Green synthesis of titanium dioxide nanoparticles using Psidium guajava extract and its antibacterial and antioxidant properties.

OBJECTIVE: To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of Psidium guajava mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs). METHODS: Synthesized TiO2 NPs were tested by disc diffusion method against against human pathogenic bacteria. The total antioxidant activity and phenolic content (Folin-Ciocalteau method) of synthesized TiO2 NPs and aqueous plant extract were determined. The scavenging radicals were estimated by DPPH method. The synthesized TiO2 NPs were characterized by XRD, FTIR, FESEM and EDX. RESULTS: FTIR spectra of synthesized TiO2 NPs exhibited prominent peaks at 3 410 cm(-1) (alkynes), 1 578 cm(-1), 1 451 cm(-1) (alkanes), and 1 123 cm(-1)(C-O absorption). The morphological characterization of synthesized TiO2 NPs was analysed by FESEM which showed spherical shape and clusters with an average size of 32.58 nm. The maximum zone of inhibition was observed in the synthesized TiO2 NPs (20 µg/mL) against Staphylococcus aureus (25 mm) and Escherichia coli (23 mm). The synthesized TiO2 NPs showed more antibacterial activity than the standard antibiotic disk, tetracycline which drastically reduces the chances for the development of antibiotics resistance of bacterial species. The plant aqueous extract and synthesized TiO2 NPs were found to possess maximum antioxidant activity when compared with ascorbic acid. The content of phenolic compounds (mg/g) in leaf aqueous extract and synthesized TiO2 NPs were found to be 85.4 and 18.3 mgTA/g, respectively. CONCLUSIONS: Green synthesized TiO2 NPs provides a promising approach can satisfy the requirement of large-scale industrial production bearing the advantage of low-cost, eco-friendly and reproducible.

Acaricidal activity of synthesized titanium dioxide nanoparticles using Calotropis gigantea against Rhipicephalus microplus and Haemaphysalis bispinosa.

OBJECTIVE: To assess the acaricidal activity of titanium dioxide nanoparticles (TiO2 NPs) synthesized from flower aqueous extract of Calotropis gigantea(C. gigantea) against the larvae of Rhipicephalus (Boophilus) microplus [R. (B.) microplus] and the adult of Haemaphysalis bispinosa (H. bispinosa). METHODS: The lyophilized C. gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH)2 (10 mM) and magnetically stirred for 6 h. Synthesized TiO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Energy dispersive X-ray spectroscopy (EDX). The synthesised TiO2 NPs were tested against the larvae of R. (B.) microplus and adult of H. bispinosa were exposed to filter paper impregnated method. RESULTS: XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm. The functional groups for synthesized TiO2 NPs were 1 405.19, and 1 053.45 cm(-1) for -NH2 bending, primary amines and amides and 1 053.84 and 1 078.45 cm(-1) for C-O. SEM micrographs of the synthesized TiO2 NPs showed the aggregated and spherical in shape. The maximum efficacy was observed in the aqueous flower extract of C. gigantea and synthesized TiO2 NPs against R. (B.) microplus (LC50=24.63 and 5.43 mg/L and r(2)=0.960 and 0.988) and against H. bispinosa (LC50= 35.22 and 9.15 mg/L and r(2) = 0.969 and 0.969), respectively. CONCLUSIONS: The synthesized TiO2 NPs were highly stable and had significant acaricidal activity against the larvae of R. (B.) microplus and adult of H. bispinosa. This study provides the first report of synthesized TiO2 NPs and possessed excellent anti-parasitic activity.

Larvicidal activity of green synthesized silver nanoparticles using bark aqueous extract of Ficus racemosa against Culex quinquefasciatus and Culex gelidus.

