Introduction: Pain is considered an unpleasant sensory and emotional experience, being considered as one of the most important causes of human suffering. Computational chemistry associated with bioinformatics has stood out in the process of developing new drugs, through natural products, to manage this condition. Objective: To analyze, through literature data, recent molecular coupling studies on the antinociceptive activity of essential oils and monoterpenes. Data source: Systematic search of the literature considering the years of publications between 2005 and December 2019, in the electronic databases PubMed and Science Direct. Eligibility Criteria: Were considered as criteria of 1) Biological activity: non-clinical effects of an OE and/or monoterpenes on antinociceptive activity based on animal models and in silico analysis, 2) studies with plant material: chemically characterized essential oils and/or their constituents isolated, 3) clinical and non-clinical studies with in silico analysis to assess antinociceptive activity, 4) articles published in English. Exclusion criteria were literature review, report or case series, meta-analysis, theses, dissertations, and book chapter. Results: Of 16,006 articles, 16 articles fulfilled all the criteria. All selected studies were non-clinical. The most prominent plant families used were Asteraceae, Euphorbiaceae, Verbenaceae, Lamiaceae, and Lauraceae. Among the phytochemicals studied were a-Terpineol, 3-(5-substituted-1,3,4-oxadiazol-2-yl)-N′-[2-oxo-1,2-dihydro-3H-indol-3ylidene] propane hydrazide, b-cyclodextrin complexed with citronellal, (−)-a-bisabolol, b-cyclodextrin complexed with farnesol, and p-Cymene. The softwares used for docking studies were Molegro Virtual Docker, Sybyl ® X, Vlife MDS, AutoDock Vina, Hex Protein Docking, and AutoDock 4.2 in PyRx 0.9. The molecular targets/complexes used were Nitric Oxide Synthase, COX-2, GluR2-S1S2, TRPV1, b-CD complex, CaV 1 , CaV 2.1 , CaV 2.2 , and CaV 2.3 , 5-HT receptor, delta receptor, kappa receptor, and MU (m)

2-Allylphenol (2-AP) is a synthetic phenylpropanoid, structurally related to cardanol, thymol, and ortho-eugenol. Phenylpropanoids are described in the literature as being capable of promoting biological activity. Due to the similarity between 2-AP and other bioactive phenylpropanoids, the present research aims at evaluating the antioxidant, antinociceptive, and anti-inflammatory potential of 2-AP in silico, in vitro, and in vivo. At 30 min prior to the start of in vivo pharmacological testing, administration of 2-AP (25, 50, 75, and 100 mg/kg i.p.), morphine (6 mg/kg i.p.), dexamethasone (2 mg/kg s.c.), or vehicle alone was performed. In the acetic acid-induced abdominal writhing tests, pretreatment with 2-AP significantly reduced the number of abdominal writhes, as well as decreased licking times in the glutamate and formalin tests. Investigation of the mechanism of action using the formalin model led to the conclusion that the opioid system does not participate in its activity. However, the adenosinergic system is involved. In the peritonitis tests, 2-AP inhibited leukocyte migration and reduced releases of proinflammatory mediators TNF-α and IL-1β. In vitro antioxidant assays demonstrated that 2-AP presents significant ability to sequester superoxide radicals. In silico docking studies confirmed interaction between 2-AP and the adenosine A2a receptor through hydrogen bonds with the critical asparagine 253 residues present in the active site. Investigation of 2-AP demonstrated its nociception inhibition and ability to reduce reactive oxygen species. Its interaction with A2a receptors may well be related to proinflammatory cytokines TNF-α and IL-1β reduction activity, corroborating its antinociceptive effect.

Lippia pedunculosa Hayek (EOLp) presents tripanocid and amebicid effects. However essential oil needs to be further studied in experimental models of analgesia and inflammation once the prevalence of pain in the population generates great suffering and disability and the drugs most often used have undesirable side effects. We also evaluated whether the inclusion complex formulation EOLp/β-cyclodextrin (β-CD) was able to improve the antinociceptive activity of the EOLp alone. Data were evaluated by analysis of variance (ANOVA), followed by Tukey’s test. Differences were considered significant if p<0.05. EOLp presented better antinociceptive effect when compared to the EOLp/β-CD inclusion complex. Thus, cyclodextrins appear not to be efficient for essential oils with peroxide substances. However, in peritonitis, EOLp reduced total leucocyte migration and IL-1β levels in the peritoneal fluid, which confirmed its anti-inflammatory effect. The observed effects suggest that EOLp is the best promising option for the treatment of inflammation and pain-related disorders.