Chinnaperumal Kamaraj

Fungus-mediated biosynthesis and characterization of TiO2 nanoparticles and their activity against pathogenic bacteria

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.

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.

Adulticidal and larvicidal efficacy of some medicinal plant extracts against tick, fluke and mosquitoes

The adulticidal and larvicidal effect of indigenous plant extracts were investigated against the adult cattle tick Haemaphysalis bispinosa Neumann, 1897 (Acarina: Ixodidae), sheep fluke Paramphistomum cervi Zeder, 1790 (Digenea: Paramphistomatidae), fourth instar larvae of malaria vector, Anopheles subpictus Grassi and Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). The aim of this study was to evaluate the toxic effect of leaf hexane, chloroform, ethyl acetate, acetone and methanol extracts of Annona squamosa L., Centella asiatica (L.) Urban, Gloriosa superba L., Mukia maderaspatensis (L.) M.Roem, Pergularia daemia (Forsk.) Chiov. and Phyllanthus emblica L. were exposed to different concentrations. All plant extracts showed moderate toxic effect on parasites after 24h of exposure; however, the highest mortality was found in leaf hexane extract of A. squamosa, methanol extracts of G. superba and P. emblica against H. bispinosa (LC(50)=145.39, 225.57 and 256.08ppm); methanol extracts of C. asiatica, G. superba, P. daemia and P. emblica against P. cervi (LC(50)=77.61, 60.16, 59.61, and 60.60ppm); acetone, ethyl acetate extracts of A. squamosa, methanol extract of C. asiatica, acetone extracts of G. superba, ethyl acetate, hexane and methanol extracts of P. daemia against A. subpictus (LC(50)=17.48, 18.60, 26.62, 18.43, 34.06, 13.63, and 50.39ppm); and chloroform, ethyl acetate extracts of A. squamosa, ethyl acetate extract of P. daemia, ethyl acetate and methanol extracts of P. emblica against C. tritaeniorhynchus (LC(50)=63.81, 60.01, 31.94, 69.09, and 54.82ppm), respectively. These results demonstrate that methanol extracts of C. asiatica, G. superba, P. daemia and P. emblica extracts may serve as parasites control even in their crude form.

Efficacy of anthelmintic properties of medicinal plant extracts against Haemonchus contortus

The development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. Among these alternatives are several medicinal plants traditionally used as anthelmintics. This present work evaluated the efficacy of ethyl acetate, acetone, and methanol dried leaf and seed extracts of five medicinal plants were tested in vitro ovicidal and larvicidal activities on Haemonchus contortus. The in vitro assay was based on egg hatch assay (EHA) and larval development assay (LDA), all plant extracts were evaluated at five concentrations 50, 25, 12.5, 6.25 and 3.13 mg/ml. The leaf and seed ethyl acetate, acetone and methanol of Annona squamosa, Eclipta prostrata, Solanum torvum, Terminalia chebula, and Catharanthus roseus extracts were showed complete inhibition (100%) at the maximum concentration tested (50 mg/ml). The overall findings of the present study have shown that our experimental plant extracts contain possible anthelmintic compounds.

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 Braggs Law and Scherrers 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.

Anthelmintic activity of botanical extracts against sheep gastrointestinal nematodes, Haemonchus contortus

The source of chemical anthelmintics (levamisole, flubendazole, and thiabendazole) had limited the success of gastrointestinal nematodiasis control in sheep and goats and thus awakened interest in the study of medicinal plant extracts as alternative sources of anthelmintics. The egg hatching and larvicidal effect of indigenous plant extracts were investigated against the sheep parasite, Haemonchus contortus. The purpose of the present study was to assess the efficacy of leaf, bark, and seed ethyl acetate, acetone and methanol extracts of Andrographis paniculata (Burm.f.) Wall. ex Nees., Anisomeles malabarica (L.) R. Br., Annona squamosa L., Datura metel L., and Solanum torvum Swartz were tested against the parasitic nematode of small ruminants H. contortus using egg hatch assay (EHA) and larval development assay (LDA). The assays were run in 24-well cell culture plates at room temperature with five replicates. All plant extracts showed moderate parasitic effects after 48 and exposure for egg hatching and LDA, respectively; however, 100% egg hatching and larvicidal inhibition were found in the methanol extracts of A. paniculata, A. squamosa, D. metel, and S. torvum at 25 mg/ml and the effect was similar to positive control of Albendazole (0.075 mg/ml) and Ivermectin (0.025mg/ml) against H. contortus, respectively. The EHA result showed the ED50 of methanol extracts of A. paniculata and D. metel, which were 2.90 and 3.08 mg/ml, and in larval development assay, the ED50 was 4.26and 3.86 mg/ml, respectively. These effects remain to be confirmed through in vivo studies.

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.

Green Synthesis of Silver and Titanium Dioxide Nanoparticles Using Euphorbia prostrata Extract Shows Shift from Apoptosis to G0/G1 Arrest followed by Necrotic Cell Death in Leishmania donovani

ABSTRACT The aim of the present study was to synthesize silver (Ag) and titanium dioxide (TiO2) nanoparticles (NPs) using green synthesis from aqueous leaf extract of Euphorbia prostrata as antileishmanial agents and to explore the underlying molecular mechanism of induced cell death. In vitro antileishmanial activity of synthesized NPs was tested against promastigotes of Leishmania donovani by alamarBlue and propidium iodide uptake assays. Antileishmanial activity of synthesized NPs on intracellular amastigotes was assessed by Giemsa staining. The leishmanicidal effect of synthesized Ag NPs was further confirmed by DNA fragmentation assay and by cell cycle progression and transmission electron microscopy (TEM) of the treated parasites. TEM analysis of the synthesized Ag NPs showed a spherical shape with an average size of 12.82 ± 2.50 nm, and in comparison to synthesized TiO2 NPs, synthesized Ag NPs were found to be most active against Leishmania parasites after 24 h exposure, with 50% inhibitory concentrations (IC50) of 14.94 μg/ml and 3.89 μg/ml in promastigotes and intracellular amastigotes, respectively. A significant increase in G0/G1 phase of the cell cycle with a subsequent decrease in S (synthesis) and G2/M phases compared to controls was observed. The growth-inhibitory effect of synthesized Ag NPs was attributed to increased length of S phase. A decreased reactive oxygen species level was also observed, which could be responsible for the caspase-independent shift from apoptosis (G0/G1 arrest) to massive necrosis. High-molecular-weight DNA fragmentation as a positive consequence of necrotic cell death was also visualized. We also report that the unique trypanothione/trypanothione reductase (TR) system of Leishmania cells was significantly inhibited by synthesized Ag NPs. The green-synthesized Ag NPs may provide promising leads for the development of cost-effective and safer alternative treatment against visceral leishmaniasis.

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 antibacterial activity of selected medicinal plant extracts from south India against human pathogens

Abstract 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.