Quercetin inhibits degranulation and superoxide generation in PMA stimulated neutrophils

Abstract

Activated neutrophils represent the main source of myeloperoxidase (MPO), superoxide (SO) and subsequently derived oxygen metabolites. They have important microbicidal activities, however in inflammatory conditions they may secondarily attack surrounding tissues. Overproduction of reactive oxygen species, prolonged or excessive liberation of MPO and other effective yet also toxic substances from neutrophils may participate in disturbed apoptosis, intensify the inflammatory processes and result in serious human diseases. The inhibitory effect of quercetin on PMA stimulated SO generation in isolated human neutrophils was found to be dose-dependent, without affecting the activity of intact isolated neutrophils. At comparable conditions, quercetin was more potent in inhibiting MPO release than SO generation. Our results indicate that quercetin could support resolution of inflammation through decreased activity of neutrophils, i.e. respiratory burst and degranulation.

Evaluation of Antiradical and Anti-Inflammatory Activities of Ethyl Acetate and Butanolic Subfractions ofAgelanthus dodoneifolius(DC.) Polhill & Wiens (Loranthaceae) Using Equine Myeloperoxidase and Both PMA-Activated Neutrophils and HL-60 Cells

“…Moreover, polyphenols such as flavonoids are well known anti-inflammatory compounds and their anti-inflammatory mechanism may involve the inhibition of degranulation [ 35 , 36 ]. Other studies have reported the inhibitory effect of phenolic compounds on the neutrophil degranulation and it has been shown that flavonoids such as quercetin and rutin were potent inhibitors [ 10 , 37 ]. In addition, these two compounds were found to be present in Agelanthus dodoneifolius leaves as reported previously [ 13 ].…”

Orally administered Chrysin improves post‐thawed sperm quality and fertility of rooster

“…The exact mechanism(s) of action for Chrysin has not been elucidated; however, following mechanisms are proposed for flavonoids. (i) direct interaction with radicals and scavenging them as well as inhibition of xanthine oxidase activity (Nijveldt et al., ); (ii) reducing the immobilized leucocytes and degranulation of neutrophils through modulation of plasma membrane Ca +2 channels (Nijveldt et al., ; Pecivova, Macickova, Svitekova, & Nosal, ); (iii) possessing iron‐chelating and ion‐stabilizing properties which remove the causal factor of free radical development (Kumar & Pandey, ). Furthermore, Chrysin administration to adult rats has upregulated the antioxidant enzyme activity (CAT, SOD and GSH‐Px) present in sperm cell (Ciftci et al., ).…”

Phagocytosis, Degranulation and Extracellular Traps Release by Neutrophils—The Current Knowledge, Pharmacological Modulation and Future Prospects

“…Immunomodulatory, anti-inflammatory or antimicrobial properties of Hypericium species are unknown. Another example of a plant-derived compound decreasing degranulation of neutrophils is quercetin ( Kanashiro et al, 2007 ; Pečivová et al, 2012 ). Although quercetin is widespread in many plant species, in both mentioned articles quercetin was used as a synthesized compound.…”