A systematic review and meta-analysis of the effect of thymol as an anti-inflammatory and wound healing agent: A review of thymol effect on inflammation and wound healing: A review of thymol effect on inflammation and wound healing

Phytother Res. 2022 Sep;36(9):3415-3443. doi: 10.1002/ptr.7541. Epub 2022 Jul 18.

Abstract

Thymol (THY) exhibits antibacterial and antioxidant properties. Recent studies have also shown that THY presents anti-inflammatory and healing properties. This review focused on in vitro and in vivo investigations related to THY utilization, as an anti-inflammatory and/or wound healing agent. PubMed, WebOfScience, and Scopus were examined. Independent reviewers conducted all diagram steps. PRISMA was followed for data extraction. RoB 2 and SYRCLE were utilized to assess the risk of bias for in vitro and animal studies. Meta-analysis was performed for in vitro and in vivo articles that investigated THY as an anti-inflammatory agent. Thirty-six and 15 articles were included in the qualitative analysis and meta-analysis, respectively. Studies showed high risk of bias related to sampling, allocation procedures, randomization, and blinding. Even so, for in vitro studies, significant result was observed for IL-2. For in vivo studies, significant results were found for IL-1, IL-17, TNF-α, AST, MPO, and CRP, with higher levels noticed in control groups. THY presents significant properties as anti-inflammatory, ameliorating affections of the digestive system, cardiovascular problems, respiratory system and dermal damages, and burns. Researches are needed to clarify THY dose-response relationship and its mechanism of action, especially in the application of THY as a healing agent.

Keywords: anti-inflammatory; meta-analysis; monoterpene; systematic review; thymol; wound healing.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Anti-Inflammatory Agents / therapeutic use
  • Burns*
  • Inflammation / drug therapy
  • Thymol* / pharmacology
  • Thymol* / therapeutic use
  • Wound Healing

Substances

  • Anti-Inflammatory Agents
  • Thymol