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Evidence-Based Complementary and Alternative Medicine
Volume 2013, Article ID 795916, 7 pages
Research Article

Antioxidant Effects of Quercetin and Naringenin Are Associated with Impaired Neutrophil Microbicidal Activity

1Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Avenida Colombo 5.790, 87020-900 Maringá, PR, Brazil
2Departamento de Química, Faculdade de Ciências, Universidade Estadual Paulista, Avenida Eng. Luiz Edmundo Carrijo Coube 14-01, 17033-360 Bauru, SP, Brazil

Received 3 April 2013; Revised 16 May 2013; Accepted 18 June 2013

Academic Editor: Chong-Zhi Wang

Copyright © 2013 Francielli de Cássia Yukari Nishimura et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Naringenin and quercetin are considered antioxidant compounds with promising activity against oxidative damage in human cells. However, no reports have described their effects on reactive oxygen species (ROS) production by phagocytes during microbicidal activity. Thus, the present study evaluated the effects of naringenin and quercetin on ROS production, specifically hypochlorous acid (HOCl), and their involvement in the microbicidal activity of neutrophils. Naringenin and quercetin inhibited HOCl production through different systems, but this inhibition was more pronounced for quercetin, even in the cell-free systems. With regard to the microbicidal activity of neutrophils, both naringenin and quercetin completely inhibited the killing of Staphylococcus aureus. Altogether, these data indicate that the decrease in the oxidant activity of neutrophils induced by these compounds directly impaired the microbicidal activity of neutrophils. Naringenin and quercetin exerted their effects by controlling the effector mechanisms of ROS production, with both positive and negative effects of these antioxidant agents in oxidative stress conditions and on ROS in the microbicidal activity of phagocytes. The present results challenge the traditional view of antioxidants as improvers of pathological conditions.