Antinociceptive, anti-inflammatory and antipyretic effects of 1.5-diphenyl-1H-Pyrazole-3-carbohydrazide, a new heterocyclic pyrazole derivative David do Carmo Malvar a,d, ⁎, Raquel Teixeira Ferreira a , Raphael Andrade de Castro a , Ligia Lins de Castro a , Antonio Carlos Carreira Freitas b , Elson Alves Costa c , Iziara Ferreira Florentino c , João Carlos Martins Mafra b , Glória Emília Petto de Souza d , Frederico Argollo Vanderlinde a a Universidade Federal Rural do Rio de Janeiro, Instituto de Biologia, Departamento de Ciências Fisiológicas, Seropédica, RJ, Brazil b Universidade Federal do Rio de Janeiro, Núcleo de Pesquisas de Produtos Naturais, Cidade Universitária, Rio de Janeiro, RJ, Brazil c Universidade Federal de Goiás, Instituto de Ciências Biológicas, Departamento de Ciências Fisiológicas, Goiânia, GO, Brazil d Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Departamento de Física e Química, Ribeirão Preto, SP, Brazil abstract article info Article history: Received 15 September 2013 Accepted 4 December 2013 Available online xxxx Keywords: 1.5-Diphenyl-1H-Pyrazole-3-carbohydrazide Anti-inflammatory activity Antinociceptive activity Antipyretic activity Cyclooxygenase PGE 2 TNF-α Aims: Heterocyclic pyrazole derivative has been described for the treatment of pain and inflammatory diseases. This study evaluated the in vivo, antinociceptive, anti-inflammatory and antipyretic effects of 1.5-diphenyl-1H- Pyrazole-3-carbohydrazide (1.5-DHP) and the in vivo or in vitro mechanism of action. Main methods: Acetic acid-induced writhing, hot-plate and formalin-induced nociception tests were used to eval- uate the antinociceptive effect, while the rota-rod test was used to assess the motor activity. Croton oil-induced ear edema and carrageenan-induced peritonitis tests were used to investigate the anti-inflammatory effect of 1.5-DHP. The antipyretic effect was assessed using the LPS-induced fever model. The mechanism of action was evaluated by PGE 2 and TNF-α measurement and cyclooxygenase inhibition assay. Key findings: Oral administration (p.o.) of 1.5-DHP (1, 3, 10 mg/kg) caused a dose-related inhibition of the acetic acid-induced writhing, however the highest dose was not effective on the hot-plate and rota-rod. In the formalin- induced nociception, 1.5-DHP (10 mg/kg, p.o.) inhibited only the late phase of nociception. This same dose of 1.5- DHP also reduced the croton oil-induced ear edema. 1.5-DHP (3, 10, 30 mg/kg, p.o.) produced a dose-related reduction of leukocyte migration on the carrageenan-induced peritonitis. 1.5-DHP (60 mg/kg, p.o.) reduced the fever and the increase of PGE 2 concentration in the cerebrospinal fluid induced by LPS. 1.5-DHP inhibited both COXs in vitro. Finally, 1.5-DHP (10 mg/kg, p.o.) reduced the TNF-α concentration in peritoneal exudates after carrageenan injection. Significance: These results indicate that 1.5-DHP produces anti-inflammatory, antinociceptive and antipyretic effects by PGE 2 synthesis reduction through COX-1/COX-2 inhibition and by TNF-α synthesis/release inhibition. © 2013 Elsevier Inc. All rights reserved. Introduction Pyrazole compounds are synthetic molecules that have, in their mo- lecular structure, a pyrazoline ring, which is a five-membered heterocy- cle with two adjacent nitrogen and three carbon atoms (Borne, 1995; Gursoy and Demirayak, 2000). The discovery of this class of drugs allowed the development of several agents widely used in many coun- tries (Rahman and Siddiqui, 2010) such as analgesics, antipyretics and/or anti-inflammatory drugs, which include dipyrone, antipyrine, aminopyrine and phenylbutazone (Brogden, 1986; Rainsford, 2007). Molecular modifications of pyrazole compounds can lead to various drug prototypes with a wide range of pharmacological activity, such as antipyretic, analgesic, anti-inflammatory, soothing, muscle relaxant, anti-epileptic, anti-depressant, antimicrobial and antihypertensive activities (Rahman and Siddiqui, 2010). Therefore, the development of new pyrazole derivatives aims to maintain the desired effects of the old pyrazole derivatives, such as antipyrine or dipyrone, but with less toxicity (Borne, 1995). These compounds have some structural analogy as they are acylhydrazone pyrazole and N-phenylpyrazole derivatives (arylamines, arylhydrazones and thioaryl). Among these, DuP 697, a diaryl heterocy- cle, which has a key structural feature described as critical to its analge- sic and anti-inflammatory activity, has been proposed as a prototype inhibitor of COX-2 (Gans et al., 1990; Pinto et al., 1996). This feature resides on its 1.2-diaryl substitution in the pyrazole ring and gives rise Life Sciences xxx (2013) xxx–xxx ⁎ Corresponding author at: Universidade Federal Rural do Rio de Janeiro, Instituto de Biologia, Departamento de Ciências Fisiológicas, Br 465, Km 7/Pavilhão de Química/sala 30. 23.890-000, Seropédica, RJ, Brazil. Tel./fax: +55 21 26823222. E-mail address: dcmalvar@gmail.com (D.C. Malvar). LFS-13815; No of Pages 8 0024-3205/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.lfs.2013.12.005 Contents lists available at ScienceDirect Life Sciences journal homepage: www.elsevier.com/locate/lifescie Please cite this article as: Malvar DC, et al, Antinociceptive, anti-inflammatory and antipyretic effects of 1.5-diphenyl-1H-Pyrazole-3- carbohydrazide, a new heterocyclic pyrazole derivative, Life Sci (2013), http://dx.doi.org/10.1016/j.lfs.2013.12.005