The exopolysaccharide secreted by Lacticaseibacillus paracasei subsp. paracasei SS-01 strain (LP-EPS) is isolated and purified from yogurt. It is a polysaccharide with a branched and multi-stranded structure, which exists in a smooth rod-like or cloud-like state, and possesses a good thermal stability and a molecular weight of 49.68 kDa (±4.436%). LP-EPS shows a high antioxidant capacity, anti-inflammatory and anti-sensitizing activity during in vitro experimental studies, with half clearance (IC50) rates of 0.449, 1.314, and 2.369 mg/mL for the ABTS, DPPH, and OH radicals, respectively, and a half inhibition rate (IC50) of hyaluronidase of 1.53 mg/mL. A cell-based assay, enzyme-linked immunosorbent assay (ELISA), and quantitative real-time fluorescence PCR (qRT-PCR) show that LP-EPS effectively treats or ameliorates the skin inflammatory responses triggered by UVB irradiation, as evidenced by a highly significant decrease in the secretion of inflammatory factors by human skin keratinocytes (HaCaT), and a highly significant downregulation of the mRNA expression of MAPK/AP-1 pathway cytokines.

Purpose Damage caused by oxidative stress leads to the premature aging of cells. Mogrosides, the main active components of Siraitia grosvenorii , have strong antioxidant activity; however, it is unclear whether mogroside V (MV) exerts these effects in skin cells. This was investigated in the present study by evaluating the protective effects of MV against oxidative damage induced by hydrogen peroxide (H 2 O 2 ) in skin fibroblasts. Methods Mouse skin fibroblasts (MSFs) were treated with H 2 O 2 and cell viability, total antioxidant capacity, reactive oxygen species (ROS) production, malondialdehyde (MDA) content, and antioxidant enzyme activity were assessed. Results Treatment with MV reduced the ROS level and MDA content in MSFs treated with H 2 O 2 . This was accompanied by increased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities. Conclusion MV reduces H 2 O 2 -induced oxidative stress and enhances endogenous antioxidant activity in skin fibroblasts. Thus, MV can potentially be used as an ingredient in anti-aging cosmetic products.

Fibroblasts account for more than 95% of dermal cells maintaining dermal structure and function. However, UVA penetrates the dermis and causes oxidative stress that damages the dermis and accelerates skin aging. Puerarin, the main active ingredient of Puerariae lobata, has been demonstrated to withstand oxidative stress caused by a variety of factors. However, there are limited findings on whether puerarin protects fibroblasts from UVA-induced oxidative stress damage. The effects of puerarin on human skin fibroblasts (HSF) under UVA-induced oxidative stress were investigated in this study. It is found that puerarin upregulates antioxidant enzymes’ mRNA expression level and their content through modulating the KEAP1-Nrf2/ARE signaling pathway, thus improving cell antioxidant capacity and successfully eliminating UVA-induced reactive oxygen species (ROS) and lipid oxidation product malondialdehyde (MDA). Additionally, puerarin blocks the overexpression of human extracellular signal-regulated kinase (ERK), human c-Jun amino-terminal kinase (JNK), and P38, which downregulates matrix metalloproteinase 1 (MMP-1) expression and increases type I collagen (COL-1) expression. Moreover, preliminary research on mouse skin suggests that puerarin can hydrate, moisturize, and increase the antioxidant capacity of skin tissue. These findings suggest that puerarin can protect the skin against photoaging.

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.

As a probiotic, Weizmannia coagulans (W. coagulans) is often used in food and medicine to regulate intestinal flora and resist specific inflammation. In this study, the anti-acne efficacy and mechanism of YTCY extracellular proteins (YTCY-EPs) from a strain of W. coagulans are analyzed. The main components of YTCY-EPs, extracted and separated from the fermentation broth, are peptides ranging from 1.51–11.44 kDa, accounting for about 80%. Among the peptides identified by LC/MS-MS, YTCY A-F possess the properties of antimicrobial peptides, while YTCY 1–4 possess antioxidative properties. These peptides have a strong effect on Cutibacterium acnes (C. acnes) and significantly inhibit Staphylococcus aureus. The adhesion of YTCY-EPs has a 50% inhibition rate. It is found that YTCY-EPs possess strong antioxidant and anti-inflammatory properties, and can reduce the downstream TLR2/NF-κB and MAPKs/AP-1 pathways by regulating the nuclear translocation of NF-κB and AP-1 in vitro. The transcriptional expression of inflammatory cytokines, inflammatory chemokines, and matrix metalloproteinase genes is also regulated, thereby slowing the recruitment of inflammatory cells and the development of inflammation, and increasing keratinocyte mobility. YTCY-EPs can also effectively solve such problems as erythema, papules, cysts, skin lesions, hyperkeratinization, and desquamation caused by C. acnes in rabbit ears. Additionally, the treatment effectively improves the condition of wounds and inflammation. The results of this study prove that YTCY-EPs can be used as a potential anti-acne raw material in cosmetics.