Kim JH, et al. Nutr Res Pract. 2015 Oct;9(5):480-488. https://doi.org/10.4162/nrp.2015.9.5.480

We investigated the protective effect and mechanisms of apigenin against cognitive impairments in a scopolamine-injected mouse model. Our results showed that intraperitoneal (i.p.) injection of scopolamine leads to learning and memory dysfunction, whereas the administration of apigenin (synthetic compound, 100 and 200 mg/kg/day) improved cognitive ability, which was confirmed by behavioral tests such as the T-maze test, novel objective recognition test, and Morris water maze test in mice. In addition, scopolamine-induced lipid peroxidation in the brain was attenuated by administration of apigenin. To further evaluate the protective mechanisms of apigenin on cognitive and memory function, Western blot analysis was carried out. Administration of apigenin decreased the B-cell lymphoma 2-associated X/B-cell lymphoma 2 (Bax/Bcl-2) ratio and suppressed caspase-3 and poly ADP ribose polymerase cleavage. Furthermore, apigenin down-regulated the β-site amyloid precursor protein-cleaving enzyme, along with presenilin 1 (PS1) and PS2 protein levels. Apigenin-administered mice showed lower protein levels of a receptor for advanced glycation end-products, whereas insulin-degrading enzyme, brain-derived neurotrophic factor (BDNF), and tropomyosin receptor kinase B (TrkB) expression were promoted by treatment with apigenin. Therefore, this study demonstrated that apigenin is an active substance that can improve cognitive and memory functions by regulating apoptosis, amyloidogenesis, and BDNF/TrkB signaling pathways.

Cholinergic dysfunction and oxidative stress are the most common causes of Alzheimer's disease (AD). Safflower seed contains various anti-oxidant and cholinergic improvement compounds, such as serotonin and its derivatives. In the present study, we investigated the protective effects and mechanisms of a safflower seed extract on scopolamine-induced memory impairment in a mouse model. The safflower seed extract was orally administered at a dose of 100 mg kg⁻¹ day⁻¹, and then behavior tests (such as T-maze and novel object recognition tests) were conducted. Acetyl cholinesterase (AChE) activity, reactive oxygen species (ROS) production, and antioxidant enzymes in the brain were measured. In behavior tests, the novel route exploration and object recognition were improved by the administration of the safflower seed extract, which suggests that the safflower seed extract improves memory function in the scopolamine-treated mouse model. In addition, the safflower seed extract-administered group showed inhibition of the AChE activity and improved cholinergic dysfunction. Furthermore, the administration of the safflower seed extract resulted in lower ROS production and higher antioxidant enzyme levels as compared to the scopolamine-treated group, suggesting the protective role of the safflower seed extract against oxidative stress. The results of the present study suggest that the safflower seed extract improves scopolamine-induced memory deficits via the inhibition of cholinergic dysfunction and oxidative stress. Therefore, safflower seeds might become a promising agent for memory improvement in AD patients.

Kim BK, et al. Nutr Res Pract. 2014 Dec;8(6):638-643. https://doi.org/10.4162/nrp.2014.8.6.638

Lee AY, et al. Nutr Res Pract. 2016 Jun;10(3):274-281. https://doi.org/10.4162/nrp.2016.10.3.274