Lung inflammation and genotoxicity in mice lungs after pulmonary exposure to candle light combustion particles

Toxicol Lett. 2017 Jul 5:276:31-38. doi: 10.1016/j.toxlet.2017.04.015. Epub 2017 Apr 29.


Candle burning produces a large amount of particles that contribute substantially to the exposure to indoor particulate matter. The exposures to various types of combustion particles, such as diesel exhaust particles, have been associated with increased risk of lung cancer by mechanisms that involve oxidative stress, inflammation and genotoxicity. The aim of this study was to compare pulmonary effects of candle light combustion particles (CP) with two benchmark diesel exhaust particles (A-DEP and SRM2975). Intratracheal (i.t.) instillation of CP (5mg/kg bodyweight) in C57BL/6n mice produced a significant influx of alveolar macrophages and polymorphonuclear leukocytes and increased concentrations of proteins and lactate dehydrogenase activity in bronchoalveolar fluid. Lower levels of these markers of inflammation and cytotoxicity were observed after i.t. instillation of the same dose of A-DEP or SRM2975. The i.t. instillation of CP did not generate oxidative damage to DNA in lung tissue, measured as DNA strand breaks and human 8-oxoguanine glycosylase-sensitive sites by the comet assay. The lack of genotoxic response was confirmed in lung epithelial (A549) cells, although the exposure to CP increased intracellular levels of reactive oxygen species. In conclusion, pulmonary exposure to particles from burning candles is associated with inflammation and cytotoxicity in the lungs.

Keywords: A-DEP; Candle light combustion particles; Comet assay; DNA damage; Inflammation; Oxidative stress; SRM2975.

Publication types

  • Comparative Study

MeSH terms

  • A549 Cells
  • Air Pollution, Indoor*
  • Animals
  • Bronchoalveolar Lavage Fluid / chemistry
  • Bronchoalveolar Lavage Fluid / immunology
  • DNA Damage*
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Inflammation Mediators / metabolism
  • Inhalation Exposure / adverse effects*
  • Lighting / instrumentation*
  • Lung / drug effects*
  • Lung / immunology
  • Lung / metabolism
  • Macrophages, Alveolar / drug effects
  • Macrophages, Alveolar / immunology
  • Macrophages, Alveolar / metabolism
  • Mice, Inbred C57BL
  • Neutrophil Infiltration / drug effects
  • Neutrophils / drug effects
  • Neutrophils / immunology
  • Neutrophils / metabolism
  • Oxidative Stress / drug effects
  • Particle Size
  • Particulate Matter / toxicity*
  • Pneumonia / chemically induced*
  • Pneumonia / genetics
  • Pneumonia / immunology
  • Pneumonia / metabolism
  • Reactive Oxygen Species / metabolism
  • Vehicle Emissions / toxicity*


  • Inflammation Mediators
  • Particulate Matter
  • Reactive Oxygen Species
  • Vehicle Emissions