This study examines the synergistic interaction between the immunomodulatory functions of lactic acid bacteria postbiotics and the anti-inflammatory properties of Smilax china L. extract through a combined fermentation process. Using atopic dermatitis (AD) as a model, characterized by an immune imbalance that leads to skin inflammation, we developed a fermented product, MB-2006, and compared its effects to those of the heat-killed probiotics Lactobacillus acidophilus (LAC) and Lactobacillus rhamnosus (LRH). Our experiments focused on elucidating the mechanism of action of MB-2006 in AD-like HaCaT keratinocyte cells, particularly its impact on the NF-κB pathway, a pivotal regulator of inflammation. MB-2006 proved more effective in reducing inflammation markers, such as IL-4 and thymic stromal lymphopoietin (TSLP), and in inhibiting NF-κB activation compared to LAC and LRH. Significantly, MB-2006 also reduced the expression of thymus- and activation-regulated chemokine (TARC), highlighting a synergistic effect that enhances its therapeutic potential. These results suggest that the combined fermentation of Smilax china L. extract with lactic acid bacteria enhanced both the anti-inflammatory and immunomodulatory effects, presenting a promising integrative approach to treating conditions like AD. Further studies are needed to validate these results in clinical settings and fully explore the potential of this synergistic fermentation process.

Polydeoxyribonucleotide (PDRN) has emerged as a potent bioactive compound with proven efficacy in wound healing, tissue regeneration, and anti-inflammatory applications and is predominantly derived from salmonid gonads. However, this study presents a groundbreaking advancement by successfully extracting and characterizing PDRN from microbial sources, specifically Lactobacillus rhamnosus, marking the first report to utilize microbial-, biome-, or Lactobacillus-derived PDRN (L-PDRN). The findings demonstrate the enhanced biological properties of L-PDRN over traditional salmon-derived PDRN across several assays. L-PDRN exhibited superior antioxidant activity, with significantly higher SOD-like and DPPH radical scavenging activities compared to PDRN, particularly at higher concentrations. In wound-healing assays, L-PDRN demonstrated superior efficacy in promoting cell migration and wound closure, even under inflammatory conditions induced by tumor necrosis factor (TNF-α). Additionally, L-PDRN demonstrated the potential for enhanced immunostimulatory effects under non-inflammatory conditions while maintaining anti-inflammatory properties under lipopolysaccharide (LPS) stimulation. Electrophoretic analysis revealed that L-PDRN consists of smaller DNA fragments (under 100 bp) compared to salmon-derived PDRN (200–800 bp), suggesting greater bioavailability and skin absorption. Mechanistic studies confirmed that L-PDRN activates the focal adhesion kinase (FAK) and protein kinase B (AKT) signaling pathway through the A2A receptor, similar to PDRN, while also engaging alternative pathways for p38 and ERK phosphorylation, highlighting its signaling versatility. This study underscores the potential of L-PDRN as a multifunctional and sustainable alternative to salmon-derived PDRN, offering enhanced bioactivity, scalability, and environmental benefits. The novel approach of utilizing microbial-derived PDRN opens new avenues for therapeutic applications in oxidative stress management, tissue regeneration, and immune modulation, paving the way for a paradigm shift in PDRN sourcing and functionality.

Air pollution has considerable effects on the human skin, showing that every single pollutant has a different toxicological impact on it. The oxidative stress that exceeds the skin’s antioxidant capacity can lead to oxidative damage and premature skin aging by repeated air pollutant contact. In this study, according to the generalized protocol available to objectively substantiate the ‘anti-pollution’ claim, we evaluated several biomarkers after pollutants exposure in Raw 264.7 macro-phages and HaCaT keratinocytes to investigate the possibility of anti-pollution cosmetic material of fermented extract from Smilax china leaves (FESCL). FESCL decreased pollutants-induced luciferase activity in a dose-dependent manner, and FESCL significantly inhibited XRE-luciferase activity at a concentration of 1%. The IC₅₀ value of FESCL showed the same DPPH scavenging activity at 0.0625% as ascorbic acid, and the maximum DPPH scavenging activity (92.44%) at 1%. The maximum permissible non-cytotoxic concentrations of FESCL for a Raw 264.7 cell was determined to be 2%, where PGE₂ production of FESCL was inhibited by 78.20%. These results show the anti-pollution activity of FESCL against the pollutant-stimulated human living skin explants. In conclusion, we confirmed the anti-pollution potential of FESCL as one of the functional materials in cosmetic formulation.

There is a global and increasing demand for natural ingredients that support the human immune response. In this study, the immunomodulatory effect and mechanism of action of rice bran extract fermented by Lentinus edodes was investigated. The potential immunomodulatory effect of fermented rice bran (FRB) and processed rice bran (RB) was evaluated using male BALB/c mice whose immunity was lowered by Cyclophosphamide (CY). The changes in the weight of the thymus and the spleen, immunoglobulins, and cytokine expressions were measured as biomarkers of immunomodulating potential after 14 days of oral administration of FRB and RB (0.5 g/kg-body weight (b.w.), respectively). The FRB and RB groups treated with CY resulted in increased weight of the thymus (1.73 ± 0.40 and 1.45 ± 0.43 mg/g-b.w., respectively) compared to the CY-treated control group (1.05 ± 0.36 mg/g-b.w.). The levels of the immunoglobulin (Ig) G in the group treated with FRB (21.98 ± 2.17, p < 0.01) were significantly increased when compared to the RB group (18.48 ± 1.52 μg/mL, p < 0.01). The expression of serum cytokines, including IL-1α (p < 0.05), IL-2 (p < 0.05), IL-6 (p < 0.001), IL-12 p70 (p < 0.01), IFN-γ (p < 0.01), and TNF-α (p < 0.01) were also significantly increased by the administration of FRB (0.5 g/kg-b.w.). Similarly, the expression of spleen cytokines, including IL-1α (p < 0.05), IL-2 (p < 0.05), IFN-γ (p < 0.01), and TNF-α (p < 0.05), was also significantly increased in the group receiving the FRB (0.5 g/kg-b.w.). The natural killer cell (NK) cell activities at a 1:25 ratio of YAC-1 cells to splenocytes were significantly increased in positive control red ginseng extract 0.5 g/kg (38.64 ± 2.13%, p < 0.05), FRB (34.85 ± 3.45%, p < 0.05), and RB (25.00 ± 4.18%), compared to that of negative control CY group (12.67 ± 3.23%). These results suggest that FRB administration could stimulate the innate immune system by increasing the expression of cytokines in splenocytes and serum, especially IFN-γ, IL-2, and IL-12 (p70), which are associated with TNF-α and NK cell activities. The above results could provide the biochemical rationale to further evaluate the use of FRB for immunomodulatory applications.

Yoo Kyung Kim, Hyeon Jeong Kim, Min-Kyu Yun, Seunghun Lee, and Dae-Jung Kang. J. Microbiol. Biotechnol. 2025;35:1-9. https://doi.org/10.4014/jmb.2508.08003