Paper Title
THYMOQUINONE ATTENUATES GRANULE EXOCYTOSIS IN FMLF-INDUCED HUMAN NEUTROPHILS

Abstract
Polymorphonuclear neutrophils (PMNs) are key players in host defense against pathogens through the robust production of reactive oxygen species (ROS) which are highly cytotoxic as well as the liberation of antibacterial and proteolytic enzymes. However, inappropriate or excessive ROS production and liberation of proteolytic enzymes in the extracellular environment may induce severe tissue injuries, thereby contributing to the physiopathology of acute and chronic inflammatory disorders. Thymoquinone (TQ) is a natural molecule from black cumin oil, well known for its anti-inflammatory action in vivo. However, its effect on PMNs has not yet been well studied. In the present work, we examined the effect of TQ on fMLF induced granule exocytosis in human neutrophils. Our data showed that TQ attenuates specific and azurophilic granules exocytosis as shown by the decrease of cell surface expression of gp91PHOX, CD11b and release of MPO (Myeloperoxydase). This effect was mainly through inhibition of MAPK pathways involved in the process of granules exocytosis. TQ thus holds promising therapeutic potential in treating inflammatory disorders. Keywords - Thymoquinone; Neutrophils; ROS, Degranulation; MAPK Pathway.