scholarly journals Inhibitory effect of dihydromyricetin on the proliferation of JAR cells and its mechanism of action

2020 ◽  
Author(s):  
Yanzhen Zuo ◽  
Yanjie Lu ◽  
Qian Xu ◽  
Dayong Sun ◽  
Xiujun Liang ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Inhibitory Effect ◽  
Jar Cells

A novel triazolic naphthofuranquinone induces autophagy in reservosomes and impairment of mitosis in Trypanosoma cruzi

Parasitology ◽  
2011 ◽  
Vol 139 (1) ◽  
pp. 26-36 ◽  
Author(s):  
M. C. FERNANDES ◽  
E. N. DA SILVA ◽  
A. V. PINTO ◽  
S. L. DE CASTRO ◽  
R. F. S. MENNA-BARRETO
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Mechanism Of Action ◽  
Folk Medicine ◽  
Flow Cytometric Analysis ◽  
Inhibitory Effect ◽  
Membrane Structures ◽  
Starting Point ◽  
Nitro Derivatives ◽  
Good Starting Point

SUMMARYChagas' disease, caused by the protozoan Trypanosoma cruzi, represents a serious health problem in Latin America, and the available chemotherapy, which is based on 2 nitro-derivatives, is not satisfactory. In folk medicine, natural products including naphthoquinones have been employed for the treatment of different parasitic diseases. In the pursuit of alternative drugs for Chagas' disease, we investigated the mechanism of action of the triazolic naphthoquinone (TN; 2,2-dimethyl-3-(4-phenyl-1H-1,2,3-triazol-1-yl)-2,3-dihydronaphtho[1,2-b]furan-4,5-dione), which is the most active compound against T. cruzi trypomastigotes among a series of naphthofuranquinones. TN was active against the 3 parasite forms producing a dose-dependent inhibitory effect. In epimastigotes, TN induced reservosome disruption, flagellar blebbing, Golgi disorganization, the presence of cytosolic concentric membrane structures and abnormal multiflagellar parasites. The treatment also led to the appearance of well-developed endoplasmic reticulum profiles surrounding organelles that associated with an increase in monodansylcadaverine labelling, suggesting autophagy as part of the TN mechanism of action. Interestingly, no ultrastructural damage was detected in the mitochondria of naphthoquinone-treated epimastigotes. Flow cytometric analysis demonstrated an impairment of mitosis, an increase in ROS production and the maintenance of mitochondrial membrane potential. TN could be a good starting point in the investigation of a chemotherapeutic approach for the treatment of Chagas' disease.

Studies on the Mechanism of Action of the Inhibitory Effect of the Somatostatin Analog SMS 201–995 on the Growth of the Prolactin/Adrenocorticotropin-Secreting Pituitary Tumor 7315a

Endocrinology ◽  
1986 ◽  
Vol 118 (6) ◽  
pp. 2188-2194 ◽  
Author(s):  
STEVEN W. J. LAMBERTS ◽  
JEAN-CLAUDE REUBI ◽  
PIET UITERLINDEN ◽  
JOKE ZUIDERWIJK ◽  
PAUL VAN DEN WERFF ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Pituitary Tumor ◽  
Inhibitory Effect ◽  
Somatostatin Analog

Uncoupling of Lipolysis from Cyclic AMP by Procaine: a Tool for Studying the Mechanism of Action of Antilipolytic Agents

1975 ◽  
Vol 53 (4) ◽  
pp. 603-609 ◽  
Author(s):  
Mario D'Costa ◽  
Aubie Angel
Keyword(s):  
Adipose Tissue ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mechanism Of Action ◽  
Initial Rate ◽  
Direct Action ◽  
Inhibitory Effect ◽  
Glycerol Release ◽  
Cyclic Amp Accumulation ◽  
Low K

The initial rate of net glycerol release in norepinephrine-stimulated adipose tissue fragments was inhibited (40–78%) by procaine–HCl (1–5 mM), whereas basal (unstimulated) lipolysis was unaffected. A dose-related inhibition of norepinephrine-induced lipolysis by procaine–HCl (0.1–1 mM) also occurred in adipocytes. Procaine-induced antilipolysis was associated with an augmented rather than a reduced hormone-stimulated increment in intracellular cyclic AMP. The dissociation of lipolysis from cyclic AMP accumulation has been termed the uncoupling effect of procaine. This effect of procaine was employed to define the precise mechanism of action of the antilipolytic drug clofibrate (Atromid-S®) which inhibits lipolysis by reducing cyclic AMP. A reduction in cyclic AMP by clofibrate was demonstrated in norepinephrine-stimulated cells exposed to procaine (uncoupled system). Thus, the inhibitory effect of clofibrate on cyclic AMP could not be attributed to accumulation of products of lipolysis. Because neither procaine–HCl nor clofibrate had any effect on the low Km 3′:5′-cyclic-AMP phosphodiesterase (EC 3.1.4.17) activity in hormone stimulated cells, the clofibrate-induced reduction in cyclic AMP was attributed to its direct action on adipocyte adenylate cyclase.

