[Show abstract][Hide abstract] ABSTRACT: Development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug discovery to develop new, more effective, affordable and accessible anti-malarial agents.
Inspired by their ethnobotanical reputation for being effective against febrile diseases, antiplasmodial potential of ethyl acetate extracts (EAE) and methanol extracts (ME) of 17 medicinal plants collected from the Eastern Ghats of South India and Buchpora, North India were explored against Plasmodium falciparum in vitro using the SYBR Green assay. The results were validated both by confirmation that the fall in fluorescence signal was not due to quenching effects mediated by phytochemical extracts and by Giemsa-stained microscopy.
Using EAE or ME, promising antiplasmodial activity (IC50 Pf3D7 ≤ 20 μg/ml), was seen in Aerva lanata (Whole aerial parts-EAE), Anisomeles malabarica (Leaf-EAE), Anogeissus latifolia (bark-EAE), Cassia alata (leaves-EAE), Glycyrrhiza glabra (root-EAE), Juglans regia (seed-ME), Psidium guajava (leaf-ME and EAE) and Solanum xanthocarpum (Whole aerial parts-EAE). EAEs from leaves of Couroupita guianensis, Euphorbia hirta, Pergularia daemia, Tinospora cordifolia and Tridax procumbens as also ME from Ricinus communis (leaf and seed) showed good antiplasmodial activity (Pf 3D7 IC50 21 - 40 μg/ml). Moderate activity (Pf 3D7 IC50: 40-60 μg/mL) was shown by the leaf EAEs of Cardiospermum halicacabum, Indigofera tinctoria and Ricinus communis while the remaining extracts showed marginal (Pf 3D7 IC50 60 to >100 μg/ml) activities. The promising extracts showed good resistance indices (0.41 - 1.4) against the chloroquine resistant INDO strain of P. falciparum and good selectivity indices (3 to > 22.2) when tested against the HeLa cell line.
These results provide validity to the traditional medicinal usage of some of these plants and further make a case for activity-guided purification of new pharmacophores against malaria.
[Show abstract][Hide abstract] ABSTRACT: Malaria is an overwhelming impact in the poorest countries in the world due to their prevalence, virulence and drug resistance ability. Currently, there is inadequate armoury of drugs for the treatment of malaria. This underscores the continuing need for the discovery and development of new effective and safe antimalarial drugs. To evaluate the in vitro and in vivo antimalarial activity of the leaf ethyl acetate extract of Murraya koenigii, bioassay-guided chromatographic fractionation was employed for the isolation and purification of antimalarial compounds. The in vitro antimalarial activity was assayed by the erythrocytic stages of chloroquine-sensitive strain of Plasmodium falciparum (3D7) in culture using the fluorescence-based SYBR Green I assay. The in vivo assay was done by administering mice infected with Plasmodium berghei (NK65) four consecutive daily doses of the extracts through oral route following Peter’s 4-day curative standard test. The percentage suppression of parasitaemia was calculated for each dose level by comparing the parasitaemia in untreated control with those of treated mice. Cytotoxicity was determined against HeLa cells using MTT assay. Histopathology was studied in kidney, liver and spleen of isolated compound-treated Swiss albino mice. The leaf crude ethyl acetate extract of M. koenigii showed good in vitro antiplasmodial activity against P. falciparum. The in vivo test of the leaf crude ethyl acetate extract (600 mg/kg) showed reduced malaria parasitaemia by 86.6 % against P. berghei in mice. Bioassay-guided fractionation of the leaf ethyl acetate extract of M. koenigii led to the isolation of two purified fractions C3B2 (2.84 g) and C3B4 (1.97 g). The purified fractions C3B2 and C3B4 were found to be active with IC50 values of 10.5 ± 0.8 and 8.25 ± 0.2 μg/mL against P. falciparum, and in vivo activity significantly reduced parasitaemia by 82.6 and 88.2 % at 100 mg/kg/body weight on day 4 against P. berghei, respectively. The isolated fractions C3B2 and C3B4 were monitored by thin-layer chromatography until a single spot was obtained with R
f values of 0.36 and 0.52, respectively. The pure compounds obtained in the present investigation were subjected to UV–visible spectroscopy, Fourier transformer infrared spectroscopy, 1D and 2D 1H-Nuclear magnetic resonance (NMR), 13C NMR, DEPT, COSY and Mass spectral analysis. Based on the spectral analysis, it is concluded that the isolated compounds were myristic acid (C3B2) and β-caryophyllene (C3B4). The cytotoxic effect of myristic acid and β-caryophyllene showed the TC50 values of >100 and 80.5 μg/mL, respectively against HeLa cell line. The histopathology study showed that protection against nephrotoxicity of kidney, hepatic damage of liver and splenocytes protection in spleen was achieved with the highest dose tested at 100 mg/kg/body weight. The present study provides evidence of antiplasmodial compounds from M. koenigii and is reported for the first time.
