scholarly journals Targeting of Hematin by the Antimalarial Pyronaridine

2006 ◽  
Vol 50 (6) ◽  
pp. 2197-2200 ◽  
Author(s):  
Saranya Auparakkitanon ◽  
Soebsakul Chapoomram ◽  
Kannika Kuaha ◽  
Thamrong Chirachariyavej ◽  
Prapon Wilairat
Keyword(s):  
Plasmodium Falciparum ◽  
Blood Cell ◽  
Mechanism Of Action ◽  
Red Blood Cell ◽  
Mannich Base ◽  
Cell Lysis ◽  
Clinical Testing ◽  
Growth Studies

ABSTRACT Pyronaridine, 2-methoxy-7-chloro-10[3′,5′-bis(pyrrolidinyl-1-methyl-)4′hydroxyphenyl]aminobenzyl-(b)-1,5-naphthyridine, a new Mannich base schizontocide originally developed in China and structurally related to the aminoacridine drug quinacrine, is currently undergoing clinical testing. We now show that pyronaridine targets hematin, as demonstrated by its ability to inhibit in vitro β-hematin formation (at a concentration equal to that of chloroquine), to form a complex with hematin with a stoichiometry of 1:2, to enhance hematin-induced red blood cell lysis (but at 1/100 of the chloroquine concentration), and to inhibit glutathione-dependent degradation of hematin. Our observations that pyronaridine exerted this mechanism of action in situ, based on growth studies of Plasmodium falciparum K1 in culture showing antagonism of pyronaridine in combination with antimalarials (chloroquine, mefloquine, and quinine) that inhibit β-hematin formation, were equivocal.

LIPIODOL reduces the lytic activity of detergent sclerosants in vitro

2021 ◽  
pp. 026835552110183
Author(s):  
Joseph Gracé ◽  
David Connor ◽  
Lourens Bester ◽  
Christopher Rogan ◽  
Kurosh Parsi
Keyword(s):  
Blood Cell ◽  
Contrast Agents ◽  
Red Blood Cell ◽  
Cell Lysis ◽  
Vascular Anomalies ◽  
Lytic Activity ◽  
Sodium Tetradecyl Sulfate ◽  
Limited Information ◽  
Embolic Agents

Objectives Contrast agents are used widely in the interventional setting and in particularly in the management of vascular anomalies and have also been used in combination with sclero-embolic agents. There is limited information on the interaction of contrast agents with sclerosant agents when used as mixtures. The aim of this study was to determine the effect of mixing radiological contrast agents with detergent sclerosants and measuring the effect on change in lytic activity of detergent sclerosants in vitro and by proxy the change in potency. Methods Red blood cell lysis was assessed following the incubation of two commonly used contrast agents, LIPIODOL® and ULTRAVIST®, mixed with detergent sclerosants, FIBROVEIN®, sodium tetradecyl sulfate (STS), and AETHOXYSKLEROL®, polidocanol (POL). Results The density of both contrast agents was higher than STS and POL and neither of the detergent sclerosants were miscible in LIPIODOL. LIPIODOL on its own caused cell lysis (1.01%, p < 0.05) whereas ULTRAVIST did not. Fifty per cent cell lysis for sclerosant and LIPIODOL mix occurred at concentrations of: 0.041% (2.4 times greater than the control, p < 0.05) and 0.08% (3.6 times greater than the control, p = 0.06) for STS and POL, respectively. Conclusions LIPIODOL, when mixed with sclerosant detergents (ratio 1:1) causes a reduction in the lytic activity of sclerosants and this effect was statistically significant and most prominent in lower sclerosant concentration mixtures.

Investigation of the Free and Total Thyroxine-binding Capacity of Plasma Proteins in Thyroid Disorders

1971 ◽  
Vol 10 (04) ◽  
pp. 299-304
Author(s):  
József Takó ◽  
János Fischer ◽  
Jusztina Juhász ◽  
Ilona Sztraka ◽  
István Kapus ◽  
...  
Keyword(s):  
Blood Cell ◽  
Thyroid Function ◽  
Oral Contraceptives ◽  
Red Blood Cell ◽  
Plasma Proteins ◽  
Binding Capacity ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Total Thyroxine

SummaryThe results of thyroid function tests have been compared with data on the thyroxine-binding capacity of plasma proteins in hyper-, hypo- and euthyroid cases, the latter including women taking oral contraceptives (Infecundin). It was found that there exists a significant correlation of exponential nature between the in vitro red blood cell 125I-triiodothyronine uptake (RCU) and the free thyroxine-binding capacity of the thyroxine-inding globulin (TBG).

Patents on Red Blood Cell Manufacturing In Vitro

2011 ◽  
Vol 1 (2) ◽  
pp. 173-181
Author(s):  
Laurence Guyonneau-Harmand ◽  
Luc Douay
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Manufacturing

scholarly journals In vitro activities of novel catecholate siderophores against Plasmodium falciparum.

1996 ◽  
Vol 40 (9) ◽  
pp. 2094-2098 ◽  
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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