Monoterpenes, compounds mainly presented in essential oils, have important pharmacological actions. Isopropoxy-carvacrol (IPC) is a derivative of the monoterpene carvacrol, and its pharmacological properties have not yet been investigated. The aim of this study was to analyse the acute anti-inflammatory and antinociceptive properties of IPC. Mice (25-30 g) and rats (150-230 g) were pre-treated (i.p.) with IPC at the doses of 10, 30 or 100 mg/kg or vehicle (Tween 80, 0.5%), 30 min. before injection of the phlogistic agents. Both the first and the second phases of formalin-induced nociception were significantly reduced by IPC (100 mg/kg). Injection of carrageenan in mice paw reduced the threshold of stimulus intensity, applied with an analgesymeter, necessary to cause paw withdrawal, which was significantly reduced by 100 mg/kg of IPC. The area under curve (0-4 hr) of rat paw oedema induced by injection of carrageenan was also significantly diminished by the administration of IPC (100 mg/kg). Administration of 12-O-tetradecanoylphorbol-13-acetate (TPA) markedly increased mice ear oedema and myeloperidase (MPO) activity. Topical co-administration of IPC (0.3-3 mg/ear) during the induction did not affect TPA-induced ear oedema, but significantly decreased MPO activity in the ears, when compared with the vehicle. In in vitro experiments, IPC reduced lipoperoxidation induced by different stimuli, showed nitric oxide scavenger activity and did not interfere with murine macrophage viability in concentrations up to 100 lg/mL. These results demonstrate that IPC exerts acute anti-inflammatory and antinociceptive activities, suggesting that it may represent an alternative in the development of new future therapeutic strategies.

This study investigated the antioxidant and anti-inflammatory effects from the inner bark of Mimosa tenuiflora. The hydroethanol extract (HEE) and its hexane (HXF), chloroform (CLF), ethyl acetate (EAF) and hydromethanol (HMF) fractions were prepared and submitted to phytochemical screening and antioxidant activity. In vivo anti-inflammatory effect was investigated by using 12-Otetradecanoylphorbol 13-acetate (TPA)-induced edema and myeloperoxidase (MPO) activity in mice ears. Phytochemical prospection of HEE revealed the presence of flavonoids, tannins, xantones, triterpenes, esteroids and phenols. Higher total phenol content was found in EAF and higher percentages of inhibition of 2,2-diphenyl-1-picrylhydrazyl free DPPH radical were found for HEE, EAF or HMF. Lipid peroxidation (LP) induced by 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH) was greatly inhibited by HEE or EAF, while inhibition of FeSO 4-induced LP was higher for HMF. The coadministration of HEE (1 or 3 mg/ear) decreased edema (p<0.001) and MPO activity (p<0.05). All fractions reduced mice ear edema at the same extent, however, while EAF and HMF reduced MPO activity in mice ear at both 1 and 3 mg/ear (p<0.001 and p<0.05 respectively), CLF only at 3 mg/ear (p<0.05) and HXF did not affect this parameter. Taken together, these results demonstrate that inner bark of M. tenuifolia possesses antioxidant and anti-inflammatory effects.