RESUMEN
Oroxylin A is a flavonoid and was originally isolated from the root of Scutellaria baicalensis Georgi., one of the most important medicinal herbs in traditional Chinese medicine. The aim of this study was to investigate the ameliorating effects of oroxylin A on memory impairment using the passive avoidance test, the Y-maze test, and the Morris water maze test in mice. Drug-induced amnesia was induced by administering scopolamine (1 mg/kg, i.p.) or diazepam (1 mg/kg, i.p.). Oroxylin A (5 mg/kg) significantly reversed cognitive impairments in mice by passive avoidance and the Y-maze testing (P<.05). Oroxylin A also improved escape latencies in training trials and increased swimming times and distances within the target zone of the Morris water maze (P<.05). Moreover, the ameliorating effects of oroxylin A were antagonized by both muscimol and diazepam (0.25 mg/kg, i.p., respectively), which are GABA(A) receptor agonists. Furthermore, oroxylin A (100 microM) was found to inhibit GABA-induced inward Cl(-) current in a single cortical neuron. These results suggest that oroxylin A may be useful for the treatment of cognitive impairments induced by cholinergic dysfunction via the GABAergic nervous system.
Asunto(s)
Reacción de Prevención/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Flavonoides/farmacología , Aprendizaje por Laberinto/efectos de los fármacos , Memoria/efectos de los fármacos , Receptores de GABA-A/efectos de los fármacos , Amnesia/inducido químicamente , Amnesia/prevención & control , Análisis de Varianza , Animales , Reacción de Prevención/fisiología , Trastornos del Conocimiento/tratamiento farmacológico , Trastornos del Conocimiento/fisiopatología , Femenino , Masculino , Aprendizaje por Laberinto/fisiología , Memoria/fisiología , Ratones , Ratones Endogámicos ICR , Antagonistas Muscarínicos , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción/efectos de los fármacos , Tiempo de Reacción/fisiología , Receptores de GABA-A/fisiología , Escopolamina , Estadísticas no ParamétricasRESUMEN
BACKGROUND/OBJECTIVE: Neuroendocrine hormones are derived from the hypothalamus. The central nervous system, particularly the hypothalamus, is capable of modulating the cytolytic activity of adherent natural killer (NK) cells. In addition, electroacupuncture (EA) stimulation of the Zusanli (ST36) acupoint enhances splenic NK cell and cytokine activities in rats. However, it is still unclear whether the anterior hypothalamus affects this immunomodulation. Therefore, the aim of the present study was to examine the effect of EA stimulation at the Zusanli acupoint on the NK cell activity modulated by an anterior hypothalamic area lesion. METHODS: Male Sprague-Dawley rats were used. Lesions were placed by means of a direct current through a concentric electrode. The electric acupuncture stimulation was delivered for 30 min per each experiment at the right ST36 acupoint with an electrical stimulator. The NK cell activity of the spleen was measured by a fluorescence assay. RESULTS: The NK cell activity was significantly reduced on the 2nd day after the lesion, but was restored to that of the sham group by the 7th day. However, when EA was applied for 2 days after the operation, the NK cell activity of the lesion group was restored to that of the sham group. After 7 days of EA, the NK cell activity of the lesion group was slightly higher than that of the sham group. CONCLUSION: From these results, we can suggest that EA enhances or restores the NK cell activity suppressed by an anterior hypothalamic area lesion.