Prunus domestica L. Fruit Extract Mitigates the Depletion of Rat Hippocampal Neurogenesis and Memory Deficits Observed in a D-Galactose-Induced Aging Rat Model

Background/Objectives: Accumulation of oxidative damage and brain inflammation plays a role in aging-associated memory impairment. D-galactose (D-gal) is a monosaccharide used to induce aging in rat models by promoting oxidative damage and neuroinflammation. Prunus domestica L. (PD) contains high levels of flavonoid compounds, which possess antioxidant, anti-inflammatory, neuroprotective and anti-aging properties. This study investigated the effects of PD fruit extract on memory, vascular-associated cell proliferation, immature neuronal cells, and survival of neurons in the dentate gyrus (DG) using a rat model of D-gal-induced aging. Methods: Forty-eight male Sprague–Dawley (SD) rats, two months old, were randomly assigned to eight groups: vehicle (0.9% normal saline), D-gal (50 mg/kg), PD (75, 100, and 150 mg/kg), or D-gal (50 mg/kg) co-administered with PD (75, 100 or 150 mg/kg). Spatial memory was assessed using the novel object location (NOL) test. Hippocampal neurogenesis and vascular-associated cell proliferation in the DG were evaluated using immunofluorescence staining for the co-localization of the markers Ki-67/rat endothelial cell antigen-1 (RECA-1) and 5-bromo-2′-deoxyuridine/neuronal nuclear protein (BrdU/NeuN), as well as doublecortin (DCX). Results: Rats treated with D-gal alone did not show a significant preference for the novel location. Additionally, D-gal treatment reduced the numbers of Ki-67-, Ki-67/RECA-1-, BrdU/NeuN-, and DCX-stained cells in the hippocampus. Conversely, co-administration of PD fruit extract was associated with a significant preference for the novel location, and this treatment also attenuated the D-gal-triggered reductions in cellular markers. Conclusions: These finding suggest that PD fruit extract exerts a neuroprotective effect against D-gal-induced brain aging, potentially preserving spatial memory-related performance in rats.