OBJECTIVE: To investigate the larvicidal activity of synthesized silver nanoparticles (Ag NPs) utilizing aqueous bark extract of Ficus racemosa (F. racemosa) was tested against fourth instar larvae of filariasis vector, Culex quinquefasciatus (Cx. quinquefasciatus) and japanese encephalitis vectors, Culex gelidus (Cx. gelidus). METHODS: The synthesized Ag NPs was characterized by UV-vis spectrum, X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The larvicidal activities were assessed for 24 h against the larvae of Cx. quinquefasciatus and Cx. gelidus with varying concentrations of aqueous bark extract of F. racemosa and synthesized Ag NPs. LC(50) and r(2) values were calculated. RESULTS: The maximum efficacy was observed in crude aqueous extract of F. racemosa against the larvae of Cx. quinquefasciatus and Cx. gelidus (LC(50)=67.72 and 63.70 mg/L; r(2)=0.995 and 0.985) and the synthesized Ag NPs (LC(50)=12.00 and 11.21 mg/L; r(2)=0.997 and 0.990), respectively. Synthesized Ag NPs showed the XRD peaks at 2 θ values of 27.61, 29.60, 35.48, 43.48 and 79.68 were identified as (210), (121), (220), (200) and (311) reflections, respectively. The FTIR spectra of Ag NPs exhibited prominent peaks at 3,425, 2,878, 1,627 and 1,382 in the region 500-3,000 cm(-1). The peaks correspond to the presence of a stretching vibration of (NH) C=O group. SEM analysis showed shape in cylindrical, uniform and rod with the average size of 250.60 nm. CONCLUSIONS: The biosynthesis of silver nanoparticles using bark aqueous extract of F. racemosa and its larvicidal activity against the larvae of disease spreading vectors. The maximum larvicidal efficacy was observed in the synthesized Ag NPs.

Novel and simple approach using synthesized nickel nanoparticles to control blood-sucking parasites.

The present study was on assessment of the anti-parasitic activities of nickel nanoparticles (Ni NPs) against the larvae of cattle ticks Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum (a.) anatolicum (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, Culex quinquefasciatus and Culex gelidus (Diptera: Culicidae). The metallic Ni NPs were synthesized by polyol process from Ni-hydrazine as precursor and Tween 80 as both the medium and the stabilizing reagent. The synthesized Ni NPs were characterized by Fourier transform infrared (FTIR) spectroscopy analysis which indicated the presence of Ni NPs. Synthesized Ni NPs showed the X-ray diffraction (XRD) peaks at 42.76°, 53.40°, and 76.44°, identified as 111, 220, and 200 reflections, respectively. Scanning electron microscopy (SEM) analysis of the synthesized Ni NPs clearly showed that the Ni NPs were spherical in shape with an average size of 150 nm. The Ni NPs showed maximum activity against the larvae of R. (B.) microplus, H. a. anatolicum, A. subpictus, C. quinquefasciatus and C. gelidus with LC(50) values of 10.17, 10.81, 4.93, 5.56 and 4.94 mg/L; r(2) values of 0.990, 0.993, 0.992, 0.950 and 0.988 and the efficacy of Ni-hydrazine complexes showed the LC(50) values of 20.35, 22.72, 8.29, 9.69 and 7.83 mg/L; r(2) values of 0.988, 0.986, 0.989, 0.944 and 0.978, respectively. The findings revealed that synthesized Ni NPs possess excellent larvicidal parasitic activity. To the best of our knowledge, this is the first report on larvicidal activity of blood feeding parasites using synthesized Ni NPs.

Eco-friendly approach using marine actinobacteria and its compounds to control ticks and mosquitoes.

