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1.
Shuaibu MN Pandey K Wuyep PA Yanagi T Hirayama K Ichinose A Tanaka T Kouno I 《Parasitology research》2008,103(6):1333-1338
Stem barks of Anogeissus leiocarpus and Terminalia avicennoides widely used in Africa for treatment of some parasitic diseases were collected and made into methanolic extracts. The extracts
were tested on four strains of promastigote forms of Leishmania in vitro. Solvent fractionation in aqueous, butanolic, and ethyl acetate layer indicated butanol and aqueous fractions to
have a superior leishmanicidal activity. Chromatographic separation of the butanolic fraction on Sephadex LH-20 followed by
nuclear magnetic resonance and correlation high-performance liquid chromatography revealed the presence of known hydrolyzable
tannins and some related compounds—with castalagin as the major compound. The observed activity ranged from 62.5 to ≥150,
112.5 to ≥500, and 55 to >150 μg/ml for the crude methanolic extract, different solvent fractions, and the isolated compounds,
respectively, on the four different Leishmania strains. 相似文献
2.
Sawangjaroen N Phongpaichit S Subhadhirasakul S Visutthi M Srisuwan N Thammapalerd N 《Parasitology research》2006,98(6):588-592
The anti-amoebic activities of chloroform, methanol and water extracts from 12 Thai medicinal plants (39 extracts) commonly used by AIDS patients in southern Thailand were screened, at a concentration of 1,000 μg/ml, against Entamoeba histolytica strain HTH-56:MUTM and strain HM1:IMSS growing in vitro. The extracts were incubated with 2×105
E. histolytica trophozoites/ml of medium at 37°C under anaerobic conditions for 24 h. The cultures were examined with an inverted microscope and scored (1–4) according to the appearance and numbers of the trophozoites. The extracts that caused inhibition were selected and retested using the same conditions but with concentrations that ranged from 31.25 to 1,000 μg/ml using E. histolytica strain HM1:IMSS, and the IC50 values for each extract were calculated. The chloroform extracts from Alpinia galanga (IC50 55.2 μg/ml), Barleria lupulina (IC50 78.5 μg/ml), Boesenbergia pandurata (IC50 45.8 μg/ml), Piper betle (IC50 91.1 μg/ml) and Piper chaba (IC50 71.4 μg/ml) and the methanol extract from B. pandurata (IC50 57.6 μg/ml) were all classified as “active”, i.e. with an IC50 of less than 100 μg/ml, whereas those from Murraya paniculata (IC50 116.5 μg/ml) and Zingiber zerumbet (IC50 196.9 μg/ml) were classified as being “moderately active”. The IC50 of a standard drug, metronidazole, was 1.1 μg/ml. 相似文献
3.
In order to assess the potential of the stem bark of Kigelia africana (Lam.) Benth as source of new anti-malarial leads, n-hexane and ethyl acetate (EtOAc) extracts and four compounds isolated
from the stem bark were screened in vitro against the chloroquine-resistant W-2 and two field isolates of Plasmodium falciparum using lactate dehydrogenase assay. The products were also tested for their cytotoxicity on LLC/MK2 monkey kidney cells. The
EtOAc extract exhibited a significant antiplasmodial activity (IC50 = 11.15 μg/mL on W-2; 3.91 and 4.74 μg/mL on field CAM10 and SHF4 isolates, respectively), whereas the n-hexane fraction
showed a weak activity (IC50 = 73.78 μg/mL on W-2 and 21.85 μg/mL on SHF4). Three out of the four compounds showed good activity against all the three
different parasite strains (IC50 < 5 μM). Specicoside exhibited the highest activity on W-2 (IC50 = 1.54 μM) followed by 2β, 3β, 19α-trihydroxy-urs-12-en-28-oic acid (IC50 = 1.60 μM) and atranorin (IC50 = 4.41 μM), while p-hydroxycinnamic acid was the least active (IC50 = 53.84 μM). The EtOAc extract and its isolated compounds (specicoside and p-hydroxycinnamic acid) were non-cytotoxic (CC50 > 30 μg/mL), whereas the n-hexane extract and two of its products, atranorin and 2β, 3β, 19α-trihydroxy-urs-12-en-28-oic
acid showed cytotoxicity at high concentrations, with the last one being the most toxic (CC50 = 9.37 μg/mL). These findings justify the use of K. africana stem bark as antimalaria by traditional healers of Western Cameroon, and could constitute a good basis for further studies
towards development of new leads or natural drugs for malaria. 相似文献
4.
