Cocoa (Theobroma cacao L.) photobiological effect on human fibroblast cells (HFF-1) exposed to ultraviolet B (UVB) radiation.

Abstract

This study aimed to investigate the in vitro photobiological action of cocoa solution on a human fibroblast cell line (HFF-1) exposed to ultraviolet B (UVB) radiation. Three experimental models were utilized, where fibroblast cells were treated with different concentrations of cocoa as follows: 50; 100; 250; 500; 750; 1000 or 1500 µg/ml and concomitantly exposed to UVB 7 kJ/m² for 10 min. The following parameters were examined 1) analysis of the pre-treatment action of cocoa; 2) investigation of the co-treatment activity of cocoa at the time of exposure; and 3) study the effect of cocoa in the post-treatment of the damage initiated by UVB. Cocoa exhibited biological action only in the post-treatment model at almost all tested concentrations compared to cells exposed to UVB alone. Further, fibroblast cells treated only with cocoa displayed higher levels of proliferation as evidenced by a decrease in the levels of basal reactive oxygen species (ROS) and nitric oxide (NO). In addition, cocoa also modulated the cell cycle of cells in the absence of UVB exposure by increasing the G2/M phase, although this did not generate significant changes in cells exposed concomitantly to cocoa and UVB. Therefore, data demonstrated that exposure to cocoa improved fibroblast cell-based control rates and exhibited an important reparative activity against damage initiated by UVB in human fibroblasts. Cocoa may thus be considered as a potential beneficial agent to be utilized in UVB-damaged skin cells.