Chronic infrared‐A irradiation‐induced photoaging of human dermal fibroblasts from different donors at physiological temperature

Abstract

Infrared radiation is closely associated with skin diseases, such as photodermatosis and wrinkle formation, and erythema. 1,2 Infrared-A (IRA, 700-1400 nm) radiation constitutes approximately 30% of solar infrared radiation, which can penetrate down to the hypodermis and affect various types of cells in the skin. 3,4 However, the effects of IRA irradiation on skin cells are controversial, probably because of differences in IRA exposure conditions, such as the intensity of irradiation, exposure period, and temperature. 5,6 In addition, heat stresses during IRA irradiation on skin can induce various harmful effects, including the generation of reactive oxygen species (ROS) and apoptotic signals, making it difficult to understand the biological effects of IRA irradiation alone. 7,8 Hence, it is necessary to study the cellular effects of IRA irradiation alone under defined conditions of duration, frequency, and dose of IRA irradiation, as well as

Protection of Skin Fibroblasts from Infrared-A-Induced Photo-Damage Using Ginsenoside Rg3(S)-Incorporated Soybean Lecithin Liposomes

“…Owing to the amphiphilic characteristics of the ginsenoside Rg3 20(S) isomer, the hydrophilic sugar moiety of amphiphilic Rg3(S) could be located on the exterior or interior of liposomes, while the hydrophobic moiety could be embedded into the lipid layer after formulation. To examine the bioactivity of Rg3/Lipo for protection against IRA-induced photodamage, NHDFs were selected as a model fibroblast because of their vulnerability to IRA irradiation, as described in our previous study [ 5 ]. To mimic natural IRA conditions, the natural level of IRA (38-42 mW/cm 2 ) was irradiated for 4 h per day over 10 days [ 15 ].…”

“…According to our previous study, IRA radiation with a wavelength of 700–1400 nm plays a crucial role in skin damage and aging, even without heat stress [ 5 ]. A previous study reported that the expression levels of genes related to skin aging and inflammation, such as interleukin-6 and matrix metalloproteinase-1, could be regulated by Rg3 after IRA irradiation without heat control [ 4 ].…”

“…However, the biological benefits of Rg3 against photodamage by natural levels of infrared-A (IRA; wavelength of 700–1400 nm) irradiation without heat effects have not yet been studied in detail. Previously, we demonstrated that repeated IRA irradiation under physiological conditions significantly reduced cell proliferation and induced cellular apoptosis and senescence [ 5 ]. Therefore, it is necessary to evaluate the biological activity of Rg3 in the presence of IRA irradiation at natural levels in skin cells.…”