ABSTRACT
Seed oil (Pp-oil) of Plukenetia polyadenia is used by native people of the Brazilian Amazon against arthritis and rheumatism, spreading it on the arms and legs to reduce the pain and inflammation. Pp-oil was obtained by pressing dried seeds at room temperature to give a 47.0% yield of oil. It was then subjected to fatty acid composition analysis. The principal fatty acids were linoleic acid (46.5%), α-linolenic acid (34.4%) and oleic acid (13.9%). Then, it was evaluated for its antinociceptive activity in mice, using the acetic acid-induced abdominal writhing, hot plate and formalin test models. Additionally, its toxicity was determined. The Pp-oil proved to have no toxicological effects, showing dose-dependent antinociceptive effect under chemical stimulation. At oral doses of 25-100 mg/kg, Pp-oil significantly reduced the abdominal writhes in the writhing test. A higher oral dose of 200 mg/kg did not induce alterations in the latency time of the hot plate test when compared to the control, suggesting an analgesic activity of peripheral origin. At oral doses of 50 and 100 mg/kg, the Pp-oil significantly reduced the second phase of the algic stimulus in the formalin test. In addition, the antinociception of Pp-oil was reversed by naloxone in the evaluation of its mechanism of action. Therefore, the Pp-oil proved to be safe at very high doses and to show significant analgesic properties. The role of Pp-oil is still being investigated with respect the mechanism of action, but the results suggest that opiod receptors could be involved in the antinociception action observed for the oil of P. polyadenia.
Subject(s)
Analgesics/adverse effects , Analgesics/pharmacology , Euphorbiaceae/chemistry , Fatty Acids/adverse effects , Fatty Acids/pharmacology , Oils, Volatile/adverse effects , Oils, Volatile/pharmacology , Analgesics/chemistry , Animals , Fatty Acids/chemistry , Male , Mice , Naloxone/pharmacology , Oils, Volatile/chemistry , Pain/drug therapy , Pain Measurement/methodsABSTRACT
The ear is one of the most common sites of keloid formation, usually associated with the wearing of earrings. However, although this is a small perforating lesion that is equal on both sides, keloids are bigger and more prevalent on the posterior surface. In this study, 141 keloids were evaluated, most of which were located on the posterior surface of the earlobe and caused by the piercing of the ear. Most of the earrings and piercing jewellery used had metallic backs. The more frequent occurrence of earlobe keloids on the posterior surface of the ear therefore may be associated with the exacerbation of local neurogenic inflammation caused by the metallic backs.
