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1.
Shuaibu MN Wuyep PT Yanagi T Hirayama K Ichinose A Tanaka T Kouno I 《Parasitology research》2008,102(4):697-703
The antitrypanosomal activity of methanolic extracts of Anogeissus leiocarpus and Terminalia avicennoides were evaluated in vitro against four strains of Trypanosoma species with minimum inhibitory concentration (MIC) value range of 12.5–50 mg/ml. Successive fractionations of the two plant
extracts in water, butanol and ethyl acetate gave a range of activity (MIC, 20 to ≥50 μg/ml). Activity-guided and chromatographic
analysis of butanolic fractions on Sephadex LH-20 column followed by high-performance liquid chromatography, nuclear magnetic
resonance analysis and both ultraviolet and thin layer chromatography revealed hydrolysable tannins with a range of activity
(MIC, 7.5–27.5 μg/ml or 14–91 μM). Effect of the compounds on fibroblasts did not reveal serious toxicity at moderate concentration
but is concentration dependent. 相似文献
2.
Passero LF Castro AA Tomokane TY Kato MJ Paulinetti TF Corbett CE Laurenti MD 《Parasitology research》2007,101(3):677-680
The crude methanolic extract from leaves of Jacaranda puberula showed activity against Leishmania (Leishmania) amazonensis. The extract presented active against promastigote forms with an inhibitory concentration 50% (IC50) value of 88.0 μg/ml, but only moderated activity against amastigote forms; however in higher concentrations the extract
showed cytotoxic effects. The bio-guided chromatographic fractionation the crude methanolic extract against amastigotes yielded
a fraction with an IC50 value of 14.0 μg/ml (without cytotoxic activity) in relation to the crude extract (IC50 value, 359.0 μg/ml). These data indicate that J. puberula leaves contain active compounds, which should be further investigated for the development of new potential drugs against
cutaneous leishmaniasis. 相似文献
3.
Sundaram Ravikumar Ganesan Ramanathan Samuel Jacob Inbaneson Andy Ramu 《Parasitology research》2011,108(1):107-113
The ocean covers more than 70% of earth surface and hosts most 300,000 described species of plants and animals to use, which
have been virtually unexploited for the development of medicines. Marine plants are the good source of biologically active
entities which exhibit therapeutic properties, when applied single or in combination of different plant extracts (polyherbal).
Polyherbal preparations are always a complex mixture of different forms and thus different compounds, which might act as agonistic,
synergistic, complementary, antagonistic or toxic way. The present study was initially carried out to test the antiplasmodial
activity of 13 mangrove plants and eight seaweeds species distributed along the coast of south India. Of these, mangrove species
Aegiceras corniculatum and the seaweed species Chaetomorpha antennina have shown maximum antiplasmodial activity. Hence, the present study was mooted out to increase the percentage of antiplasmodial
activity when applied as polyherbal preparations. The effect of marine polyherbal preparations from the methanolic extracts
of two marine plants A. corniculatum and C. antennina for their antiplasmodial activity was tested. It shows that the polyherbal extract showed 63.50 ± 0.408% suppression of parasitaemia
against Plasmodium falciparum at 1.5 mg ml−1 concentration. In vivo test was carried out with rat animal model to find out the effectiveness of the polyherbal extracts
in the live system, which reveals that polyherbal extracts have exhibited remarkable antiplasmodial activity (50.57 ± 0.465%)
against Plasmodium berghei at 120 mg kg−1 bw. This study shows that combinations of mangrove plants and seaweeds extracts had a source of lead compounds for the development
of new drugs for the treatment of malaria. 相似文献
4.
