Mosquito-borne diseases represent a deadly threat for millions of people worldwide. However, the use of synthetic insecticides to control Culicidae may lead to resistance, high operational costs and ...adverse non-target effects. Nowadays, plant-borne mosquitocides may serve as suitable alternative in the fight against mosquito vectors. In this study, the mosquito larvicidal activity of Origanum vulgare (Lamiaceae) leaf essential oil (EO) and its major chemical constituents was evaluated against the malaria vectors Anopheles stephensi and An. subpictus, the filariasis vector Culex quinquefasciatus and the Japanese encephalitis vector Cx. tritaeniorhynchus. The chemical composition of the EO was analyzed by gas chromatography–mass spectroscopy. GC–MS revealed that the essential oil of O. vulgare contained 17 compounds. The major chemical components were carvacrol (38.30%) and terpinen-4-ol (28.70%). EO had a significant toxic effect against early third-stage larvae of An. stephensi, An. subpictus, Cx. quinquefasciatus and Cx. tritaeniorhynchus, with LC50 values of 67.00, 74.14, 80.35 and 84.93μg/ml. The two major constituents extracted from the O. vulgare EO were tested individually for acute toxicity against larvae of the four mosquito vectors. Carvacrol and terpinen-4-ol appeared to be most effective against An. stephensi (LC50=21.15 and 43.27μg/ml, respectively) followed by An. subpictus (LC50=24.06 and 47.73μg/ml), Cx. quinquefasciatus (LC50=26.08 and 52.19μg/ml) and Cx. tritaeniorhynchus (LC50=27.95 and 54.87μg/ml). Overall, this research adds knowledge to develop newer and safer natural larvicides against malaria, filariasis and Japanese encephalitis mosquito vectors.
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•Origanum vulgare essential oil (EO) was tested against larvae of 4 mosquito vectors.•Chemical compositions of the EO were analyzed by GC and GC–MS.•Carvacrol and terpinen-4-ol were the major constituents of the EO.•LC50 values against the four mosquito vectors ranged from 21.15 to 27.95μg/ml.•Carvacrol and terpinen-4-ol may be considered as eco-friendly larvicides.
Different types of thiosemicarbazone derivatives were designed and tested for their Drug-Like Molecular (DLM) nature by using Lipinski and Veber rules. Subsequently, compounds with DLM properties ...were synthesized and characterized by spectral methods. In vitro antimalarial activity studies of the synthesized thiosemicarbazone derivatives have been carried out against Plasmodium falciparum, 3D7 strain using fluorescence assay method and found that the compounds, (E)-2-(1-(4-fluorophenyl)ethylidene)hydrazine-1-carbothioamide (6), (E)-2-(1-(3-bromophenyl) ethylidene) hydrazine-1-carbothioamide (15) and (E)-2-(3,4,5-trimethoxybenzylidene) hydrazine-1-carbothioamide (29) showed notable antimalarial activity with EC50 values of 13.54 μM, 15.83 μM and 14.52 μM respectively.
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The synthesis of eco-friendly nanoparticles is evergreen branch of nanoscience with a growing number of biomedical implications. In this study, we investigated the synthesis of polydisperse and ...stable silver nanoparticles (AgNP) using a cheap leaf extract of
Malva sylvestris
(Malvaceae). Bio-reduced AgNP were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The acute toxicity of
M. sylvestris
leaf extract and green-synthesized AgNP was evaluated against larvae of the malaria vector
Anopheles stephensi
, the dengue vector
Aedes aegypti
and the filariasis vector
Culex quinquefasciatus
. Compared to the leaf aqueous extract, AgNP showed higher toxicity against
A. stephensi
,
A. aegypti
, and
C. quinquefasciatus
with LC
50
values of 10.33, 11.23, and 12.19 μg/mL, respectively. Green-synthesized AgNP were found safer to non-target organisms
Diplonychus indicus
and
Gambusia affinis
, with respective LC
50
values ranging from 813.16 to 1044.52 μg/mL. Overall, this research firstly shed light on the mosquitocidal potential of
M. sylvestris
, a potential bio-resource for rapid, cheap and effective synthesis of polydisperse and highly stable silver nanocrystals.
There is a strong policy impetus for the One Health cross-sectoral approach to address the complex challenge of zoonotic diseases, particularly in low/lower middle income countries (LMICs). Yet the ...implementation of this approach in LMIC contexts such as India has proven challenging, due partly to the relatively limited practical guidance and understanding on how to foster and sustain cross-sector collaborations. This study addresses this gap by exploring the facilitators of and barriers to successful convergence between the human, animal and environmental health sectors in India.
A mixed methods study was conducted using a detailed content review of national policy documents and in-depth semi-structured interview data on zoonotic disease management in India. In total, 29 policy documents were reviewed and 15 key informant interviews were undertaken with national and state level policymakers, disease managers and experts operating within the human-animal-environment interface of zoonotic disease control.
