Wound healing properties of jojoba liquid wax: An in vitro study

Aim of the studyThe wound healing properties of jojoba (Simmondsia chinensis) liquid wax (JLW) were studied in vitro on HaCaT keratinocytes and human dermal fibroblasts, which are involved in wounded skin repair.Materials and methodsJLW cytotoxicity was evaluated by the crystal violet staining and the neutral red uptake endpoint. Induction of wound healing by JLW was assessed by scratch wound assay on cell monolayers. The involvement of signaling pathways was evaluated by the use of the Ca2+ chelator BAPTA and of kinase inhibitors, and by Western blot analysis of cell lysates using anti-phospho antibodies. Collagen and gelatinase secretion by cells were assayed by in-cell ELISA and zymography analysis, respectively.ResultsCytotoxicity assays showed that the toxic effects of JLW to these cells are extremely low. Scratch wound experiments showed that JLW notably accelerates the wound closure of both keratinocytes and fibroblasts. The use of inhibitors and Western blot revealed that the mechanism of action of JLW is strictly Ca2+ dependent and requires the involvement of the PI3K-Akt-mTOR pathway and of the p38 and ERK1/2 MAPKs. In addition, JLW was found to stimulate collagen I synthesis in fibroblasts, while no effect was detected on the secretion of MMP-2 and MMP-9 gelatinases by HaCaT or fibroblasts.ConclusionsTaken together, data provide a pharmacological characterization of JLW properties on skin cells and suggest that it could be used in the treatment of wounds in clinical settings.