Saline Extract from Moringa oleifera Leaves Has Antidepressant and Anxiolytic Effects in Mouse Models

Plant extracts can be therapeutic alternatives for depression and anxiety. However, some plant-derived preparations can also be toxic. Moringa oleifera leaves are used in human nutrition due to their high nutritional value and antioxidant activity. This study investigated a saline extract from M. oleifera leaves (MoLE) for secondary metabolites, proteins, cytotoxicity, hemolytic activity, in vivo acute oral toxicity, and neurobehavioral effects. MoLE contains flavonoids (rutin and vitexin), lectin, and a trypsin inhibitor. It is neither cytotoxic nor hemolytic for human cells and did not present acute oral toxicity (2000 mg/kg) to mice. The elevated plus maze test showed that MoLE (500, 1000, and 2000 mg/kg, p.o.) significantly increased the number of entries as well as the time spent by mice in open arms, while it decreased the number of entries and the time spent in closed arms when compared to the control. MoLE (500, 1000, and 2000 mg/kg, p.o.) reduced immobility time of mice in the tail suspension and forced swimming tests, compared to the control. The anxiolytic-like effect of MoLE is possibly mediated by a GABA mimetic action once it is prevented by pre-treatment with flumazenil. The present study demonstrated that MoLE has antidepressant and anxiolytic effects in mice and is a promising herbal medicine.