Ticks and mosquitoes are ectoparasitic arthropods that can transmit a variety of diseases to humans and animals during blood feeding and causing serious infectious disorders. The purpose of the present study was to assess the acaricidal and insecticidal property of ethyl acetate extract and its compounds isolated from marine actinobacteria, Streptomyces VITSTK7 sp. against the larvae of cattle ticks, Haemaphysalis bispinosa and Rhipicephalus (Boophilus) microplus (Acari: Ixodidae); fourth-instar larvae of malaria vector, Anopheles subpictus; and filarial vector, Culex quinquefasciatus (Diptera: Culicidae). The ethyl acetate extract was loaded on silica gel column and separated with chloroform, methanol, and acetone as the solvents system. The separation of fractions was visualized by the thin layer chromatography (TLC) plate, further confirmed by high-performance liquid chromatography, and followed by gas liquid chromatography. Three major fractions were analyzed in mass spectroscopy (MS) and matched with existing compounds in the data base. Based on the fragment pattern, it led to the major compounds which were predicted as cyclopentanepropanoic acid, 3,5-bis(acetyloxy)-2-[3-(methoxyimino)octyl], methyl ester (13.3 %) 1; 5-azidomethyl-3-(2-ethoxy carbonyl-ethyl)-4-ethoxycarbonylmethyl-1H-pyrrole-2-carboxylic acid, ethyl ester (18.2 %) 2; and akuammilan-16-carboxylic acid, 17-(acetyloxy)-10-methoxy, methyl ester (16R) (53.3 %) 3. The maximum efficacy was observed in compounds 1, 2, and 3, and the ethyl acetate extract of Streptomyces VITSTK7 sp. against the larvae of H. bispinosa (LC(50) = 1,573.36, 1,333.09, 1,073.29, and 409.71 ppm; r(2) = 0.0.990, 0.934, 0.935, and 0.908), R. microplus (LC(50) = 1,877.86, 815.83, 1,631.14, and 441.54 ppm; r(2) = 0.981, 0.926, 0.0970, and 0.915), A. subpictus (LC(50) = 273.89, 687.69, 464.75, and 223.83 ppm; r(2) = 0.758, 0.924, 0.841, and 0.902), and C. quinquefasciatus (LC(50) = 430.06, 881.59, 777.0, and 195.70 ppm; r(2) = 0.839, 0.859, 0.870, and 0.882), respectively. Results of the present study provide evidence that the maximum parasitic activity of ethyl acetate extract and a synergistic effect of combinations of different compounds have been suggested. The control (distilled water) showed nil mortality in the concurrent assay. In the present study, a novel, targeted, simple, and eco-friendly approach has been suggested to control blood-feeding parasites.

Larvicidal activity of isolated compound 5-(2,4-dimethylbenzyl) pyrrolidin-2-one from marine Streptomyces VITSVK5 sp. against Rhipicephalus (Boophilus) microplus, Anopheles stephensi, and Culex tritaeniorhynchus.

The aim of the present study was to assess the larvicidal property of marine actinobacterial compound 5-(2,4-dimethylbenzyl) pyrrolidin-2-one (DMBPO) extracted and isolated from Streptomyces VITSVK5 sp. tested against the larvae of Rhipicephalus (Boophilus) microplus Canestrini (Acari: Ixodidae), Anopheles stephensi Liston, and Culex tritaeniorhynchus Giles (Diptera: Culicidae). The isolate bacteria was taxonomically characterized, identified, and designated as Streptomyces VITSVK5 sp. The crude extract was loaded on silica gel column and eluted with chloroform:methanol. The isolated pure compound was analyzed by thin layer chromatography using chloroform and methanol as the solvent system and confirmed by high-performance liquid chromatography. The structure of the purified compound was established from infrared, ultraviolet, (1)H-nuclear magnetic resonance (NMR), (13)C-NMR, and mass spectral data. The chemical shift assignments obtained for the aliphatic compound from (1)H-NMR corresponding to the molecular formula C(13)H(17)NO. Bioassay-guided fractionation led to the isolation of compound which was identified as DMBPO. In the present study, Streptomyces VITSVK5 sp. crude extract and different fractions were tested against the larvae of parasites at the concentration of 1,000 ppm. Those fractions showing 100% mortality in 24 h alone was selected for further column chromatographic separation. The purified compound, C(13)H(17)NO, was tested in the concentrations of 500, 250, 125, 62.5, and 31.25 ppm and observed the percent larval mortality of 100, 70, 64, 40, and 28 against R. microplus; 100, 79, 63, 36, and 22 against A. stephensi; and 100, 84, 67, 42, and 27 against C. tritaeniorhynchus, respectively. The crude extract showed parasitic effects after 24 h of exposure at 1,000 ppm, and parasite mortality was observed against the larvae of R. microplus (LC(50) = 210.39 ppm, r (2) = 0.873); A. stephensi (LC(50) = 169.38 ppm, r (2) = 0.840); and C. tritaeniorhynchus (LC(50) = 198.75 ppm, r (2) = 0.887). The maximum efficacy was observed in purified marine actinobacterial compound DMBPO with LC(50) and r (2) values against the larvae of R. microplus (84.31 ppm, 0.889); A. stephensi (88.97 ppm, 0.817), and C. tritaeniorhynchus (74.95 ppm, 0.781), respectively. The control (distilled water) showed nil mortality in the concurrent assay.

