Biological Activities and Gene Expression Effects of Blended Essential Oils in Promoting Dermal Wound Healing

Essential oils (EOs) are highly concentrated plant-derived compounds that have been used for centuries for their benefits in medicinal, food-processing, and commercial purposes - notably within the realm of cultural and luxury industries. However, only a single essential oil has been extensively studied for biological activities and wound healing. This study aimed to investigate the synergistic potential of blended essential oils (BEO) composed of tea tree essential oil (TTO), lavender essential oil (LEO), rosemary essential oil (REO), and turmeric essential oil (TEO) for its biological activities and wound healing effects on human dermal fibroblast (HDF) cells. BEO exhibited the strongest antioxidant activity against 2,2 diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals with IC50 values of 10.669 and 108.497 mg/mL, respectively. It exhibited the lowest cytotoxicity against Vero cells and also demonstrated promising anti-inflammatory and anti-collagenase activities. The in vitro scratch wound healing assay on human dermal fibroblast cells indicated that BEO significantly increased cell migration rate after 48 h of incubation. The gene expression study revealed that BEO promoted wound healing by upregulating the COL1A1 gene, which is involved in type I collagen synthesis. This study is the first to confirm that the blended essential oil (BEO) has the significant potential for use as wound healing agent.