Differential biological activity of two extracts of ripe fruits of Carica candamarcensis Hook on human neutrophils / Actividad biologica diferencial de dos extractos de frutos maduros de Carica candamarcensis Hook en neutrófilos humanos

We evaluated the effect of the total macerate (TM) and seed oil (SO) of mature Carica candamarcensis fruits, on the release of Matrix metalloproteinase 9 (MMP9) and the phosphorylation of MAPK in neutrophils. The antioxidant capacity of these extracts was evaluated by ABTS assay. Neutrophils stimulated with different dilutions of TM or SO were analyzed for cytotoxicity, MMP9 release, and MAPK phosphorylation, using trypan blue exclusion assays, zymography, and immunoblotting, respectively. Both extracts show antioxidant activity, being higher in TM; none presented cytotoxic effect. The 5% and 2.5% dilutions of TM significantly reduced MMP9 release, and all decreased MAPK phosphorylation. SO significantly increased the release o f MMP9 and MAPK phosphorylation, the effect being greater when they were prestimulated with lipopolysaccharide.TM may have anti - inflammatory potential, while SO could have a priming effect that needs to be confirmed

Evaluamos el efecto del macerado total (MT) y aceite de semillas (AV) de frutos maduros de Carica candamarcensis , en la liberación de Matriz metaloproteinasa 9 (MMP9) y la fosfor ilación de MAPK en neutrófilos. La capacidad antioxidante de estos extractos se evaluó por ensayo ABTS. En neutrófilos estimulados con diferentes diluciones de MT o AV se analizó la citotoxicidad, liberación de MMP9 y fosforilación de MAPK, mediante ensayo s de exclusión con azul de tripano, zimografía e inmunotransferencia, respectivamente. Ambos extractos muestran actividad antioxidante, siendo mayor en MT; ninguno presentó efecto citotóxico. Las diluciones 5% y 2,5% de MT redujeron significativamente la l iberación de MMP9, y todas disminuyeron la fosforilación de MAPK. El AV incrementó significativamente la liberación de MMP9 y la fosforilación de MAPK, el efecto fue mayor cuando se preestimularon con lipopolisacárido. El MT puede tener potencial antiinfla matorio, mientras que el AV podría tener un efecto "priming" que necesita ser corroborado.

Eimeria bovis-triggered neutrophil extracellular trap formation is CD11b-, ERK 1/2-, p38 MAP kinase- and SOCE-dependent.

Eimeria bovis is an important coccidian parasite that causes high economic losses in the cattle industry. We recently showed that polymorphonuclear neutrophils (PMN) react upon E. bovis sporozoite exposure by neutrophil extracellular trap (NET) formation. We focused here on the molecular mechanisms that are involved in this process. The sporozoite encounter led to an enhanced surface expression of neutrophil CD11b suggesting a potential role of this receptor in E. bovis-mediated NETosis. Antibody-mediated blockage of CD11b confirmed this assumption and led to a significantly decreased sporozoite-triggered NET. In addition, E. bovis-induced NETosis was found to be Ca(2+)-dependent since the inhibition of store-operated calcium entry (SOCE) significantly diminished NET. Furthermore, NADPH oxidase, neutrophil elastase (NE) and myeloperoxidase (MPO) were confirmed as key molecules in sporozoite-triggered NETosis, as inhibition thereof blocked parasite-triggered NET. PMN degranulation analyses revealed a significant release of matrix metalloprotease-9 containing granules upon sporozoite exposure. We further show a significantly enhanced phosphorylation of ERK1/2 and p38 MAPK in sporozoite-exposed PMN indicating a key role of this signaling pathway in E. bovis-mediated NETosis. Accordingly, ERK 1/2 and p38 MAPK inhibition led to a significant decrease in NET formation. Finally, we demonstrate that sporozoite-induced NETosis is neither a stage-, species-, nor host-specific process.