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Nanosized materials have been an important subject in basic and applied sciences. A novel, low-cost, green and reproducible bacteria, Aeromonas hydrophila mediated biosynthesis of titanium dioxide nanoparticles (TiO2 NPs) was reported. The resulting nanoparticles were characterized by FTIR, XRD, AFM and FESEM with EDX. FTIR showed characteristic bands (1643 and 3430 cm−1) finds the role of carboxyl group O H stretching amine N H stretch in the formation of TiO2 NPs. The XRD spectrum confirmed that the synthesized TiO2 NPs were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.47°, 31.77°, 36.11°, 41.25°, 54.39°, 56.64° and 69.54° were identified as 110, 100, 101, 111, 211, 220 and 301 reflections, respectively. The crystallite sizes were calculated using Scherrer’s formula applied to the major intense peaks and found to be the size of 40.50 nm. The morphological characterization was analyzed by FESEM and the analysis showed the NPs smooth shaped, spherical and uneven. GC–MS analysis showed the main compounds found in A. hydrophila were uric acid (2.95%), glycyl- l -glutamic acid (6.90%), glycyl- l -proline (74.41%) and l-Leucyl-d-leucine (15.74%). The potential glycyl- l -proline could have played an important role as a capping agent. A possible mechanism for the biosynthesis of TiO2 NPs has been proposed. The antibacterial activity of the synthesized TiO2 NPs was assessed by well diffusion method toward A. hydrophila, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis and showed effective inhibitory activity against S. aureus (33 mm) and S. pyogenes (31 mm).

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 1 1 1, 2 2 0, and 2 0 0 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 LC50 values of 10.17, 10.81, 4.93, 5.56 and 4.94 mg/L; r2 values of 0.990, 0.993, 0.992, 0.950 and 0.988 and the efficacy of Ni-hydrazine complexes showed the LC50 values of 20.35, 22.72, 8.29, 9.69 and 7.83 mg/L; r2 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.

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.

Objective The present study was to evaluate the antibacterial properties of 21 crude extracts from leaf and flower of Aristolochia indica (A. indica), Cassia angustifolia (C. angustifolia) , leaf of Catharanthus roseus (C. roseus), Diospyros melanoxylon (D. melanoxylon), Dolichos biflorus (D. biflorus), Gymnema sylvestre (G. sylvestre ) and Justicia procumbens (J. procumbens). Methods The ethyl acetate, acetone and methanol extract of medicinal plants were evaluated against Gram-positive Bacillus cereus (B. cereus) and Gram-negative bacteria Aeromonas hydrophila (A. hydrophila), Enterobacter aerogenes (E. aerogenes), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) by using well diffusion assay and minimum inhibitory concentration (MIC). Results The crude plant extracts demonstrated broad spectrum activity against all bacteria. The highest inhibitory zone was observed in leaf methanol extract of A. indica against E. aerogenes (25 mm), and E. coli (20 mm), flower methanol extract of C. angustifolia against B. cereus (22 mm) and leaf acetone extract of G. sylvestre against B. cereus (22mm). The MIC values of leaf methanol extract of A. indica against K. pneumonia (22.6μg/ml), and flower extract showed against E. coli (MIC: 24.2μg/ml), leaf ethyl acetate extract of C. angustifolia against K. pneumoniae (MIC: 28.4μg/ml). Acetone ethyl acetate and methanol extracts of D. melanoxylon and D. biflorus showed the lowest MIC activity value of >30 μg/ml against all tested pathogens. Conclusion The antibacterial activity could be confirmed in most species used in traditional medicine in South India. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.

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.

