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1.
Asokan Bagavan Abdul Abdul Rahuman Naveen Kumar Kaushik Dinkar Sahal 《Parasitology research》2011,108(1):15-22
Malaria is a major global public health problem, and the alarming spread of drug resistance and limited number of effective
drugs now available underline how important it is to discover new antimalarial compounds. In the present study, ten plants
were extracted with ethyl acetate and methanol and tested for their antimalarial activity against chloroquine (CQ)-sensitive
(3D7) and CQ-resistant (Dd2 and INDO) strains of Plasmodium falciparum in culture using the fluorescence-based SYBR Green assay. Plant extracts showed moderate to good antiparasitic effects. Promising
antiplasmodial activity was found in the extracts from two plants, Phyllanthus emblica leaf 50% inhibitory concentration (IC50) 3D7: 7.25 μg/mL (ethyl acetate extract), 3.125 μg/mL (methanol extract), and Syzygium aromaticum flower bud, IC50 3D7:13 μg/mL, (ethyl acetate extract) and 6.25 μg/mL (methanol extract). Moderate activity (30–75 μg/mL) was found in the
ethyl acetate and methanol extracts of Abrus precatorius (seed) and Gloriosa superba (leaf); leaf ethyl acetate extracts of Annona squamosa and flower of Musa paradisiaca. The above mentioned plant extracts were also found to be active against CQ-resistant strains (Dd2 and INDO). Cytotoxicity
study with P. emblica leaf and S. aromaticum flower bud, extracts showed good therapeutic indices. These results demonstrate that leaf ethyl acetate and methanol extracts
of P. emblica and flower bud extract of S. aromaticum may serve as antimalarial agents even in their crude form. The isolation of compounds from P. emblica and S. aromaticum seems to be of special interest for further antimalarial studies. 相似文献
2.
Antimalarial activity of betulinic acid and derivatives in vitro against Plasmodium falciparum and in vivo in P. berghei-infected mice 总被引:1,自引:1,他引:0
Matheus Santos de Sá José Fernando Oliveira Costa Antoniana Ursine Krettli Mariano Gustavo Zalis Gabriela Lemos de Azevedo Maia Ivana Maria Fechine Sette Celso de Amorim Camara José Maria Barbosa Filho Ana Maria Giulietti-Harley Ricardo Ribeiro dos Santos Milena Botelho Pereira Soares 《Parasitology research》2009,105(1):275-279
Malaria is one of the most important tropical diseases and mainly affects populations living in developing countries. Reduced
sensitivity of Plasmodium sp. to formerly recommended antimalarial drugs places an increasing burden on malaria control programs as well as on national
health systems in endemic countries. The present study aims to evaluate the antimalarial activity of betulinic acid and its
derivative compounds, betulonic acid, betulinic acid acetate, betulinic acid methyl ester, and betulinic acid methyl ester
acetate. These substances showed antiplasmodial activity against chloroquine-resistant Plasmodium falciparum parasites in vitro, with IC50 values of 9.89, 10.01, 5.99, 51.58, and 45.79 μM, respectively. Mice infected with Plasmodium berghei and treated with betulinic acid acetate had a dose-dependent reduction of parasitemia. Our results indicate that betulinic
acid and its derivative compounds are candidates for the development of new antimalarial drugs. 相似文献
3.
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
4.
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
5.
Kemgne EA Mbacham WF Boyom FF Zollo PH Tsamo E Rosenthal PJ 《Parasitology research》2012,110(1):109-117
In a search for new plant-derived antimalarial extracts, 19 fractions were obtained from three Annonaceae species, Uvariopsis congolana (leaf, stem), Polyalthia oliveri (stem bark), and Enantia chlorantha (stem, stem bark) with yields ranging from 0.33% to 4.60%. The extracts were prepared from 500 g of each plant part, using
organic solvents to afford five methanolic fractions (acetogenin rich), five water fractions, five hexane fractions, and four
interface precipitates. Evaluation of the activity of fractions in vitro against field isolates of the malaria parasite Plasmodium falciparum showed that acetogenin-rich fractions and interface precipitates were the most potent, with IC50 values ranging from 0.05 to 8.09 μg/ml. Sensitivity of parasite isolates to plant extracts varied greatly, with over 100-fold
difference from isolate to isolate in some cases. The active acetogenin-rich fractions and interface precipitates were assessed
in combination with chloroquine in the same conditions, and showed additive interaction in the huge majority of cases. Synergistic
interactions were found in some cases with acetogenin-rich fractions. Acute toxicity of promising fractions was evaluated
through oral administration in Swiss albino mice. Tested fractions appeared to be safe, with LD50 values higher than 2 g/kg. In summary, acetogenin-rich fractions from Annonaceae species showed high potency against P. falciparum field isolates and safety by oral administration in mice, supporting their detailed investigation for antimalarial drug discovery. 相似文献
6.
