Skin-Protective and Anti-Wrinkle Effects of Hot Water Extract from Green Tea Seed Shell

다국어 초록 (Multilingual Abstract)

To evaluate the skin cell protective and anti-wrinkle efficacy of hot water extract (HWE) from green tea seed shells, this study investigated the extraction yield, total flavonoid and polyphenol contents, cell protection, reactive oxygen species (ROS) scavenging effect, the inhibition of 3,4-dihydroxyphenylalanine (DOPA) oxidation, induction of keratin formation, collagen synthesis, and improvement in wrinkle. The yield of the green tea seed shell HWE was 2.1 g/g, with total polyphenol and flavonoid contents of 18.26 mg/g and 2.87 mg/g, respectively. The cell viability exhibited low cytotoxicity at concentrations below 90 μg/ml and provided protective effects against H2O2-induced oxidative stress. The ROS scavenging activity increased in a dose-dependent manner, reaching 49.3% at 70 μg/ml. In the case of DOPA oxidation, it inhibited by 46.2%, suggesting a whitening effect. Moreover, the expression of keratin and collagen synthesis in keratinocytes was enhanced in a concentration-dependent manner. Specifically, the collagen synthesis level in the 70 μg/ml treatment group reached 57.6% of that in the TGF-β1 positive control group. Elastase inhibition activity also increased with concentration, showing a maximum inhibition rate of 65.6% at 70 μg/ml, suggesting potential anti-wrinkle effects. These results suggest that green tea seed shell HWE possesses antioxidant and wrinkle-improving properties with low cytotoxicity, and may serve as a promising functional cosmetic and health care ingredient.