Full-text · Article · Mar 2014 · Parasitology Research
[Show abstract][Hide abstract] ABSTRACT: Silver nanoparticles (Ag NPs) were synthesized by using aqueous leaves extracts of Euphorbia prostrata as a simple, non-toxic and ecofriendly green material. The present study was based on assessments of the pesticidal activity to determine the efficacies of aqueous leaves extracts of E. prostrata, silver nitrate (AgNO 3) solution (1mM) and synthesized Ag NPs against the adult of Sitophilus oryzae L. The synthesized nanoparticles were characterized with UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM) analysis. The nanoparticles were rod in shape and size of 25-80nm with an average size of 52.4 nm. Pesticidal bioassay tests were conducted at varying concentrations for 14 days. The LD 50 values of aqueous extract, AgNO 3 solution and synthesized Ag NPs were 213.32, 247.90, 44.69 mg/kg -1 ; LD 90 =1648.08, 2675.13, 168.28 mg/kg -1 , respectively. These results suggest that the leaves aqueous extracts of E. prostrata, and synthesized Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of the S. oryzae. This is the first report on the pesticidal activity of the plant extracts and synthesized nanoparticles.
Full-text · Article · Mar 2014 · Journal of Biopesticides
[Show abstract][Hide abstract] ABSTRACT: Titanium dioxide nanoparticles (TiO2 NPs) are widely used in paints, printing ink, rubber, paper, cosmetics, sunscreens, car materials, cleaning air products, industrial photocatalytic processes, and decomposing organic matters in wastewater due to their unique physical, chemical, and biological properties. The present study was conducted to assess the antiparasitic efficacies of synthesized TiO2 NPs utilizing leaf aqueous extract of Solanum trilobatum against the adult head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae); larvae of cattle tick Hyalomma anatolicum (a.) anatolicum Koch (Acari: Ixodidae), and fourth instar larvae of malaria vector Anopheles subpictus Grassi (Diptera: Culicidae). The green synthesized TiO2 NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), and Atomic force microscopy (AFM). XRD analysis of synthesized TiO2 NPs revealed that the particles were in the form of nanocrystals as evidenced by the major peaks at 2θ values of 27.52°, 36.21°, and 54.43° identified as 110, 101, and 211 reflections, respectively. FTIR spectra exhibited a prominent peak at 3,466 cm−1 and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. SEM images displayed NPs that were spherical, oval in shape, individual, and some in aggregates with an average size of 70 nm. Characterization of the synthesized TiO2 NPs using AFM offered a three-dimensional visualization and uneven surface morphology. The pediculocidal and acaricidal activities of synthesized TiO2 NPs showed the percent mortality of 31, 42, 63, 82, 100; 36, 44, 67, 89, and 100 at 2, 4, 6, 8, and 10 mg/L, respectively, against P. h. capitis and H. a. anatolicum. The average larval percent mortality of synthesized TiO2 NPs was 38, 47, 66, 79, and 100 at 1, 2, 3, 4, and 5 mg/L, respectively, against A. subpictus. The maximum activity was observed in the aqueous leaf extract of S. trilobatum, TiO(OH)2 solutions (bulk), and synthesized TiO2 NPs with LC50 values of 35.14, 25.85, and 4.34 mg/L; 47.15, 29.78, and 4.11 mg/L; and 28.80, 24.01, and 1.94 mg/L, and r
2 values of 0.982, 0.991, and 0.992; 0.947, 0.987, and 0.997; and 0.965, 0.998 and 0.985, respectively, against P. h. capitis, H. a. anatolicum, and A. subpictus. This study provides the first report on the pediculocidal, acaricidal, and larvicidal activity of synthesized TiO2 NPs. This is an ideal eco-friendly, novel, low-cost, and simple approach to satisfy the requirement of large-scale industrial production bearing the advantage for the control of P. h. capitis, H. a. anatolicum, and A. subpictus.
