Equol's efficacy is greater than astaxanthin for antioxidants, extracellular matrix integrity & breakdown, growth factors and inflammatory biomarkers via human skin gene expression analysis

Skin homeostasis and dermal aging can be influenced by phytochemicals. Astaxanthin is a powerful antioxidant and anti-inflammatory agent, while equol's beneficial properties have been recently reported. The purpose of this in vitro study was to compare astaxanthin versus equol at a 1% concentration by a single topical application using epidermal full-thickness skin cultures. After 24 h (exposure) human gene expression was quantified by qPCR-mRNA across 9 functional categories for 63 genes. For 39 biomarkers equol significantly altered the parameters compared to astaxanthin. Astaxanthin significantly influenced 6 genes compared to equol. The results revealed significantly greater effects of equol compared to astaxanthin for the antioxidants, growth factors, extracellular integrity and extracellular breakdown, and the inflammatory biomarkers. These findings indicate that equol's efficacy is greater than astaxanthin for various skin biomarkers and suggest that equol may be incorporated into topical and oral applications to improve skin health and reduce photo-aging.