Skin Moisturizing and Antiphotodamage Effects of Tyndallized Lactobacillus acidophilus IDCC 3302

Photoaging is generally the result of chronic exposure to the sun and ultraviolet (UV) radiation, which causes skin damage. In this study, we developed a UVB-induced hairless mouse model to determine whether Lactobacillus acidophilus IDCC 3302 tyndallizate (ACT3302) can enhance photodamaged skin repair. Mice (6 weeks old) were divided into six groups containing normal, UVB-treated vehicle, and UVB-treated ACT3302 (1 × 10⁵, 1 × 10⁶, 1 × 10⁷, and 1 × 10⁸ cells). Epidermal thickness was increased by UVB, but the thickening was lessened by ACT3302 as was the transepidermal water loss (TEWL). However, ACT3302 increased capacitance and decreased TEWL. Skin tissue staining to evaluate skin collagen increases in the number of skin collagen bundles in UVB-treated ACT3302 mice. UVB irradiation increased matrix metalloproteinase (MMP) and proinflammatory cytokine expression and activated mitogen-activated protein kinases in hairless mice; these changes were also attenuated by ACT3302. We conclude that ACT3302 effectively suppressed wrinkle formation induced by UVB irradiation through MMP downregulation. Therefore, ACT3302 potentially prevents skin photoaging and wrinkle formation.