Molecular mechanism of the anti-inflammatory effects of plant essential oils: A systematic review

• Published in: Journal of ethnopharmacology Vol. 301; no. NA; p. 115829
• Main Authors: Zhao, Qian, Zhu, Liyun, Wang, Sunan, Gao, Yongsheng, Jin, Fei
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 30.01.2023
• Subjects: Anti-inflammatory; Anti-Inflammatory Agents - chemistry; Anti-Inflammatory Agents - pharmacology; Anti-Inflammatory Agents - therapeutic use; Clinical trials; Cytokines - metabolism; Humans; Inflammation - drug therapy; Inflammation - metabolism; Inflammatory response; NF-kappa B - metabolism; Oils, Volatile - chemistry; Oils, Volatile - pharmacology; Oils, Volatile - therapeutic use; Plant essential oils; Plant Extracts - pharmacology; Plant Oils - therapeutic use; Signaling pathway; Toxicology; Clinical trials; Inflammatory response; Toxicology; Signaling pathway; Plant essential oils; Anti-inflammatory
• ISSN: 0378-8741; 1872-7573; 1872-7573
• DOI: 10.1016/j.jep.2022.115829

Plant essential oils (PEOs) extracted from aromatic compounds of the plant contain complex mixtures of volatile and lipophilic bioactive compounds. In ancient Egypt, Arabia, Greece, and China, PEOs were traditional used in aromatherapy for various health disorders, including pain and inflammation. In this review, we provide an overview of the anti-inflammatory effects of PEOs and the underlying mechanisms associated with anti-inflammatory effects using in vitro and in vivo models. Further, clinical trials associated with PEOs were explored. The literature search was performed using various web-based tools and databases like Google Scholar, Web of Science, PubMed, CNKI and SCOPUS. The keywords used for conducting the literature review were general terms like “essential oils” followed by (AND) the subject of interest like “in vitro and/or in vivo anti-inflammatory models,” “inflammatory response,” “inflammatory indicators,” “pro-inflammatory cytokines,” “signaling pathway,” “anti-inflammatory mechanism,” “toxicology and side effects” and “clinical trials.” The articles selected were published between 2017 and 2022. The articles prior to 2017 were only considered if they were associated with molecular mechanisms or signaling pathways involved in the inflammatory responses. In vitro and in vivo inflammation models have been used to study the anti-inflammatory effects of 48 PEOs. Studies have reported that PEOs targets and inhibit multiple dysregulated signaling pathways associated with inflammation, including Toll-like receptors, nuclear transcription factor-κ B, mitogen-activated protein kinases, Nod-like receptor family pyrin domain containing 3, and auxiliary pathways like the nuclear factor erythroid 2-related factor 2/antioxidant response element and Janus kinase/signal transducers and activators of transcription) signaling pathways. PEOs extracted from different plant materials had varied qualitative and quantitative compositions of biologically active compounds. Different anti-inflammatory potentials and different molecular signal transduction have been attributed to PEOs-derived bioactive compounds with different chemical structures. The data on therapeutic efficacy and the long-term side effects of PEOs as an anti-inflammatory drug are still unknown due to the lack of clinical trials on PEOs. There is still insufficient evidence to draw conclusions on anti-inflammatory properties of PEOs without promising outcomes from clinical trials. [Display omitted] •Combine inflammation-related indicators and the pathogenesis of inflammation.•Summarize the research articles related to the anti-inflammatory activity of plant essential oils.•Comprehensive analysis of anti-inflammatory signaling pathways of plant essential oils (or bioactive ingredients).•The anti-inflammatory effects of plant essential oils were discussed objectively based on toxicology and clinical trials.