Lactic Acid Bacteria Improve the Photoprotective Effect via MAPK/AP-1/MMP Signaling Pathway on Skin Fibroblasts

Ultraviolet B (UVB) exposure causes a breakdown of collagen, oxidative stress, and inflammation. UVB activates mitogen-activated protein kinase (MAPK), activator protein-1 (AP-1), and matrix metalloproteinases (MMPs). In this study, we evaluated 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)) radical scavenging activity and the photoprotective effect of lactic acid bacteria LAB strains, including Lactobacillus, Bifidobacterium, and Streptococcus genera in UVB-exposed skin fibroblasts. Nine LAB strains displayed antioxidant activity by regulating superoxide dismutase in UVB-exposed skin fibroblasts. Four LAB strains (MG4684, MG5368, MG4511, and MG5140) recovered type I procollagen level by inhibiting MMPs, MAPK, and AP-1 protein expression. Additionally, these four strains reduced the expression of proinflammatory cytokines by inhibiting oxidative stress. Therefore, L. fermentum MG4684, MG5368, L. rhamnosus MG4511, and S. thermophilus MG5140 are potentially photoprotective.