Full-text · Article · Nov 2013 · Parasitology Research
[Show abstract][Hide abstract] ABSTRACT: Malaria caused by the protozoan parasite Plasmodium falciparum, is a major health problem of the developing world. In the present study medicinal plants from Eastern Ghats of South India have been extracted with ethyl acetate and assayed for growth inhibition of asexual erythrocytic stages of chloroquine (CQ)-sensitive (3D7) and (CQ)-resistant (INDO) strains of P. falciparum in culture using the fluorescence-based SYBR Green I assay. Studied extracts showed a spectrum of antiplasmodial activities ranging from (a) very good (IC(50)<10-10μg/mL: Cyperus rotundus and Zingiber officinale); (b) good (IC(50), >10-15μg/mL: Ficus religiosa and Murraya koenigii); (c) moderate (IC(50)>15-25μg/mL: Ficus benghalensis); (d) poor activity (IC(50)>25-60μg/mL) and (e) inactive (IC(50)>60μg/mL). Resistance indices ranging from 0.78 to 1.28 suggest that some of these extracts had equal promise against the CQ resistant INDO strain of P. falciparum. Cytotoxicity assessment of the extracts against HeLa cell line using MTT assay revealed that the selectivity indices in the range of 3-15 suggesting a good margin of safety.
Full-text · Article · Feb 2013 · Experimental Parasitology
[Show abstract][Hide abstract] ABSTRACT: 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 150nm. 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 4.94mg/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 7.83mg/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.
[Show abstract][Hide abstract] ABSTRACT: Infections due to protozoa of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The aim of this study was to evaluate the in vitro antileishmanial activity of the acetone and methanol leaf extracts of Anisomeles malabarica, flower of Gloriosa superba, leaf of Ocimum basilicum, leaf and seed of Ricinus communis against promastigotes form of Leishmania donovani. Antiparasitic evaluations of different plant crude extracts were performed on 96 well plates at 37°C for 24-48h. Out of the 10 experimental plant extracts tested, the leaf methanol extracts of A. malabarica, and R. communis showed good antileishmanial activity (IC(50)=126±19.70 and 184±39.33μg/mL), respectively against promastigotes. Effective antileishmanial activity was observed making these plants as good candidates for isolation of antiprotozoal compounds which could serve as new lead structures for drug development.
[Show abstract][Hide abstract] ABSTRACT: 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 88ml of 1mM silver nitrate (AgNO(3)) solution at room temperature for 30min 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 420nm 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 42.46nm. 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 (1mM). 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 6.30mg/L; LC(90) values of 175.46, 192.17 and 18.14mg/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 7.61mg/L; LC(90) values of 205.12, 82.99 and 22.68mg/L and r(2) values of 0.968, 0.945and 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.
No preview · Article · Jun 2012 · Experimental Parasitology
[Show abstract][Hide abstract] ABSTRACT: In the present study, the biosynthesis of TiO2 nanoparticles (TiO2 NPs) was achieved by a novel, biodegradable and convenient procedure using Aspergillus flavus as a reducing and capping agent. Research on new, simple, rapid, eco-friendly and cheaper methods has been initiated. TiO2 NPs were characterized by FTIR, XRD, AFM, SEM and TEM studies. The X-ray diffraction showed the presence of increased amount of TiO2 NPs which can state by the presence of peaks at rutile peaks at 1 0 0, 0 0 2, 1 0 0 and anatase forms at 1 0 1 respectively. SEM observations revealed that synthesized TiO2 NPs were spherical, oval in shape; individual nanoparticles as well as a few aggregate having the size of 62–74 nm. AFM shows crystallization temperature was seen on the roughness of the surface of TiO2. The Minimum inhibitory concentration value for the synthesized TiO2 NPs was found to be 40 μg ml−1 for Escherichia coli, which was corresponding to the value of well diffusion test. This is the first report on antimicrobial activity of fungus-mediated synthesized TiO2 NPs, which was proved to be a good novel antibacterial material.
No preview · Article · Jun 2012 · Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy
[Show abstract][Hide abstract] ABSTRACT: 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.
This antimalarial in vitro study was planned to correlate and validate the traditional usage of medicinal plants against malaria.
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.
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).