Evaluation of stem aqueous extract and synthesized silver nanoparticles using Cissus quadrangularis against Hippobosca maculata and Rhipicephalus (Boophilus) microplus.

The present study was to determine the efficacies of anti-parasitic activities of synthesized silver nanoparticles (Ag NPs) using stem aqueous extract of Cissus quadrangularis against the adult of hematophagous fly, Hippobosca maculata (Diptera: Hippoboscidae), and the larvae of cattle tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Contact toxicity method was followed to determine the potential of parasitic activity. Twelve milliliters of stem aqueous extract of C. quadrangularis was treated with 88 ml of 1mM silver nitrate (AgNO(3)) solution at room temperature for 30 min and the resulting solution was yellow-brown color indicating the formation extracellular synthesis of Ag NPs. The synthesized Ag NPs were characterized with UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) spectroscopy. The synthesized Ag NPs were recorded by UV-visible spectrum at 420 nm and XRD patterns showed the nanoparticles crystalline in nature. FTIR analysis confirmed that the bioreduction of Ag((+)) ions to Ag NPs were due to the reduction by capping material of plant extract. FESEM image of Ag NPs showed spherical and oval in shape. By using the Bragg's Law and Scherrer's constant, the average mean size of synthesized Ag NPs was 42.46 nm. The spot EDX analysis showed the complete chemical composition of the synthesized Ag NPs. The mortality obtained by the synthesized Ag NPs from the C. quadrangularis was more effective than the aqueous extract of C. quadrangularis and AgNO(3) solution (1 mM). The adulticidal activity was observed in the aqueous extract, AgNO(3) solution and synthesized Ag NPs against the adult of H. maculata with LC(50) values of 37.08, 40.35 and 6.30 mg/L; LC(90) values of 175.46, 192.17 and 18.14 mg/L and r(2) values of 0.970, 0.992 and 0.969, respectively. The maximum efficacy showed in the aqueous extract, AgNO(3) solution and synthesized Ag NPs against the larvae of R. (B.) microplus with LC(50) values of 50.00, 21.72 and 7.61 mg/L; LC(90) values of 205.12, 82.99 and 22.68 mg/L and r(2) values of 0.968, 0.945 and 0.994, respectively. The present study is the first report on antiparasitic activity of the experimental plant extract and synthesized Ag NPs. This is an ideal eco-friendly and inexpensive approach for the control of H. maculata and R. (B.) microplus.

Antimalarial activities of medicinal plants traditionally used in the villages of Dharmapuri regions of South India.

ETHNOPHARMACOLOGICAL RELEVANCE: An ethnopharmacological investigation of medicinal plants traditionally used to treat diseases associated with fevers in Dharmapuri region of South India was undertaken. Twenty four plants were identified and evaluated for their in vitro activity against Plasmodium falciparum and assessed for cytotoxicity against HeLa cell line. AIM OF THE STUDY: This antimalarial in vitro study was planned to correlate and validate the traditional usage of medicinal plants against malaria. MATERIALS AND METHODS: An ethnobotanical survey was made in Dharmapuri region, Tamil Nadu, India to identify plants used in traditional medicine against fevers. Selected plants were extracted with ethyl acetate and methanol and evaluated for antimalarial activity against erythrocytic stages of chloroquine (CQ)-sensitive 3D7 and CQ-resistant INDO strains of Plasmodium falciparum in culture using the fluorescence-based SYBR Green I assay. Cytotoxicity was determined against HeLa cells using MTT assay. RESULTS: Promising antiplasmodial activity was found in Aegle marmelos [leaf methanol extract (ME) (IC(50)=7 µg/mL] and good activities were found in Lantana camara [leaf ethyl acetate extract (EAE) IC(50)=19 µg/mL], Leucas aspera (flower EAE IC(50)=12.5 µg/mL), Momordica charantia (leaf EAE IC(50)=17.5 µg/mL), Phyllanthus amarus (leaf ME IC(50)=15 µg/mL) and Piper nigrum (seed EAE IC(50)=12.5 µg/mL). The leaf ME of Aegle marmelos which showed the highest activity against Plasmodium falciparum elicited low cytotoxicity (therapeutic index>13). CONCLUSION: These results provide validation for the traditional usage of some medicinal plants against malaria in Dharmapuri region, Tamil Nadu, India.

