Antimalarial activity of Evolvulus alsinoids Linn.-an in vitro Plasmodium falciparum specific lactate dehydrogenase enzyme inhibition assay

The leaves of Erythrina variegata (Leguminosae) used tradisional plant of an antimalarial. In the course of our continuing search for novel an antimalarial compound from Erythrina plants, the methanol extract of the leaves ofE. variegata showed significant antimalarial activity in vitro toward Plasmodium falciparum in vitro using the lactate dehydrogenase (LDH) method. The methanol extract of the leaves of E. variegata showed against bothstrains of parasite with IC50of 6.8 ?g/ml against K1 and > 60 ?g/ml against 3D7, respectively. The methanol extract of the leaves of E. variegata was separated by using bioassay-guide fractionation. The n-buthanol fraction yieldedthe most activity, exhibiting equipotency against both strains of parasite with IC50of 5.1 ?g/ml against K1 and 13.5 ?g/ml against 3D7, respectively. Furthermore, by using the antimalarial activity to follow separation, the n-buthanol fraction was separated by combination of column chromatography to yield an active compound. The active compound showed antimalarial activity against both strains of parasite used with IC50 of 4.3 ?g/ml against K1 and 23.5 ?g/ml against 3D7, respectively. Its inhibition of the resistant strain (K1) was also much better compared to its inhibition of the sensitive strain (3D7), indicated that the leaves of E. variegata to be potential as antimalarial agents, but its lower potency compared to artemisinin and chloroquin.

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Lupane Analogue from Bark of Pithecellobium dulce and in vitro α-Glucosidase and α-Amylase Enzyme Inhibition Assay of Extract for Potential Antidiabetic Activity

Chemistry of Natural Compounds ◽

10.1007/s10600-016-1645-0 ◽

2016 ◽

Vol 52 (2) ◽

pp. 359-362 ◽

Cited By ~ 1

Author(s):

Shankar D. Katekhaye ◽

Atish Paul ◽

K. S. Laddha

Keyword(s):

Enzyme Inhibition ◽

Antidiabetic Activity ◽

Inhibition Assay ◽

Enzyme Inhibition Assay

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Field Evaluation of a Novel Colorimetric Method—Double-Site Enzyme-Linked Lactate Dehydrogenase Immunodetection Assay—To Determine Drug Susceptibilities of Plasmodium falciparum Clinical Isolates from Northwestern Thailand

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.4.1426-1429.2004 ◽

2004 ◽

Vol 48 (4) ◽

pp. 1426-1429 ◽

Cited By ~ 7

Author(s):

Alan Brockman ◽

Sittaporn Singlam ◽

Lucy Phiaphun ◽

Sornchai Looareesuwan ◽

Nicholas J. White ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Lactate Dehydrogenase ◽

Colorimetric Assay ◽

Colorimetric Method ◽

Field Evaluation ◽

Field Isolates ◽

Wide Range ◽

Dehydrogenase Enzyme ◽

Northwestern Thailand

ABSTRACT A double-site enzyme-linked lactate dehydrogenase enzyme immunodetection assay was tested against field isolates of Plasmodium falciparum for assessing in vitro drug susceptibilities to a wide range of antimalarial drugs. Its sensitivity allowed the use of parasite densities as low as 200 parasites/μl of blood. Being a nonisotopic, colorimetric assay, it lies within the capabilities of a modest laboratory at the district level.

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Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽

10.1182/blood.v76.6.1250.1250 ◽

1990 ◽

Vol 76 (6) ◽

pp. 1250-1255 ◽

Cited By ~ 36

Author(s):

S Whitehead ◽

TE Peto

Keyword(s):

Plasmodium Falciparum ◽

Growth Inhibition ◽

Antimalarial Activity ◽

Clinical Malaria ◽

Inhibitory Effect ◽

Parasite Development ◽

And Control ◽

Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

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In vitro activities of novel catecholate siderophores against Plasmodium falciparum.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.9.2094 ◽

1996 ◽

Vol 40 (9) ◽

pp. 2094-2098 ◽

Cited By ~ 13

Author(s):

B Pradines ◽

F Ramiandrasoa ◽

L K Basco ◽

L Bricard ◽

G Kunesch ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Mechanism Of Action ◽