These results provide validation for the traditional usage of some medicinal plants against malaria in Dharmapuri region, Tamil Nadu, India.
Full-text · Article · Mar 2012 · Journal of ethnopharmacology
[Show abstract][Hide abstract] ABSTRACT: a b s t r a c t The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environment friendly termite control agents. Screening for anti-termitic activity of plant extracts with some known medicinal attributes could lead to the discovery of new agents for termite con-trol. The aim of this study was to investigate the anti-termitic activity of crude leaf hexane, ethyl acetate, acetone and methanol extracts of Andrographis lineata Wallich ex Nees. (Acanthaceae), Andrographis paniculata (Burm.f.) Wall. ex Nees. (Acanthaceae), Argemone mexicana L. (Papaveraceae), Aristolochia bracteolata Lam. (Aristolochiaceae), Datura metel L. (Solanaceae), Eclipta prostrata L. (Asteraceae), Sesbania grandiflora (L.) Pers. (Fibaceae) and Tagetes erecta L. (Compositae) against C. formosanus. An impregnated filter paper no-choice bioassay method was followed. All the crude extracts showed anti-termitic activ-ity in a dose-dependent manner and exhibited a significant activity after 24 h and 48 h of exposure; the highest termite mortality was found in leaf hexane extract of A. bracteolata, ethyl acetate extract of A. paniculata, D. metel, E. prostrata, methanol extract of A. lineata and D. metel after 24 h (LD 50 = 363, 371, 298, 292, 358 and 317 ppm; LD 90 = 1433, 1659, 1308, 1538, 1703 and 1469 ppm), respectively. The hexane extract of T. erecta, acetone extract of A. mexicana, methanol extract of S. grandiflora and T. erecta showed activity after 48 h (LD 50 = 245, 253, 289, 409 ppm; LD 90 = 1378, 1511, 1508 and 2425 ppm), respectively. Among the natural products tested, may provide a renewable source of safe natural wood preservatives. These findings corroborate traditional insecticidal application of selected plants and the results can be extended for the control of termites. The primary objective of the present study was to identify novel, natural chemotypes from biologically active crude plant extracts that may be useful as part of termite treatment regimens in their natural form or as synthons for structure–activity studies in the future. The results reported here open the possibility of further investigations of efficacy on their anti-termitic properties of natural product extracts.
No preview · Article · Mar 2012 · Industrial Crops and Products
[Show abstract][Hide abstract] ABSTRACT: The present study was based on assessments of the antiparasitic activity to determine the efficacies of hexane, chloroform, ethyl acetate, acetone, methanol and aqueous leaf extracts of Euphorbia prostrata Ait. (Euphorbiaceae) and synthesised Ag nanoparticles (NPs) using aqueous leaf extract against the adult cattle tick Haemaphysalis bispinosa Neumann (Acarina: Ixodidae) and the haematophagous fly Hippobosca maculata Leach (Diptera: Hippoboscidae). Synthesised Ag NPs were characterised with ultraviolet-vis (UV-vis) spectrum, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) support the biosynthesis of Ag NPs. Parasites were exposed to varying concentrations of plant extracts and synthesised silver NPs for 24 h. All extracts showed the maximum toxic effect on parasites; however, the highest mortality was found in the hexane, chloroform, ethyl acetate, acetone, methanol and aqueous leaf extracts of E. prostrata and synthesised Ag NPs against the adult of H. bispinosa (LC(50)=45.24, 40.07, 21.91, 25.32, 19.30, 10.16 and 2.30 ppm; LC(90)=86.95, 88.66, 70.92, 83.22, 48.28, 70.27 and 8.28 ppm) and against H. maculata (LC(50)=39.37, 41.98, 19.92, 27. 93, 21.97, 9.79 and 2.55 ppm; LC(90)=89.44, 98.52, 76.59, 90.18, 55.07, 54.35 and 9.03 ppm), respectively. Mortality of 100% was found in synthesised Ag NPs at a concentration of 10 mg l(-1). UV-vis spectrograph of the colloidal solution of Ag NPs has been recorded as a function of time. The absorption spectrum of E. prostrata leaf extracts at different wavelengths ranging from 300 to 600 nm revealed a peak at 420 nm after 6 h. The FTIR spectra of Ag NPs exhibited prominent peaks at 3431; 1616; 1381; 1045; 818; 509; and 420 cm(-1). SEM analyses of the synthesised Ag NPs were rod shaped and measured 25-80 nm with an average size of 52.4 nm. The chemical composition of aqueous leaf extract was analysed by gas chromatography-mass spectrometry (GC-MS). The major chemical constituent was identified as 2-phenylethanol. These results suggest that the leaf methanol, aqueous extracts of E. prostrata and green synthesis of Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of H. bispinosa and H. maculata. In addition, toxicity tests were conducted to analyse the toxicological effects of particle size on Daphnia magna and Ceriodaphnia dubia, and the animal model test was evaluated against Bos indicus for 24-h treatment. No toxicity on daphnids and no adverse effects were noted on animals after exposure to solvent extracts and synthesised Ag NPs.
