Dicranum scoparium extract modulates the NOX2/SOD2 axis and NF-κB signaling in a fibroblast-macrophage co-culture...

Oxidative stress, apoptosis, and inflammation are interconnected pathological processes. Bryophytes, such as Dicranum scoparium, have evolved unique secondary metabolic systems, including potent antioxidants, to survive extreme environmental stressors such as dedication and UV radiation. This study aimed to characterize the chemical composition of D. scoparium aqueous extract (DSAE) and evaluate its multi-targeted therapeutic potential using an integrated metabolomics and in vitro co-culture approach.

The chemical fingerprint of DSAE was established via GC-MS using a DB-5MS column (split ratio 1:10). Cytoprotective effects were evaluated in NIH/3T3 fibroblasts across a 100-fold serial concentration range (0.027 ng/mL, 2.7 ng/mL, 270 ng/mL, 2.7 µg/mL, and 27 µg/mL). A fibroblast-macrophage co-culture model was employed to monitor intercellular signaling and the regulation of the NOX2/SOD2 and NF-κB/inflammasome pathways under H₂O₂-induced stress.

GC-MS identified 34 metabolites, including erythritol and GABA-related derivatives. DSAE (0.027 ng/mL) significantly restored cell viability (88.4 ± 4.1% vs. 50.2 ± 3.4% in H₂O₂) and reduced ROS mean fluorescence intensity by 44.6 ± 5.2%. DSAE significantly upregulated HO-1 (1.25 ± 0.14-fold, p < 0.01) and GPx1 (0.88 ± 0.09-fold, p < 0.05). In the co-culture system, DSAE accelerated wound closure speed (3.44 ± 0.26 μm/h) and suppressed the transcription of NLRP3 (1.84 ± 0.21-fold) and IL-6 (1.92 ± 0.25-fold) via NF-κB inhibition.

DSAE exerts multi-targeted cytoprotective effects by modulating the NOX2/SOD2 axis and suppressing intercellular inflammatory crosstalk. These findings suggest that D. scoparium is a valuable source of bioactive metabolites for treating chronic inflammatory and oxidative disorders.