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
7.
Shuaibu MN Wuyep PA Yanagi T Hirayama K Tanaka T Kouno I 《Parasitology research》2008,102(6):1119-1127
In vitro antiplasmodial activity of methanolic extracts of 16 medicinal plants was evaluated by fluorometric assay using PicoGreen.
The IC50s, as determined by parasite DNA concentration, ranged from <11 to >200 and <13 to >200 μg/ml for Plasmodium falciparum 3D7 and K1, respectively; and the most active extracts were those from Anogeissus leiocarpus and Terminalia avicennoides (<11–≥14 μg/ml). Aqueous, butanolic, ethyl acetate, and methanolic fractions of these two extracts revealed butanolic fraction
to have a relatively better activity (IC50, 10–12 μg/ml). Activity-guided 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 hydrolysable tannins
and some related compounds—castalagin, ellagic acid, flavogallonic acid, punicalagin, terchebulin, and two other fractions.
The IC50s of all these compounds ranged between 8–21 μg/ml (8–40 μM) against both the strains. Toxicity assay with mouse fibroblasts
showed all the extracts and isolated compounds to have IC50 ≥ 1500 μg/ml, except for Momordica balsamina with <1500 μg/l. All the extracts and isolated compounds did not affect the integrity of human erythrocyte membrane at the
observed IC50s. However, adverse effects manifest in a concentration-dependent fashion (from IC50 ≥ 500 μg/ml). 相似文献
8.
Delhaes L Abessolo H Biot C Berry L Delcourt P Maciejewski L Brocard J Camus D Dive D 《Parasitology research》2001,87(3):239-244
Previous studies have shown that ferrochloroquine (FQ) exhibited an antimalarial activity against Plasmodium spp. The present work confirmed this activity, described the curative effect on P. vinckei and investigated the FQ toxicity in vitro and in vivo. The in vitro and in vivo growth inhibition of P. falciparum and P. berghei N, respectively, showed that FQ antimalarial activity was 1.5–10 times more potent than chloroquine. FQ completely inhibited
the in vivo development of both chloroquine-susceptible and resistant P. vinckei strains and protected mice from lethal infection at a dose of 8.4 mg kg−1 day−1 given for 4 days subcutaneously or orally. This curative effect was 5–20 times more potent than chloroquine, according to
the strains' resistance to chloroquine. At this curative dose, no clinical changes were observed in mice up to 14 days after
the last administration. Nevertheless, the acute toxicity and lethality of ferrochloroquine seemed to be dependent on gastric
surfeit. The FQ security index determined in vitro confirmed that it might be a promising compound.
Received: 12 August 2000 / Accepted: 16 August 2000 相似文献
9.
