Protective role of Caesalpinia sappan extract and its main component brazilin against blue light-induced damage in human fibroblasts.

Abstract

Ultraviolet (UV) radiation is a well-known factor that causes skin aging. Recently, with the development of technology, the skin has been exposed to not only the UV radiation but also the blue light from electronic devices. Blue light is a high-energy visible light that penetrates deep into the dermal layer, producing reactive oxygen species (ROS) and resulting in skin aging. In this study, we searched for candidate materials that can inhibit blue light-induced skin aging and found Caesalpinia sappan extract (CSE) to be effective. Human dermal fibroblasts (HDFs) were treated with various concentrations of CSE and brazilin and exposed to blue light. We measured that antioxidant activity, MMP-1 levels using MMP-1 ELISA, changes in collagen type 1, collagen type 3, MMP-1, and MMP-3 mRNA expressions, and ROS generation. We confirmed that CSE has high absorption of blue light and antioxidant activity. Blue light irradiation at 30 J/cm2 decreased the expression of collagen types 1 and 3, increased the expression of matrix metalloproteinase (MMP)-1 and 3, and decreased the production of ROS in human dermal fibroblasts as compared to those of the nonirradiated group. However, pretreatment with CSE protected against the damage caused by the blue light. Brazilin, a major constituent of C.sappan, had high absorbance in the blue light region and antioxidant activities. Pretreatment with brazilin also inhibited the damage caused by the blue light in the cells. CSE and brazilin are potential agents for inhibiting skin aging caused by blue light-induced damage.