Evaluation of Catharanthus roseus leaf extract-mediated biosynthesis of titanium dioxide nanoparticles against Hippobosca maculata and Bovicola ovis.

The purpose of the present study was based on assessments of the antiparasitic activities of synthesized titanium dioxide nanoparticles (TiO(2) NPs) utilizing leaf aqueous extract of Catharanthus roseus against the adults of hematophagous fly, Hippobosca maculata Leach (Diptera: Hippoboscidae), and sheep-biting louse, Bovicola ovis Schrank (Phthiraptera: Trichodectidae). The synthesized TiO(2) NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The formation of the TiO(2) NPs synthesized from the XRD spectrum compared with the standard confirmed spectrum of titanium particles formed in the present experiments were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.43°, 36.03°, and 54.32°. The FTIR spectra of TiO(2) NPs exhibited prominent peaks at 714 (Ti-O-O bond), 1,076 (C-N stretch aliphatic amines), 1,172 (C-O stretching vibrations in alcoholic groups), 1,642 (N-H bend bond), and 3,426 (O-H stretching due to alcoholic group). SEM analysis of the synthesized TiO(2) NPs clearly showed the clustered and irregular shapes, mostly aggregated and having the size of 25-110 nm. By Bragg's law and Scherrer's constant, it is proved that the mean size of synthesized TiO(2) NPs was 65 nm. The AFM obviously depicts the formation of the rutile and anatase forms in the TiO(2) NPs and also, the surface morphology of the particles is uneven due to the presence of some of the aggregates and individual particles. Adulticidal parasitic activity was observed in varying concentrations of aqueous leaf extract of C. roseus, TiO(2) solution, and synthesized TiO(2) NPs for 24 h. The maximum parasitic activity was observed in aqueous crude leaf extracts of C. roseus against the adults of H. maculata and B. ovis with LD(50) values of 36.17 and 30.35 mg/L, and r (2) values of 0.948 and 0.908, respectively. The highest efficacy was reported in 5 mM TiO(2) solution against H. maculata and B. ovis (LD(50) = 33.40 and 34.74 mg/L; r (2) = 0.786 and 0.873), respectively, and the maximum activity was observed in the synthesized TiO(2) NPs against H. maculata and B. ovis with LD(50) values of LD(50) = 7.09 and 6.56 mg/L, and r (2) values of 0.880 and 0.913, respectively. This method is considered as an innovative alternative approach to control the hematophagous fly and sheep-biting louse.

Efficacy of plant-mediated synthesized silver nanoparticles against hematophagous parasites.

