Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Antinociceptive Activity of Thymoquinone and its Structural Analogues: A Structure-Activity Relationship Study

Damião P de Sousa¹ , Franklin FF Nóbrega², Camila CMP Santos², Rubens B Benedito², Ygor W Vieira³, Marciana P Uliana³, Timothy J Brocksom³, Reinaldo N de Almeida²

¹LaboratÃ³rio de QuÃmica de Produtos Naturais e SintÃ©ticos Bioativos (LAPROBIO), Departamento de Fisiologia, Universidade Federal de Sergipe, CEP 49100-000, SÃ£o CristÃ³vÃ£o, Sergipe; ²LaboratÃ³rio de Tecnologia FarmacÃªutica/Universidade Federal da ParaÃba, Caixa Postal 5009, CEP 58051â€“970, JoÃ£o Pessoa, ParaÃba; ³LaboratÃ³rio de QuÃmica Bio-OrgÃ¢nica, Departamento de QuÃmica, Universidade Federal de SÃ£o Carlos, Caixa Postal 676, 13565-905 SÃ£o Carlos, SP, Brazil.

For correspondence:- Damião de Sousa Email: damiaodesousa@yahoo.com.br

Received: 9 October 2011 Accepted: 19 June 2012 Published: 16 August 2012

Citation: de Sousa DP, Nóbrega FF, Santos CC, Benedito RB, Vieira YW, Uliana MP, et al. Antinociceptive Activity of Thymoquinone and its Structural Analogues: A Structure-Activity Relationship Study. Trop J Pharm Res 2012; 11(4):605-610 doi: 10.4314/tjpr.v11i4.11

© 2012 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To investigate the structural features that influence the antinociceptive activity of thymoquinone and their structural analogues.

Methods: The quinones were prepared by an oxidation procedure using molecular oxygen and catalysis with [Co^II(salen)] from the respective phenols. The antinociceptive activity of para-benzoquinones (10 mg/kg, ip) was evaluated using formalin test in mice. Vehicle (5 % Tween 80) or morphine (10 mg/kg) were used as control group and standard drug, respectively. The amount of time spent licking the injected paw was considered as the nociceptive response.

Results: Among the compounds tested, five para-benzoquinones showed antinociceptive activity. The 2-isopropyl-para-benzoquinone presented the highest potency in first and second phases and produced a near-maximal inhibition (p < 0.001) in the formalin test, similar to morphine (p < 0.001).

Conclusion: Our experimental results show that by appropriate structural modification of para-benzoquinones it may be possible to develop novel analgesic drugs.

Keywords: Quinones, Antinociceptive activity, Analgesic, Central nervous system, Structure-activity relationship, Medicinal plant