Moon HI 《Parasitology research》2007,100(5):1147-1149
Samples of Carpesium genus used as traditional remedies for the treatment of parasite infections were collected, and methanol extracts were obtained
by sonication. The ethylacetate-, n-butanol- and H2O-soluble fractions exhibited weak antiplasmodial activity (IC50 > 100 μg/ml; IC50, 50% inhibitory concentration). However, the chloroform fraction exhibited more impressive antiplasmodial activity (IC50 = 8.2 μg/ml). The antiplasmodial activity of the chloroform fractions was evaluated in vitro against the chloroquine-resistant
D10 strain of Plasmodium falciparum. Bioactivity-guided isolation of the chloroform fractions of the whole plants of Carpesium rosulatum has led to the isolation of a sesquiterpene lactone, ineupatorolides A, displaying high antiplasmodial activity (IC50 = 0.007 μg/ml). This is the first report of the isolation of ineupatorolides A from this species and of its remarkable antiplasmodial
activity. 相似文献
5.
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
6.
In the present investigation, we have evaluated the antileishmanial and antitrypanosomal activity of methanolic crude extracts
obtained from eight species of cnidarians and of a modified steroid isolated from the octocoral Carijoa riisei. The antileishmanial activity of cnidarians crude extracts showed 50% inhibitory concentration (IC50) values in the concentration range between 2.8 and 93.3 μg/mL. Trypomastigotes of Trypanosoma cruzi were less susceptible to the crude extracts, with IC50 values in the concentration range between 40.9 and 117.9 μg/mL. The steroid (18-acetoxipregna-1,4,20-trien-3-one) displayed
a strong antileishmanial activity, with an IC50 value of 5.5 μg/mL against promastigotes and 16.88 μg/mL against intracellular amastigotes. The steroid also displayed mammalian
cytotoxicity (IC50 of 10.6 μg/mL), but no hemolytic activity was observed at the highest concentration of 12.5 μg/mL. The antileishmanial effect
of the steroid in macrophages suggested other mechanism than macrophage activation, as no upregulation of nitric oxide was
observed. The antitrypanosomal activity of the steroid resulted in an IC50 value of 50.5 μg/mL. These results indicate the potential of cnidarian natural compounds as antileishmanial drug candidates. 相似文献
7.
