Larvicidal activity and GC-MS analysis of flavonoids of <i>Vitex negundo</i> and <i>Andrographis paniculata</i> against two vector mosquitoes <i>Anopheles stephensi</i> and <i>Aedes aegypti</i>

• Main Authors: Keerti Gautam, Padma Kumar, Sawitri Poonia
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2013-08-01
• Series: Journal of Vector Borne Diseases
• Subjects: Flavonoids; GC-MS analysis; larvicidal activity; vector-borne diseases
• Online Access: http://www.mrcindia.org/journal/issues/503171.pdf

<b>Background & objectives:</b> Development of insect resistance to synthetic pesticides, high operational cost and environmental pollution have created the need for developing alternative approaches to control vector-borne diseases. In the present study, larvicidal activity of flavonoid extracts of different parts of <i>Vitex negundo</i> (Linnaeus) and <i>Andrographis paniculata</i> (Nees) have been studied against the late III or early IV instar larvae of <i>Aedes</i> <i>aegypti</i> and <i>Anopheles stephensi</i> (Liston)<i>.</i> <b>Methods:</b> Flavonoids were extracted from different parts of the selected plants using standard method. Bioassay test was carried out by WHO method for determination of larvicidal activity against mosquitoes. Different compounds of the most active extract were identified by the gas chromatography-mass spectrometry (GC-MS) analysis. <b>Results:</b> Flavonoid extract of whole aerial part of <i>A. paniculata</i> was found to be inactive against the selected larvae of <i>Ae. aegypti</i> even at the concentration of 600 ppm, whereas it caused 70% mortality in <i>An. stephensi</i> at the concentration of 200 ppm. Flavonoid extract of flower-buds produced highest mortality (100%) at the concentration of 600 ppm for the late III or early IV instar larvae of <i>Ae. aegypti</i> and at the concentration of 200 ppm for the larvae of <i>An. stephensi</i>. GC-MS analysis of the most active flavonoid extract from flower-buds of <i>Vitex</i> showed 81 peaks. Phenol (26.83% area), naphthalene (4.95% area), 2,3-dihydrobenzofuran (6.79% area), Phenol-2,4-Bis (1,1-dimethyl) (4.49% area), flavones 4'-OH,5-OH,7-di-O-glucoside (0.25% area) and 5-hydroxy- 3,6,7,3',4'-pentamethoxy flavones (0.80% area) were present in major amount. <b>Conclusion:</b> Flavonoid extracts from different parts of two selected plants possess larvicidal activity against two selected mosquito species, hence, could be utilized for developing flavonoid-based, ecofriendly insecticide as an alternative to synthetic insecticides.