Activity of melatonin against Leishmania infantum promastigotes by mitochondrial dependent pathway

2014 ◽  
Vol 220 ◽  
pp. 84-93 ◽  
Author(s):  
Ehab Kotb Elmahallawy ◽  
Aroa Jiménez-Aranda ◽  
Antonio Sampedro Martínez ◽  
Javier Rodriguez-Granger ◽  
Miguel Navarro-Alarcón ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Dependent Pathway

Leishmania infantum Enhances Migration of Macrophages via a Phosphoinositide 3-Kinase γ-Dependent Pathway

2020 ◽  
Vol 6 (7) ◽  
pp. 1643-1649
Author(s):  
Maria Inês Rocha ◽  
Filipa Dias ◽  
Mariana Resende ◽  
Mafalda Sousa ◽  
Margarida Duarte ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Phosphoinositide 3 Kinase ◽  
Migration Of Macrophages ◽  
Dependent Pathway

The Mechanism of Platelet Aggregation Induced by HLA-Related Antibodies

1996 ◽  
Vol 76 (05) ◽  
pp. 774-779 ◽  
Author(s):  
John T Brandt ◽  
Carmen J Julius ◽  
Jeanne M Osborne ◽  
Clark L Anderson
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Complement Activation ◽  
Thromboembolic Disease ◽  
Clinical Samples ◽  
Hla Antigen ◽  
Aggregation Response ◽  
Immune Mediated ◽  
Dependent Pathway

SummaryImmune-mediated platelet activation is emerging as an important pathogenic mechanism of thrombosis. In vitro studies have suggested two distinct pathways for immune-mediated platelet activation; one involving clustering of platelet FcyRIIa, the other involving platelet-associated complement activation. HLA-related antibodies have been shown to cause platelet aggregation, but the mechanism has not been clarified. We evaluated the mechanism of platelet aggregation induced by HLA-related antibodies from nine patients. Antibody to platelet FcyRIIa failed to block platelet aggregation with 8/9 samples, indicating that engagement of platelet FcyRIIa is not necessary for the platelet aggregation induced by HLA-related antibodies. In contrast, platelet aggregation was blocked by antibodies to human C8 (5/7) or C9 (7/7). F(ab’)2 fragments of patient IgG failed to induce platelet activation although they bound to HLA antigen on platelets. Intact patient IgG failed to aggregate washed platelets unless aged serum was added. The activating IgG could be adsorbed by incubation with lymphocytes and eluted from the lymphocytes. These results indicate that complement activation is involved in the aggregation response to HLA-related antibodies. This is the first demonstration of complement-mediated platelet aggregation by clinical samples. Five of the patients developed thrombocytopenia in relationship to blood transfusion and two patients developed acute thromboembolic disease, suggesting that these antibodies and the complement-dependent pathway of platelet aggregation may be of clinical significance.

Leishmanicidal Activity of Plant Extracts from Sefrou, a Moroccan Focus of Leishmaniasis, against Various Leishmania Parasites in the Promastigote Stage

2018 ◽  
Vol 17 (2) ◽  
pp. 83-89 ◽  
Author(s):  
I. Zeouk ◽  
A. Et-Touys ◽  
M. Balouiri ◽  
H. Fellah ◽  
A. El Ouali Lalami ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Plant Extracts ◽  
Leishmania Infantum ◽  
Leishmania Major ◽  
Local Population ◽  
Public Health Problem ◽  
World Health ◽  
Total Phenolic ◽  
Leishmania Tropica ◽  
Cistus Salviifolius

According to the World Health Organization, leishmaniasis remains a major worldwide public health problem. The province of Sefrou located in the center of Morocco is a focus of cutaneous leishmaniasis. The present study aims at evaluating the antileishmanial potential of Berberis sp.,Crataegus oxyacantha, Cistus salviifolius, Ephedra altissima and Lavandula dentatafrequently used by the local population. Methanolic extracts were tested against the promastigote form ofLeishmania tropica, Leishmania majorandLeishmania infantumusing tetrazolium-based colorimetric (MTT) assay. The total phenol and flavonoids content of all extracts were determined using the Folin–Ciocalteu reagent, aluminum chloride, and potassium acetate solutions respectively. The plant extracts exhibited antileishmanial activity with variability depending on the tested strain and the plant species compared to Glucantime® used as control (IC50 (the half maximal inhibitory concentration) > 1,000 μg/mL). The best inhibition was observed with Berberis sp., againstLeishmania major(IC50 = 394.40 ± 3.02 μg/ml), andEphedra altissima(reported for the first time) againstLeishmania infantum(IC50 = 490.84 ± 3.15 μg/mL).Leishmania tropicahas shown the same sensitivity behavior toward the five extracts (in average IC50 = 540 ± 11.20 μg/mL). The total phenolic content was higher forCrataegus oxyacanthaandCistus salviifolius(140.67 ± 3.17 μg eq Gallic Acid (GA)/ mg of Extract (E) and 133.83 ± 9.03 μg eq GA/mg of E respectively), while flavonoid was higher forCistus salviifoliusandLavandula dentata(57.92 ± 2.46 μg eq Quercetin (Que)/ mg of Extract (E) and 41.53 ± 1.74 μg eq Que/mg of E). All the tested extracts present some promising aspects that may cure cutaneous leishmaniasis in the center of Morocco; further bioguided assays are needed to isolate the fractions and the bioactive molecule.

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