Tephrosia toxicaria Pers. reduces temporomandibular joint inflammatory hypernociception: The involvement of the HO‐1 pathway. (9th April 2014)

• Record Type: Journal Article
• Authors: do Val, D.R.; Bezerra, M.M.; Silva, A.A.R.; Pereira, K.M.A.; Rios, L.C.; Lemos, J.C.; Arriaga, N.C.; Vasconcelos, J.N.; Benevides, N.M.B.; Pinto, V.P.T.; Cristino‐Filho, G.; Brito, G.A.C.; Silva, F.R.L.; Santiago, G.M.P.; Arriaga, A.M.C.; Chaves, H.V.
• Is Part Of: European journal of pain. Volume 18:Number 9(2014)
• Page Start: 1280
• Page End: 1289
• Publication Date: 2014-04-09
• Subjects: Pain -- Periodicals; Pain -- Treatment -- Periodicals; Pain -- Physiological aspects -- Periodicals; 616.0472
• DOI: 10.1002/j.1532-2149.2014.488.x
• Languages: English
• ISSNs: 1090-3801

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="ejp488-sec-0001" sec-type="section"> <title>Background</title> <p>We investigated both the efficacy and the sub‐chronic toxicity of <italic>T</italic><italic>ephrosia toxicaria</italic> Pers. in the zymosan‐induced temporomandibular joint (TMJ) inflammatory hypernociception in rats evaluating the possible role of heme oxygenase‐1 (HO‐1).</p> </sec> <sec id="ejp488-sec-0002" sec-type="section"> <title>Methods</title> <p>Rats were pretreated with <italic>T</italic><italic>. toxicaria</italic> (0.2, 2.0 or 20 mg/kg) 60 min before the intra‐articular injection of zymosan (2 mg, 40 μL) in the left TMJ. In another series of experiments, rats were treated with ZnPP‐IX (3 mg/kg), a specific HO‐1 inhibitor, before <italic>T</italic><italic>. toxicaria</italic> (20 mg/kg). Von Frey test was used to evaluate inflammatory hypernociception (g) 4 h after zymosan injection. Six hours after zymosan injection, the synovial lavage was collected for total cell count and myeloperoxidase (MPO) activity, and joint tissue for histopathological analysis and immunohistochemistry for HO‐1. To evaluate the sub‐chronic toxicity, mice received <italic>T</italic><italic>. toxicaria</italic> (20 mg/kg) or saline once a day for 14 days to analyse body mass, organ weight and biochemical parameters.</p> </sec> <sec id="ejp488-sec-0003" sec-type="section"> <title>Results</title> <p> <italic>T</italic> <italic>. toxicaria</italic> partially reversed the zymosan‐induced head withdrawal threshold, the number of cells and the MPO activity. <italic>T</italic><italic>. toxicaria</italic> reduced the inflammatory cell influx in the synovial membrane. TMJ immunohistochemical analyses treated with <italic>T</italic><italic>. toxicaria</italic> showed increased HO‐1 expression. These effects of <italic>T</italic><italic>. toxicaria</italic> were not observed in the presence of ZnPP‐IX. <italic>T</italic><italic>. toxicaria</italic> treatment for 14 days did not show significant signs of toxicity when administrated to mice.</p> </sec> <sec id="ejp488-sec-0004" sec-type="section"> <title>Conclusions</title> <p> <italic>T. toxicaria</italic> did not produce any signs of toxicity and effectively decreased zymosan‐induced TMJ inflammatory hypernociception dependent, at least in part, upon the HO‐1 pathway integrity.</p> </sec> </abstract>