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.
ABSTRACT
OBJECTIVE@#To determine the sand flies species responsible for most transmission of Leishmania major (L. major) to human, as well as to determine the main reservoir hosts of the disease.@*METHODS@#Sand flies were collected using sticky papers and mounted in Puri's medium for species identification. Rodents were trapped by live Sherman traps. Both sand flies and rodents were subjected to molecular methods for detection of leishmanial parasite.@*RESULTS@#Phlebotomus papatasi (P. papatasi) was the common species in outdoor and indoor resting places. Employing PCR technique only three specimens of 150 P. papatasi (2%) were found naturally infected by parasites with a band of 350 bp which is equal to the L. major parasite. Forty six rodents were captured by Sherman traps and identified. Microscopic investigation on blood smear of the animals for amastigote parasites revealed 1 (3.22%) infected Meriones libycus (M. libycus). Infection of this animal to L. major was confirmed by PCR against rDNA loci of the parasite.@*CONCLUSIONS@#This is the first molecular report of parasite infection of both vector (P. papatasi) and reservoir (M. libycus) to L. major in the region. The results indicated that P. papatasi was the primary vector of the disease and circulating the parasite between human and reservoirs and M. libycus was the most important host reservoir for maintenance of the parasite source in the area.