Amoebic keratitis is difficult to treat without total efficacy in some patients because of cysts, which is less susceptible
than trophozoites to the usual treatments. The aim of this study is to evaluate the in vitro amoebicidal activity of the methanolic
extracts of Peucedanum caucasicum, Peucedanum palimbioides, Peucedanum chryseum, and Peucedanum longibracteolatum, which are endemic in Turkish flora except P. caucasicum. Extracts were evaluated for their amoebicidal activities using an inverted light microscope. In the presence of methanolic
extracts (ranging from 1.0 to 32.0 mg/ml), numbers of the viable Acanthamoeba castellani trophozoites and cysts were determined during the experimental process (72nd hour). All of the extracts showed a time and
dose-dependent amoebicidal action on the trophozoites and cysts. Among the extracts tested, P. longibracteolatum showed the strongest amoebicidal effect on the trophozoites and cysts. In the case of 32 mg/ml concentration of extract,
no viable trophozoites or cysts were determined between 24th and 72nd hour. Similar results were obtained from the extract
at 16.0 mg/ml concentration against trophozoites. At this concentration value, number of viable cysts was determined as 10.6 ± 2.1
in the 24th hour. In the presence of 8.0 mg/ml extract solution, no viable trophozoites were determined in the 48th hour.
At the same concentration, 51% of the cysts were killed by the extract in the 72nd hour. As expected, cysts were found more
resistant to the extracts than the trophozoites. 相似文献
5.
Ferreira KA Lemos-Júnior PE Lages-Silva E Ramírez LE Pedrosa AL 《Parasitology research》2007,101(5):1383-1388
Previous studies conducted in Leishmania led us to test the hypothesis that addition of human urine (HU) to the Liver Infusion Tryptose (LIT) medium would stimulate
the in vitro growth of Trypanosoma cruzi and Trypanosoma rangeli strains. Herein, we show that the addition of 3% HU to LIT medium (LIT-HU3) significantly stimulated the growth of all the
T. rangeli strains studied when compared with the parasite growth in conventional LIT medium (p < 0.05), and it was equivalent to the growth observed in LIT supplemented with fetal calf serum (FCS) in two parasite strains.
Four out of the six T. cruzi strains analyzed showed a significant increase in parasite multiplication in LIT-HU3 (p < 0.05). However, two parasite strains presented good growth in both LIT and LIT-HU, suggesting differences in the parasite’s
ability to grow in vitro. Furthermore, we have not observed differences in T. cruzi growth in LIT-HU3 and LIT supplemented with heat-denatured HU and in the metacyclogenesis of parasite strains cultured in
LIT-HU3. These results allow concluding that the addition of HU to LIT medium stimulates the in vitro growth of T. rangeli and T. cruzi and can replace FCS as a supplement in culture medium. 相似文献
6.
Passero LF Carvalho AK Bordon ML Bonfim-Melo A Toyama MH Corbett CE Laurenti MD 《Inflammation research》2012,61(3):255-263
Objective
Leishmania (Viannia) shawi was characterized only recently, and few studies concerning the immunogenic and protective properties of its antigens have been performed. The present study aimed to evaluate the protective potential of the five antigenic fractions isolated from L. (V.) shawi promastigotes in experimental cutaneous leishmaniasis. 相似文献7.
Kannathasan K Senthilkumar A Chandrasekaran M Venkatesalu V 《Parasitology research》2007,101(6):1721-1723
The early fourth instar larvae of Culex quinquefasciatus, reared in the laboratory were used for larvicidal assay with leaf extracts of Vitex negundo, Vitex trifolia, Vitex peduncularis and Vitex altissima. The methanol extracts of the four species possessed varying levels of larvicidal nature. The highest larvicidal activity
was found with the extract of V. trifolia (LC50 = 41.41 ppm) followed by V. peduncularis (LC50 = 76.28 ppm), V. altissima (LC50 = 128.04 ppm) and V. negundo (LC50 = 212.57 ppm). 相似文献
8.
Karina?M.?Rebello Luzia?M.?C.?C?rtes Bernardo?A.?S.?Pereira Bernardo?M.?O.?Pascarelli Suzana?C?rte-Real Léa?C.?Finkelstein Rosa?T.?Pinho Claudia?M.?d’Avila-Levy Carlos?R.?Alves 《Parasitology research》2009,106(1):95-104
Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and
is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we
obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of
63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the
peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data
together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation
of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant
and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that
some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues
in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection. 相似文献
9.
