Efecto antinociceptivo del extracto etanólico de las hojas de Maytenus macrocarpa (Ruiz & Pav.) Briq. ôchuchuhuasiõ mediante la prueba de contorsiones abdominales en ratones / Antinociceptive effect of the ethanol extract of the leaves of Maytenus macrocarpa (Ruiz & Pav.) Briq. ôchuchuhuasiõ Through the Writhing Test in mice

Objetivo: Determinar el efecto y actividad antinociceptiva de las hojas de Maytenus macrocarpa (Ruiz & Pav) Briq. ôchuchuhuasiõ mediante la prueba de contorsiones abdominales en roedor. Material y Métodos: Se utilizaron 40 ratones albinos machos, con pesos medios de 25g, se empleó la prueba de contorsiones abdominales para determinar la actividad antinociceptiva. El grupo Control, no recibió ninguna sustancia. Se administró extracto etanólico de las hojas de M. macrocarpa (Ruiz & Pav.) Briq. 2000 mg/kg, Tramadol 10 mg/kg y Diclofenaco sódico 10 mg/kg. Las sustancias fueron administradas por la vía oral una hora antes de la inducción de dolor. Para la validación estadística se usó la prueba de Shapiro-Wilk, ANOVA de una cola, Tukey, y Newman-Keuls. Resultados: El número de contorsiones abdominales fue 41+/- 3.04, 27+/- 3.55, 9 +/- 4.14, y 18 +/- 2.65 respectivamente. El porcentaje de inhibición de la conducta nociceptiva fue: 0%, 34%, 77%, y 55%. La prueba de ANOVA de una vía, demostró diferencias estadísticas (p<0.05, IC 95%), y la prueba de Tukey y Newman-Keuls, demostraron diferencias significativas entre los grupos, frente al control. Conclusiones: Se comprobó el efecto antinociceptivo de las hojas de Maytenus macrocarpa (Ruiz & Pav.) Briq. ôchuchuhuasiõ, en dosis de 2000 mg/kg.

Objetives: To determine the effect and antinociceptive activity of the leaves of Maytenus macrocarpa (Ruiz & Pav ) Briq . ôChuchuhuasi ô by the writhing test in rodents. Material and Methods: 40 male albino mice were used, with average weights of 25g, the writhing test was used to determine the antinociceptive activity. The experimental groups were: Control; received no substance, ethanol extract of the leaves of M. macrocarpa Briq (Ruiz & Pav.) 2000 mg/kg, Tramadol 10 mg/kg and 10mg Sodium Diclofenac /kg. The substances were administered orally one hour before the induction of pain. For statistical validation the Shapiro -Wilk test, one-tailed ANOVA, Tukey, and Newman -Keuls was used. Results: Writhing number was 41 +/- 3.04, 27 +/- 3.55, 9 +/- 4.14, and 18 +/- 2.65 respectively. The inhibition percentage of the nociceptive behavior was: 0%, 34%, 77% and 55%. The test of one-way ANOVA showed statistical differences (p < 0.05, 95% CI), and the Tukey and Newman-Keuls test showed significant differences between groups versus control. Conclusions: Antinociceptive effect of the leaves of Maytenus macrocarpa (Ruiz & Pav.) Briq ôChuchuhuasiô was found at doses of 2000 mg/kg.

Exercise alleviates hypoalgesia and increases the level of calcitonin gene-related peptide in the dorsal horn of the spinal cord of diabetic rats

OBJECTIVE: The aim of this study was to evaluate the effects of treadmill training on nociceptive sensitivity and immunoreactivity to calcitonin gene-related peptide in the dorsal horn of the spinal cord of diabetic rats. METHODS: Male Wistar rats were divided into three groups: control, diabetic and trained diabetic. Treadmill training was performed for 8 weeks. The blood glucose concentrations and body weight were evaluated 48 h after diabetes induction and every 30 days thereafter. The nociceptive sensitivity was evaluated using the tail-flick apparatus. The animals were then transcardially perfused, and the spinal cords were post-fixed, cryoprotected and sectioned in a cryostat. Immunohistochemistry for calcitonin gene-related peptide analysis was performed on the dorsal horn of the spinal cord. RESULTS: The nociceptive sensitivity analysis revealed that, compared with the control and trained diabetic animals, the latency to tail deflection on the apparatus was longer for the diabetic animals. Optical densitometry demonstrated decreased calcitonin gene-related peptide immunoreactivity in the dorsal horn of the spinal cord in diabetic animals, which was reversed by treadmill training. CONCLUSION: We concluded that treadmill training can alleviate nociceptive hypoalgesia and reverse decreased calcitonin gene-related peptide immunoreactivity in the dorsal horn of the spinal cord of diabetic animals without pharmacological treatment.