In Vitro Activities of StrychnosAlkaloids and Extracts against Plasmodium falciparum

1999 ◽  
Vol 43 (9) ◽  
pp. 2328-2331 ◽  
Author(s):  
Michel Frederich ◽  
Marie-Pierre Hayette ◽  
Monique Tits ◽  
Patrick De Mol ◽  
Luc Angenot
Keyword(s):  
Plasmodium Falciparum ◽  
Resistant Strain ◽  
Inhibitory Concentration ◽  
Sensitive Strain ◽  
Resistant Strains

ABSTRACT The in vitro antimalarial activities of 46 alkaloids and extracts from Strychnos species were evaluated. Two types of quasidimeric alkaloids exhibit high and selective activities againstPlasmodium. Strychnopentamine and isostrychnopentamine were active against chloroquine-sensitive and -resistant strains (50% inhibitory concentration [IC50] ≈ 0.15 μM), while dihydrousambarensine exhibited a 30-fold higher activity against the chloroquine-resistant strain (IC50 = 0.03 μM) than it did against the chloroquine-sensitive strain.

Synthesis, antitrypanosomal and antimycobacterial activities of coumarinic N-acylhydrazonic derivatives

2020 ◽  
Vol 16 ◽  
Author(s):  
Camila Capelini ◽  
Vitória R. F. Câmara ◽  
José D. Figueroa Villar ◽  
Juliana M. C. Barbosa ◽  
Kelly Salomão ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Sensitive Strain ◽  
Moderate Activity ◽  
Active Compounds ◽  
Meaningful Activity ◽  
The World ◽  
Resistant Strains ◽  
Vitro Effect ◽  
Tuberculosis Activity

Background: Near to 5-7 million people are infected with T. cruzi in the world, and about 10,000 people per year die of problems associated to this disease. Method: We reported herein the synthesis, antitrypanosomal and antimycobacterial activities of seventeen coumarinic N-acylhydrazonic derivatives. Results: These compounds were synthesized using methodology with reactions global yields ranging from 46%-70%. T. cruzi in vitro effect were evaluated against trypomastigote and amastigote forms and M. tuberculosis activity were towards H37Rv sensitive strain and resistant strains. Discussion: Against T. cruzi, the more active compounds revealed only moderate activity IC50/96h~20 µM for both trypomastigotes and amastigotes intracellular forms. (E)-2-oxo-N'-(3,4,5-trimethoxybenzylidene)-2H-chromene-3-carbohydrazide showed meaningful activity in INH resistant/RIP resistant strain. Conclusion: These compound acting as multitarget could be good leads for the development of new trypanocidal and bactericidal agents.

scholarly journals Modified Fixed-Ratio Isobologram Method for Studying In Vitro Interactions between Atovaquone and Proguanil or Dihydroartemisinin against Drug-Resistant Strains of Plasmodium falciparum

2004 ◽  
Vol 48 (11) ◽  
pp. 4097-4102 ◽  
Author(s):  
Quinton L. Fivelman ◽  
Ipemida S. Adagu ◽  
David C. Warhurst
Keyword(s):  
Plasmodium Falciparum ◽  
Treatment Failure ◽  
Resistant Strain ◽  
Fixed Ratio ◽  
Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
In Vitro Interactions

ABSTRACT A modified fixed-ratio isobologram method for studying the in vitro interactions between antiplasmodial drugs is described. This method was used to examine the interactions between atovaquone, proguanil, and dihydroartemisinin. The interaction between atovaquone and proguanil was synergistic against atovaquone-sensitive strains K1 and T996; however, there was a loss of synergy against atovaquone-resistant strain NGATV01 isolated after Malarone (the combination of atovaquone and proguanil) treatment failure. While the interaction between atovaquone and dihydroartemisinin was indifferent against isolate NGATV01, the interaction displayed indifference tending toward antagonism against the atovaquone-sensitive strains tested. The relevance of in vitro interactions to in vivo treatment is discussed.

