Leaf extracts from Camellia sinensis and Argania spinosa suppress oxidative stress and chemokine release in human 3-dimensional cultured epidermis exposed to PM2.5 collected with cyclonic separation

Skin is the primary tissue exposed to ambient air pollution because it acts as an interface between the body and the surrounding atmosphere. We previously reported that particulate matter 2.5 (PM2.5) induced oxidative stress and subsequent chemokine release in the human epidermis, followed by neutrophil chemotaxis. We identified in this study that the leaf extracts from Camellia sinensis and Argania spinosa showed high radical scavenging activity as evaluated by 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazinyl and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid assays. PM2.5 exposure induced lipid peroxidation, IL-8 release and neutrophil migration in human 3-dimensional cultured epidermis. Pretreatment with leaf extracts from Camellia sinensis or Argania spinosa significantly suppressed the above harmful effects elicited by PM2.5. Taken together, both extracts can protect the epidermis from PM2.5 exposure. Camellia sinensis and Argania spinosa extracts could be added to a novel cosmetic that protects skin from air pollution.