Olounladé PA Azando EV Hounzangbé-Adoté MS Ha TB Leroy E Moulis C Fabre N Magnaval JF Hoste H Valentin A 《Parasitology research》2012,110(4):1427-1433
The need for new anthelmintic with no chemical residues is becoming urgent. In a program aiming at the evaluation of plant
as sources of new active molecules, the anthelmintic activities of the essential oils (EOs) obtained from either Zanthoxylum zanthoxyloides seeds or Newbouldia laevis leaves were evaluated against Strongyloides ratti by analyzing the results of two in vitro bioassays. These two plants and their tested parts were retained after an ethnopharmacology
survey that confirmed their use by small-scale farmers for treatment of small ruminants affected by digestive helminths. The
plants were harvested in Benin, and their EO were obtained by hydrodistillation. The EO yield of extraction was 0.65% (w/w)
of for Z. zanthoxyloides seeds and 0.05% (w/w) for N. laevis. The chemical compositions of the two EOs were analyzed by gas chromatography coupled with mass spectrometry. The major constituents
of the EO from Z. zanthoxyloides consisted of the following compounds: γ-terpinene (18 %), undecane (15 %), valencene (8.3 %), decanal (8.3 %), and 3-carene
(6.7 %). In contrast, the major constituents of the EO from N. laevis leaves consisted of the following compounds: β-caryophyllene (36 %) and eugenol (5.8 %). An egg-hatching inhibition (EHI)
assay was developed and a larval migration inhibition assay was used on S. ratti to examine the effects of the EOs and to evidence their inhibitory concentrations (IC50 and IC90) values on this nematode. Furthermore, the toxicity of the two EOs on Vero cell line was evaluated. When tested on S. ratti egg hatching, the two EOs resulted in similar IC50 values (19.5 and 18.2 μg/ml for Z. zanthoxyloides and N. laevis, respectively), which were about sevenfold higher than that of the control (thiabendazole, IC50 = 2.5 μg/ml). Larval migration was inhibited at similar concentrations for: Z. zanthoxyloides (IC50 = 46 μg/ml), N. laevis (IC50 = 51 μg/ml), and the control [levamisole (IC50 = 36 μg/ml)]. No cytotoxicity was found on Vero cells because both EOs had IC50 values higher than 50 μg/ml. Therefore, we have concluded that the EOs from two plants, used in folk medicine, may contain
compounds with anthelmintic activity and could be used as improved traditional medicines or, at least, as food additives in
a combined treatment for the control of helminth infections. 相似文献
8.
The problems of resistant lines of Plasmodium falciparum are escalating. Twelve seaweeds species belong to five different families (Sargassaceae, Gracilariaceae, Hypneaceae, Corallinaceae
and Halimedaceae) were collected from Mandapam coastal area, and the seaweeds extracts were tested for in vitro antiplasmodial
activity against P. falciparum. Among the tested seaweeds, Gracilaria verrucosa (IC50 5.55 μg.ml−1) and Hypnea espera (IC50 8.94 μg.ml−1) showed good antiplasmodial activity, and these results are comparable with positive controls such as artemether (IC50 4.09 μg.ml−1) and chloroquine (IC50 19.59 μg.ml−1), respectively. Turbinaria conoides, Sargassum myriocystem, Hypnea valentiae and Jania rubens extracts showed IC50 values between 5 to 50 μg.ml−1. Sargassum sp., Turbinaria decurrens and Halimeda gracilis extracts showed IC50 values between 50 to 100 μg.ml−1. Gracilaria corticata, Jania adherens and Halimeda opuntia extracts showed IC50 value of more than 100 μg.ml−1. Statistical analysis reveals that significant in vitro antiplasmodial activity (P < 0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried
out, and it shows that no morphological changes in erythrocytes by the ethanolic extract of seaweeds extracts after 48 h of
incubation. The in vitro antiplasmodial activity might be due to the presence of sugars, proteins, phenols and carboxylic
acid in the ethanolic extracts of seaweeds. It is concluded from the present study that the ethanolic extracts of seaweeds
of G. verrucosa and Hypnea espera possess lead compounds for development of antiplasmodial drugs. 相似文献
9.
