The effect of flavonoid morin on anxiety and depression behaviors induced by amyloid-beta peptide in rats

Studies have shown that anxiety and depression appear before memory impairment in Alzheimer's disease and controlling these dysfunctions may prevent the onset and progression of memory deficit. Morin is a natural flavonol that has antioxidant, anti-inflammatory, and neuroprotective effects. In this study, we investigated the effect of morin on anxiety and depression behaviors induced by amyloid-beta peptide in rats.

Forty male Wistar rats were divided into control, morin, amyloid-beta, and amyloid-beta-morin groups. Amyloid-beta 1-42 was injected into the hippocampus (4 micrograms on each side) and morin (20 mg/kg) was treated by gavage for 14 consecutive days. At the end of the period,  elevated plus maze (EPM) and forced swimming tests were used to evaluate anxiety and depressive behaviors, respectively.

Intrahippocampal injection of amyloid-beta significantly reduced the percentage of entry into the open arm and the percentage of time remaining in the open arm in the EPM (P < 0.001). Also, the total immobility time of these animals in the forced swimming test was significantly increased (P < 0.001). Morin largely prevented these changes in amyloid-beta injected rats.

Morin prevents anxiety behaviors and depression in Alzheimer's disease model rats and may have neuroprotective effects against amyloid-beta.