Protective Effect of Curcumin Against Acute Ultraviolet B Irradiation‐induced Photo‐damage

Ultraviolet B (UVB) irradiation is one of the most dangerous insults for skin and causes sunburn, erythema, photoaging and photocarcinogenesis. Curcumin (diferuloylmethane), a yellow spice derived from dried rhizomes of Curcuma longa, has been shown to possess significant anti-inflammatory, antioxidant, anticarcinogenic, antimutagenic, anticoagulant and anti-infective effects. However, the protective effects of curcumin against acute photo-damage are poorly understood. In this study, we investigated the photoprotective effects of curcumin against UVB-induced acute photo-damage in hairless mice and immortalized human keratinocytes (HaCaT). Topical application of curcumin significantly inhibited acute UVB (540 mJ cm^-2 , for 3 successive days)-induced inflammatory cells, collagen accrementition derangement and lipid peroxidation, and effectively induced NF-E2-related factor 2 (Nrf2) nuclear accumulation in uncovered (Uncv) hairless mice skin. Treatment of HaCaT cells with curcumin significantly attenuated acute UVB (300 mJ cm^-2 )-induced lactate dehydrogenase release, intracellular reactive oxygen species production and DNA damage, activated the expression of the phase II detoxifying enzymes and promoted DNA repair activity. The photoprotective effect provided by curcumin was potential associated with modulation of Nrf2-dependent antioxidant response. Our study suggested that curcumin is a potential agent for preventing and/or treating UV radiation-induced acute inflammation and photoaging.