Pollutants like particulate matter, polycyclic aromatic hydrocarbons and gases such as ozone, nitrogen dioxide or sulfur dioxide are responsible for allergies and respiratory diseases but also a cause for increased mortality. Induction of oxidative stress and activation of inflammatory pathways are regarded as the main biological mechanisms involved.
Epigenetics, which studies modulation of gene expression caused by mechanisms other than changes in the DNA sequence, can explain how environmental factors influence our body. Whereas oxidative stress acts at the moment, epigenetic modification may lead to a long term effect, even when the environmental stress is not present anymore. This is the reason why air pollution should be analyzed for epigenetic effects.
The histone proteins are responsible for the packaging and organization of the DNA. Modifications of histone proteins define the access of transcription factors to the DNA and thus whether a gene is active or not. Recent studies showed air pollution-induced modifications of the histone H3 protein.
Air pollution also affects our skin which is especially exposed.Pollution can lead to allergic skin conditions, acne, uneven pigmentation and in general premature skin aging. In this work, human epidermal keratinocytes were used to study the effects of urban dust and benzo(a)pyrene on the epigenetic pattern of the histone H3 protein. The assay was then used to screen a series of plant extracts in order to find cosmetic actives to protect the skin against air pollution.