Santoro GF das Graças Cardoso M Guimarães LG Salgado AP Menna-Barreto RF Soares MJ 《Parasitology research》2007,100(4):783-790
In the present work, we have investigated the effect of essential oils obtained from Origanum vulgare L. (oregano) and Thymus vulgaris L. (thyme) on growth and ultrastructure of diverse evolutive forms of Trypanosoma cruzi. Culture epimastigotes and bloodstream trypomastigotes were incubated for 24 h with different concentrations of oregano or
thyme essential oils and with thymol (the main constituent of thyme), and the inhibitory concentration (IC)50 was determined by cell counting. Crude extract of oregano essential oil inhibited epimastigote growth (IC50/24 h = 175 μg/ml) and also induced trypomastigote lysis (IC50/24 h = 115 μg/ml). Thyme essential oil presented IC50/24 h values of 77 μg/ml for epimastigotes and 38 μg/ml for trypomastigotes, while treatment with thymol resulted in an IC50/24 h of 62 μg/ml for epimastigotes and 53 μg/ml for trypomastigotes. Scanning electron microscopy of treated cells showed
few morphological alterations at the plasma membrane. Observation by transmission electron microscopy showed cytoplasmic swelling
with occasional morphological alterations in plasma and flagellar membrane. Our data indicate that oregano and thyme essential
oils are effective against T. cruzi, with higher activity of thyme, and that thymol may be the main component responsible for the trypanocidal activity. 相似文献
10.
Bagavan A Rahuman AA Kamaraj C Kaushik NK Mohanakrishnan D Sahal D 《Parasitology research》2011,108(5):1099-1109
The absence of a vaccine and the rampant resistance to almost all antimalarial drugs have accentuated the urgent need for
new antimalarial drugs and drug targets for both prophylaxis and chemotherapy. The aim of the study was to discover effective
plant extracts against Plasmodium falciparum. In the present study, the hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Citrus sinensis (peel), Leucas aspera, Ocimum sanctum, Phyllanthus acidus (leaf), Terminalia chebula (seed) were tested for their antimalarial activity against chloroquine (CQ)-sensitive (3D7) strain of P. falciparum which was cultured following the candle-jar method. Antimalarial evaluations of daily replacement of culture medium containing
CQ and different plant crude extracts were performed on 96-well plates at 37°C for 24 and 48 h. Parasitemia was determined
microscopically on thin-film Giemsa-stained preparations. Plant extracts were tested for their cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl
tetrazolium bromide (MTT) assay on human laryngeal cancer cell line (HEp-2) and normal cell line (Vero). Out of the 25 extracts
tested, six showed good (IC50 4.76–22.76 μg/mL), 15 exhibited moderate (IC50 31.42–88.03 μg/mL), while four displayed mild (IC50 > 100 μg/mL) antiplasmodial activity. The leaf ethyl acetate and methanol extracts of L. aspera; ethyl acetate, acetone, and methanol extracts of P. acidus; and seed acetone extract of T. chebula had good antiplasmodial activity (IC50 = 7.81, 22.76, 9.37, 14.65, 12.68, and 4.76 μg/mL) with selectivity indices 5.43, 2.04, 4.88, 3.35, 3.42, and 9.97 for HEp-2
and >5.79, >2.20, >11.75, >3.41, >3.94, and >7.38 for Vero cells, respectively. These analyses have revealed for the first
time that the components present in the solvent extracts of L. aspera, P. acidus, and T. chebula have antiplasmodial activity. The high antiplasmodial activity observed make these plants good candidates for isolation of
anti-protozoal compounds which could serve as new lead structures for drug development. 相似文献
11.
Line-Edwige Mengome Jean Paul Akue Alain Souza Guy Raymond Feuya Tchoua Edouard Nsi Emvo 《Parasitology research》2010,107(3):643-650
Loa loa, a filarial worm, can cause fatal encephalitis in humans. In an attempt to find alternatives to the standard treatments (ivermectin
and diethylcarbamazine citrate), we tested 12 methanolic extracts of nine traditional plant remedies. The extracts (100–0.09 μg/ml)
were incubated with 20 Loa loa microfilariae isolated from patients at 37°C with 5% CO2 in modified Eagle’s medium supplemented with 10% fetal serum and antibiotics. Activity was evaluated 120 h later by counting
live microfilariae under a microscope. Cytotoxicity for eukaryotic cells was estimated by measuring 3-[4,5-dimethylthiazol-2-yl]-2-5
diphenyl tetrazolium bromide transformation to formazan at 450 nM in a spectrophotometer. The plants tested were Lophira alata, Greenwayodendron suaveolens, Uapaca togoensis, Zanthoxylum heitzii, Peperomia pellucida, Piptadeniastrum africanum, Petersianthus macrocarpus, Vernonia conferta, and Vernonia hymenolepis. Chemical screening showed that most of the extracts contained reducing sugars, tannin or polyphenols, sterols or triterpenes,
saponosides, and alkaloids. None contained carotinoids and few contained flavonoids. The 50% lethal concentration ranged from
0.22 to 70.28 μg/ml, while the 50% inhibitory concentration for eukaryotic cells (IC50) ranged from 8.52 to 119.52 μg/ml. Extracts of P. macrocarpus (selectivity index = 72.16), P. africanum (13.69), Z. heitzii (12.11), and L. alata (9.26) were highly selective for L. loa. 相似文献
12.