scholarly journals Statins as Potential Antimalarial Drugs: Low Relative Potency and Lack of Synergy with Conventional Antimalarial Drugs

2009 ◽  
Vol 53 (5) ◽  
pp. 2212-2214 ◽  
Author(s):  
Rina P. M. Wong ◽  
Timothy M. E. Davis
Keyword(s):  
Plasmodium Falciparum ◽  
Inhibitory Concentration ◽  
Antimalarial Drugs ◽  
Relative Potency ◽  
Treated Subject ◽  
In Vitro Sensitivity ◽  
Weak Activity ◽  
Resistant Strains

ABSTRACT The in vitro sensitivity of Plasmodium falciparum to atorvastatin and rosuvastatin was assessed using chloroquine-sensitive and chloroquine-resistant strains. Although atorvastatin was more potent, it had weak activity (mean 50% inhibitory concentration of ≥17 μM) and an indifferent interaction with chloroquine and dihydroartemisinin. Bioassay of plasma from an atorvastatin-treated subject showed similar results.

Immunity in trypanosomiasis

Parasitology ◽  
1959 ◽  
Vol 49 (1-2) ◽  
pp. 143-152 ◽  
Author(s):  
M. A. Soltys
Keyword(s):  
Resistant Strain ◽  
Therapeutic Dose ◽  
Sensitive Strain ◽  
Drug Resistant ◽  
Chemotherapeutic Drugs ◽  
Natural Conditions ◽  
Resistant Strains ◽  
Drug Resistant Strains

Antibody-resistant strains are less sensitive to suramin and antrycide than antibody-sensitive strains. When living trypanosomes were exposed to suramin and antrycide in vitro, antibody-resistant strains needed 50 times more drugs than antibody-sensitive trypanosomes in order to make them non-infectious to mice. In therapeutic experiments in mice the minimal therapeutic dose of drugs for antibody-sensitive strains was 0·1 mg. but for resistant strains it was 0·3 mg./20 g. mice. Rabbits treated prophylactically with suramin resisted infection with the antibody-sensitive strain for a period of 4 months, but failed to resist infection with the antibody-resistant strain after 2 months.Rabbits treated prophylactically with antrycide pro-salt, resisted infection with antibody-sensitive strains for a period of 2 months, but failed to resist infection with the antibody-resistant strain even 1 month after injection with the drug. Although trypanosomes can become drug resistant without being antibody resistant it is suggested that, under natural conditions, drug-resistant strains in animals and man develop from antibody-resistant strains, particularly when trypanostatic drugs are used. It is suggested in conclusion from these experiments that strains of trypanosomes which are exposed for some time to antibodies and become antibody resistant after passage through animals like rabbits, as well as those strains frequently passaged through mice, should be used in all tests for the efficiency of chemotherapeutic drugs.

Synthesis and Activity of Some Antimalarial Bisquinolinemethanols

1997 ◽  
Vol 50 (11) ◽  
pp. 1091 ◽  
Author(s):  
Alan F. Cowman, ◽  
Leslie W. Deady, ◽  
Eric Deharo, ◽  
José Desneves ◽  
Leann Tilley
Keyword(s):  
Plasmodium Falciparum ◽  
Resistant Strain ◽  
Cinchona Alkaloids ◽  
Cross Resistance ◽  
Side Chain ◽  
Highly Active ◽  
New Type ◽  
Resistant Strains ◽  
Further Development

A new type of bisquinoline antimalarial, containing the basic side chain of the cinchona alkaloids, has been evaluated. Five bis ethers, from 10,11-dihydrocupreine linked through the 6′-hydroxy group by -(CH2)2n- bridges (n = 2-5) (series A), and six bis amides, from 8′-amino-10,11-dihydrocinchonidine linked by -CO(CH2)2nCO- bridges (n = 1-6) (series B), were synthesized and screened against chloroquine-sensitive and -resistant strains and a mefloquine-resistant strain of Plasmodium falciparum in vitro. Two analogues of series B (n= 4; 5), with a 2-(dibutylamino)-1-hydroxyethyl side chain (series C), were also included. Compounds within series A were generally least active. Among the rest were compounds as active as mefloquine, with diminished cross-resistance to the mefloquine-resistant strain. The most potent (series B, n = 4) was highly active against chloroquine-sensitive, chloroquine-resistant and mefloquine-resistant parasites. Invivo testing, however, showed the compound to be too toxic for further development

scholarly journals Diversity-oriented synthesis derived indole based spiro and fused small molecules kills artemisinin-resistant Plasmodium falciparum

