In vitro antioxidant and wound healing activity of Sargassum polycystum hydroethanolic extract in fibroblasts and keratinocytes

Objective: To investigate the in vitro antioxidant and wound healing properties of the hydroethanolic extract of Sargassum polycystum, and elucidate the mechanism of its wound healing activity. Methods: Human dermal fibroblast and HaCaT cells were used to evaluate the proliferation by sulforhodamine B and dsDNA assay after treatment with Sargassum polycystum extracts. Scratch wound healing and phalloidin-rhodamine staining were employed to observe migratory activity and filopodia formation, respectively. Western blot and real-time RT-PCR assays were performed to determine the protein and gene expressions related to wound healing activities. Results: The phytochemical analysis found a higher level of flavonoid than phenolic compound in Sargassum polycystum extracts. In human dermal fibroblast cells, Sargassum polycystum extracts at 50 and 100 μg/mL significantly increased fibroblast proliferation and the gene expressions of hyaluronic acid synthase 1(HAS1), HAS2, HAS3, collagen type 1 alpha 1 chain(COL1A1), collagen type 3 alpha 1 chain(COL3A1), and elastin. The phosphorylation of Akt, ERK1/2, and p38 MAPK was also significantly upregulated after treatment with Sargassum polycystum extracts. Additionally, 50 and 100 μg/mL of the extracts prominently enhanced the proliferation, migration, and filopodia formation of HaCaT cells, as well as the protein levels of pFAK/FAK, pSrc/Src, pAkt/Akt, pERK1/2/ERK1/2, Rac1 and Cdc42. Conclusions: Sargassum polycystum extracts show promising wound healing activities in human dermal fibroblasts and keratinocytes.