Enzymatic hydrolysates obtained from Trametes versicolor polysaccharopeptides protect human skin keratinocyte against AAPH‑induced oxidative stress and inflammatory

BACKGROUND: Polysaccharopeptides (PSPs) extracted from Trametes versicolor show antitumor, anti-inflammatory, and immunomodulation effects. According to our previous report, the enzymatic hydrolysates obtained from T versicolor PSPs by 80 U/mL beta-1,3-D-glucanase (PSPs-EH80) did not change the functional groups of PSPs but enhanced their antioxidative activities. However, the mechanism elevating the antioxidant and anti-inflammatory effect of PSPs-EH80 is not clear. AIMS: This research focused on the protective mechanism(s) of PSPs-EH80 against free radical and 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative damage in human keratinocyte (HaCaT) cells. METHODS: We evaluated the anti-inflammatory potential of PSPs-EH80 by assessing its free radical-induced oxidative damage. Using the HaCaT cell as the experimental system, we tested the protective effects of PSPs-EH80 on a model of AAPH-induced cellular oxidative damage through the assessment of cell survival rate. Heme oxygenase 1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), cyclooxygenase-2 (COX-2), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase were determined using MTT assays and Western blotting. RESULTS: We demonstrated that PSPs-EH80 significantly enhanced keratinocyte viability, and augmented the antioxidant HO-1 expressions through upregulation of the Nrf2, compared with PSPs. Furthermore, PSPs-EH80 significantly reduced AAPH-induced COX-2 expressions through downregulation of the ERK, p38, and NF-kappaB signaling pathways. CONCLUSION: The PSPs-EH80 exhibits a stronger antioxidant and anti-inflammatory capacity than PSPs. Therefore, PSPs-EH80 could be effective for attenuating free radical-induced oxidative damage in human skin and can be applied widely in the fields of cosmetics and medicine.