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Akshaykumar Nayak ◽  
Himani Saxena ◽  
Chandramohan Bathula ◽  
Tarkeshwar Kumar ◽  
Souvik Bhattacharjee ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Small Molecules ◽  
New Drugs ◽  
Developmental Cycle ◽  
Oxygen Species ◽  
Compound Library ◽  
Diversity Oriented Synthesis ◽  
Resistant Strains ◽  
Acid Catalyzed

Abstract Background Despite numerous efforts to eradicate the disease, malaria continues to remain one of the most dangerous infectious diseases plaguing the world. In the absence of any effective vaccines and with emerging drug resistance in the parasite against the majority of anti-malarial drugs, the search for new drugs is urgently needed for effective malaria treatment. Methods The goal of the present study was to examine the compound library, based on indoles generated through diversity-oriented synthesis belonging to four different architecture, i.e., 1-aryltetrahydro/dihydro-β-carbolines and piperidine/pyrrolidine-fused indole derivatives, for their in vitro anti-plasmodial activity. Trifluoroacetic acid catalyzed transformation involving tryptamine and various aldehydes/ketones provided the library. Results Among all the compounds screened, 1-aryltetrahydro-β-carbolines 2 and 3 displayed significant anti-plasmodial activity against both the artemisinin-sensitive and artemisinin-resistant strain of Plasmodium falciparum. It was observed that these compounds inhibited the overall parasite growth in intra-erythrocytic developmental cycle (IDC) via reactive oxygen species-mediated parasitic death and thus could be potential anti-malarial compounds. Conclusion Overall the compounds 2 and 3 identified in this study shows promising anti-plasmodial activity that can kill both artemisinin-sensitive and artemisinin-resistant strains of P. falciparum.

scholarly journals Assessment of the Drug Susceptibility of Plasmodium falciparum Clinical Isolates from Africa by Using a Plasmodium Lactate Dehydrogenase Immunodetection Assay and an Inhibitory Maximum Effect Model for Precise Measurement of the 50-Percent Inhibitory Concentration

2006 ◽  
Vol 50 (10) ◽  
pp. 3343-3349 ◽  
Author(s):  
Halima Kaddouri ◽  
Serge Nakache ◽  
Sandrine Houzé ◽  
France Mentré ◽  
Jacques Le Bras
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Active Metabolite ◽  
Inhibitory Concentration ◽  
Drug Susceptibility ◽  
Maximum Effect ◽  
Malaria Parasites ◽  
Effect Model

ABSTRACT The extension of drug resistance among malaria-causing Plasmodium falciparum parasites in Africa necessitates implementation of new combined therapeutic strategies. Drug susceptibility phenotyping requires precise measurements. Until recently, schizont maturation and isotopic in vitro assays were the only methods available, but their use was limited by technical constraints. This explains the revived interest in the development of replacement methods, such as the Plasmodium lactate dehydrogenase (pLDH) immunodetection assay. We evaluated a commercially controlled pLDH enzyme-linked immunosorbent assay (ELISA; the ELISA-Malaria antigen test; DiaMed AG, Cressier s/Morat, Switzerland) to assess drug susceptibility in a standard in vitro assay using fairly basic laboratory equipment to study the in vitro resistance of malaria parasites to major antimalarials. Five Plasmodium falciparum clones and 121 clinical African isolates collected during 2003 and 2004 were studied by the pLDH ELISA and the [8-3H]hypoxanthine isotopic assay as a reference with four antimalarials. Nonlinear regression with a maximum effect model was used to estimate the 50% inhibitory concentration (IC50) and its confidence intervals. The two methods were observed to have similar reproducibilities, but the pLDH ELISA demonstrated a higher sensitivity. The high correlation (r = 0.98) and the high phenotypic agreement (κ = 0.88) between the two methods allowed comparison by determination of the IC50s. Recently collected Plasmodium falciparum African isolates were tested by pLDH ELISA and showed drug resistance or decreased susceptibilities of 62% to chloroquine and 11.5% to the active metabolite of amodiaquine. No decreased susceptibility to lumefantrine or the active metabolite of artemisinin was detected. The availability of this simple and highly sensitive pLDH immunodetection assay will provide an easier method for drug susceptibility testing of malaria parasites.

