Natural products for orofacial nociception in pre-clinical studies: A systematic review.

OBJECTIVE: The aim of this systematic review was to summarize the use of natural products (NP) in the treatment of orofacial nociception in animal models. METHODS: Pre-clinical studies that have evaluated the efficacy of NPs in experimental orofacial nociception were sought in the Medline, Web of Science, Scopus, Embase, SciELO, LILACS and Scholar databases in January 2020, covering the period since the inception of each one. Two reviewers independently selected the studies, extracted the data and evaluated the risk of bias of the included studies. RESULTS: We included 41 records in qualitative synthesis. Fifty different NPs were investigated. All studies presented positive results for at least one orofacial nociception test. Regarding the risk of bias, most studies presented poor experimental design, mainly lack of randomization and blinding. The main class of isolated compounds tested was terpenes, of which monoterpenes were investigated in the majority of the studies. CONCLUSION: These results indicate that NPs are effective in treating experimental orofacial nociception and highlight some of these NPs, mainly terpenes, suggesting their potential for translational research.

Therapeutic Potential of Vanillin and its Main Metabolites to Regulate the Inflammatory Response and Oxidative Stress.

Many phenolic compounds found in foods and medicinal plants have shown interesting therapeutic potential and have attracted the attention of the pharmaceutical industry as promising pharmacologically active compounds in health promotion and disease prevention. Vanillin is a phenolic aldehyde, widely used as a flavoring agent in the food, pharmaceutical, and cosmetics industries. A variety of pharmacological activities has been attributed to this compound and its main metabolites, vanillic acid and vanillyl alcohol, including their anti-inflammatory ability. The relationship of the anti- inflammatory effects of vanillin, vanillic acid, and vanillyl alcohol and their actions on oxidative stress is well established. Considering that the inflammatory process is related to several pathologies, including new diseases with few therapeutic options, and limited efficiency, the search for effective treatment strategies and discovery of new anti-inflammatory agents capable of modulating inflammation becomes necessary. Therefore, in this review, we discuss the therapeutic potential of vanillin and its main metabolites for the treatment of inflammatory diseases and their actions on redox status. In addition, the molecular docking evaluation of vanillin, its metabolites and isoeugenol were carried out into the phospholipase A2 binding site.

Orofacial antinociceptive effect of the ethanolic extract of Annona vepretorum Mart. (Annonaceae).

Annona vepretorum Mart. (Annonaceae) is a species popularly known in Brazil as "araticum" and "pinha da Caatinga". We have evaluated the antinociceptive effects of A. vepretorum in formalin-, capsaicin-, and glutamate-induced orofacial nociception in mice. Male Swiss mice were pretreated with either saline (p.o.), A. vepretorum ethanol extract (Av-EtOH 25, 50 and 100 mg/kg, p.o.), or morphine (10 mg/kg, i.p.), before formalin, capsaicin, or glutamate was injected into the right upper lip. Pre-treatment with Av-EtOH at all doses produced a reduction in face-rubbing behavior induced by formalin in both phases, and these pre-treatments also produced a significant antinociceptive effect in the capsaicin and glutamate tests. Pre-treatment with naloxone (1.5 mg/kg, i.p.) did not reverse the antinociceptive activity of the extract at the dose of 100 mg/kg in the first phase of this test. Our results suggest that Av-EtOH might be useful in the treatment of orofacial pain.