Repair Effects of Chlorella vulgaris Extract in Non-Chronic Skin Wounds During the Remodeling Phase

Algal polysaccharides have been linked to repair signaling pathways related to transforming growth factor-β1 (TGF-β1), a mediator of skin wound healing. However, to our knowledge, no study has directly confirmed the efficacy of Chlorella vulgaris extract in repairing non-chronic wounds, and the underlying mechanism remains unexplored. Hence, we investigated the potential involvement of the TGF-β1/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) pathway in this process. Following preliminary structural characterization of the Chlorella vulgaris extract (CE), its cell migration, proliferation and scratch wound closure rate were determined in a wound remodeling phase HaCaT cell model. Compared to the model group, CE effectively was associated with enhanced cell migration and proliferation. At 100 μg/mL, CE was associated with significant upregulation of aquaporin-3 and filaggrin expression. It was associated with inhibited the nuclear translocation of nuclear factor of activated T-cells 1 and nuclear factor erythroid 2-related factor 2. Mechanistically, CE was associated with increased TGF-β1 secretion and mTOR phosphorylation without significantly altering AKT phosphorylation, suggesting a potential involvement of the TGF-β1/mTOR signaling pathway rather than the canonical AKT/mTOR axis. Hemolysis and chicken chorioallantoic membrane assays indicated satisfactory biocompatibility, supporting the safety of the extract for topical application. These findings suggest a possible association between microalgal extracts and insights for developing natural cosmetic ingredients. However, further studies are required to confirm the mechanistic relationships suggested by these findings.