QUERCUS ACUTISSIMA LEAF POWDER.

This ingredient operates through several key pathways. Its astringent nature, attributed to tannins, helps to constrict skin tissues, visibly reducing pore size and controlling sebum production, which is particularly beneficial for oily and acne-prone complexions. A high concentration of polyphenols, flavonoids, and proanthocyanidins provides significant antioxidant defense, neutralizing free radicals and protecting skin from environmental aggressors. Furthermore, it demonstrates anti-inflammatory, antimicrobial, and antibacterial activities, contributing to clearer, calmer skin. Preliminary data from studies on *Quercus acutissima* bark extract in rats indicates an inhibition of androgen-related pathogenesis of acne by reducing testosterone conversion and sebum synthesis through 5α-reductase inhibition. Oak root extract has also been shown to form a protective layer on the skin, enhancing hydration and defense against external factors. Additionally, the high tannin content in *Quercus* species bark suggests a potential for tyrosinase inhibition, which could contribute to skin brightening.