Atividade analgésica do extrato de Schinus terebinthifolius e de derivados 1,2,3,4,6-Pentagaloil-O-β-Glucopiranosideo e robustaflavona em modelos experimentais de nocicepção em roedores

Abstract

Previous studies from our group showed that essential oil of Schinus terebinthifolius and compound(R)-(+)-limonene exhibited anti-hyperalgesic effects against mechanical stimulus. The chemical composition of essential oil and extract are completely different and this plant is widely used by Mato Grosso do Sul state as anti-inflammatory, and analgesic agent guiding to the focus of our study in the analgesic property of the extract. In this way, the aims of this research was evaluate the anti-nociceptive and anti-hyperalgesic of methanolic extract (MEST), and two pure compounds, the 1,2,3,4,6--penta-O-galloyl-β-glucopyranoside and robustaflavone, obtained from S. terebinthifolius leaves in animal models of pain and arthritis. The products were administrated by oral route for mice and the extract was analysed in CFA- and carrageenan-induced persistent mechanical hyperalgesia, formalin-induced nociception, CFA- induced knee oedema, cold- and hot-hipersensitivity, depression, locomotor activity (open field test) and formalin test while the two isolated compounds was tested only in formalin test. The 1,2,3,4,6-penta-O-galloyl-β- glucopyranoside and robustaflavone were detected and isolated from the MEST. The MEST inhibited the mechanical hyperalgesia, knee edema, and cold hyperalgesia, but not the depressive like behavior, induced by the intraplantar injection of CFA. The MEST, 1,2,3,4,6-penta-O-galloyl- β-glucopyranoside and robustaflavone prevented the anti-nociceptive effects in both formalin phases of nociception and the mechanical induced by carrageenan. The MEST did not induce alterations in the open field test.The MEST was effective for inhibition of pain and arthritic parameters, but not against depressive-like behavior, without altering locomotor activity. The compounds seem to be the active principle(s) present in the MEST because they proved to be anti nociceptive and anti-hyperalgesic in models of acute pain. The present results may open new possibilities for the development of new anti-hyperalgesic and anti-arthritic agents from S. terebinthifolius