Fidelis Cho-Ngwa Melanie Abongwa Moses N Ngemenya Kennedy D Nyongbela 《BMC complementary and alternative medicine》2010,10(1):62
Background
The current treatment of onchocerciasis relies on the use of ivermectin which is only microfilaricidal and for which resistant parasite strains of veterinary importance are increasingly being detected. In the search for novel filaricides and alternative medicines, we investigated the selective activity of crude extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi, a model parasite for O. volvulus. These plants are used to treat the disease in North West Cameroon. 相似文献10.
Methanolic extracts of Anogeissus leiocarpus has been considered locally to have the same antimalarial activities as artemisinin derivatives. This work studied the in
vivo antiplasmodial activity of methanolic extracts of A. leiocarpus and its effect on oxidative stress and lipid profile in mice infected with Plasmodium bergheii. Mice used for this study were divided into five groups; four of the groups were infected with P. bergheii. The first group was not infected with the parasite. The second group was infected with parasite but not treated with antimalarial
drugs (negative control). The third group was infected and treated with artesunat at 5 mg/kg body weight (positive control),
while the fourth and fifth groups were infected and treated with 100 and 200 mg/kg body weight of extract of stem bark of
A. leiocarpus, respectively. The rate of parasite clearance was higher in the group treated with 200 mg/kg body weight of extract of A. leiocarpus when compared with the groups treated with artesunat. Malondialdehyde (MDA) level was significantly higher (P < 0.05) in the serum of negative control as compared with other groups which have received treatment. MDA level was moderately
higher in the liver homogenates of infected mice treated with artesunat than in other groups. There were significant increases
(P < 0.05) in the levels of serum and liver superoxide dismutase of infected mice treated with 200 mg/kg body weight of A. leiocarpus when compared with other groups. Serum low density lipoprotein, total triglyceride, and total cholesterol were moderately
higher in the group treated with artesunat than other groups, while high density lipoprotein (HDL) level was higher in the
two groups treated with A. leiocarpus as compared with the group treated with artesunat. This study shows that the methanolic extract of A. leiocarpus has high antimalarial activities, high antioxidant property, and capable of boosting HDL level in malaria-infected organisms. 相似文献
11.
Ródio C da Rocha Vianna D Kowalski KP Panatieri LF von Poser G Rott MB 《Parasitology research》2008,104(1):191-194
The crude extract and hexane, dichloromethane, and methanol fractions obtained from the aerial parts of Pterocaulon polystachyum (Asteraceae) were assayed against Acanthamoeba castellanii, a free-living ameba that causes acute amebic keratitis. Because of its capacity to form cysts, some strains of this protozoan
are excellent opportunists and therapy resistant, necessitating a search for new drugs in order to develop more dynamic therapies
that make it easier for patients to maintain long-term treatment. In this context, plants with medicinal properties have been
analyzed. The broad-spectrum activity against a range of pathogenic fungi shown by extracts of P. polystachyum, together with the use of antifungal drugs as antiprotozoals, made it important to evaluate the amebicidal activity of these
plant extracts against A. castellanii. The greatest activity was observed in the treatment with the hexane fraction, which lysed approximately 66% and 70% of the
trophozoites in 48 and 72 h, respectively, preventing encystment. 相似文献
12.
