Brain activities of streptozotocin-induced diabetic Wistar rats treated with gliclazide: Behavioural, biochemical and histomorphology studies.

Gliclazide (GLD), a sulphonylurea is efficacious in the treatment of diabetes type-2. However, there is limited information on its activity in the brain, especially in diabetics. This research investigated the brain activities of GLD following streptozotocin-induced diabetes in Wistar rats. Twenty five adult male Wistar rats (200-250 g) were grouped (n = 5) as: Control (distilled water, 5 mL/kg) and GLD (150 mg/kg) groups; and the diabetic groups, untreated streptozotocin (STZ, 35 mg/kg), and STZ (35 mg/kg) treated with GLD (150 mg/kg) for two and four weeks, and already on high fat diet. The animals' body weights and blood glucose levels were checked weekly. After the experimental duration, spontaneous alternation and novel object recognition tests were carried out and the animals sacrificed. Perfusion with phosphate buffered saline preceded brain excision for biochemical analyses, with halves fixed in 10% neutral buffered formalin for histology. Compared with the control, results showed (p < 0.05) declined spontaneous alternation and exploratory activities with no preference for familiar or novel objects, body weights loss, raised blood glucose, increased malondialdehyde with decreased superoxide dismutase concentrations, and no apparent adverse effect on hippocampal and prefrontal cortical Nissl substance in the untreated diabetic group. The adverse observations were attenuated in the GLD treated diabetic groups; although the spontaneous alternation in the four weeks GLD treated diabetic group improved (p < 0.05), exploration of objects increased (p < 0.05) without preference. The present results showed that treatment with GLD for two and four weeks mitigated STZ activities, even though there was less improvement in neurocognitive activities.

Characterization of hippocampal histomorphology following R. vomitoria root extract treatment / Caracterización de la histomorfología del hipocampo después del tratamiento con extracto de la raíz de R. vomitoria

Rauwolfia vomitoria Afzel. is an antipsychotic plant used by several African communities in the management of psychiatric conditions with good outcomes. Concerns about its dosages on brain activity lead to this investigation of its action on the hippocampal microstructure.Twenty-four adult male Wistar rats of average weight 200 g, were assigned into four groups (n = 6): control; 200, 300 and 400 mg/kg body weight of RVroot bark extract, respectively. The administration was once daily, and orally for seven days. Daily observation of the animals was done till on day eight when they were sacrificed after deep anaesthesia. Each brain was processed for histology and immunohistochemical studies. Animals in the 200, 300 and 400 mg/kg RV groups appeared generally dull and drowsy, and barely fed. Their hippocampal histology showed neuronal atrophy and karyorrhexis, with no difference in cell count, although the pyramidal cell numbers decreased in the 300 and 400 mg/kg RV groups. Neuron-specific enolase decreased in the 400 mg/kg RV group, while neurofilament decreased in all test groups. Glial fibrillary acidic protein expression and density increased in the 200 and 300 mg/kg RV groups, but not the 400 mg/kg RV group, all compared with the control group.The given doses of RV root bark extractin adult Wistar rats showed sedative activities with hippocampal histopathological changes, which may not be reversible, thereby leading to the hippocampal functional deficit.

Introducción: Rauwolfia vomitoria (RV) Afzel es una planta antipsicótica utilizada por varias comunidades africanas en el tratamiento de enfermedades psiquiátricas con buenos resultados. Las preocupaciones sobre sus efecto sobre la actividad cerebral conducen a esta investigación de su acción sobre la microestructura del hipocampo.Materiales y métodos: Se asignaron veinticuatro ratas Wistar macho adultas de un peso medio de 200 g, en cuatro grupos (n = 6): control; 200, 300 y 400 mg / kg de peso corporal de extracto de corteza de raíz de RV, respectivamente. La administración fue una vez al día y por vía oral durante siete días. Se realizó una observación diaria de los animales hasta el día ocho, cuando fueron sacrificados después de una anestesia profunda. Cada cerebro fue procesado para estudios histológicos e inmunohistoquímicos.Resultados: Los animales en los grupos de RV de 200, 300 y 400 mg / kg parecían generalmente apagados y somnolientos, y apenas alimentados. Su histología hipocampal mostró atrofia neuronal y cariorrexis, sin diferencia en el recuento celular, aunque el número de células piramidales disminuyó en los grupos de RV de 300 y 400 mg / kg. La enolasa específica de neuronas disminuyó en el grupo de RV de 400 mg / kg, mientras que el neurofilamento disminuyó en todos los grupos de prueba. La expresión y densidad de la proteína fibrilar ácida glial aumentó en los grupos de RV de 200 y 300 mg / kg, pero no en el grupo de RV de 400 mg / kg, todos en comparación con el grupo de control.Conclusión: Las dosis administradas de extracto de corteza de raíz de RV en ratas Wistar adultas mostraron actividades sedantes, con cambios histopatológicos del hipocampo, que pueden no ser reversibles, lo que conduce al déficit funcional del hipocampo.