Malaria is a major global public health problem, and the alarming spread of drug resistance and limited number of effective
drugs now available underline how important it is to discover new antimalarial compounds. An ethnopharmacological investigation
was undertaken on Western Ghats plants traditionally used to treat malaria in India; 50 plants were very carefully selected
from a total of 372 plants, and 200 extracts were prepared and tested for in vitro antiplasmodial activity alone and in combination
with chloroquine (CQ) against CQ-resistant Plasmodium falciparum (strain MRC-Pf-43). In in vitro antiplasmodial activity, when plant extract alone is used, 29 extracts (or 14.5%) showed
significant high in vitro antiplasmodial activity with IC50 values ranging from 3.96 to 4.85 μg/ml, 53 extracts (or 26.5%) showed significant good in vitro antiplasmodial activity with
IC50 values ranging from 5.02 to 9.87 μg/ml, and 28 extracts (or 14%) showed significant moderate in vitro antiplasmodial activity
with IC50 values ranging from 10.87 to 14 μg/ml, respectively. In combination with CQ, 103 extracts (or 51.5%) showed significant synergistic
in vitro antiplasmodial activities with synergistic factor values ranging from 1.03 to 1.92, and these activities were up
to a fold higher with CQ, suggesting synergistic interactions of the two drugs. Our investigation has confirmed that above
62.1% of the plant extracts showed moderate to high in vitro antiplasmodial activity when used alone, and in combination with
CQ, 55.7% of the extracts showed borderline to good synergistic activity. 相似文献
10.
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
11.
Nduati E Diriye A Ommeh S Mwai L Kiara S Masseno V Kokwaro G Nzila A 《Parasitology research》2008,102(6):1227-1234
The folate derivatives folic acid (FA) and folinic acid (FNA) decrease the in vivo and in vitro activities of antifolate drugs
in Plasmodium falciparum. However, the effects of 5-methyl-tetrahydrofolate (5-Me-THF) and tetrahydrofolate (THF), the two dominant circulating folate
forms in humans, have not been explored yet. We have investigated the effects of FA, FNA, 5-Me-THF, and THF on the in vitro
activity of the antimalarial antifolates pyrimethamine and chlorcycloguanil and the anticancer antifolates methotrexate (MTX),
aminopterin, and trimetrexate (TMX), against P. falciparum. The results indicate that these anticancers are potent against P. falciparum, with IC50 < 50 nM. 5-Me-THF does not significantly decrease the activity of all tested drugs, and none of the tested folate derivatives
significantly decrease the activity of these anticancers. Thus, malaria folate metabolism has features different from those
in human, and the exploitation of this difference could lead to the discovery of new drugs to treat malaria. For instance,
the combination of 5-Me-THF with a low dose of TMX could be used to treat malaria. In addition, the safety of a low dose of
MTX in the treatment of arthritis indicates that this drug could be used alone to treat malaria.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
This study was supported by Pfizer-Royal Society Award, UK (to AN), the EU Commission under Framework 6 as part of the AntiMal
Integrated Project 018834, and the European & Developing Countries Clinical Trials Partnership (EDCPT). 相似文献
12.
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
13.
New stilbene glycoside, piceid-(1→6)-β-d-glucopyranoside (compound 2, Fig. 1), was isolated from the MeOH extract of the leaves of Parthenocissus tricuspidata (Vitaceae) together with four known compounds, piceid (compound 1, Fig. 1), resveratrol (compound 3, Fig. 1), longistylin
A (compound 4, Fig. 1), and longistylin C (compound 5, Fig. 1). Their structures were determined spectroscopically, particularly
by 2D nuclear magnetic resonance (NMR) spectroscopic and chemical analysis. The antiplasmodial activity of isolated compounds
were determined in vitro against a chloroquine-sensitive strain of Plasmodium falciparum (D10). Among the compounds isolated, piceid-(1→6)-β-d-glucopyranoside (2) had the most potential inhibition, with inhibitory concentration (IC50) values of 5.3 μM. To our knowledge, antiplasmodial activity of functional group position of stilbene is now being reported
for the first time in this study. The result shows that the 3, 4′-position in stilbenes might play an essential role in antiplasmodial
activity.
Il Hong Son and Ill-Min Chung equally contributed to this work. 相似文献
14.
Jean Bickii Guy Raymond Feuya Tchouya Jean Claude Tchouankeu Etienne Tsamo 《African journal of traditional, complementary, and alternative medicines》2007,4(2):135-139
In the search of active principles from the stem bark of Entandrophragma angolense, we submitted the compounds isolated from the dichloromethane - methanol (1:1) extract of the stem bark to antimalarial test against chloroquine resistant strain W2 of Plasmodium falciparum malaria parasite. Only 7α-obacunyl acetate and a cycloartane derivative exhibited a good activity, with IC50s of 2 and 5.4 µg/ml respectively. Other compounds were moderately active. 相似文献
15.