Passero LF Tomokane TY Corbett CE Laurenti MD Toyama MH 《Parasitology research》2007,101(5):1365-1371
In this study, we compared the anti-leishmanial activity of three crotalic venoms (Crotalus durissus terrificus–Cdt, Crotalus durissus cascavella–Cdca, and Crotalus durissus collilineatus–Cdcol). Different concentrations of each venom incubated with Leishmania (Leishmania) amazonensis promastigotes were used. Cdt venom exhibited a higher anti-leishmanial activity (Inhibitory concentration-IC50-value of 4.70 ± 1.72 μg/ml) in comparison
with that of Cdca venom (IC50 value of 9.41 ± 1.21 μg/ml), while Cdcol venom increased parasite numbers in 50% at a concentration of 44.30 ± 2.18 μg/ml. In addition, this venom showed a low anti-leishmanial
activity in higher concentrations (IC50 value of 281.00 ± 9.50 μg/ml). The main fractions of Cdca venom were isolated and assayed under similar conditions used for assessing crude venom. The most active fractions were gyroxin
and crotamine that had IC50 values of 3.80 ± 0.52 μg/ml and 19.95 ± 4.21 μg/ml, respectively. Convulxin also inhibited parasite
growth rate, although this effect was not dose-dependent. Crotoxin was the least effective fraction with an IC50 value of
99.80 ± 2.21 μg/ml. None of the protein fractions presented cytotoxic effects against J774 cells in culture. In vivo assays
using BALB/c mice revealed that crotoxin and crotamine were the main toxic fractions. In conclusion, C. durissus cascavella venom has three main fractions with anti-leishmanial activity. These results open new possibilities to find proteins that
might be used as possible agents against cutaneous leishmaniasis. 相似文献
13.
Leishmaniasis is a major health problem worldwide and tools available for their control are limited. Effective vaccines are
still lacking, drugs are toxic and expensive, and parasites develop resistance to chemotherapy. In this context, new antimicrobials
are urgently needed to control the disease in both human and animal. Here, we report the enzymatic and functional characterization
of a Leishmania virulence factor, Leishmania major Protein disulfide isomerase (LmPDI) that could constitute a potential drug target. LmPDI possesses domain structure organization
similar to other PDI family members (a, a′, b, b′ and c domains), and it displays the three enzymatic and functional activities
specific of PDI family members: isomerase, reductase and chaperone. These results suggest that LmPDI plays a key role in assisting
Leishmania protein folding via its capacity to catalyze formation, breakage, and rearrangement of disulfide bonds in nascent polypeptides.
Moreover, Bacitracin, a reductase activity inhibitor, and Ribostamycin, a chaperone activity inhibitor, were tested in LmPDI
enzymatic assays and versus Leishmania promastigote in vitro cultures and Leishmania amastigote multiplication inside infected THP-1-derived macrophages. Bacitracin inhibited both isomerase and reductase activities,
while Ribostamycin had no effect on the chaperone activity. Interestingly, Bacitracin blocked in vitro promastigote growth
as well as amastigote multiplication inside macrophages with EC50 values of 39 μM. These results suggest that LmPDI may constitute an interesting target for the development of new anti-Leishmania drugs. 相似文献
14.
A. Bagavan C. Kamaraj A. Abdul Rahuman G. Elango A. Abduz Zahir G. Pandiyan 《Parasitology research》2009,104(5):1109-1117
The acetone, chloroform, ethyl acetate, hexane and methanol extracts of peel and leaf extracts of Citrus sinensis, Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were tested against fourth instar larvae of malaria vector, Anopheles subpictus Grassi, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) and feeding deterrence to nymphs of cotton pest, Aphis gossypii Glover (Homoptera: Aphididae). The larval and nymph mortality were observed after 24 h of exposure. All extracts showed moderate
larvicidal and nymphicidal effects; however, the highest mortality was found in peel chloroform extract of C. sinensis, leaf ethyl acetate extracts of O. canum and O. sanctum and leaf chloroform extract of R. nasutus against the larvae of A. subpictus (LC50 = 58.25, 88.15, 21.67 and 40.46 ppm; LC90 = 298.31, 528.70, 98.34 and 267.20 ppm), peel methanol extract of C. sinensis, leaf methanol extract of O. canum, ethyl acetate extracts of O. sanctum and R. nasutus against the larvae of C. tritaeniorhynchus (LC50 = 38.15, 72.40, 109.12 and 39.32 ppm; LC90 = 184.67, 268.93, 646.62 and 176.39 ppm), peel hexane extract of C. sinensis, leaf methanol extracts of O. canum and R. nasutus and leaf ethyl acetate extract of O. sanctum against the nymph of A. gossypii (LC50 = 162.89, 80.99, 73.27 and 130.19 ppm; LC90 = 595.40, 293.33, 338.74 and 450.90 ppm), respectively. These results suggest that the peel methanol extracts of C. sinensis and O. canum, ethyl acetate leaf extract of O. sanctum and leaf chloroform and ethyl acetate extract of R. nasutus have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus, C. tritaeniorhynchus and A. gossypii. 相似文献
15.
