Detection and localization of barakol binding sites in rat brains

Abstract

Barakol is the bioactive substance purified from the fresh young leaves and flowers of the Cassia siamea Lamk.. This substances has been shown to contain potent depressive effect. Previous reports suggested the substance may exert its effect in the central nervous system but no substantial evidences support on this matter. To determine the binding sites of barakol, this study was done by labeled iodine-125 into anhydrobarakol hydrochloride as radioligand for detection and localization of its binding sites in the rat brain by in vitro autoradiographic technique. High grain density was uniformly observed in the caudate-putamen, accumben nucleus, cerebral cortex, hippocampus, thalamic nuclei, granular cell layer of cerebellum, inferior colliculus and substantia nigra. The observed density in these area was reduced to the level of background density after adding cold ligand into hot ligand. This preliminary study suggested that the anhydrobarakol hydrochloride may exerts its effect through specific binding sites in those brain areas which is different from those of dopamine D1, D2, serotonin and GABA.