Study on the mechanism of UV-induced skin photodamage repair regulated by Naematelia aurantialba fermentation broth through SIRT signaling pathway.

The exposure to ultraviolet (UV) radiation is one of the key exogenous processes that contribute to photoaging, oxidative stress, and barrier dysfunction. Naematelia aurantialba is a very rare medicinal and edible fungus which is an organism with a large pharmacological potential, yet there is a gap in understanding the molecular processes involved in the anti-photoaging and soothing repair actions that the fermentation product is known to possess. The aim of this study was to understand the protective role of Naematelia aurantialba fermentation broth (NAF) against UV-induced skin cells damage and the possible molecular mechanisms of damage. The fermentation of Lactobacillus plantarum was used to prepare NAF. Its physicochemical characteristics were measured by use of DPPH, hydroxyl radical scavenging, and elastase inhibition and its biocompatibility by use of erythrocyte hemolysis experiment. We created UVA induced HFF-1 photoaging model, UVB induced HaCaT barrier damage model, and capsaicin induced sensitive model in order to measure cell viability and expression of factors associated with them. It was found that NAF had a large free radical scavenging capacity and elastase activity, and had a great biocompatibility over its interesting concentration (hemolysis rate < 5%). Molecularly, NAF activates mitochondrial homeostasis, boosting the gene and protein expression of the SIRT1 and SIRT3 proteins, and thereby strongly prevents the release of the enzyme, matrix metalloproteinase-1 (MMP-1) and suppressed collagenase degradation. At the same time, NAF prevents the capsaicin-induced overexpression of TRPV1 substantially preventing neurogenic inflammation, and increases aquaporin 3 (AQP3) and claudin-1 (CLDN1), mending the skin barrier. The NAF can produce various anti-photoaging, soothing, and barrier repair effects by activating the dermal SIRT1/3- MMP -1 axis, and blocking the epidermal TRP V1 pathway, which justifies its potential as an innovative functional plant raw material.