The present study describes a novel green synthesis of silver nanoparticles by using Aristolochia indica leaf extract. The green synthesized silver nanoparticles had been confirmed by UV-Vis spectrum and Scanning electron microscope (SEM) analysis. Based on the findings, it seems very reasonable to believe that this greener way of synthesizing silver nanoparticles is an environmentally viable technique. Introduction The Ag NPs were reported to possess anti-bacterial (Sathishkumar et al., 2009), antiviral (Rogers et al., 2008), anti-fungal activities (Panacek et al., 2009). Synthesis of nanoparticles using plants or microorganisms can potentially eliminate this problem by making the nanoparticles more bio-compatible. Indeed, over the past several years, plants, algae, fungi, bacteria, and viruses have been used for low-cost, energy-efficient, and non-toxic production of metallic nanoparticles (Thakkar et al., 2009). Aristolochia indica commonly known as Eeswara mooligai, has been used as a traditional medicine to treat on the sting of scorpion or centipede and on insect bites. The hexane, ethyl acetate and methanol extracts of Aristolochia indica were found to possess adulticidal, repellent and larvicidal activities against adult and early fourth-instar larvae of Culex gelidus and Culex quinquefasciatus (Kamaraj et al., 2010), and the bio insecticidal effects of methanol extract of Aristolochia baetica showed larval growth inhibition against Tribolium castaneum (Jbilou et al. 2008). The recent reports include the synthesis of nanoparticles using medicinal plants (Mukunthan and Elumalai 2011). This stands as a great application in the field of nano-medicine. Medicinal property of the extract and nano-silver could play vital role in treatment of many diseases. Materials and methods Plants and Chemicals Aristolochia indica L. (Aristolochiaceae) leaves were collected from Malaiyur Hills, Dharmapuri district. Tamil Nadu, South India, in June 2011.The taxonomic identification was made by Dr. C. Hema, Department of Botany, Arignar Anna Government Arts College for Women, Walajapet, Vellore, India. The voucher specimen (ZD/AB/K127) was deposited in our research laboratory for further reference. Silver nitrate (AgNO3, analytical grade) was purchased from Sigma-Aldrich, USA (99.9% pure). Synthesis of Ag NPs by Aristolochia indica leaf extract Aristolochia indica leaves were washed thoroughly in tap water for 10 min in order to remove the dust particles and rinsed briefly in deionized water. The plant leaf broth solution was prepared by taking 10 g of washed and finely cut leaves in a 250 mL Erlenmeyer flask along with 100 mL of deionized water and then boiling the mixture at 60◦C for 5min. After boiling, the solution was decanted, and 15mL of this broth was added to 85mL of 3mM aqueous AgNO3 solution and the resulting solution became brown in colour. This extract was filtered through nylon mesh (spectrum), followed by Millipore hydrophilic filter (0.22μm) and used for further experiments (Parashar et al., 2009). A control setup was also maintained without Aristolochia indica extract and colour intensity of the extracts was measured at 420 nm at different intervals (5, 10, 15, 20, 25 and 30 min). Results UV-vis spectra The aqueous AgNO3 solution turned into yellowish brown colour within 1 h of the addition of leaf aqueous extract of A. indica and is shown in (Fig. 1) Intensity of brown colour increased in direct proportion to the incubation period. It was due to the excitation of surface plasmon resonance (SPR) effect and reduction of AgNO3. The silver SPR was observed at 420 nm which steadily increases in intensity as a function of time of reaction (ranging from 5 to 30 min) without showing any shift of the wavelength. Scanning electron microscope (SEM) analysis SEM determinations of the sample (AgNO3) showed the formation of nanoparticles, which were confirmed to be of silver by SEM. SEM analyses of the synthesized Ag NPs were clearly distinguishable which measured an average size of 112.35 nm (Figs. 2 a and b). The asymmetrical dispersed nanoparticles and mostly aggregated infrequently free crystals structures. Discussion The aqueous AgNO3 solution turned into yellowish brown colour within 1 hj with the addition of leaf extract of Aristolochia indica The silver SPR was observed at 420 nm which steadily increased in intensity as a function of time of reaction (ranging from 5 to 30 min) without showing any shift of the wavelength maximum. In UV spectral analysis, the generation of colour was due to excitation of surface plasmon in metal nanoparticles (Mulvaney, 1996). Mukherjee et al. (2008) have reported that the reduction process of Ag+ to Ag NPs occurs possibly in the presence of enzyme NADPH-dependent dehydrogenase. The exact route in which the electrons are shuttled is a matter of investigation. The information regarding environment responsible for high stability of metal nanoparticles is not comprehensively available. These sharp

Objective To assess the acaricidal activity of titanium dioxide nanoparticles (TiO 2 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 TiO 2 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 TiO 2 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 TiO 2 NPs were 1 405.19, and 1 053.45 cm −1 for -NH 2 bending, primary amines and amides and 1 053.84 and 1 078.45 cm −1 for C-O. SEM micrographs of the synthesized TiO 2 NPs showed the aggregated and spherical in shape. The maximum efficacy was observed in the aqueous flower extract of C. gigantea and synthesized TiO 2 NPs against R. (B.) microplus (LC 50 =24.63 and 5.43 mg/L and r 2 =0.960 and 0.988) and against H. bispinosa (LC 50 = 35.22 and 9.15 mg/L and r 2 = 0.969 and 0.969), respectively. Conclusions The synthesized TiO 2 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 TiO 2 NPs and possessed excellent anti-parasitic activity.