Fermented Plant-Derived Phytoconstituents in Biocosmetics: Pharmacological Enhancements and Applications

The application of plant-derived extracts in dermatological and cosmeceutical formulations is often limited by poor bioavailability, low skin permeability, and the instability of bioactive compounds. Fermentation has emerged as a promising biotechnological approach to enhance phytochemical composition and biological activity through microbial biotransformation. This review aims to critically evaluate the effects of fermentation on plant-derived phytoconstituents and their relevance in cosmeceutical dermatology. A structured literature search was conducted using Scopus and PubMed databases for studies published between 2015 and 2025. A total of 32 records were initially identified. After screening titles and abstracts, 19 articles were assessed for full-text eligibility. Following full-text evaluation, 5 studies met the inclusion criteria and were included in the qualitative synthesis. The findings indicate that fermentation modifies phytochemical profiles, by converting glycosides into more bioactive aglycones resulting in improved skin permeability and biological activity. Fermented extracts demonstrate enhanced antioxidant capacity, increased tyrosinase inhibition, and improved photoprotective effects compared to non-fermented counterparts. Mechanistically, these effects were associated with modulation of oxidative stress pathways and inflammatory mediators, including upregulation of SOD and CAT and suppression of IL-6 and TNF-α. However, the available evidence is predominantly limited to in vitro studies, with variability in fermentation conditions and microbial systems. This review provides an integrated and critical perspective linking biochemical transformation, skin permeability, and dermatological relevance. Future research should prioritize standardization and clinical validation to support translational application.