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Journal of Mosquito Research
2013, Vol.3, No.13, 89-96
http://jmr.sophiapublisher.com
Research Report
Open Access
Bioactivity of
Acyranthes aspera
(Amaranthaceae) Foliage against the Japanese
Encephalitis Vector
Culex vishnui
Group
Kuntal Bhattacharya , Goutam Chandra
Mosquito and Microbiology Research Units, Parasitology Laboratory, Department of Zoology, The University of Burdwan, Burdwan-713104, West Bengal, India
Corresponding author email:
goutamchandra63@yahoo.co.in
;
Author
Journal of Mosquito Research, 2013, Vol.3, No.13 doi: 10.5376/jmr.2013.03.0013
Copyright
© 2013 Kuntal Bhattacharya and Goutam Chandra. This is an open access article published under the terms of the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background and objective: Failure to develop proper vaccines against mosquito borne diseases, a global health problem,
imposes sole reliance on the vector managerial steps for reducing the disease incidences. Easy abundance, cost effectiveness, target
specificity as well as bio-degradability of botanicals draw the most attention as vector control agents than their synthetic counterparts
which facilitate vector resistance and intoxicate natural resources. The present study estimated larvicidal activities of the crude and
solvent extracts of
Acyranthes aspera
against the vector of Japanese encephalitis
Culex vishnui
group under laboratory conditions.
Methods: Crude extracts of
A. aspera
foliage ranging from 0.1% to 0.5% concentrations were examined for larvicidal activity against
1
st
to 4
th
instars larvae of
Cx. vishnui
group. Extractions of the active fractions were carried out by means of six different solvents in a
non-polar to polar approach viz. petroleum ether, n-hexane, ethyl acetate, chloroform: methanol (1:1 v/v), acetone, and absolute
alcohol. Dose dependent mortality was established through graded concentrations ranging from 20 ppm to 100 ppm using the
bioactive fractions. Further, determinations of LC
50
and LC
90
values of crude and bioactive fractions were accomplished through
log-probit analyses. Statistical justifications of the larvicidal property were established through ANOVA analyses regarding instars,
time and concentrations as three completely randomized independent variables. Costing impacts on the non-target water fauna of the
bio-active portion were assessed under laboratory conditions.
Result: In a 72 hour bioassay experiment with crude extract, the highest mortality was recorded in 0.5% concentration. Acetone
extractive was found to exert efficient larvicidal activity amongst all the solvent extractives. Cent per cent mortalities were exhibited
by 1
st
and 2
nd
instars larvae at 48 hours of exposure while 3
rd
instars larvae showed 97.32% mortality at 72 hours of exposure with
LC
50
value of 32.15 ppm. An obvious dose-dependent mortality was established through regression analyses, as the rate of mortality
(Y) was positively correlated with the concentration (X). The non-target populations were primarily non-responsive to plant
extracts under study.
Conclusion: Extract of
A. aspera
foliage is of great consequence having appreciable larvicidal activity against
Cx. vishnui
group
.
The
compound is environment friendly and largely non-toxic to non-target organisms.
Keywords
Acyranthes aspera
; Larvicide;
Culex vishnui
group; Non-target organism
Introduction
Mosquitoes, hematophagous dipteran flies, toil as the
chief vector for the transmission of malaria, filariasis,
dengue fever, yellow fever, schistosomiasis, Japanese
encephalitis and many more noxious diseases
pertaining to numerous deaths annually. Mosquito bite
induces both immediate (types I and III) and delayed
(type IV) hypersensitivity responses (Clements, 1992)
leading to the development of angioedema, intense
itching, redness and swellings in humans. In tropical
country like India, over 40 million people get infected
each year (Ghosh et al., 2012) with mosquito borne
diseases. Amongst these, Japanese encephalitis,
prevalent in Southeast Asia and the Far East, is caused
Preferred citation for this article:
Kuntal Bhattacharya and Goutam Chandra, 2013, Bioactivity of
Acyranthes aspera
(Amaranthaceae) Foliage against the Japanese Encephalitis Vector
Culex
vishnui
Group, Journal of Mosquito Research, Vol.3, No.13 89-96 (doi: 10.5376/jmr.2013.03.0013)
Received: 24 Sep, 2013
|
Accepted: 10 Oct., 2013
|
Published: 05 Nov., 2013