Inflammatory Mediators and Oxidative Stress in Animals Subjected to Smoke Inhalation: A Systematic Review

Abstract

Background: The inhalation injury is usually initiated by uninhibited absorption of smoke, favoring the release of cytokines and other lipid mediators from inflammatory cells in lung airways and parenchyma.

Objectives: To systematically review, examine, and synthesize the main inflammatory mediators analyzed in published studies in animals subjected to smoke inhalation, as well as oxidative stress.

Search strategy: A comprehensive literature search was conducted through MEDLINE-PubMed, Web of Science, and Scopus.

Selection criteria: Studies with animals subjected to lung damage from smoke inhalation that evaluated the presence and the action of inflammatory mediators and oxidative stress.

Results: A total of 1332 studies were initially identified, with only 31 meeting the inclusion criteria. The inflammatory mediators and oxidative stress markers studied and presented in the articles described herein were varied; however, the most cited ones were tumor necrosis factor-alpha (6), IL-8 and IL-6 (both studied in five articles), IL-1β and nuclear factor kappa β (both studied in 4 articles), malondialdehyde (11 studies), and myeloperoxidase (7). It is worth noting that most studies evaluated more than one inflammatory mediator and oxidative stress marker.

Conclusion: Based on this review, we could observe that the main inflammatory mediators and oxidative stress markers analyzed were TNF-α, IL-8, IL-6, IL-1β, nuclear factor kappa β, MDA, and MPO. However, it is necessary to increase the rigor of study design and data, in order to have studies that are more homogeneous and with appropriate methodological quality.

Keywords: Cytokine; Inflammatory mediator; Oxidative stress; Pulmonary injury; Smoke inhalation.