Our findings suggest that there is limited policy visibility of zoonotic diseases, although global zoonoses, especially those identified to be of pandemic potential by international organisations (e.g. CDC, WHO and OIE) rather than local, high burden endemic diseases, have high recognition in the existing policy agenda setting. Despite the widespread acknowledgement of the importance of cross-sectoral collaboration, a myriad of factors operated to either constrain or facilitate the success of cross-sectoral convergence at different stages (i.e. information-sharing, undertaking common activities and merging resources and infrastructure) of cross-sectoral action. Importantly, participants identified the lack of supportive policies, conflicting departmental priorities and limited institutional capacities as major barriers that hamper effective cross-sectoral collaboration on zoonotic disease control. Building on existing informal inter-personal relationships and collaboration platforms were suggested by participants as the way forward.
Our findings point to the importance of strengthening existing national policy frameworks as a first step for leveraging cross-sectoral capacity for improved disease surveillance and interventions. This requires the contextual adaptation of the One Health approach in a manner that is sensitive to the underlying socio-political, institutional and cultural context that determines and shapes outcomes of cross-sector collaborative arrangements.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•Eco-friendly control tools against malaria and Japanese encephalitis vectors are a priority.•Silver nanoparticles (AgNP) were fabricated using Ichnocarpus frutescens aqueous extract ...as a reducing and capping agent.•AgNP were characterized by UV–vis spectrophotometry, FTIR, SEM, TEM, AFM, EDX and XRD.•AgNP showed potent larvicidal activity against malaria and arbovirus vectors, LC50 ranged from 14 to 17μg/mL.•Biotoxicity against non-target aquatic organisms was neglible, LC50 ranged from 636 to 2098μg/mL.
Mosquito (Diptera: Culicidae) vectors are solely responsible for transmitting important diseases such as malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and Zika virus. Eco-friendly control tools of Culicidae vectors are a priority. In this study, we proposed a facile fabrication process of poly-disperse and stable silver nanoparticles (Ag NPs) using a cheap leaf extract of Ichnocarpus frutescens (Apocyanaceae). Bio-reduced Ag NPs were characterized by UV–vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The acute toxicity of I. frutescens leaf extract and green-synthesized Ag NPs was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Compared to the leaf aqueous extract, Ag NPs showed higher toxicity against A. subpictus, A. albopictus, and C. tritaeniorhynchus with LC50 values of 14.22, 15.84 and 17.26μg/mL, respectively. Ag NPs were found safer to non-target mosquito predators Anisops bouvieri, Diplonychus indicus and Gambusia affinis, with LC50 values ranging from 636.61 to 2098.61μg/mL. Overall, this research firstly shed light on the mosquitocidal potential of I. frutescens, a potential bio-resource for rapid, cheap and effective synthesis of poly-disperse and highly stable silver nanocrystals.
Mosquitoes (Diptera: Culicidae) are vectors of important pathogens and parasites, including malaria, dengue, chikungunya, Japanese encephalitis, lymphatic filariasis and Zika virus. The application ...of synthetic insecticides causes development of resistance, biological magnification of toxic substances through the food chain, and adverse effects on the environment and human health. In this scenario, eco-friendly control tools of mosquito vectors are a priority. Here single-step fabrication of silver nanoparticles (AgNP) using a cheap aqueous leaf extract of Zornia diphylla as reducing and capping agent pf Ag+ ions has been carried out. Biosynthesized AgNP were characterized by UV–visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of Z. diphylla leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the Z. diphylla leaf extract and Ag NP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized Ag NP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 12.53, 13.42 and 14.61μg/ml, respectively. Biosynthesized Ag NP were found safer to non-target organisms Chironomus circumdatus, Anisops bouvieri and Gambusia affinis, with the respective LC50 values ranging from 613.11 to 6903.93μg/ml, if compared to target mosquitoes. Overall, our results highlight that Z. diphylla-fabricated Ag NP are a promising and eco-friendly tool against larval populations of mosquito vectors of medical and veterinary importance, with negligible toxicity against other non-target organisms.
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•Eco-friendly control tools against malaria and arbovirus vectors are a priority.•Silver nanoparticles (Ag NP) were biosynthesized using Zornia diphylla aqueous extract as a reducing and capping agent.•Ag NP were characterized by UV–visible spectrophotometry, FTIR, SEM, TEM, EDX and XRD.•Ag NP showed potent larvicidal activity against malaria and arbovirus vectors, LC50 ranged from 12.53 to 14.61μg/ml.•Biotoxicity against non-target aquatic organisms was negligible.
