RESUMO
Abstract: The aim of this study was to evaluate the functional interaction of Glycyrrhiza glabra root extract (GGRE) on the large conductance Ca 2+ - activated K + (BKCa) channels expressed in the peripheral nervo us system by using nociception and inflammation models in rodents in vivo . Besides toxicity studies and open field tests, nociception and inflammation tests were performed on rodents. Different doses of GGRE were given orally to rats and mice. Naloxone, in domethacin, morphine, NS1619 and iberiotoxin (IbTX) were administered. GGRE had both anti - nociceptive and anti - inflammatory activity in rats and mice. GGRE exhibited an analgesic effect by decreasing the time - course of the pain threshold or reaction time i n some nociceptive tests. Furthermore, GGRE reduced level of pro - inflammatory cytokines, including TNF - α and IL - 1ß. As a conclusion, GGRE can alleviate the pain sensation of the afferent nerves and can reduce inflammation and associated pain by activating B KCa channels and reducing the levels of TNF - α, IL1ß
Resumen: El objetivo de este estudio fue evaluar la interacción funcional del extracto de raíz de Glycyrr hiza glabra (GGRE) en los canales de K + (BKCa) activados por Ca 2+ de gran conductancia expresados en el sistema nervioso periférico mediante el uso de modelos de nocicepción e inflamación en roedores in vivo . Además de los estudios de toxicidad y las prueb as de campo abierto, se realizaron pruebas de nocicepción e inflamación en roedores. Se administraron por vía oral diferentes dosis de GGRE a ratas y ratones. Se administraron naloxona, indometacina, morfina, NS1619 e iberiotoxina (IbTX). GGRE tenía activi dad tanto antinociceptiva como antiinflamatoria en ratas y ratones. GGRE mostró un efecto analgésico al disminuir la evolución temporal del umbral del dolor o el tiempo de reacción en algunas pruebas nociceptivas. Además, GGRE redujo el nivel de citocinas proinflamatorias, incluidas TNF - α e IL - 1ß. Como conclusión, GGRE puede aliviar la sensación de dolor de los nervios aferentes y puede reducir la inflamación y el dolor asociado activando los canales BKCa y reduciendo los niveles de TNF - α, IL1ß.
Assuntos
Animais , Ratos , Extratos Vegetais/administração & dosagem , Glycyrrhiza/química , Neuralgia/tratamento farmacológico , Fenóis/análise , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Análise de Variância , Ratos Wistar , Raízes de Plantas , Modelos Animais , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , InflamaçãoRESUMO
BACKGROUND: Some cannabinoids, a family of compounds derived from Cannabis sativa (marijuana), have previously shown vasodilator effects in several studies, a feature that makes them suitable for the generation of a potential treatment for hypertension. The mechanism underlying this vasodilator effect in arteries is still controversial. In this report, we explored how the synthetic cannabinoids ACPA (CB1-selective agonist) and JWH-133 (CB2-selective agonist) regulate the vascular tone of rat superior mesenteric arteries. METHODS: To screen the expression of CB1 (Cannabinoid receptor 1) and CB2 (Cannabinoid receptor 2) receptors in arterial rings or isolated smooth muscle cells obtained from the artery, immunocytochemistry, immunohistochemistry, and confocal microscopy were performed. In addition, the effects on vascular tone induced by the two cannabinoids were tested in isometric tension experiments in rings obtained from superior mesenteric arteries. The participation of voltage and calcium-activated potassium channel of big conductance (BKCa) and the role of nitric oxide (NO) release on the vascular effects induced by ACPA and JWH-133 were tested. RESULTS: CB1 and CB2 receptors were highly expressed in the rat superior mesenteric artery, in both smooth muscle and endothelium. The vasodilation effect shown by ACPA was endothelium-dependent through a mechanism involving CB1 receptors, BKCa channel activation, and NO release; meanwhile, the vasodilator effect of JWH-133 was induced by the activation of CB2 receptors located in smooth muscle and by a CB2 receptor-independent mechanism inducing NO release. CONCLUSIONS: CB1 and CB2 receptor activation in superior mesenteric artery causes vasorelaxation by mechanisms involving BKCa channels and NO release.