The purpose of the present study was to investigate the acaricidal and larvicidal activity against the larvae of Haemaphysalis bispinosa Neumann (Acarina: Ixodidae) and larvae of hematophagous fly Hippobosca maculata Leach (Diptera: Hippoboscidae) and against the fourth-instar larvae of malaria vector, Anopheles stephensi Liston, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) of synthesized silver nanoparticles (AgNPs) utilizing aqueous leaf extract from Musa paradisiaca L. (Musaceae). The color of the extract changed to light brown within an hour, and later it changed to dark brown during the 30-min incubation period. AgNPs results were recorded from UV-vis spectrum at 426 nm; Fourier transform infrared (FTIR) analysis confirmed that the bioreduction of Ag(+) ions to silver nanoparticles are due to the reduction by capping material of plant extract, X-ray diffraction (XRD) patterns clearly illustrates that the nanoparticles formed in the present synthesis are crystalline in nature and scanning electron microscopy (SEM) support the biosynthesis and characterization of AgNPs with rod in shape and size of 60-150 nm. After reaction, the XRD pattern of AgNPs showed diffraction peaks at 2θ = 34.37°, 38.01°, 44.17°, 66.34° and 77.29° assigned to the (100), (111), (102), (110) and (120) planes, respectively, of a faced centre cubic (fcc) lattice of silver were obtained. For electron microscopic studies, a 25 µl sample was sputter-coated on copper stub, and the images of nanoparticles were studied using scanning electron microscopy. The spot EDX analysis showed the complete chemical composition of the synthesized AgNPs. The parasite larvae were exposed to varying concentrations of aqueous extract of M. paradisiaca and synthesized AgNPs for 24 h. In the present study, the percent mortality of aqueous extract of M. paradisiaca were 82, 71, 46, 29, 11 and 78, 66, 38, 31and 16 observed in the concentrations of 50, 40, 30, 20, 10 mg/l for 24 h against the larvae of H. bispinosa and Hip. maculata, respectively. The maximum efficacy was observed in the aqueous extract of M. paradisiaca against the H. bispinosa, Hip. maculata, and the larvae of A. stephensi, C. tritaeniorhynchus with LC(50) values of 28.96, 31.02, 26.32, and 20.10 mg/lm, respectively (r (2) = 0.990, 0.968, 0.974, and 0.979, respectively). The synthesized AgNPs of M. paradisiaca showed the LC(50) and r (2) values against H. bispinosa, (1.87 mg/l; 0.963), Hip. maculata (2.02 mg/l; 0.976), and larvae of A. stephensi (1.39; 0.900 mg/l), against C. tritaeniorhynchus (1.63 mg/l; 0.951), respectively. The χ (2) values were significant at p < 0.05 level.

Feeding deterrent activity of synthesized silver nanoparticles using Manilkara zapota leaf extract against the house fly, Musca domestica (Diptera: Muscidae).

With a greater awareness of the hazards associated with the use of synthetic organic insecticides, there has been an urgent need to explore suitable alternative products for pest control. Musca domestica is ubiquitous insect that has the potential to spread a variety of pathogens to humans and livestock. They are mechanical carriers of more than hundred human and animal intestinal diseases and are responsible for protozoan, bacterial, helminthic, and viral infections. The present work aimed to investigate the feeding deterrent activity of synthesized silver nanoparticles (Ag NPs) using leaf aqueous extract of Manilkara zapota against M. domestica. The synthesized Ag NPs were recorded from UV-vis spectrum at 421 nm and scanning electron microscopy confirm the biosynthesis and characterization of Ag NPs with spherical and oval in shape and size of 70-140 nm. The FTIR analysis of the purified nanoparticles showed the presence of bands 1,079, 1,383, 1,627, 2,353, and 2,648 cm(-1), which were complete synthesis of AgNPs; the XRD pattern of AgNPs showed diffraction peaks at 2θ values of 38.06°, 44.37°, 64.51°, and 77.31° sets of lattice planes were observed (111), (200), (220), and (311) facts of silver, respectively. Adult flies were exposed to different concentrations of the aqueous extract of synthesized Ag NPs, 1 mM silver nitrate (AgNO(3)) solution and aqueous extract of M. zapota for 1, 2, and 3 h; however, AgNPs showed 72% mortality in 1 h, 89% mortality was found in 2 h, and 100% mortality was found in 3 h exposure at the concentration of 10 mg/mL and the leaf aqueous extract showed 32% mortality in 1 h, 48% mortality was found in 2 h, and 83% mortality was found in 3 h exposure at concentration of 50 mg/mL. The most efficient activity was observed in synthesized Ag NPs against M. domestica (LD(50) = 3.64 mg/mL; LD(90) = 7.74 mg/mL), the moderate activity reported in the aqueous extract of M. zapota (LD(50) = 28.35 mg/mL; LD(90) = 89.19 mg/mL) and nil activity were observed in AgNO(3) solution at 3 h exposure time at 10 mg/mL. Dimethyl 2, 2-dichlorovinyl phosphate (DDVP) was used as a positive control and showed the LD(50) value of 3.38 mL/L. These results suggest that the synthesized Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of the adult of M. domestica. This method is considered as a new approach to control sanitary pest. Therefore, this study provides first report on the feeding deterrent activity of synthesized Ag NPs against housefly.