Mosquitoes (Diptera: Culicidae) represent a key threat for millions of people worldwide, since they act as vectors for devastating parasites and pathogens. In this scenario, eco-friendly control ...tools against mosquito vectors are a priority. Green synthesis of silver nanoparticles (AgNP) using a cheap, aqueous leaf extract of Anisomeles indica by reduction of Ag+ ions from silver nitrate solution has been investigated. Bio-reduced AgNP were characterized by UV–visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX) and X-ray diffraction analysis (XRD). The acute toxicity of A. indica leaf extract and biosynthesized AgNP was evaluated against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. Both the A. indica leaf extract and AgNP showed dose dependent larvicidal effect against all tested mosquito species. Compared to the leaf aqueous extract, biosynthesized AgNP showed higher toxicity against An. subpictus, Ae. albopictus, and Cx. tritaeniorhynchus with LC50 values of 31.56, 35.21 and 38.08 μg/mL, respectively. Overall, this study firstly shed light on the mosquitocidal potential of A. indica, a potential bioresource for rapid, cheap and effective AgNP synthesis.
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•Eco-friendly green synthesis of silver nanoparticles (AgNP) was performed using Anisomeles indica leaf extract.•Green synthesized AgNP were characterized by UV–vis, FTIR, SEM, EDX, TEM and XRD.•Potent larvicidal activity was noticed against filariasis, malaria and dengue mosquito vectors.•LC50 value ranged from 31.56 to 38.08 μg/mL.
Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Eco-friendly mosquitocides are a priority. In Ayurvedic medicine, Plectranthus species have been used to treat ...heart disease, convulsions, spasmodic pain and painful urination. In this research, we evaluated the acute toxicity of essential oil from Plectranthus barbatus and its major constituents, against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. The chemical composition of P. barbatus essential oil was analyzed by gas chromatography–mass spectroscopy. Nineteen components were identified. Major constituents were eugenol (31.12 %), α-pinene (19.38 %) and β-caryophyllene (18.42 %). Acute toxicity against early third-instar larvae of An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus was investigated. The essential oil had a significant toxic effect against larvae of An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus, with 50 % lethal concentration (LC₅₀) values of 84.20, 87.25 and 94.34 μg/ml and 90 % lethal concentration (LC₉₀) values of 165.25, 170.56 and 179.58 μg/ml, respectively. Concerning major constituents, eugenol, α-pinene and β-caryophyllene appeared to be most effective against An. subpictus (LC₅₀ = 25.45, 32.09 and 41.66 μg/ml, respectively), followed by Ae. albopictus (LC₅₀ = 28.14, 34.09 and 44.77 μg/ml, respectively) and Cx. tritaeniorhynchus (LC₅₀ = 30.80, 36.75 and 48.17 μg/ml, respectively). Overall, the chance to use metabolites from P. barbatus essential oil against mosquito vectors seems promising, since they are effective at low doses and could be an advantageous alternative to build newer and safer mosquito control tools.
Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in ...tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and eco-friendly reducing and capping agents. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Heliotropium indicum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. Adult mosquitoes were exposed to varying concentrations of aqueous extract of H. indicum and synthesized AgNPs for 24 h. AgNPs were rapidly synthesized using the leaf extract of H. indicum, and the formation of nanoparticles was observed within 6 h. The results recorded from UV–vis spectrum, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the adult of A. stephensi (lethal dose (LD)₅₀ = 26.712 μg/mL; LD₉₀ = 49.061 μg/mL), A. aegypti (LD₅₀ = 29.626 μg/mL; LD₉₀ = 54.269 μg/mL), and C. quinquefasciatus (LD₅₀ = 32.077 μg/mL; LD₉₀ = 58.426 μg/mL), respectively. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H.indicum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of the A. stephensi, A. aegypti, and C. quinquefasciatus. This is the first report on the adulticidal activity of the plant extracts and AgNPs.
Mosquitoes are blood-feeding insects and serve as the most important vectors for spreading human diseases such as malaria, yellow fever, dengue fever, and filariasis. The continued use of synthetic ...insecticides has resulted in resistance in mosquitoes. Synthetic insecticides are toxic and affect the environment by contaminating soil, water, and air, and then natural products may be an alternative to synthetic insecticides because they are effective, biodegradable, eco-friendly, and safe to environment. Botanical origin may serve as suitable alternative biocontrol techniques in the future. The present study was carried out to establish the larvicidal potential of leaf extracts of
Gmelina asiatica
and synthesized silver nanoparticles using aqueous leaf extract against late third instar larvae of
Anopheles stephensi
,
Aedes aegypti
, and
Culex quinquefasciatus
. Larvae were exposed to varying concentrations of plant extracts and synthesized AgNPs for 24 h. The results were recorded from UV–visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy analysis support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the larvae of
An. stephensi
(lethal dose (LC
50
) = 22.44 μg/mL; LC
90
40.65 μg/mL),
Ae. aegypti
(LC
50
= 25.77 μg/mL; LC
90
45.98 μg/mL), and
C. quinquefasciatus
(LC
50
= 27.83 μg/mL; LC
90
48.92 μg/mL), respectively. No mortality was observed in the control. This is the first report on mosquito larvicidal activity of plant-synthesized nanoparticles. Thus, the use of
G. asiatica
to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach and the AgNps formed can be potential mosquito larvicidal agents.
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