Enhanced Skin-Protective Effects of a Novel <i>Centella asiatica</i> Variety (BT-Care) Cultivated for 75 Days via Modulation of Antioxidant Defense, Collagen Synthesis, and Skin Barrier Function

<i>Centella asiatica</i> L. Urban (CA) is traditionally used in skin wound healing, and stable cultivation-related studies are currently being conducted to meet the growing demand in the food, cosmetics, and pharmaceutical industries. This study aimed to analyze the growth rate and target bioactive compound levels of a novel variety, giant CA (BT-care), according to cultivation period, and to compare the effects of extracts harvested at specific cultivation periods on skin health in human keratinocytes with those of general CA. Although yields increased with prolonged BT-care cultivation, the levels of madecassoside, asiaticoside, total polyphenols and radical scavenging activity were significantly higher at 75 days post-transplantation. Compared to general CA, BT-care extracts obtained at day 75 significantly enhanced glutathione peroxidase expression among antioxidant-associated genes in ultraviolet B (UVB)-irradiated HaCaT cells. In addition, BT-care dose-dependently upregulated gene expression involved in collagen synthesis, wrinkle prevention, and skin barrier reinforcement. Furthermore, the high-concentration of BT-care significantly reduced the phosphorylation of c-JUN NH₂-terminal protein kinase and p38 mitogen-activated protein kinases. After 75 days of cultivation, BT-care significantly modulated protein levels associated with skin homeostasis, recovery, collagen synthesis, and skin barrier-related gene expression, which may be attributed to the elevated levels of active compounds. These findings indicate that BT-care may serve as a promising resource for food, cosmetic, and pharmaceutical applications aimed at promoting skin health.