Antinociceptive activity of the monoterpene α-phellandrene in rodents: possible mechanisms of action.

OBJECTIVES: The aim of this work was to investigate the antinociceptive property of α-phellandrene (α-PHE) in experimental nociception models and possible mechanisms involved. METHODS: Mass spectrometry was used to evaluate the purity and molecular mass of α-PHE. Macrophages from mice peritoneal cavity were used in an MTT test. Rodents were used in tests of chemical and mechanical nociception. In the study of the mechanisms, the animals were treated with pharmacological tools and then submitted to the glutamate test. KEY FINDINGS: α-PHE purity was 98.2% and molecular mass 136.1 Da. α-PHE did not show cytotoxicity. In the writhing and capsaicin tests, α-PHE promoted the antinociceptive effect in all evaluated doses (minimum dose 3.125 mg/kg). In the formalin test, α-PHE (50 mg/kg) was effective in inhibiting both phases. In the glutamate test, the monoterpene (12.5 mg/kg) decreased the nociceptive response. In carrageenan-induced hyperalgesia, α-PHE (50 mg/kg) decreased the hypernociception index. In the study of the mechanisms involved, pretreatment with naloxone reversed the α-PHE antinociceptive effect, the same occurred with glibenclamide, l-arginine, atropine and yohimbine. α-PHE did not show muscle relaxant activity or central depressant effects in open field and rota rod tests. CONCLUSIONS: α-PHE has an antinociceptive effect and it possibly involves the glutamatergic, opioid, nitrergic, cholinergic and adrenergic systems.

Comparison of clinical parameters in captive Cracidae fed traditional and extruded diets.

The Cracidae family of neotropical birds is regarded as one of the most severely threatened in the world. They traditionally have been extensively hunted, and, thus, ex situ efforts for their conservation are recommended and involve the optimization of their care in captivity. Nutrition is a fundamental aspect of husbandry, which influences survival and reproduction in captivity. In this study, a total of 29 animals, including 3 species (Penelope obscura, Penelope superciliaris, and Aburria jacutinga), were subjected to monthly physical examination and blood sampling before and after dietary conversion from the traditional diet of broiler feed, fruits, and vegetables to a nutritionally balanced commercial diet specifically designed for wild Galliformes. The diet change produced differences in several parameters tested, including an increase (P < 0.05) in hemoglobin concentration for all species. Increases (P < 0.05) in erythrocyte count, packed cell volume, and body weight were observed in P. obscura, with a concomitant decrease in the standard deviation for such parameters that show improved uniformity. Globulins and lipase also were reduced (P < 0.05) in P. obscura. Although leukocyte count was lowered and eosinophils were increased in all 3 species after dietary conversion, only these 2 changes were significant (P < 0.05) in P. superciliaris. A. jacutinga had higher (P < 0.05) blood glucose concentrations than the other species, but diet had no effect on this parameter. Blood uric acid concentrations were higher (P < 0.05) after conversion to the commercial diet in P superciliaris. The provision of a commercial extruded diet as a single food source was beneficial, which led to a general improvement in clinical aspects and group uniformity in these 3 species of Cracidae.