Vascular dementia (VD), caused by impaired cerebral blood flow, is the most common form of dementia after Alzheimer's disease (AD) in the elderly and is characterized by severe neuronal damage and cognitive decline. Nitric oxide (NO) is an important determinant of vascular homeostasis, and its deficiency is associated with the progression of VD. In this study, we investigated the role of nitrite ion, a NO metabolite in a botanical mixture (BM) of fermented garlic, fermented Scutellaria baicalensis, and Rhodiola rosea on neuron loss and cognitive impairment using a VD rat model. The BM containing the NO metabolite alleviated cognitive deficits and enhanced neural plasticity, as reflected by an increase in long-term potentiation. The BM also alleviated neuron apoptosis, decreased GFAP expression, and oxidative stress, and increased parvalbumin and brain-derived neurotrophic factor (BDNF) levels. These results indicate that BM exerts neuroprotective effects and alleviates cognitive dysfunction while enhancing neuroplasticity, and thus has therapeutic potential against VD.