Skin health function of fermented green tea extract with Pediococcus pentosaceus MGE 3023

Environmental factors, including ultraviolet (UV) radiation, are major contributors to skin damage, inflammation, and impairment of skin barrier function. Green tea ( Camellia sinensis ) is rich in polyphenolic catechins, which exhibit antioxidant and other biological activities relevant to skin health. However, the functional efficacy of conventional extracts may be limited by poor stability and potential cytotoxicity at higher concentrations. Microbial fermentation has emerged as an effective strategy to modify plant-derived compounds and enhance their biological activities. In this study, we investigated whether microbial fermentation could improve the skin-related bioactivity of green tea extract. The extract was fermented using Pediococcus pentosaceus MGE 3023, which was selected through preliminary screening based on cytocompatibility, antioxidant potential, and induction of hyaluronan synthase 2 (HAS2). The effects of fermented green tea extract were evaluated in vitro in human HaCaT keratinocytes by assessing cell viability, HAS2 expression, UV-induced cytotoxicity, wound closure, and inflammatory cytokine expression. The fermented extract significantly improved keratinocyte viability compared with the non-fermented extract. It also increased HAS2 expression, an indirect indicator of moisturizing potential, while protecting cells against UV-induced cytotoxicity and enhancing wound closure. Furthermore, the fermented extract markedly reduced the expression of the pro-inflammatory cytokine TNF-α in UV-irradiated cells. Collectively, these findings demonstrate that fermentation with P. pentosaceus MGE 3023 improves the in vitro biological properties of green tea extract and suggest its potential as a bioactive ingredient for skin-related applications.