Lousicidal activity of synthesized silver nanoparticles using Lawsonia inermis leaf aqueous extract against Pediculus humanus capitis and Bovicola ovis.

In the present work, we describe inexpensive, nontoxic, unreported and simple procedure for synthesis of silver nanoparticles (Ag NPs) using leaf aqueous extract of Lawsonia inermis as eco-friendly reducing and capping agent. The aim of the present study was to assess the lousicidal activity of synthesized Ag NPs against human head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae), and sheep body louse, Bovicola ovis Schrank (Phthiraptera: Trichodectidae). Direct contact method was conducted to determine the potential of pediculocidal activity and impregnated method was used with slight modifications to improve practicality and efficiency of tested materials of synthesized Ag NPs against B. ovis. The synthesized Ag NPs characterized with the UV showing peak at 426 nm. X-ray diffraction (XRD) spectra clearly shows that the diffraction peaks in the pattern indexed as the silver with lattice constants. XRD analysis showed intense peaks at 2θ values of 38.34°, 44.59°, 65.04°, and 77.77° corresponding to (111), (200), (220), and (311) Bragg's reflection based on the fcc structure of Ag NPs. Fourier transform infrared spectroscopy (FTIR) spectra of Ag NPs exhibited prominent peaks at 3,422.13, 2,924.12, 2,851.76, 1,631.41, 1,381.60, 1,087.11, and 789.55 cm(-1). Scanning electron microscopy (SEM) micrograph showed mean size of 59.52 nm and aggregates of spherical shape Ag NPs. Energy dispersive X-ray spectroscopy (EDX) showed the complete chemical composition of the synthesized Ag NPs. In pediculocidal activity, the results showed that the optimal times for measuring percent mortality effects of synthesized Ag NPs were 26, 61, 84, and 100 at 5, 10, 15, and 20 min, respectively. The average percent mortality for synthesized Ag NPs was 33, 84, 91, and 100 at 10, 15, 20, and 35 min, respectively against B. ovis. The maximum activity was observed in the aqueous leaf extract of L. inermis, 1 mM AgNO(3) solution, and synthesized Ag NPs against P. humanus capitis with LC(50) values of 18.26, 7.77, and 1.33 mg l(-1) and r (2) values of 0.863, 0.900, and 0.803 and against B. ovis showed with LC(50) values of 21.19, 8.49, and 1.41 mg l(-1) and r (2) values of 0.920, 0.938 and 0.870, respectively. The findings revealed that synthesized Ag NPs possess excellent anti-lousicidal activity.

Efficacy of adulticidal and larvicidal properties of botanical extracts against Haemaphysalis bispinosa, Hippobosca maculata, and Anopheles subpictus.

The aim of the present study was to investigate the adulticidal and larvicidal activity of dried leaf hexane, ethyl acetate, acetone, and methanol extracts of Nelumbo nucifera, Manilkara zapota, Ipomoea staphylina, and Acalypha indica against the adults of Haemaphysalis bispinosa (Acarina: Ixodidae), hematophagous fly Hippobosca maculata (Diptera: Hippoboscidae), and fourth instar larvae of malaria vector Anopheles subpictus (Diptera: Culicidae). Parasites were exposed to varying concentrations of plant extracts for 24 h. All extracts showed moderate parasitic effects; however, the percent parasitic mortality observed in the crude leaf hexane, ethyl acetate, acetone, and methanol extracts of N. nucifera and M. zapota against H. bispinosa were 80, 74, 72, and 100 and 100, 83, 74, and 91, respectively, and the activity for I. staphylina and A. indica against Hip. maculata were 100, 93, 87, and 66 and 78, 90, 87, and 100 at 2,000 ppm, respectively; the larvicidal activity for the same extracts of I. staphylina against A. subpictus were 76, 82, 84, and 100 at 100 ppm, respectively. The maximum efficacy was observed in the leaf methanol extract of N. nucifera, hexane extract of M. zapota and leaf hexane extract of I. staphylina, and methanol extract of A. indica against the adults of H. bispinosa and Hip. maculata with LC(50) and LC(90) values of 437.14 and 200.81, and 415.14 and 280.72 ppm, 1,927.57 and 703.52 ppm, and 1,647.70 and 829.39 ppm, respectively. The effective larvicidal activity was observed in leaf methanol extract of I. staphylina against A. subpictus with LC(50) and LC(90) values of 10.39 and 37.71 ppm, respectively. Therefore, this study provides the first report on the adulticidal and larvicidal activity of crude solvent extracts. This is an ideal eco-friendly approach for the control of H. bispinosa, Hip. maculata, and the medically important vector A. subpictus.