Brenzan MA Nakamura CV Prado Dias Filho B Ueda-Nakamura T Young MC Aparício Garcia Cortez D 《Parasitology research》2007,101(3):715-722
Infections by protozoans of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment
of leishmaniasis are the pentavalent antimonials, which show renal and cardiac toxicity. As part of a search for new drugs
against leishmaniasis, we evaluated the in vitro leishmanicidal activity of the (−) mammea A/BB. The compound (−) mammea A/BB
is a coumarin-type mammea purified from a dichloromethane crude extract of leaves of Calophyllum brasiliense Cambess (Clusiaceae). The isolated compound was characterized using spectral analyses by UV, infrared, nuclear magnetic resonance
of 1H, 13C, distortionless enhancement by polarization transfer, correlation spectroscopy, heteronuclear multiple bond correlation,
and heteronuclear multiple quantum coherence. The compound (−) mammea A/BB showed significant activity against promastigote
and amastigote forms of L. amazonensis, with IC50 (50% inhibition concentration of cell growth) at a concentration of 3.0 and 0.88 μg/ml and IC90 (90% inhibition concentration of cell growth) of 5.0 and 2.3 μg/ml, respectively. The coumarin (−) mammea A/BB showed no
cytotoxicity against J774G8 macrophages in culture, when it was tested at high concentrations that inhibited promastigote
forms. Electron microscopy studies revealed considerable ultrastructural changes when promastigote forms of L. amazonensis were treated with 3.0 μg/ml of the coumarin (−) mammea A/BB for 72 h. We observed significant changes such as mitochondrial
swelling with concentric membranes in the mitochondrial matrix and intense exocytic activity in the region of the flagellar
pocket. Other alterations included the appearance of binucleate cells and multiple cytoplasmic vacuolization. These results
showed that (−) mammea A/BB is a potent growth inhibitor of L. amazonensis and caused important changes in the parasite’s ultrastructure. This study provided new perspectives on the development of
novel drugs with leishmanicidal activity obtained from natural products. 相似文献
16.
Silva-Lopez RE Morgado-Díaz JA Alves CR Côrte-Real S Giovanni-De-Simone S 《Parasitology research》2004,93(4):328-331
Extracellular proteolytic activity was detected in a Leishmania (L.) amazonensis culture supernatant and a 56-kDa protein was purified using (NH4)2SO4 precipitation followed by affinity chromatography on aprotinin–agarose. A rabbit serum obtained against the 56-kDa extracellular serine protease was used in order to analyze its location in L. (L.) amazonensis parasites. Immunocytochemistry studies revealed that the enzyme is mainly found in the flagellar pocket and cytoplasmic vesicles of promastigote forms, whereas in amastigotes, it is located in electron-dense structures resembling megasomes. These results indicate that the 56-kDa serine protease is released into the extracellular environment through the flagellar pocket; and its intracellular location suggests either a correlated enzymatic activity or intracellular trafficking. 相似文献
17.
