RETRACTED ARTICLE:Mosquito larvicidal properties of silver nanoparticles synthesized using Heliotropium indicum (Boraginaceae) against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus (Diptera: Culicidae)
Authors: Marimuthu Govindarajan
Mohan Rajeswary
Udaiyan Muthukumaran
Kaliyan Veerakumar
Journal: Parasitology Research (2014)
Discipline: MICROBIOLOGY
Keywords: Mosquitoes; Biological control; Plant-derived molecules; Silver nanoparticles; Helitropium indicum
Affiliations: Unit of Vector Biology and Phytochemistry, Department of Zoology, Annamalai University, Annamalainagar, 608002, Tamilnadu, India.

Abstract:  Mosquitoes transmit dreadful diseases to human beings wherein biological control of these vectors using plant-derived molecules would be an alternative to reduce mosquito population. In the present study activity of aqueous leaf extract and silver nanoparticles (AgNPs) synthesized using Helitropium indicum plant leaves against late third instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. The range of varying concentrations of synthesized AgNPs (8, 16, 24, 32, and 40 μg/mL) and aqueous leaf extract (30, 60, 90, 120, and 150 μg/mL) were tested against the larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The synthesized AgNPs from H. indicum were highly toxic than crude leaf aqueous extract in three important vector mosquito species. The results were recorded from UV-Vis spectrum, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis, transmission electron microscopy, and histogram. The synthesized AgNPs showed larvicidal effects after 24 h of exposure. Considerable mortality was evident after the treatment of H. indicum for all three important vector mosquitoes. The LC50 and LC90 values of H. indicum aqueous leaf extract appeared to be effective against A. stephensi (LC50, 68.73 μg/mL; LC90, 121.07 μg/mL) followed by A. aegypti (LC50, 72.72 μg/mL; LC90, 126.86 μg/mL) and C. quinquefasciatus (LC50, 78.74 μg/mL; LC90, 134.39 μg/mL). Synthesized AgNPs against the vector mosquitoes of A. stephensi, A. aegypti, and C. quinquefasciatus had the following LC50 and LC90 values: A. stephensi had LC50 and LC90 values of 18.40 and 32.45 μg/mL, A. aegypti had LC50 and LC90 values of 20.10 and 35.97 μg/mL, and C. quinquefasciatus had LC50 and LC90 values of 21.84 and 38.10 μg/mL. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H. indicum and green synthesis of silver nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of A. stephensi, A. aegypti, and C. quinquefasciatus. This is the first report on the mosquito larvicidal activity of the plant extracts and synthesized nanoparticles. 

Retracted: Yes

PubPeer comments:
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 Figure 3 show the color change upon mixing of AgNO3 and Heliotropicum indicum leaf extract. However these photos look very similar to photos in 2 other papers by the same authors (doi: 10.1007 s00436-014-4077-4 and 10.1007 s00436-014-3823-y), where they represent the generation of nanoparticles using F. elephantum leaf extract. The light reflection of the right flask suggests that the photo was taken from a different height, but the aluminum foil covers look remarkably similar. Could the authors comment on these similarities, please? ![file] , 
 https: link.springer.com article 10.1007 s00436-021-07123-w The Editors-in-Chief have retracted this article because it shows significant overlap with previously published articles by the same authors (Veerakumar et al., 2013, 2014). Additionally, Fig. 3 of this article appears to be identical to Fig. 3 in (Veerakumar et al., 2014). The Editors-in-Chief therefore no longer have confidence in the reliability of the data reported in the article. None of the authors agree to this retraction. References Veerakumar K, Govindarajan M, Rajeswary M (2013) Green synthesis of silver nanoparticles using Sida acuta (Malvaceae) leaf extract against Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti (Diptera: Culicidae). Parasitol Res 112:4073u20134085. https: doi.org 10.1007 s00436-013-3598-6 Veerakumar K, Govindarajan M, Rajeswary M, Muthukumaran U (2014)Low-cost and eco-friendly green synthesis of silver nanoparticles using Feronia elephantum (Rutaceae) against Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti (Diptera: Culicidae). Parasitol Res 113:1775u20131785. https: doi.org 10.1007 s00436-014-3823-y ,