Robinin Isolated from Solanum asperum Exhibits Pharmacological Actions in the Central Nervous System of Adult Zebrafish (Danio rerio)

This study investigated the anxiolytic, anticonvulsant and memory preservation effects of the flavonoid robinin. The compound, administered at doses of 4, 20 and 40 mg/kg, did not show toxicity after 96 hours of monitoring. In behavioral experiments with zebrafish, robinin did not cause significant changes in motor functions, but it impairs locomotor activity and demonstrates anxiolytic properties, evidenced by the increase in the time spent in the clean zone of the protector. A minimum effective dose (4 mg/kg) was blocked by flumazenil, providing an interaction with GABAA receptors and decreasing an anxiolytic profile similar to that of diazepam, without causing sedation. In addition, a dose of 40 mg/kg was able to reverse seizures, increasing the latency to enter the seizure stages, an effect that was also blocked by flumazenil. Robinin (40 mg/kg) also prevented memory variation in an inhibitory avoidance test. In silico ADME tests indicated that robinine presents gradual intestinal absorption and low distribution in the central nervous system. In molecular docking, the compound was exposed in the layer with CAII and GABAA receptors, corroborating the anxiolytic and anticonvulsant effects.