Abstract:
To systematically evaluate the protective effect and mechanism of
Lactobacillus delbrueckii subsp.
Lactis ABSN20244504 against skin photodamage, this study investigated he inhibitory effect of
Lactobacillus delbrueckii subsp.
lactis ABSN20244504 (LDSL-ABSN20244504) on ultraviolet B (UVB)-induced photodamage. In this study, a UVB-induced mouse photodamage model was used to evaluate the protective effects of LDSL-ABSN20244504 against skin photodamage by assessing skin tissue sections, levels of oxidative stress in serum and skin, inflammatory markers, the mRNA expression of nuclear factor kappa-light-chain-enhancer of activated B cells p65 subunit (NF-
κB p65), inhibitor of nuclear factor kappa B alpha (I
κB-
α), tumor necrosis factor-alpha (TNF-
α), interleukin-6 (IL-6), IL-10, superoxide dismutase 1 (SOD1), SOD2, catalase (CAT), AMP-activated protein kinase (AMPK), liver kinase B1 (LKB1), sirtuin 1 (SIRT1), mammalian target of rapamycin (mTOR), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1
α), adaptor protein phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1), and forkhead box O (FOXO), the levels of glutathione 1 (GSH1), as well as the protein expression of NAD(P)H:quinone oxidoreductase 1 (NQO1), glutamate-cysteine ligase catalytic subunit (GCLC), and nuclear factor erythroid 2–related factor 2 (Nrf2). Treatment with LDSL-ABSN20244504 alleviated UVB-induced photodamage in mice, as evidenced by reduced epidermal hyperplasia and dermal loss, decreased mast cell production, and mitigation of epidermal structural damage. Compared with the model group, LDSL-ABSN20244504 increased the levels of total superoxide dismutase (T-SOD), catalase (CAT), IL-4, and IL-10 in the serum and skin tissue of skin-injured mice, while decreasing the levels of hydrogen peroxide (H
2O
2), advanced glycation end products (AGEs), IL-6, IL-1
β, and TNF-α. Additionally, LDSL-ABSN20244504 elevated the levels of Na
+/K
+-ATPase and nicotinamide adenine dinucleotide kinase (NADK) in the skin tissue of skin-injured mice. RT-qPCR results showed that LDSL-ABSN20244504 upregulated the mRNA expression of SOD1, SOD2, CAT, GSH1, I
κB-
α, IL-10, AMPK, LKB1, SIRT1, PGC-1
α, APPL1, and FOXO, and downregulated the mRNA expression of NF-
κB p65, TNF-
α, IL-6, and mTOR in the skin tissue of skin-injured mice. Moreover, LDSL-ABSN20244504 also upregulated the protein expression of NQO1, GCLC and Nrf2 in the skin tissue of skin-injured mice. These findings indicate that LDSL-ABSN20244504 inhibits UVB-induced skin damage, with an effect superior to that of the antioxidant vitamin C, and that oral administration of live LDSL-ABSN20244504 is more effective than topical application of inactivated LDSL-ABSN20244504 to the skin.