K. G. Naber U. Theuretzbacher G. Moneva-Koucheva H. Staß 《European journal of clinical microbiology & infectious diseases》1999,18(11):783-789
Twelve healthy volunteers participated in a randomized crossover study to compare urinary concentrations, serum parameters,
and urinary bactericidal activity of ciprofloxacin after single intravenous (i.v.) doses of 200 mg and 400 mg and an oral
(p.o.) dose of 500 mg. The median serum concentrations at 1 h after administration were 1 μg/ml, 4.3 μg/ml, and 2.2 μg/ml,
respectively. Between the first collection period (0–2 h) and the last collection period (38–48 h), the median urinary concentrations
decreased from 394 μg/ml, 675 μg/ml, and 585 μg/ml, respectively, to 0.3 μg/ml, 0.6 μg/ml, and 1 μg/ml, respectively. The
urinary concentrations after the 400 mg i.v. and the 500 mg p.o. doses were not statistically different but were significantly
higher than those after the 200 mg i.v. dose. The urinary bactericidal titers (UBTs), defined as the highest urinary dilution
bactericidal for the organism tested, were determined against Escherichia coli (ATCC 25922) and eight uropathogens up to 48 h after administration of ciprofloxacin. The UBTs after the 400 mg i.v. and
the 500 mg p.o. doses were similar and were significantly higher (P<0.05) than those following the 200 mg i.v. dose. After 400 mg i.v. and 500 mg p.o., median UBTs of ≥1 : 4 were present up
to 48 h for all strains for which the MIC was ≤0.5 μg/ml, except for one nalidixic-acid resistant Escherichia coli strain for which the MIC was 0.25 μg/ml. Species for which the MIC is ≥1 μg/ml showed median UBTs of ≥1 : 4 for 8–16 h. Median
UBTs of ≥1 : 4 were present up to 8 and 12 h for both Pseudomonas strains tested. A once-daily dosage of 400 mg i.v. or 500 mg p.o. might be sufficient for treatment of urinary tract infections
caused by highly susceptible pathogens. A twice-daily dosing scheme seems to be preferable for complicated infections caused
by pathogens with intermediate susceptibilty (MIC≥1 μg/ml) or for empiric therapy. 相似文献
13.
The leishmanicidal activity of Aloe vera leaf exudate (AVL) has been demonstrated in promastigotes and axenic amastigotes, but its effectiveness in animal models
has not been evaluated. The presence of alkaloids, triterpenes, cyanidines, proanthocyanidines, tannins, and saponins in AVL
was identified. Its effectiveness in four Leishmania donovani strains was studied both in promastigotes (IC50 ranged from 70–115 μg/ml) and amastigotes (IC50 ranged from 3.1–11.4 μg/ml). In amastigotes, the killing by AVL was facilitated through its induction of nitric oxide in
leishmania-infected macrophages. The safety index was good as AVL up to 300 μg/ml remained non-toxic to monocytes and macrophages. In
a L. donovani BALB/c mouse model, oral or subcutaneous administration of AVL (15 mg/kg body weight × 5 days) reduced parasitemia by >90%
in the liver, spleen, and bone marrow without impairment of hepatic and renal functions. Collectively, we conclude that AVL
shows promising antileishmanial activity and may provide a new lead agent in the treatment of Leishmaniasis.
