Inhibition of Na,K-ATPase by oleandrin and oleandrigenin, and their detection by digoxin immunoassays

Abstract Ingestion of oleander plant, containing the cardiac glycoside oleandrin, has been reported to induce fatal poisonings. Derivatives of oleandrin are structurally similar to digoxin. We investigated the cross-reactivities of oleandrin and its aglycone metabolite, oleandrigenin, in several commercially available digoxin immunoassays; assessed their ability to inhibit Na,K-ATPase catalytic activity; and measured their binding to proteins in serum. As assayed with ACS:180, Stratus, RIA, On-Line, and TDx digoxin assays, oleandrin at 100 micromol/L in digoxin-free serum gave apparent digoxin values of 0, 0.83, 2.24, 2.37, and 5.34 nmol/L, respectively, whereas oleandrigenin at that concentration gave results of 0, 0.52, 0.77, 4.94, and 1.40 nmol/L. Study of Na,K-ATPase inhibition showed IC50 values (micromol/L) of 0.22 for ouabain, 0.62 for oleandrin, 1.23 for oleandrigenin, and 2.69 for digoxin. At 25 degrees C, 96% of oleandrin and 48% of oleandrigenin were bound to serum proteins. Because detection of oleandrin and oleandrigenin by digoxin immunoassays is variable between assays as well as between congeners, assessment of cross-reactivity is warranted for each assay. The inhibition of Na,K-ATPase by oleandrin and oleandrigenin confirms that they likely exert their toxic effects through inhibition of sodium pump activity. In cases of digitalis-like poisoning with suspicion of oleander ingestion, a combination of digoxin immunoassays may be useful to effectively rule out the presence of oleander.

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Synthesis of Novel 1,2,3-Triazole Derivatives of Isocoumarins and 3,4-Dihydroisocoumarin with Potential Antiplasmodial Activity In Vitro

Medicinal Chemistry ◽

10.2174/1573406416666200602161047 ◽

2020 ◽

Vol 16 ◽

Author(s):

Lucas da Silva Santos ◽

Matheus Fillipe Langanke de Carvalho ◽

Ana Claudia de Souza Pinto ◽

Amanda Luisa da Fonseca ◽

Julio César Dias Lopes ◽

...

Keyword(s):

Triazole Ring ◽

Antiplasmodial Activity ◽

World Health ◽

Dipolar Cycloaddition ◽

Terminal Alkynes ◽

The World ◽

Ic50 Values ◽

Derivatives Of ◽

Active Substances

Background: Malaria greatly affects the world health, having caused more than 228 million cases only in 2018. The emergence of drug resistance is one of the main problems in its treatment, demonstrating the urge for the development of new antimalarial drugs. Objective: Synthesis and in vitro antiplasmodial evaluation of triazole compounds derived from isocoumarins and a 3,4- dihydroisocoumarin. Method: The compounds were synthesized in 4 to 6-step reactions with the formation of the triazole ring via the Copper(I)-catalyzed 1,3-dipolar cycloaddition between isocoumarin or 3,4-dihydroisocoumarin azides and terminal alkynes. This key reaction provided compounds with an unprecedented connection of isocoumarin or 3,4-dihydroisocoumarin and the 1,2,3-triazole ring. The products were tested for their antiplasmodial activity against a Plasmodium falciparum chloroquine resistant and sensitive strains (W2 and 3D7, respectively). Results: Thirty-one substances were efficiently obtained by the proposed routes with an overall yield of 25-53%. The active substances in the antiplasmodial test displayed IC50 values ranging from 0.68-2.89 μM and 0.85-2.07 μM against W2 and 3D7 strains, respectively.

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Interaction of alcohol and kola nut on brain sodium pump activity in Wistar rats

Toxicological and Environmental Chemistry ◽

10.1080/02772240802028682 ◽

2009 ◽

Vol 91 (2) ◽

pp. 357-362

Author(s):

G.O. Obochi ◽

A.E. Abara ◽

S.P. Malu ◽

M.U. Eteng ◽

I.B. Umoh

Keyword(s):

Wistar Rats ◽

Sodium Pump ◽

Pump Activity

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Synthesis and biological evaluation of 4-substituted aryl-piperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo [5.2.1.02,6] dec-8-ene-3,5-dione as anti-cancer and anti-angiogenesis agents

10.21203/rs.2.19336/v2 ◽

2020 ◽

Author(s):

Lifang Guo ◽

Benshan Xu ◽

Zirui Wan ◽

Lulu Ren ◽

Jie Zhang ◽

...

