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This study investigated the effects of Lactobacillus curvatus fermentation on the oxidative stress attenuating effects of Euryale ferox on H2O2-induced human skin fibroblasts (HSF). The results showed that Lactobacillus curvatus fermentation (i) increases the content of the various bioactive components of Euryale ferox and is found to have smaller molecular weights of polysaccharides and polypeptides; (ii) increases the overall intracellular and extracellular antioxidant capacity of H2O2-induced HSF while reducing reactive oxygen species (ROS) levels. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) all showed simultaneous increases in activity. Aside from that, the Nrf2 and MAPK signaling pathways are activated to regulate downstream-associated proteins such as the Bax/Bcl-2 protein ratio, matrix metalloproteinase 1 (MMP-1) activity, and human type I collagen (COL-1). These results suggested that the fermentation of Euryale ferox with Lactobacillus curvatus enhances its antioxidant capacity and attenuates apoptosis and senescence caused by oxidative stress. [ABSTRACT FROM AUTHOR]

Background: UVA radiation can cause skin oxidative stress. Tremella fuciformis polysaccharides (TFPS) are the main active ingredient in Tremella. Previous studies have shown that TFPS have protective effects on UVA‐induced oxidative stress cells, but the specific protective mechanism has not been clarified. Objective: This study aims to explore the potential protective mechanism of Tremella fuciformis polysaccharides on UVA‐induced damage to human dermal fibroblasts cells. Methods: We evaluated the protective ability of TFPS against UVA‐induced damage by detecting cell survival rate, the content of reactive oxygen species (ROS) and malondialdehyde (MDA) in the cells, and the scavenging activity of ABTS free radicals, as well as the enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH‐Px), and the Nrf2‐Keap‐1 pathway protein and gene were measured to study the protective mechanism of TFPS from photodamage. Results: TFPS pretreatment can reduce the oxidative stress of UVA‐treated human dermal fibroblasts cells. After TFPS pretreatment, the content of ROS and MDA in the cell decreased significantly and the total antioxidant activity was increased. Among them, the active of CAT, SOD, and GSH‐Px in the cells increased significantly. TFPS can also protect fibroblasts by up‐regulating Nrf2 and down‐regulating Keap1 expression. Finally, it was also found that TFPS pretreatment increased the content of collagen I, elastin, and hyaluronic acid (HA) in skin fibroblasts treated with UVA. Conclusion: These results indicate that a certain concentration of TFPS can effectively alleviate skin damage caused by UVA, and they may be used as an effective component of cosmetics. [ABSTRACT FROM AUTHOR]

Oxidative stress is an important factor on both aging and disease. Among foods endowed with beneficial healthy properties, rice is a very useful material, not only because it has a good amino acid ratio and produces antioxidant peptides through microbial fermentation, but also for its inexpensive availability. In this study, rice was treated with Lactobacillus plantarum , and the resulting mixture of small peptides with less than 11 amino acids (RFP) was extracted and purified from the fermentation broth. Subsequently, the antioxidant activity of RFP was assessed using the chemical model, cell biology, and animal model methods. RFP enhanced the expression of the antioxidant enzyme genes downstream of the KEAP1-NRF2/ARE pathway by promoting nuclear factor-erythroid 2-related factor 2 (NRF2) nuclear translocation while simultaneously removing lipid oxidation products and excess free radicals. These results suggest that RFP is a potential substance for resisting aging and disease caused by oxidative stress.