Silymarin and silybin in suppression of UVA-induced oxidative stress in normal human dermal fibroblasts

A standardized extract from the seeds of Silybum marianum , silymarin (SM) and its main component silybin (SB) have been studied for 3 decades for their potential to reduce skin carcinogenesis induced chemically and by chronic exposure to UVB (280–320 nm) light as they possess several biological activities including anti-oxidant, anti-inflammatory, immunomodulatory and cellular regeneration. However, protection of SM/SB against UVA radiation (320–400 nm) has not been almost studied. Previously, we only demonstrated the regenerative effects of SM and SB on UVA-damaged HaCaT keratinocytes. Thus here we studied possible UVA (320–400 nm) photoprotective effects of SM and SB on primary human dermal fibroblasts (HDF). HDF were isolated from superfluous skin of donors undergoing plastic surgery operations (Department of Plastic and Aesthetic Surgery). Cells were pre-treated with the SM/SB for 1 h and then were exposed to UVA radiation using a solar simulator. Our results demonstrated that HDF pre-treatment with SM and SB resulted in reduction in ROS production, depletion in intracellular GSH level, caspase-3 activity, DNA single strand breaks formation. Effectiveness of SM and SB was comparable. This work was financially supported by the GACR grant 15–10897 S, IGA_LF_2017_011 and the Institutional Support of Palacký University in Olomouc RVO 61989592.