# “Protective” Imazalil vs Its Negative Effects on Immune System Cells—Neutrophils

## TL;DR

Imazalil, a fungicide, can impair neutrophil functions like phagocytosis and chemotaxis at low to high doses, potentially weakening immune defenses.

## Contribution

This study reveals non-linear effects of imazalil on neutrophil activity at environmentally relevant concentrations.

## Key findings

- Imazalil reduced neutrophil phagocytosis at environmental doses.
- Higher doses of imazalil impaired chemotaxis and increased NADPH oxidase activity.
- The highest imazalil concentration increased nitric oxide production in neutrophils.

## Abstract

Neutrophils are the most numerous population of peripheral blood leukocytes and play a key role in innate immunity, participating in antibacterial, antifungal, antiviral, and antitumor responses. Their activity can be modulated by endogenous and exogenous factors, including pesticides, among which fungicides such as the commonly used imazalil (IMZ) constitute a significant group. The objective of this study was to assess the effect of IMZ (at an environmental dose of 0.07 ng/mL, as well as 10- and 100-fold higher doses) on selected functions of neutrophils. This study demonstrated that neutrophils incubated with IMZ at a dose detectable in the serum, exhibited lower phagocytotic capacity. In addition, at a 10-fold higher dose, this compound reduced the chemotactic capacity of neutrophils and led to increased activity of NADPH oxidase in these cells. Furthermore, it was observed that at the highest concentration used in this study IMZ intensified the production of nitric oxide. The exposure of neutrophils—the first line of defense—to IMZ affected their locomotion and pathogen-eliminating function. Moreover, the response of neutrophils was not proportionate to the concentration of IMZ used in the study.