Accelerated Healing by Topical Administration of Salvia Officinalis Essential Oil on Pseudomonas Aeruginosa and Staphylococcus Aureus Infected Wound Model

Background: Salvia officinalis L. (Lamiaceae) is known to have antibacterial properties possibly conducive to the healing process of infected wounds.

Purpose: The present study aimed to evaluate the effects of an ointment containing Salvia officinalis essential oil (SOO) on an infected wound model.

Methods: Essential oil hydrodistillated from the dried leaves of the plant was analyzed by GC-FID and GC-MS. After creating two full-thickness cutaneous wounds, mice were classified into four groups, control, and animals treated with 2 % mupirocin® (standard positive drug), and 2 % and 4 % (w/w) of SOO. In order to evaluate the effects of SOO on the wound healing phases, the expression levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), cyclin-D1, Bcl-2, fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factors (VEGF) were analyzed using qRT-PCR. Immunohistochemistry analysis, tissue total antioxidant capacity (TAC) and malondialdehyde (MDA) were further assessed in all groups.

Results: Concerning essential oil, the main compounds were found to be cis-thujone (26.8 %), camphor (16.4 %), trans-thujone (14.1 %) and 1,8-cineole (10.8 %). Our findings showed that the topical application of SOO was able to shorten the inflammatory phase and accelerate the cellular proliferation, re-vascularization, collagen deposition and re-epithelialization in comparison to the control group (p < 0.05). Moreover, increased mRNA levels of FGF-2 and VEGF, and up-regulation of cyclin-D1 and Bcl-2 were observed following the topical application of SOO compared to the control group (p < 0.05). The expression levels of IL-6, IL-1β and TNF-α were reduced in animals treated with SOO on days 3, 7 and 14 (p < 0.05).

Conclusions: Administration of SOO increased the TAC level and reduced the MDA content and levels of IL-1β and TNF-α. It is concluded that SOO is able to accelerate the wound healing process by regulating the expression of pro-inflammatory cytokines, growth factors, and antioxidant properties.

Keywords: Angiogenesis; Collagen deposition; Infected wound healing; Inflammation; Re-epithelialization; Salvia officinalis essential oil.