Oleic acid exhibits an expressive anti-inflammatory effect in croton oil-induced irritant contact dermatitis without the occurrence of toxicological effects in mice. (1st March 2021)

• Record Type: Journal Article
• Authors: Pegoraro, Natháli Schopf; Camponogara, Camila; Cruz, Letícia; Oliveira, Sara Marchesan
• Is Part Of: Journal of ethnopharmacology. Volume 267(2021)
• Publication Date: 2021-03-01
• Subjects: Oleic acid -- Anti-inflammatory -- Skin inflammation -- Cytokines -- Glucocorticoids -- Adverse effects; ALT glutamic pyruvic transaminase -- ANOVA analysis of variance -- AST glutamic oxaloacetic transaminase -- CONCEA Brazilian Council of Animal Experimentation -- Emax maximal effect -- HTAB hexadecyltrimethylammonium bromide -- ICD irritant contact dermatitis -- Imax maximum inhibition -- IL-1β interleukin 1 beta -- MPO myeloperoxidase -- NF-κB nuclear factor-kappa B -- OA oleic acid -- OD optical density -- Pemulen® 0.3% OA Pemulen® TR2-based semisolid containing 0.3% oleic acid -- Pemulen® 1% OA Pemulen® TR2-based semisolid containing 1% oleic acid -- Pemulen® 3% OA Pemulen® TR2-based semisolid containing 3% oleic acid -- s.c. subcutaneous injection -- SEM standard error of the mean -- TMB tetramethylbenzidine -- TNF-α tumour necrosis factor-alpha -- TPA 12-O-tetradecanoylphorbol 13-acetate -- ω-9 omega 9; Ethnopharmacology -- Periodicals; Pharmacognosy -- Periodicals; Herbs -- Periodicals; Herbs -- Periodicals; Pharmacognosy -- Periodicals; Pharmacognosie -- Périodiques; Herbes -- Périodiques; 615.1
• DOI: 10.1016/j.jep.2020.113486
• Languages: English
• ISSNs: 0378-8741

Abstract

Abstract: Ethnopharmacological relevance: Cutaneous inflammatory diseases, such as irritant contact dermatitis, are usually treated with topical corticosteroids, which cause systemic and local adverse effects limiting their use. Thus, the discovery of new therapeutic alternatives able to effectively treat skin inflammatory disorders, without causing adverse effects, is urgently needed. Aim of the study : To investigate the topical anti-inflammatory effect of oleic acid (OA), a monounsaturated fatty acid, into Pemulen® TR2-based semisolid dosage forms, employing a croton oil-induced irritant contact dermatitis model in mice. Materials and methods: Male Swiss mice were submitted to skin inflammation protocols by acute and repeated applications of croton oil. The anti-inflammatory activity of Pemulen® TR2 hydrogels containing OA was evaluated by assessing oedema, inflammatory cell infiltration, and pro-inflammatory cytokine IL-1β levels. The mechanisms of action of OA were evaluated using cytokine IL-1β application or pretreatment with the glucocorticoid antagonist mifepristone. Possible toxic effects of OA were also assessed. Results: Pemulen® TR2 3% OA inhibited the acute ear oedema [maximal inhibition (Imax ) = 76.41 ± 5.69%], similarly to dexamethasone (Imax = 84.94 ± 2.16%), and also inhibited ear oedema after repeated croton oil application with Imax = 85.75 ± 3.08%, similar to dexamethasone (Imax = 81.03 ± 4.66%) on the day 7 of the experiment. Croton oil increased myeloperoxidase activity, which was inhibited by Pemulen® TR2 3% OA (Imax = 71.37 ± 10.97%) and by 0.5% dexamethasone (Imax = 96.31 ± 3.73%). Pemulen® TR2 3% OA also prevented the increase in pro-inflammatory cytokine IL-1β levels induced by croton oil (Imax = 94.18 ± 12.03%), similar to 0.5% dexamethasone (Imax = 87.21 ± 10.58%). Besides, both Pemulen® TR2 3% OA and 0.5% dexamethasone inhibited IL-1β-induced ear oedema with an Imax of 80.58 ± 2.45% and 77.46 ± 1.92%, respectively. OA and dexamethasone anti-inflammatory effects were prevented by 100% and 91.43 ± 5.43%, respectively, after pretreatment with mifepristone. No adverse effects were related to Pemulen® TR2 3% OA administration. Conclusions: OA demonstrated anti-inflammatory efficacy similar to dexamethasone, clinically used to treat skin inflammatory conditions, without presenting adverse effects. Graphical abstract: Image 1 Highlights: Hydrogels containing oleic acid reduce the croton oil-induced inflammation. Oleic acid also reduces IL-1β-induced mice ear oedema. Anti-inflammatory effect of oleic acid seems to occur via the glucocorticoid receptor. Oleic acid did not present adverse effects among those evaluated. Oleic acid could represent a therapeutic alternative to treat skin inflammation.