The Peperomia pellucida (Piperaceae) is an herbaceous plant commonly found in the American and Asian continents. In the Amazon the species is known by the name of erva-de-jabuti. This plant is used in folk medicine to treat a wide range of symptoms and diseases such as conjunctivitis, headache, asthma, gastric ulcer, inflammation and arthritis. Pellucidin A is an isolated compound of the species Peperomia pellucida and this study aimed to analyze the antinociceptive and anti-inflammatory activity of this compound, as well as to elucidate its mechanism of action. For the assays, male albino mice (25-40 g) were used, which were initially treated with pellucidin A at the doses of 0.5; 1 and 5 mg / kg (i.p.) and subjected to locomotor evaluation by the open field test and animal models of acute pain, such as acetic acid-induced abdominal writhing tests, formalin tests and the hot plate test. The acetic acid-induced abdominal contortion test was realized to elucidate the mechanism of action in which the animals were treated at the standard dose of 5 mg/kg (i.p.) and for anti-inflammatory analysis of the compound was used model of granuloma induced by pellets of cotton, in which the animals were treated in the dose of 10 mg/kg (i.p.). The compound did not show capacity to change the ambulation of the animals at any of the administered doses. In the contortion test, pellucidin A was able to inhibit the number of abdominal writhings in 43% at the dose of 1 mg/kg, and 65% at the dose of 5 mg/kg. In the formalin test, an antinociceptive effect was observed at the dose of 5 mg/kg, with a 68% reduction in the lymph time of the animal's paw in the inflammatory phase, showing a similar response to Indomethacin used at a dose of 10 mg/kg as positive control for this phase. Animals treated with pellucidin A and subjected to the hot plate assay did not show any change in their latency time on the plate, showing a similar response to the animals treated just with the vehicle solution. For the elucidation of the action mechanism, the pellucidin A was administered at the standard dose of 5 mg/kg (i.p.) and associated with Indomethacin (5 mg/kg i.p.), NS-398 (10 mg/kg i.p.) cyproeptadine (0.5 mg/kg i.p.), naloxone (1 mg/kg i.p.) and L-NAME (5 mg/kg i.p.). The pellucidin A has shown a synergistic action when associated with cyproeptadine and L-NAME, with a decrease in the pattern of abdominal writhing by 97% when associated with cyproheptadine and 96% with L-NAME. In the analysis of the action of pellucidin A (10 mg/kg i.p.) in the granuloma test induced by cotton pellets, pellucidin A presented anti-inflammatory activity, reduced granuloma formation in 24% in the treated mice. The results confirm the hypothesis that pellucin A presents analgesic activity capable of interfering in the inflammatory process, acting as a possible glucocorticoid agonist.
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