Melaleuca (Melaleuca alternifolia) essential oil demonstrates tissue-remodeling and metabolism-modulating activities in human skin cells

Abstract Melaleuca (Melaleuca alternifolia) essential oil (MEO), commonly known as tea tree oil, is popularly used in skincare products. In the current study, we investigated the biological activity of a commercially available MEO (with terpinen-4-ol as the major active component) in pre-inflamed human dermal fibroblasts, which were designed to simulate chronic inflammation. We analyzed the levels of seventeen biomarkers that are important in inflammation and tissue remodeling. Additionally, we studied the effect of MEO on genome-wide gene expression. MEO showed a robust antiproliferative activity against the cells. It also increased the levels of monocyte chemoattractant protein 1, an inflammatory chemokine, and several tissue remodeling molecules such as epidermal growth factor receptor, matrix metalloproteinase 1, and tissue inhibitor of metalloproteinase-1 and -2. It was also noted that MEO diversely modulated global gene expression. Furthermore, Ingenuity Pathway Analysis showed that MEO affects many important signaling pathways that are closely related to metabolism, which suggests its potential modulation of metabolism. The results provide an important evidence of the biological activity of MEO in human dermal fibroblasts. They also suggest that MEO plays useful roles in tissue remodeling and metabolism; however, further research is needed to explore the mechanisms underlying these actions.