Combination of Nicotinamide and Agastache rugosa Extract: A Potent Strategy for Protecting Hs68 Cells from UVB-Induced Photoaging.

This study investigated the protective effects of nicotinamide (NAM) and Agastache rugosa extract (AR) against ultraviolet B (UVB)-induced photoaging in Hs68 cells. The results demonstrated that NAM and AR, alone or in combination, exhibited concentration-dependent protective effects against UVB radiation. The highest synergistic effect was observed at a NAM:AR ratio of 6:4. This combination exhibited a synergistic protective effect against UVB-induced photoaging. The sample concentration required for 80% cell survival was 9.70 μM and 131.16 ppm for NAM and AR, respectively. However, when combined, they exhibited strong synergistic effects with concentrations as low as 0.11 μM and 17.50 ppm. Moreover, 5.26 μM of NAM and 1,082.13 ppm of AR were required to inhibit 30% of reactive oxygen species, but the combination treatment required 0.62 μM and 95.49 ppm, respectively. This combination significantly reduced the production of matrix metalloproteinase and increased collagen production. These findings highlight the potential of combining NAM and AR as functional cosmetic materials to protect against UVB-induced photoaging. The synergistic effects observed in this study provide valuable information for developing novel strategies for cosmetic combinations that target UVB-mediated skin damage.