Chitra Mandal and Mitali Chatterjee should be considered as joint senior authors. 相似文献
14.
Pujals G Suñé-Negre JM Pérez P García E Portus M Tico JR Miñarro M Carrió J 《Parasitology research》2008,102(6):1243-1247
The aim of the present study was to evaluate the in vitro activity and cytotoxicity of meglumine antimoniate microspheres
produced by spray drying on Leishmania infantum and the effect of the excipients used in them. The parasite strain shows sensitivity to the meglumine antimoniate microspheres
prepared. All the antimony IC50 values from encapsulated meglumine antimoniate (3.80 ± 0.34 to 9.53 ± 0.70 μg SbV/ml for promastigotes assay) are considerably
lower compared to the mean value of IC50 in Glucantime solution (112 ± 12.74 μg SbV/ml). Interesting IC50 values for the excipient chitosan (112.64 ± 0.53 mg/ml for promastigotes and 100.81 ± 26.45 mg/ml for amastigotes) were obtained
(without cytotoxic activity), whereas the rest of the excipients did not show any activity. This new delivery system could
offer a new pharmacological tool for the treatment of leishmaniosis that reduces the doses required, lowering toxic side effects
because of meglumine antimoniate. 相似文献
15.
Polanco-Hernández G Escalante-Erosa F García-Sosa K Acosta-Viana K Chan-Bacab MJ Sagua-Franco H González J Osorio-Rodríguez L Moo-Puc RE Peña-Rodríguez LM 《Parasitology research》2012,110(1):31-35
Ethanol extracts of Senna villosa, Serjania yucatanensis, Byrsonima bucidaefolia, and Bourreria pulchra were evaluated for their in vitro activity against epimastigotes and trypomastigotes of Trypanosoma cruzi. Results showed that the leaf extracts of S. yucatanensis and B. pulchra were the most active against epimastigotes (IC100 = 100 μg/mL) and trypomastigotes of T. cruzi (95% or more reduction in the number of parasites at 100 and 50 μg/mL). However, only the leaf extract of S. yucatanensis showed significant trypanocidal activity when tested in vivo, reducing 75% of the parasitemia in infected mice at 100 mg/kg.
This same extract inhibited the egress of trypomastigotes from infected cells and proved not to be cytotoxic (IC50 = 318.8 ± 2.3 μg/mL). 相似文献
16.
In this study, we are reporting antileishmanial activity of a marine sponge Haliclona exigua, belonging to phylum Porifera. The crude methanol extract and its three fractions were tested both in vitro and in vivo.
The crude extract exerted almost complete inhibition of promastigotes at 50 μg/ml and 76.4 ± 6.5% inhibition of intracellular
amastigotes at 100 μg/ml concentration with IC50 values of 18.6 μg/ml and 47.2 μg/ml, respectively. When administered to Leishmania donovani infected hamsters at a dose of 500 mg/kg × 5, p.o., it resulted in 72.2 ± 10.4% inhibition of intracellular amastigotes.
At a lower dose (250 mg/kg), it exhibited 43.9 ± 5.1% inhibition. Among the fractions, highest antileishmanial activity both
in vitro (>90%) and in vivo (60.9 ± 18.3%) was observed in n-butanol (soluble) fraction with IC50 values of 8.2 μg/ml and 31.2 μg/ml against promastigotes and intracellular amastigotes, respectively. Hexane fraction also
showed comparatively good activity against both the stages of parasites in vitro but was moderately active in leishmania-infected
hamsters. Chloroform fraction resulted in 45 ± 10.2% inhibition in vivo at a dose of 500 mg/kg × 5, p.o., whereas it was inactive
in vitro. n-Butanol (insoluble) fraction was inactive both in vitro and in vivo. Araguspongin C, an alkaloid isolated from n-butanol (soluble) fraction exhibited moderate inhibition of promastigotes and intracellular amastigotes at 100 μg/ml but
showed weak antileishmanial action in vivo. Our findings indicate that this marine sponge has the potential to provide new
lead toward development of an effective antileishmanial agent and, hence, calls for more exhaustive studies for exploiting
the vast world of marine resources to combat the scourge of several parasitic diseases. 相似文献
17.