Amoebic keratitis is difficult to treat without total efficacy in some patients because of cysts, which is less susceptible
than trophozoites to the usual treatments. We investigated the in vitro effectiveness of the methanolic extract of four Allium species from Turkey against Acanthamoeba castellanii and its cytotoxicity on corneal cells in vitro. Extracts were evaluated for their amoebicidal activities using an inverted
light microscope. The effect of the Allium species with concentrations ranging from 1.0 to 32.0 mg/ml on the proliferation of A. castellanii trophozoites and cysts were examined in vitro. For the determination of the cytotoxicity of the Allium species on corneal cells, agar diffusion tests were performed. According to the results obtained from the tests, A. scrodoprosum subsp. rotundum showed remarkable amoebicidal effect on A. castellanii, while the others remained inactive. In the case of cyctotoxic activities, the methanolic extracts of A. scrodoprosum showed no cytotoxicity for the cells in the concentration of 32 mg/ml, while the others exerted significant cytotoxic activities
between the concentrations of 1 and 16 mg/ml. As a result, the methanolic extract of A. scrodoprosum could be concluded as a new natural agent against Acanthamoeba. On the other hand, it still needs to be further evaluated by in vivo test systems to confirm the efficiency of its biological
effect. 相似文献
18.
Gupta G Majumdar S Adhikari A Bhattacharya P Mukherjee AK Majumdar SB Majumdar S 《Medical microbiology and immunology》2011,200(4):241-253
Visceral leishmaniasis (VL), caused by the protozoan parasite, Leishmania
donovani, is characterized by an infection in the liver and spleen. The failure of the first-line drugs has led to the development
of new strategies for combating VL. Recently, our group has shown that interferon-γ-inducible protein (IP)-10, a CXC chemokine,
renders protection against VL. In the present study, we have elucidated the mechanism by which IP-10 renders protection in
in vivo
L.
donovani infection. We observed that IP-10–treated parasitized BALB/c mice showed a strong host-protective T helper cell (Th) 1 immune
response along with marked decrease in immunosuppressive cytokines, tumor growth factor (TGF)-β, and interleukin (IL)-10 secreting
CD4+ T cells. This IP-10-mediated decrease in immunosuppressive cytokines was correlated with the reduction in the elevated frequency
of CD4+CD25+ T regulatory (Treg) cells along with the reduced TFG-β production from these Treg cells in Leishmania-infected mice. This reduction in TGF-β production was due to effective modulation of TGF-β signaling by IP-10, which reduced
the immunosuppressive activity of Treg cells. Thus, these findings put forward a detailed mechanistic insight into IP-10-mediated
regulation of the Treg cell functioning during experimental VL, which might be helpful in combating Leishmania-induced pathogenesis. 相似文献
19.
20.
Nisha Mathew M. G. Anitha T. S. L. Bala S. M. Sivakumar R. Narmadha M. Kalyanasundaram 《Parasitology research》2009,104(5):1017-1025
Screening of natural products for mosquito larvicidal activity against three major mosquito vectors Aedes aegypti, Culex quinquefasciatus, and Anopheles stephensi resulted in the identification of three potential plant extracts viz., Saraca indica/asoca, Nyctanthes arbor-tristis, and Clitoria ternatea for mosquito larval control. In the case of S. indica/asoca, the petroleum ether extract of the leaves and the chloroform extract of the bark were effective against the larvae of C. quinquefasciatus with respective LC50 values 228.9 and 291.5 ppm. The LC50 values of chloroform extract of N. arbor-tristis leaves were 303.2, 518.2, and 420.2 ppm against A. aegypti, A. stephensi, and C. quinquefasciatus, respectively. The methanol and chloroform extracts of flowers of N. arbor-tristis showed larvicidal activity against larvae of A. stephensi with the respective LC50 values of 244.4 and 747.7 ppm. Among the methanol extracts of C. ternatea leaves, roots, flowers, and seeds, the seed extract was effective against the larvae of all the three species with LC50 values 65.2, 154.5, and 54.4 ppm, respectively, for A. stephensi, A. aegypti, and C. quinquefasciatus. Among the three plant species studied for mosquito larvicidal activity, C. ternatea was showing the most promising mosquito larvicidal activity. The phytochemical analysis of the promising methanolic extract
of the seed extract was positive for carbohydrates, saponins, terpenoids, tannins, and proteins. In conclusion, bioassay-guided
fractionation of effective extracts may result in identification of a useful molecule for the control of mosquito vectors. 相似文献