Toxicity of saponin isolated from Gymnema sylvestre R. Br. (Asclepiadaceae) against Culex tritaeniorhynchus Giles (Diptera: Culicidae) Japanese encephalitis vector mosquito in India

Abstract

SUMMARYTo determine the larvicidal activity of various extracts of Gymnema sylvestre against the Japanese Encephalitis vector, Culex tritaeniorynchus in Tamilnadu, India. To identify the active principle present in the promising fraction obtained in Chlorofom:Methanol extract of Fraction 2. The G. sylvestre leaf extracts were tested, employing WHO procedure against fourth instar larvae of C. tritaeniorhynchus and the larval mortalities were recorded at various concentrations (6.25, 12.5, 25.0, 50 and 100 µg/mL); the 24h LC 50 values of the G. Sylvestre leaf extracts were determined following Probit analysis. It was noteworthy that treatment level 100 µg/mL exhibited highest mortality rates for the three different crude extracts and was significantly different from the mean mortalities recorded for the other concentrations

Phytochemical Profiling and Larval Control of Erythrina variegata Methanol Fraction against Malarial and Filarial Vector

“…Furthermore, the larvicidal activity of Gymnema sylvestre tested against Cx. tritaeniorhynchus with LC 50 values of acetone, chloroform, and methanol extracts were 34.756, 31.351, and 28.577 mg/ml, respectively [28].…”

Bioefficacy of Duranta erecta leaf extract on yellow fever and dengue vector, Aedes aegypti Linn. in Nigeria

“…The mosquito larvae were hatched from the egg colony using modified methods reported by Elumalai et al (2012). The eggs were washed with 0.01% formaldehyde solution for 30 to 40 min as a precaution against possible microsporidian infections which might interfere with the normal development of the immature stages of mosquitoes and soaked in water to facilitate hatching.…”

“…The experimental design was the modified version of that reported by Elumalai et al ( 2012). Seven groups of concentrations of aqueous extracts (aqE) of D. erecta leaf A, B, C, D, E, F and G were used for the bioassay experiment.…”

“…Similar studies on the larvicidal activities of plants belonging to different families have been reported by various authors. According to Elumalai et al (2012), methanolic leaf extract of Gymnema sylvestre (LC 50 value of 28.577ppm) was effective against C. tritaeniorhynchus larvae, A. millefolium methanolic stem extract (LC 50 value of 120.0ppm) against C. quinquefasciatus (Parvela, 2008), 1% Suneem a derivative of neem oil (LC 50 value of 2mg/L) against larvae of A. aegypti (Ndione et al, 2007), aqueous extract of D. erecta at 3.0% concentration of leaf extract achieved 100% mortality of fourth instar C. quinquefasciatus larvae (MaConnell et al, 2010) and ethyl acetate extract of Sphaeranthu sindicus whole plant was found to be effective with an LC 50 value of 201.11 ppm against the larvae of A. aegypti followed by hexane leaf extract of Abailon indicum (LC 50 value of 261.31 ppm) (Tennyson et al, 2012b).…”