scholarly journals Studies on the Mechanism of Action of the Inhibitory Effect of Prostaglandin F2α on Cyclic AMP Accumulation in Rat Corpora Lutea of Various Ages1

1979 ◽  
Vol 21 (5) ◽  
pp. 1175-1183 ◽  
Author(s):  
M. Iqbal Khan ◽  
Sten Rosberg ◽  
Michal Lahav ◽  
Sergio A. Lamprecht ◽  
Gunnar Selstam ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Mechanism Of Action ◽  
Prostaglandin F2α ◽  
Inhibitory Effect ◽  
Corpora Lutea ◽  
Cyclic Amp Accumulation

Inhibitory Effect of Glucocorticosteroids on Anti-IgE-Induced Histamine Release from Human Basophilic Leukocytes: Evidence for a Dual Mechanism of Action

Allergy ◽  
1984 ◽  
Vol 39 (3) ◽  
pp. 217-230 ◽  
Author(s):  
Hårkan Bergstrand ◽  
Anette Björnsson ◽  
Britta Lundquist ◽  
Annika Nilsson ◽  
Ralph Brattsand
Keyword(s):  
Histamine Release ◽  
Mechanism Of Action ◽  
Inhibitory Effect ◽  
Dual Mechanism

scholarly journals Ribavirin Causes Error Catastrophe during Hantaan Virus Replication

2003 ◽  
Vol 77 (1) ◽  
pp. 481-488 ◽  
Author(s):  
William E. Severson ◽  
Connie S. Schmaljohn ◽  
Ali Javadian ◽  
Colleen B. Jonsson
Keyword(s):  
Mechanism Of Action ◽  
Inhibitory Effect ◽  
Viral Rna ◽  
Hantaan Virus ◽  
Slight Reduction ◽  
Mrna Levels ◽  
N Protein ◽  
High Mutation Frequency ◽  
Error Catastrophe ◽  
Infected Cells

ABSTRACT Except for ribavirin, no other antiviral drugs for treating hantaviral diseases have been identified. It is well established that ribavirin will inhibit the production of infectious Hantaan virus (HTNV); however, its mechanism of action is unknown. To characterize the inhibitory effect of ribavirin on HTNV, the levels of viral RNAs, proteins, and infectious particles were measured for 3 days posttreatment of HTNV-infected Vero E6 cells. HTNV-infected cells treated with ribavirin showed a slight reduction in the levels of cRNA, viral RNA, and mRNA populations on the first day postinfection. The amount of cRNA and viral RNA increased to that observed for untreated HTNV-infected cells on day 2, whereas mRNA levels were more greatly reduced on days 2 and 3. Despite the finding of S-segment mRNA, albeit low, three of the viral proteins—nucleocapsid (N) protein and glycoproteins G1 and G2—could not be detected by immunohistochemistry in ribavirin-treated cells. To test the hypothesis that these effects were caused by incorporation of ribavirin into nascent RNA and a resultant “error catastrophe” was occurring, we cloned and sequenced the S-segment cRNA/mRNA from ribavirin-treated or untreated cells from day 3. We found a high mutation frequency (9.5/1,000 nucleotides) in viral RNA synthesized in the presence of ribavirin. Hence, the transcripts produced in the presence of the drug were not functional. These results suggest that ribavirin's mechanism of action lies in challenging the fidelity of the hantavirus polymerase, which causes error catastrophe.

Effect of metal ions on pea alcohol dehydrogenase

1979 ◽  
Vol 44 (3) ◽  
pp. 799-803 ◽  
Author(s):  
Sylva Leblová ◽  
Noemi Nováková ◽  
Marie Stiborová
Keyword(s):  
Heavy Metal ◽  
Alcohol Dehydrogenase ◽  
Metal Ions ◽  
Mechanism Of Action ◽  
Heavy Metal Ions ◽  
Inhibitory Effect ◽  
Zinc Ions ◽  
Pea Seeds

The effect of Cu2+, Ag+, Zn2+, Cd2+ and Co2+ on alcohol dehydrogenase (ADH) isolated from germinating pea seeds was examined. The enzyme is inhibited approximately to the same degree if incubated 5 to 30 min with Ag+, Cu2+, and Cd2+; the same degree of inhibition can be brought about by zinc ions only if concentration by one order higher (10-4M) is used. Co2+-ions do not inhibit pea alcohol dehydrogenase even at 10-3M concentration. NAD and Zn2+ decrease the inhibitory effect of Cd2+ yet not the effect of Cu2+ or Ag+. The differences in the mechanism of action of individual heavy metal ions on plant ADH are discussed.

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