Assessment of antinociceptive, anti-inflammatory and antioxidant properties of Cymbopogon winterianus leaf essential oil.

The present study investigated the antinociceptive, anti-inflammatory and antioxidant effects of the leaf essential oil (LEO) of Cymbopogon winterianus Jowitt (Poaceae). In the acetic acid-induced writhing and formalin tests, the LEO (50, 100, and 200 mg/kg, p.o.) significantly reduced (p < 0.05) the number of writhings and paw licking times in the first (0-5 min) and second (15-30 min) phases, respectively. In contrast, the LEO did not alter the latency time for mice licking the rear paws in hot-plate test. The LEO inhibited the carrageenan-induced neutrophil migration to the peritoneal cavity in a dose-dependent manner (35.5%, 42.8%, and 66.1% at doses of 50, 100, and 200 mg/kg, respectively, p < 0.001). Moreover, LEO exhibited higher scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC(50) (12.66 ± 0.56 µg/mL). Our present results demonstrated that the LEO has antinociceptive, anti-inflammatory, and antioxidant properties.

Isopropoxy-carvacrol, a derivative obtained from carvacrol, reduces acute inflammation and nociception in rodents.

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 (25­30 g) and rats (150­230 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 (0­4 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 (0.3­3 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.

Assessment of antinociceptive and anti-inflammatory activities of Porophyllum ruderale (Jacq.) Cass., Asteraceae, aqueous extract

The present work investigated the antinociceptive and antiinflammatory activities of the Porophyllum ruderale (Jacq.) Cass., Asteraceae, aqueous extract (PRAE). For this purpose, acetic acid writhing, paw licking induced by formalin, hot-plate and pleurisy tests were performed. The doses of 100, 200 and 400 mg/kg (p.o.) significantly inhibited the writhing 63.4, 89.6 and 94.8 percent, respectively, in comparison with control group. The lick of the paw 1st phase was reduced at the dose of 400 mg/ kg (24.9 percent), while the 2nd phase had reduction at doses 200 and 400 mg/ kg (23.1 and 34.4 percent), respectively. The PRAE inhibited the carrageenaninduced neutrophil migration to the peritoneal cavity in a higher dose (p<0.05). Taken together, our results suggest that the PRAE can constitute target potential for use in therapies of the pain and inflammation.

Antinociceptive and anti-inflammatory effects of the essential oil of Eugenia candolleana DC., Myrtaceae, on mice / Efeito antinociceptivo e antiinflamatório do óleo essencial de Eugenia candolleana DC. (Myrtaceae) em roedores

Eugenia candolleana DC. (Myrtaceae), commonly known as "murta" or "murtinha", is a plant species without any chemical or pharmacological study described in the literature. It has been popularly used for the treatment of pain and fever. This report aimed to investigate the possible antinociceptive and anti-inflammatory effects of the essential oil extracted from fresh leaves of Eugenia candolleana DC. (EOEc) in rodents. Following intraperitoneal injection, EOEc (25, 50 and 100 mg/kg) reduced the number of writhes significantly in a writhing test and the number of paw licks during phase two of formalin test (p < 0.001). However, administration of EOEc did not alter the time of reaction in hot plate test. Furthermore, EOEc inhibited (p < 0.01) the carrageenan-induced leukocyte migration to the peritoneal cavity. These results indicate antinociceptive and anti-inflammatory properties of EOEc probably mediated via inhibition of prostaglandin synthesis or other peripherally pathway.

Eugenia candolleana DC. (Myrtaceae), conhecida popularmente como "murta" ou "murtinha", é uma espécie vegetal sem estudos químicos e farmacológicos descritos na literatura, distribuída no Nordeste brasileiro, principalmente, na Zona da Mata. Na medicina popular do Estado de Sergipe é utilizada no tratamento de distúrbios febris e da dor. O presente estudo buscou avaliar as possíveis atividades antinociceptiva e antiinflamatória do óleo essencial extraído das folhas de E. candolleana DC (OEEc) em roedores. A administração intraperitoneal (i.p.) do OEEc (25, 50 e 100 mg/kg) reduziu significativamente o número de contorções no teste das contorções abdominais e a duração da lambida da pata na segunda fase do teste da formalina (p < 0,001). Entretanto, a administração do OEEc não alterou o tempo de reação no teste da placa quente. No experimento de peritonite induzido por carragenina, o OEEc reduziu de forma significativa (p < 0,01) a migração de leucócitos para a cavidade peritoneal. Os resultados obtidos sugerem que o OEEc possui ação antinociceptiva, provavelmente mediado por mecanismos periféricos, e ação antiinflamatória.