scholarly journals Synthesis, antimalarial activity evaluation and molecular docking studies of some novel dispiro-1,2,4,5-tetraoxanes

2015 ◽  
Vol 10 (4) ◽  
pp. 917 ◽  
Author(s):  
Mukesh Kumar Kumawat ◽  
Dipak Chetia
Keyword(s):  
Plasmodium Falciparum ◽  
Molecular Docking ◽  
Resistant Strain ◽  
Antimalarial Activity ◽  
Binding Pocket ◽  
Docking Studies ◽  
Spectroscopic Techniques ◽  
Molecular Docking Studies ◽  
Activity Screening

<p class="Abstract">Seven novel dispiro-1,2,4,5-tetraoxane derivatives were synthesized and characterized by a number of analytical and spectroscopic techniques. The molecules were subsequently screened for in vitro antimalarial activity against chloroquine resistant strain of <em>Plasmodium falciparum</em> (RKL-9). At antimalarial activity screening, two compounds, namely 5d (MIC = 15.6 µg/mL or 64.5 µM) and 5f (MIC = 15.6 µg/mL or 54.6 µM) were found to be about 1.5 times more potent against chloroquine resistant strain-RKL-9 compared to chloroquine (MIC = 25.0 µg/mL or 78.3 µM). Molecular docking studies of potent ligands were also performed in cysteine protease binding pocket residues of falcipain-2 as a target protein.</p><p> </p>

scholarly journals IN VITRO STUDY OF URSOLIC ACID COMBINATION FIRST-LINE ANTITUBERCULOSIS DRUGS AGAINST DRUG-SENSITIVE AND DRUG-RESISTANT STRAINS OF Mycobacterium tuberculosis

2017 ◽  
Vol 10 (4) ◽  
pp. 216 ◽  
Author(s):  
Dian Ayu Eka Pitaloka ◽  
Elin Yulinah Sukandar
Keyword(s):  
Ursolic Acid ◽  
Drug Combination ◽  
Resistant Strain ◽  
Inhibitory Concentration ◽  
In Vitro Study ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Minimum Concentration ◽  
Different Strains

Objective: The resurgence of tuberculosis (TB) caused by Mycobacterium TB (MTB) is associated with the rapid spread of multidrug-resistant,therefore, the development of new antimycobacterial agents is necessary. The aim of this study was to evaluate the antimycobacterial activity ofursolic acid (UA) when it using alone and combination with TB drugs.Methods: MTB H37Rv strain, streptomycin-rifampicin resistant strain, and isoniazid-ethambutol resistant strain were evaluated by susceptibility testusing a serial number of UA (25-150 µg/mL). Minimum inhibitory concentration (MIC) was read as minimum concentration of drugs that completelyinhibit visible growth of organism. Activities of drug combination of UA with TB drug were determined in Lowenstein-Jensen media by calculatingthe fractional inhibitory concentration index.Results: The results showed that MIC of UA was 50 µg/mL against three different strains of MTB. The combination of UA and TB drugs displayedsynergistic interaction, and no antagonism result from the combination was observed for strains of MTB.Conclusion: These results indicate that UA may serve as a promising lead compound for future antimycobacterial drug development.Keywords: Ursolic acid, Tuberculosis, Drug combination, Susceptibility test

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