The Protective Effect of Carotenoids, Polyphenols and Sex Hormones on Skin Cells under Oxidative Stress

Skin ageing is influenced by several factors including environmental exposure, hormonal changes and oxidative stress. Reactive oxygen species (ROS) can be formed by extrinsic factors, such as sun exposure, or can result from mitochondrial dysfunction, which occurs during ageing. ROS activate the nuclear factor-kappa B (NFƙB) transcription systems leading to inflammatory processes and increased production of matrix metalloproteinase (MMPs) by skin cells, which leads to collagen degradation. Several studies have shown the protective role of estrogens and of various phytonutrients on skin health.

Aim:
To examine the damage caused by ROS that originate in the mitochondria due to its dysfunction, or by H2O2, and to examine the protective role of phytonutrients, estradiol, and dihydrotestosterone.

Methods:
Human dermal fibroblasts and keratinocyte were used to determine ROS levels, measured by FACS, and their effect on cell viability by XTT assay, ELISA determined MMP1 and pro-collagen secretion as markers of skin damage. Rotenone was used to cause mitochondrial dysfunction.

Results:
Rotenone leads to ROS production, cell death, upregulation of MMP1 secretion and decreased collagen secretion. This was accompanied by activation of the antioxidant response element/Nrf2 (ARE/Nrf2) and NFƙB transcriptional activity. Pretreatment with dietary compounds and hormones reduced ROS level, cell viability, and MMP1 secretion and increased pro-collagen secretion.

Conclusion:
These effects can be partially explained by the increased activity of the ARE/Nrf2, and the decreased activity of NFƙB transcriptional activities. This study indicates that phytonutrients and sex hormones protect skin cells from ROS-induced damage and may improve skin health and appearance.