F. Fuentes M. J. Giménez F. Marco L. Alou L. Aguilar J. Prieto 《European journal of clinical microbiology & infectious diseases》2000,19(2):137-139
The in vitro susceptibility to trovafloxacin and gemifloxacin of Streptococcus pneumoniae strains exhibiting decreased susceptibility to ciprofloxacin (MIC ≥2 μg/ml; 30 strains with intermediate resistance [MIC
2 μg/ml] and 43 strains with complete resistance [MIC ≥4 μg/ml]) was determined. Seventy-three strains collected in a surveillance
study carried out from May 1996 to April 1997 in Spain (prior to commercialisation of trovafloxacin and gemifloxacin) from
patients with respiratory tract infections were tested. The antibacterial activity of gemifloxacin was affected to a lesser
extent than that of trovafloxacin by the increase in the MIC of ciprofloxacin, with gemifloxacin showing significantly (P≤0.001) better antibacterial activity than trovafloxacin in all ciprofloxacin MIC categories (MIC50/MIC90 values of 0.015/0.03,
0.015/0.06, 0.03/0.06 and 0.12/0.25 μg/ml for gemifloxacin vs 0.12/0.12, 0.12/1, 0.25/0.5 and 2/4 μg/ml for trovafloxacin
in the 2, 4, 8 and ≥16 μg/ml ciprofloxacin MIC categories, respectively). Nine (12.3%) of these 73 strains exhibited decreased
susceptibility to trovafloxacin (≥2 μg/ml), whereas all strains were inhibited by 0.25 μg/ml of gemifloxacin. 相似文献
18.
Ravikumar S Inbaneson SJ Suganthi P Gokulakrishnan R Venkatesan M 《Parasitology research》2011,108(6):1411-1416
Malaria is a major health problem in many developing countries. The drugs resistant Plasmodium falciparum causes the most virulent form of malaria in humans and it is described as a public health disaster causing increased morbidity
and mortality. Thirteen seaweeds species which belong to four different families (Rhodomelaceae, Cladophoraceae, Ulvaceae,
and Caulerpaceae) were collected from Mandapam coastal area and the seaweeds extracts were tested for in vitro antiplasmodial
activity against P. falciparum. Among them, Caulerpa toxifolia (IC50 5.06 μg·ml−1) showed potential antiplasmodial activity than other seaweeds extracts and it can be comparable with the positive control
artemether (IC50 4.09 μg·ml−1). Caulerpa peltata (IC50 16.69 μg·ml−1) also exhibited good antiplasmodial activity and the IC50 value is lesser than the positive control chloroquine (IC50 19.59 μg·ml−1). Statistical analysis reveals that significant in vitro antiplasmodial activity (P < 0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried
out and it shows that no morphological changes in erythrocytes by the ethanolic extract of seaweeds extracts after 48 h of
incubation. The in vitro antiplasmodial activity might be due to the presence of sugars, proteins, and phenols in the ethanolic
extracts of seaweeds. It is concluded from the present study that, the ethanolic extracts of seaweeds of C. toxifolia and C. peltata possesses lead compounds for development of antiplasmodial drugs. 相似文献
19.