No preview · Article · Feb 2012 · Veterinary Parasitology
[Show abstract][Hide abstract] ABSTRACT: Mosquitoes have developed resistance to various synthetic insecticides, making its control increasingly difficult. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The aim of this study was to evaluate the adult emergence inhibition (EI) and adulticidal activity of the leaf hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wall. ex Nees., Cocculus hirsutus L. Diels, Eclipta prostrata L. and Tagetes erecta L. were tested against japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). All plant extracts showed moderate EI and adulticidal activity effects after 24h of exposure at 1,000ppm; however, the highest EI activity was found in leaf methanol extracts of A. marmelos, A. paniculata,T. erecta, and chloroform extract of E. prostrata (EI50=141.94, 214.17, 166.43, and 184.58ppm; EI90=590.26, 882.34, 532.00 and 571.81ppm); and the effective adulticidal activity was observed in acetone extract of A.marmelos, hexane of A.lineata, ethlyl acetate of A.paniculata, methanol extracts of C.hirsutus, E.prostrata, and T.erecta (LD50=139.05, 251.24, 205.06, 222.10, 166.73, and 232.74ppm; LD90=426.19, 837.09, 813.59, 794.42, 579.43 and 807.41ppm), respectively against C. tritaeniorhynchus. These results suggest that the leaf methanol extract of C. hirsutus, E. prostrata, and T. erecta have the potential to be used as an ideal eco-friendly approach for the control of the C. tritaeniorhynchus. Therefore, this study provides first report on the mosquito EI and adulticidal activity of plant extracts against a vector.
Full-text · Article · Jan 2012 · Journal of King Saud University - Science
[Show abstract][Hide abstract] ABSTRACT: In the present study, the biosynthesis of TiO(2) nanoparticles (TiO(2) NPs) was achieved by a novel, biodegradable and convenient procedure using Aspergillus flavus as a reducing and capping agent. Research on new, simple, rapid, eco-friendly and cheaper methods has been initiated. TiO(2) NPs were characterized by FTIR, XRD, AFM, SEM and TEM studies. The X-ray diffraction showed the presence of increased amount of TiO(2) NPs which can state by the presence of peaks at rutile peaks at 100, 002, 100 and anatase forms at 101 respectively. SEM observations revealed that synthesized TiO(2) NPs were spherical, oval in shape; individual nanoparticles as well as a few aggregate having the size of 62-74 nm. AFM shows crystallization temperature was seen on the roughness of the surface of TiO(2). The Minimum inhibitory concentration value for the synthesized TiO(2) NPs was found to be 40 μg ml(-1) for Escherichia coli, which was corresponding to the value of well diffusion test. This is the first report on antimicrobial activity of fungus-mediated synthesized TiO(2) NPs, which was proved to be a good novel antibacterial material.
No preview · Article · Jan 2012 · Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy
[Show abstract][Hide abstract] ABSTRACT: 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.
No preview · Article · Oct 2011 · Parasitology Research
[Show abstract][Hide abstract] ABSTRACT: 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, 1H-nuclear magnetic resonance (NMR), 13C-NMR, and mass spectral data. The chemical shift assignments obtained for the aliphatic compound from 1H-NMR corresponding to the molecular formula C13H17NO. 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, C13H17NO, 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 (LC50 = 210.39 ppm, r
2 = 0.873); A. stephensi (LC50 = 169.38 ppm, r
2 = 0.840); and C. tritaeniorhynchus (LC50 = 198.75 ppm, r
2 = 0.887). The maximum efficacy was observed in purified marine actinobacterial compound DMBPO with LC50 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.
Full-text · Article · Oct 2011 · Parasitology Research