Keyword(s):

Biological Evaluation ◽

Cytotoxic Activities ◽

Chemical Structures ◽

Piperazine Derivatives ◽

Anti Cancer ◽

Ic50 Values ◽

And Migration ◽

Anti Tumor Activity ◽

Synthesis And Biological Evaluation ◽

Derivatives Of

Abstract Background: A series of aryl-piperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo [5.2.1.02,6] dec-8-ene-3,5-dione were synthesized. The chemical structures of the desired compounds were identified by 1H NMR, ESI-MS and elementary analytical. The anti-cancer and anti-angiogenesis activities of the newly synthesized compounds were evaluated by proliferation and migration assays, respectively. Results: The screening results demonstrated that compounds 2 and 5 showed potent anti-tumor activity (IC50 values ranging from 7.1 to 15.9μM) with low cytotoxic activities (IC50＞79.3μM). Although compound 5 showed little effects on endothelia proliferation (IC50=65.3μM), it indeed significantly abrogated endothelia cell migration (IC50=6.7μM). Conclusions: This work may impart new direction for the investigations of aryl-piperazine derivatives and lead to the development of potent novel anti-tumor and anti-angiogenesis agents.

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Chlormadinone acetate, a progesterone derivative that binds to the digitalis receptor, inhibits the sodium pump in the isolated rat diaphragm

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y85-007 ◽

1985 ◽

Vol 63 (1) ◽

pp. 44-47 ◽

Cited By ~ 3

Author(s):

Ivan Bihler ◽

Frank S. LaBella ◽

P. C. Sawh

Keyword(s):

Sodium Pump ◽

Sugar Transport ◽

Diaphragm Muscle ◽

Rat Diaphragm ◽

Bathing Medium ◽

Chlormadinone Acetate ◽

Muscle Tissues ◽

Pump Activity ◽

Intact Muscle ◽

Resting Muscle

Rb+ uptake, intracellular Na+ and K+ levels, and the tissue–medium distribution of the nonmetabolized glucose analog, 3-O-methyl-D-glucose (3-MG) were measured in rat diaphragms incubated with chiormadinone acetate, 6-chloro-4,6-pregnadien-17-ol-3,20-dione 17-acetate (CMA), in the presence and absence of ouabain. CMA in concentrations of 5 × 10−7 M or higher significantly depressed 86Rb uptake, and promoted an increase in internal Na+ and a decrease in internal K+, indicating inhibition of the sodium pump. Sugar transport in resting muscle parallels the changes in internal Na+ levels and is an additional indicator of sodium pump activity. Equilibration of 3-MG between tissue and medium was accelerated by CMA, in parallel to the rise in internal Na+ level. Effects of CMA on Na+ levels and sugar transport, but not on Rb+ uptake, were additive to those of various concentrations of ouabain, suggesting interaction with sites not affected by ouabain. These results on diaphragm muscle confirm our previous studies on isolated cardiac muscle preparations showing that CMA, added to the aqueous bathing medium, inhibits the sodium pump in intact muscle tissues.

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Postsynaptic Muscarinic Receptor and Sodium-Pump Activity

Progress in Brain Research - The Cholinergic Synapse ◽

10.1016/s0079-6123(08)64697-x ◽

1979 ◽

pp. 495

Author(s):

T.L. Török ◽

E.S. Vizi

Keyword(s):

Muscarinic Receptor ◽

Sodium Pump ◽

Pump Activity

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Identification of promising objects for the synthesis of thiosulphonate derivatives of benzoquinone and hydroquinone

Chemistry, Technology and Application of Substances ◽

10.23939/ctas2021.02.047 ◽

2021 ◽

Vol 4 (2) ◽

pp. 47-53

Author(s):

N. Y. Monka ◽

◽

N. E. Stadnytska ◽

I. R. Buchkevych ◽

K. O. Kaplia ◽

...

Keyword(s):

Biological Activity ◽

Biological Activities ◽

Experimental Studies ◽

New Drugs ◽

Reduced Form ◽

Free Form ◽

Wide Range ◽

On Line ◽

Living Organisms ◽

Derivatives Of

Benzoquinone and its reduced form hydroquinone belong to phenolic compounds and are found in living organisms in free form or in glycosides. They are active substances of some medicinal plants and have a pharmacological effect on the human body. Accordingly, their derivatives are important objects for chemical synthesis and development of new drugs. This article presents the findings of the structural design of substances with benzoquinone or hydroquinone fragment and sulfur-containing compound. By use of appropriate on-line programs a predictive screening of the biological activity and cytotoxicity of thiosulfonate derivatives of benzoquinone and hydroquinone has been conducted. It has been found that they have immense methodological potential to be synthesized by substances with a wide range of biological activities and a high value of probable activity, which substantiates the feasibility of conducting experimental studies on their biological activity, particularly anticancer.

