Keratinocyte wound healing activity of galactoglycerolipids from the fern Ophioglossum vulgatum L

The genus Ophioglossum consists of ferns with different therapeutic properties, including vulnerary virtues. The species Ophioglossum vulgatum L. is traditionally used on wounds and burns as an ointment, suggesting the occurrence of lipophilic compounds with tissue repair properties. We isolated and characterized a galactosyldiacylglycerol mixture (1), composed mainly of 1,2-di-O-linolenoyl-3-O-β-D-galactopyranosyl-glycerol, from the frond dichloromethane extract. The wound healing properties of 1 were assessed in vitro on keratinocytes. Scratch wound assays showed increased wound closure rates in keratinocyte monolayers exposed to subtoxic doses, previously determined in cytotoxicity assays. The strongest effect, obtained at a dose of 5 μg/mL, approached that of a platelet lysate used in clinical settings. The use of inhibitors of the main cellular pathways involved in wound repair, revealed important roles for intracellular calcium and the ERK1/2 MAP kinase. Conversely, a PCR array of genes involved in wound healing showed an almost total absence of gene modulation. Taken together, the data suggest that 1 acts through a Ca²⁺-dependent, nongenomic mechanism involving the activation of ERK1/2 MAP kinase. Hence, 1 is a main candidate to explain the wound healing virtues of O. vulgatum ointment, and is proposed as a possible new drug in tissue repair and regenerative medicine.