Ribonucleotide Reductase ◽

Antimalarial Activity ◽

Iron Chelators ◽

Resistant Clone ◽

Iron Deprivation ◽

Level Of Activity ◽

Susceptible Clone

The activities of novel iron chelators, alone and in combination with chloroquine, quinine, or artemether, were evaluated in vitro against susceptible and resistant clones of Plasmodium falciparum with a semimicroassay system. N4-nonyl,N1,N8-bis(2,3-dihydroxybenzoyl) spermidine hydrobromide (compound 7) demonstrated the highest level of activity: 170 nM against a chloroquine-susceptible clone and 1 microM against a chloroquine-resistant clone (50% inhibitory concentrations). Compounds 6, 8, and 10 showed antimalarial activity with 50% inhibitory concentrations of about 1 microM. Compound 7 had no effect on the activities of chloroquine, quinine, and artemether against either clone, and compound 8 did not enhance the schizontocidal action of either chloroquine or quinine against the chloroquine-resistant clone. The incubation of compound 7 with FeCI3 suppressed or decreased the in vitro antimalarial activity of compound 7, while no effect was observed with incubation of compound 7 with CuSO4 and ZnSO4. These results suggest that iron deprivation may be the main mechanism of action of compound 7 against the malarial parasites. Chelator compounds 7 and 8 primarily affected trophozoite stages, probably by influencing the activity of ribonucleotide reductase, and thus inhibiting DNA synthesis.

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Synthesis and in Vitro Antimalarial Activity of Alkyl Esters Gallate as a Growth Inhibitors of Plasmodium Falciparum

Oriental Journal Of Chemistry ◽

10.13005/ojc/340207 ◽

2018 ◽

Vol 34 (2) ◽

pp. 655-662 ◽

Cited By ~ 2

Author(s):

Ade Arsianti ◽

Hendry Astuti ◽

Fadilah Fadilah ◽

Daniel Martin Simadibrata ◽

Zoya Marie Adyasa ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Antimalarial Activity ◽

Growth Inhibitors ◽

Alkyl Esters

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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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00367-06 ◽

2006 ◽

Vol 50 (10) ◽

pp. 3343-3349 ◽

Cited By ~ 61

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.

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

Bangladesh Journal of Pharmacology ◽

10.3329/bjp.v10i4.24532 ◽

2015 ◽

Vol 10 (4) ◽

pp. 917 ◽

Cited By ~ 1

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

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 Plasmodium falciparum (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.

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Overexpression of Plasmodium falciparum M1 Aminopeptidase Promotes an Increase in Intracellular Proteolysis and Modifies the Asexual Erythrocytic Cycle Development

Pathogens ◽

10.3390/pathogens10111452 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1452

Author(s):

Carolina C. Hoff ◽

Mauro F. Azevedo ◽

Adriana B. Thurler ◽

Sarah El Chamy Maluf ◽

Pollyana M. S. Melo ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Antimalarial Activity ◽

Fold Increase ◽

Cysteine Proteases ◽

Aminopeptidase Activity ◽

Lower Sensitivity ◽

Wild Type ◽

Erythrocytic Cycle ◽

Transgenic Parasite

Plasmodium falciparum, the most virulent of the human malaria parasite, is responsible for high mortality rates worldwide. We studied the M1 alanyl-aminopeptidase of this protozoan (PfA-M1), which is involved in the final stages of hemoglobin cleavage, an essential process for parasite survival. Aiming to help in the rational development of drugs against this target, we developed a new strain of P. falciparum overexpressing PfA-M1 without the signal peptide (overPfA-M1). The overPfA-M1 parasites showed a 2.5-fold increase in proteolytic activity toward the fluorogenic substrate alanyl-7-amido-4-methylcoumarin, in relation to the wild-type group. Inhibition studies showed that overPfA-M1 presented a lower sensitivity against the metalloaminopeptidase inhibitor bestatin and to other recombinant PfA-M1 inhibitors, in comparison with the wild-type strain, indicating that PfA-M1 is a target for the in vitro antimalarial activity of these compounds. Moreover, overPfA-M1 parasites present a decreased in vitro growth, showing a reduced number of merozoites per schizont, and also a decrease in the iRBC area occupied by the parasite in trophozoite and schizont forms when compared to the controls. Interestingly, the transgenic parasite displays an increase in the aminopeptidase activity toward Met-, Ala-, Leu- and Arg-7-amido-4-methylcoumarin. We also investigated the potential role of calmodulin and cysteine proteases in PfA-M1 activity. Taken together, our data show that the overexpression of PfA-M1 in the parasite cytosol can be a suitable tool for the screening of antimalarials in specific high-throughput assays and may be used for the identification of intracellular molecular partners that modulate their activity in P. falciparum.

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