Background & aim: In traditional medicine, medicinal plants containing flavonoid compounds were used for several years in the treatment of various diseases. Quercetin is one of the flavonoid composition family that has a maximum antioxidant flavonoid content. The aim of this study was to investigate the physiological features of rats peripheral blood neutrophils treated with quercetin.

Methods: In the present experimental study, the rats peripheral blood neutrophils was isolated and then teated with various concentrations of quercetin (0, 5, 10 and 20 µg/ml). The metabolic activity, phagocytosis capabilities, germicidal and respiratory burst of neutrophils were measured. Kruskal-Wallis test was used to compare the analysis.

Results: The results demonestrated that the respiratory burst of neutrophils treated by quercitine was significantly increased at minimum concentrations of 10 micrograms per ml. Simmilary, the phagocytic ability of neutrophils was significantly increased at minimum concentrations of 10 micrograms per ml. Albith, the phagocytic ability of neutrophils was increasesd in 5 micrograms per ml, howevet this finding didn’t show any significant change.Moreover, the application of quercetin at minimum concentrations of 10 micrograms per ml lead to a significant reduction in killing and survival of neutrophils in the treatment group compared to that of the control group (P<0/05).

Conclusion: Quercetin could be considered as a natural immunomodulator of innate responses. This might be due to the inflammation control of neutrophils.