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Novel O-alkyl Derivatives of Naringenin and Their Oximes with Antimicrobial and Anticancer Activity

Molecules ◽

10.3390/molecules24040679 ◽

2019 ◽

Vol 24 (4) ◽

pp. 679 ◽

Cited By ~ 12

Author(s):

Joanna Kozłowska ◽

Ewa Grela ◽

Dagmara Baczyńska ◽

Agnieszka Grabowiecka ◽

Mirosław Anioł

Keyword(s):

Cancer Cell Line ◽

Human Colon ◽

Colon Cancer Cell Line ◽

Human Colon Cancer ◽

Anticancer Properties ◽

Alkyl Derivatives ◽

Ic50 Values ◽

Oxime Derivatives ◽

Derivatives Of ◽

Ht 29

In our investigation, we concentrated on naringenin (NG)—a widely studied flavanone that occurs in citrus fruits. As a result of a reaction with a range of alkyl iodides, 7 novel O-alkyl derivatives of naringenin (7a–11a, 13a, 17a) were obtained. Another chemical modification led to 9 oximes of O-alkyl naringenin derivatives (7b–13b, 16b–17b) that were never described before. The obtained compounds were evaluated for their potential antibacterial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The results were reported as the standard minimal inhibitory concentration (MIC) values and compared with naringenin and its known O-alkyl derivatives. Compounds 4a, 10a, 12a, 14a, 4b, 10b, 11b, and 14b were described with MIC of 25 µg/mL or lower. The strongest bacteriostatic activity was observed for 7-O-butylnaringenin (12a) against S. aureus (MIC = 6.25 µg/mL). Moreover, the antitumor effect of flavonoids was examined on human colon cancer cell line HT-29. Twenty-six compounds were characterized as possessing an antiproliferative activity stronger than that of naringenin. The replacement of the carbonyl group with an oxime moiety significantly increased the anticancer properties. The IC50 values below 5 µg/mL were demonstrated for four oxime derivatives (8b, 11b, 13b and 16b).

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Immunoradiometric method and electrophoretic system compared for quantifying bone alkaline phosphatase in serum

Clinical Chemistry ◽

10.1093/clinchem/41.6.853 ◽

1995 ◽

Vol 41 (6) ◽

pp. 853-857 ◽

Cited By ~ 16

Author(s):

V O Van Hoof ◽

M Martin ◽

P Blockx ◽

A Prove ◽

A Van Oosterom ◽

...

Keyword(s):

Alkaline Phosphatase ◽

Malignant Disease ◽

Screening Method ◽

Bone Alkaline Phosphatase ◽

Cross Reactivity ◽

Osteoblastic Activity ◽

Alp Activity ◽

Agarose Electrophoresis ◽

End Stage ◽

Rule Out

Abstract Agarose electrophoresis (Isopal, Beckman) and an immunoradiometric assay (IRMA) involving specific monoclonal antibodies (Ostase, Hybritech), two methods for the quantification of serum bone alkaline phosphatase (ALP, EC 3.1.3.1), a marker of osteoblastic activity, were compared in 293 patients: 79 with end-stage renal failure treated with hemodialysis and 214 with malignant disease. Overall correlation between the two methods was good (r = 0.92), except (a) for low values of bone ALP and (b) in some samples with high total liver ALP activity--both due to considerable cross-reactivity of the anti-bone ALP antibodies of the Ostase kit with liver ALP. This interference was not constant and was not evenly distributed across all concentrations of bone ALP. Low bone ALP determined with the IRMA (< or = 5 micrograms/L) was confirmed by electrophoresis (< or = 21 U/L), but bone ALP activity determined by electrophoresis to be low (< or = 21 U/L) was not correlated with the IRMA results. After standardizing our results by computing z-values for bone ALP, delta z (= zOstase - zIsopal) was significantly correlated with liver ALP activity (r = 0.73, P < 0.0001). We conclude that the IRMA for quantifying bone ALP is acceptable as a screening method. However, when high values for bone ALP are found with the Ostase method, confirmation by electrophoresis remains mandatory to rule out cross-reactivity with high amounts of liver ALP. For detecting low bone ALP activities, electrophoresis remains the method of choice.

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