Acaricidal, pediculocidal and larvicidal activity of synthesized ZnO nanoparticles using wet chemical route against blood feeding parasites.

The present study was based on assessments of the anti-parasitic activities to determine the efficacies of synthesized zinc oxide nanoparticles (ZnO NPs) prepared by wet chemical method using zinc nitrate and sodium hydroxide as precursors and soluble starch as stabilizing agent against the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae); head louse Pediculus humanus capitis, De Geer (Phthiraptera: Pediculidae); larvae of malaria vector, Anopheles subpictus, Grassi; and filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae). R. microplus larvae were exposed to filter paper envelopes impregnated with different ZnO NP concentrations. Direct contact method was conducted to determine the potential of pediculocidal activity. Parasite larvae were exposed to varying concentrations of synthesized ZnO NPs for 24 h. The results suggested that the mortality effects of synthesized ZnO NPs were 43% at 1 h, 64% at 3 h, 78% at 6 h, and 100% after 12 h against R. microplus activity. In pediculocidal activity, the results showed that the optimal times for measuring mortality effects of synthesized ZnO NPs were 38% at 10 min, 71% at 30 min, 83% at 1 h, and 100% after 6 h against P. humanus capitis. One hundred percent lice mortality was observed at 10 mg/L treated for 6 h. The mortality was confirmed after 24 h of observation period. The larval mortality effects of synthesized ZnO NPs were 37%, 72%, 100% and 43%, 78% and 100% at 6, 12, and 24 h against A. subpictus and C. quinquefasciatus, respectively. It is apparent that the small size and corresponding large specific surface area of small nanometer-scale ZnO particles impose several effects that govern its parasitic action, which are size dependent. ZnO NPs were synthesized by wet chemical process, and it was characterized with the UV showing peak at 361 nm. X-ray diffraction (XRD) spectra clearly shows that the diffraction peaks in the pattern indexed as the zinc oxide with lattice constants a = 3.249 and c = 5.206 Å. The FTIR spectrum showed the range of 400-4,000 cm(-1). The band at 899.56 cm(-1); 1,151.87 cm(-1); 1,396 cm(-1); and these bands showed the complete composition of ZnO NPs. SEM micrograph showed 60-120-nm size and aggregates of spherical shape nanoparticles. EDX showed the complete chemical composition of the synthesized nanoparticles of zinc oxide. The maximum efficacy was observed in zinc oxide against the R. microplus, P. humanus capitis, and the larvae of A. subpictus, C. quinquefasciatus with LC(50) values of 29.14, 11.80, 11.14, and 12.39 mg/L; r (2) = 0.805, 0.876, 0.894, and 0.904, respectively. The synthesized ZnO NPs showed the LC(50) and r (2) values against the R. microplus (13.41 mg/L; 0.982), P. humanus capitis (11.80 mg/L; 0.966), and the larvae of A. subpictus (3.19; 0.945 mg/L), against C. quinquefasciatus (4.87 mg/L; 0.970), respectively. The control (distilled water) showed nil mortality in the concurrent assay. This is the first report on anti-parasitic activity of the synthesized ZnO NPs.