For decades, drug resistance has been the major obstacle in the fight against malaria, and the search for new drugs together
with the combination therapy constitutes the major approach in responding to this situation. The present study aims at assessing
the in vitro antimalarial activity of four compounds isolated from Kigelia africana stem bark (atranorin - KAE1, specicoside - KAE7, 2β,3β,19α-trihydroxy-urs-12-20-en-28-oic acid – KAE3, and p-hydroxy-cinnamic acid – KAE10) and their drug interactions among themselves and their combination effects with quinine and
artemether. The antiplasmodial activity and drug interactions were evaluated against the multidrug-resistant W2mef strain
of Plasmodium falciparum using the parasite lactate dehydrogenase assay. Three of the four compounds tested were significantly active against W2mef:
specicoside (IC50 = 1.02 ± 0.17 μM), 2β,3β,19α-trihydroxy-urs-12-en-28-oic acid (IC50 = 1.86 ± 0.15 μM) and atranorin (IC50 = 1.78 ± 0.18 μM), whereas p-hydroxy-cinnamic acid showed a weak activity (IC50 = 12.89 ± 0.87 μM). A slight synergistic effect was observed between atranorin and 2β,3β,19α-trihydroxy-urs-12-en-28-oic
acid (Combination index, CI = 0.82) whereas the interaction between specicoside and p-hydroxy-cinnamic acid were instead antagonistic (CI = 2.67). All the three compounds showed synergistic effects with artemether,
unlike the slight antagonistic interactions of atranorin and 2β,3β,19α-trihydroxy-urs-12-en-28-oic acid in combination with
quinine. K. africana compounds are therefore likely to serve as leads in the development of new partner drugs in artemether-based combination
therapy. 相似文献
20.
Determinants for the Development of Oropharyngeal Colonization or Infection by Fluconazole-Resistant Candida Strains in HIV-Infected Patients 总被引:3,自引:0,他引:3
M. Masiá Canuto F. Gutiérrez Rodero V. Ortiz de la Tabla Ducasse I. Hernández Aguado C. Martín González A. Sánchez Sevillano A. Martín Hidalgo 《European journal of clinical microbiology & infectious diseases》2000,19(8):593-601
A point prevalence study to document oral yeast carriage was undertaken. Risk factors for the development of oropharyngeal
colonization or infection by fluconazole-resistant Candida strains in HIV-infected patients were investigated with a case-control design. Cases included all patients with fluconazole-resistant
strains (MIC≥64 μg/ml), and controls were those with susceptible (MIC≤8 μg/ml) or susceptible-dependent-upon-dose (MIC 16–32 μg/ml)
strains. One hundred sixty-eight Candida strains were isolated from 153 (88%) patients, 28 (16%) of whom had oropharyngeal candidiasis. Overall, 19 (12%) of the patients
harbored at least one resistant organism (MIC≥64 μg/ml). Among patients with resistant strains, tuberculosis (P<0.001), esophageal candidiasis (P=0.001), clinical thrush (P<0.001), and a CD4+ cell count <200/mm3 (P=0.03) were more frequent. These patients had also been treated more commonly with antituberculous drugs (adjusted odds ratio
[OR] 6.13; 95% confidence interval [CI] 2.11–17.80), ciprofloxacin (OR 6.0; 95% CI 1.23–29.26), fluconazole (OR 4.59; 95%
CI 1.55–13.52), and steroids (OR 4.13; 95% CI 1.11–15.39). Multivariate analysis showed that the determinants for fluconazole
resistance were therapy with antituberculous drugs (OR 3.61; 95% CI 1.08–12.07;P=0.03) and one of the following: previous tuberculosis (OR 3.53; 95% CI 1.08–14.57;P=0.03) or fluconazole exposure (OR 3.41; 95% CI 1.10–10.54). Findings from this study indicate that treatment with antituberculous
drugs, previous tuberculosis, and fluconazole exposure are the strongest determinants for development of oropharyngeal colonization
or infection by fluconazole-resistant Candida strains in HIV-infected patients. 相似文献