W. Raether B. Enders J. Hofmann U. Schwannecke H. Seidenath H. Hänel M. Uphoff 《Parasitology research》1989,75(8):619-626
Deoxyfloxacrine derivatives (1-hydrazone: S 83 0083; 1-imine: S 84 7277) and floxacrine derivatives (10-methoxy-floxacrine: L 84 7667; 1-imine: L 84 7693) selected from a series of newly synthesized 3-aryl-7-chloro-3,4-dihydro-1,9(2H, 10H)-acridinediones were evaluated for blood schizontocidal activities in mice infected with asexual stages of various drug-resistant lines ofP. berghei and in New World monkeys infected with blood schizonts of different chloroquine-resistant strains ofP. falciparum. All compounds tested showed high activity against drug-resistant lines ofP. berghei (ED50: 1.0–4.4 mg/kg×5, per os) and were distinctly superior in their antimalarial potency to floxacrine. Compounds L 84 7667 and L 84 7693 proved to be highly active against the FCBR strain ofP. falciparum in vitro (IC50: 0.73–1.78 nmol); they effected temporary clearance of parasitemias due to the Palo Alto strain ofP. falciparum in squirrel monkeys at oral doses of 15 mg/kg given daily for 5 consecutive days. Compounds S 83 0083 and S 84 7277, showing moderate in vitro effects (12.9–24.8 nmol), cleared parasitemias of the FCBR strain ofP. falciparum in owl monkeys at oral doses of 20 mg/kg (S 84 7277) given daily for 5 or 7 consecutive days (follow-up period, 17 and 30 days, respectively) or at doses of 20 mg/kg (×4) (S 83 0083) followed by doses of 40 mg/kg (×3) within a follow-up period of 30 days. These observations suggest that the range of doses required for the cure of establishedP. falciparum infections is probably too large to cover infections with strains of the least susceptibility and might evoke toxic reactions by the potential candidates tested. 相似文献
16.
Aly NS Hiramoto A Sanai H Hiraoka O Hiramoto K Kataoka H Wu JM Masuyama A Nojima M Kawai S Kim HS Wataya Y 《Parasitology research》2007,100(5):1119-1124
N-89, a new antimalarial endoperoxide, was selected as a promising antimalarial compound showing high activity and selectivity.
To study the mechanism of N-89 action, N-89 resistant strain (NRC10) was obtained by intermittent drug pressure. NRC10 had
a tenfold increase in the EC50 value of N-89. No cross-resistance was obtained with other antimalarial compounds. Comparative proteome analysis of N-89
sensitive and NRC10 strains revealed over-expression of 12 spots and down-regulation of 14 spots in NRC10. Fifteen proteins
were identified of Plasmodium falciparum origin. The identified proteins representing several functions, mainly related to the glycolytic pathway, and metabolism
of protein and lipid. Our results suggest that identified proteins may be candidates of antimalarial endoperoxide targets. 相似文献
17.
In Vitro Culture and Drug Sensitivity Assay of Plasmodium falciparum with Nonserum Substitute and Acute-Phase Sera 总被引:1,自引:0,他引:1 下载免费PDF全文
Pascal Ringwald Fleurette Solange Meche Jean Bickii Leonardo K. Basco 《Journal of clinical microbiology》1999,37(3):700-705
The short-term in vitro growth of Plasmodium falciparum parasites in the asexual erythrocytic stage and the in vitro activities of eight standard antimalarial drugs were assessed and compared by using RPMI 1640 medium supplemented with 10% nonimmune human serum, 10% autologous or homologous acute-phase serum, or 0.5% Albumax I (lipid-enriched bovine serum albumin). In general, parasite growth was maximal with autologous (or homologous) serum, followed by Albumax I and nonimmune serum. The 50% inhibitory concentrations (IC50s) varied widely, depending on the serum or serum substitute. The comparison of IC50s between assays with autologous and nonimmune sera showed that monodesethylamodiaquine, halofantrine, pyrimethamine, and cycloguanil had similar IC50s. Although the IC50s of chloroquine, monodesethylamodiaquine, and dihydroartemisinin were similar with Albumax I and autologous sera, the IC50s of all test compounds obtained with Albumax I differed considerably from the corresponding values obtained with nonimmune serum. Our results suggest that Albumax I and autologous and homologous sera from symptomatic, malaria-infected patients may be useful alternative sources of serum for in vitro culture of P. falciparum isolates in the field. However, autologous sera and Albumax I do not seem to be suitable for the standardization of isotopic in vitro assays for all antimalarial drugs. 相似文献
18.
