Effections of epigallocatechingallate on production and removal of photoproducts induced by UVB irradiation in human primary keratinocyte cells

Objective We investigated the production and removal process of photoproducts(CPDs) induced by UVB irradiation and the intervention effect of epigallocatechingallate(EGCG) in human primary keratinocyte(KC).Methods Human primary KC were cultured with or without 200μg/ml EGCG and were irradiated by different dosages of UVB.The production and removal of CPDs at different time intervals and different dosages were examined by immunohistochemical method.Results CPDs appeared in human primary KC after 30mJ/cm2 UVB irradiation and reached the peak at 1h and removed rapidly during the first 4h and then removed slowly or almost cleared out up to 24h after UVB irradiation.The quantity of CPDs was decreased when irradiated human primary KC were incubated with EGCG(P0.05).Conclusions The photodamage of human primary KC was UVB dose-dependent.EGCG can decrease the level of CPDs and rapid the removal of CPDs.