ABSTRACT
OBJECTIVE@#To investigate the larvicidal activity of essential oil and methanol extract of the Nepeta menthoides (N. menthoides) against main malaria vector, Anopheles stephensi (An. stephensi).@*METHODS@#The essential oil of plant was obtained by Clevenger type apparatus and the methanol extract was supplied with Percolation method. Larvicidal activity was tested by WHO method. Twenty five fourth-instar larvae of An. stephensi were used in the larvicidal assay and four replicates were tested for each concentration. Five different concentrations of the oil and extract were tested for calculation of LC(50) and LC(90) values.@*RESULTS@#The LC(50) and LC(90) values were determined by probit analysis. LC(50) was 69.5 and 234.3 ppm and LC(90) was 175.5 and 419.9 ppm for the extract and essential oil respectively.@*CONCLUSIONS@#According to the results of this study methanolic extract of plant exhibited more larvicidal activity than essential oil. This could be useful for investigation of new natural larvicidal compounds.
Subject(s)
Animals , Anopheles , Insecticides , Larva , Methanol , Chemistry , Nepeta , Chemistry , Oils, Volatile , Chemistry , Plant Components, Aerial , Chemistry , Plant Extracts , Chemistry , Regression AnalysisABSTRACT
Objectives: The objective of this study was to evaluate larvicidal activity of native marine algae against main malaria vector Anopheles stephensi. Study design: The total 70% methanol (MeOH) extract and partition fractions of chloroform (CHCl3), ethylacetate (EtOAc), and MeOH from two algae, Sargassum swartzii and Chondria dasyphylla were investigated for larvicidal activities against late III and early IV instar larvae of malaria vector An. stephensi. Results: Among all the fractions tested against larvae, EtOAc fraction of S. swartzii and C. dasyphylla, showed mortality rate of 96 and 95%, respectively. Probit analysis of logarithmic concentration from regression line exhibited the LC50 and LC90 values of 11.75 and 53.47 ppm respectively for S. swartzii and 10.62 and 56.39 ppm respectively for C. dasyphylla. Conclusion: This is the first report of larvicidal activities of two native algae against An. stephensi. We propose that the larvicidal activity of EtOAc fraction is related to the presence of semi-polar compounds. Further isolation and purification could lead to identify more potent compounds.