

Keywords : Qualitative Phytochemical Screening, Mosquito Larvae

Conference Date : 17/09/2021

Pages : 110

Paper ID : IESMDT108