Artitaya Thiengsusuk Wanna Chaijaroenkul Kesara Na-Bangchang 《Parasitology research》2013,112(4):1475-1481
Malaria is one of the world's leading killer infectious diseases with high incidence and morbidity. The problem of multidrug-resistant Plasmodium falciparum has been aggravating particularly in Southeast Asia. Therefore, development of new potential antimalarial drugs is urgently required. The present study aimed to investigate antimalarial activities of a total of 27 medicinal plants and 5 herbal formulations used in Thai traditional medicine against chloroquine-resistant (K1) and chloroquine-sensitive (3D7) P. falciparum clones. Antimalarial activity of the ethanolic extracts of all plants/herbal formulations against K1 and 3D7 P. falciparum clones was assessed using SYBR Green I-based assay. All plants were initially screened at the concentration of 50 μg/ml to select the candidate plants that inhibited malaria growth by ≥50 %. Each candidate plant was further assessed for the IC50 value (concentration that inhibits malaria growth by 50 %) to select the potential plants. Selectivity index (SI) of each extract was determined from the IC50 ratio obtained from human renal epithelial cell and K1 or 3D7 P. falciparum clone. The ethanolic extracts from 19 medicinal plants/herbal formulation exhibited promising activity against both K1 and 3D7 clones of P. falciparum with survival of less than 50 % at the concentration of 50 μg/ml. Among these, the extracts from the eight medicinal plants (Plumbago indica Linn., Garcinia mangostana Linn., Dracaena loureiri Gagnep., Dioscorea membranacea Pierre., Artemisia annua Linn., Piper chaba Hunt., Myristica fragrans Houtt., Kaempferia galanga Linn.) and two herbal formulations (Benjakul Formulation 1 and Pra-Sa-Prao-Yhai Formulation) showed potent antimalarial activity with median range IC50 values of less than 10 μg/ml against K1 or 3D7 P. falciparum clone or both. All except G. mangostana Linn. and A. annua Linn. showed high selective antimalarial activity against both clones with SI?>?10. Further studies on antimalarial activities in an animal model including molecular mechanisms of action of the isolated active moieties are required. 相似文献
19.
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
20.
Growing awareness in using ecofriendly and biologically compatible phytoconstituents as natural insecticides and repellents
for the safety of life and ecological balance led to conscientious efforts by scientists all over the world to search for
alternative sources of plant derivatives for effective use as mosquitocides. Encouraged by this, the essential oil and the
sesquiterpenes isolated from the leaves of Chloroxylon swietenia DC. were screened for mosquitocidal activity by fumigant toxicity against three mosquito species, Anopheles gambiae, Culex quinquefasciatus and Aedes aegypti. The essential oil had pronounced mosquitocidal activity with LD50 of 1.0, 1.2 and 1.7 × 10−3 mg/cm−3, respectively, for the three vector species. Furthermore, the major sesquiterpenes were tested at different doses, which
again showed varying levels of toxicity. However, germacrene D performed better and proved to be the potential candidate with
LD50 values of 1.8–2.8 × 10−3 mg/cm−3 followed by pregeijerene and geijerene. Nevertheless, the oil and the isolated compounds were particularly active against
A. gambiae. The essential oil from the leaves was obtained by hydrodistillation, and the chemical composition was determined by GC and
GC–MS. The main compounds identified were limonene, germacrene D, geijerene, pregeijerene, trans-β-ocimene and methyl eugenol. The present study indicates that the oil and the isolated compounds of C. swietenia displayed remarkable mosquitocidal activity suggesting that the method could be extended for future field trials in various
mosquito control programmes, and the results are compared with synthetic insecticides. 相似文献