Pharmacological evaluation of the anxiolytic-like effects of an aqueous extract of the Raphanus sativus L. sprouts in mice

Abstract

Raphanus sativus L. ( Brassicaceae ), commonly known as radish, is consumed worldwide as a vegetable. However, its benefits on mental health are unknown. The aim of this study was to evaluate its anxiolytic-like effects and safety using different experimental models. An aqueous extract of R. sativus sprouts (AERSS) was pharmacologically evaluated by intraperitoneal route (i.p.) at 10, 30, and 100 mg/kg and orally (p.o.) at 500 mg/kg on behavior by using open-field and plus-maze tests. In addition, its acute toxicity (LD 50 ) was determined by the Lorke's method. Diazepam (1 mg/kg, i.p.) and buspirone (4 mg/kg, i.p.) were the reference drugs. A significant and anxiolytic-like dosage of AERSS (30 mg/kg, i.p.) resembling the effects of reference drugs was chosen to explore the involvement of GABA A /BDZs site (flumazenil, 5 mg/kg, i.p.) and serotonin 5-HT 1A receptors (WAY100635, 1 mg/kg, i.p.) as a possible mechanism of action. A 500 mg/kg, p.o. dosage of AERSS produced an anxiolytic-like response equivalent to 100 mg/kg, i.p. No acute toxicity was observed since a LD 50 > 2000 mg/kg, i.p. The phytochemical analysis allowed the identification and quantification of major presence of sulforaphene (2500 µM), sulforaphane (15 µM), iberin (0.75 µM), and indol-3-carbinol (0.75 µM), as major constituents. Both the GABA A /BDZs site and serotonin 5-HT 1A receptors were involved in the anxiolytic-like activity of AERSS, depending on the pharmacological parameter or the experimental assay tested. Our results demonstrate that the anxiolytic activity of R. sativus sprouts involves GABA A /BDZs site and serotonin 5-HT 1A receptors supporting its health benefits in the treatment of anxiety beyond the satisfaction of basic nutritional needs. • Raphanus sativus sprouts aqueous extract produces anxiolytic-like effects. • Anxiolytic-like effects of Raphanus sativus involves GABA A /BDZs site and serotonin 5-HT 1A receptors. • No acute toxicity was observed after intraperitoneal administration of Raphanus sativus in mice.