Eriodictyol and Homoeriodictyol Improve Memory Impairment in Aβ25–35-Induced Mice by Inhibiting the NLRP3 Inflammasome

Abstract

(1) Alzheimer’s disease (AD) is a neurodegenerative disorder, and it is now widely accepted that neuroinflammation plays a key role in its pathogenesis. Eriodictyol (Eri) and homoeriodictyol (Hom), dihydroflavonoids extracted from a variety of plants, have been confirmed to display a relationship with neuroprotection. (2) Methods: An AD mouse model was constructed by intracerebroventricular (ICV) injection of the Aβ25–35 peptide, and Eri and Hom were administered orally for 4 weeks. UPLC-MS/MS was used to determine whether Eri and Hom cross the blood–brain barrier to exert their therapeutic effects. Histological changes in the brain and levels of Aβ were evaluated, and Y-maze and new object recognition experiments were conducted to assess the effects of Eri and Hom on Aβ25–35-induced memory impairment in mice. The levels of oxidative stress and apoptosis in peripheral immune cells and progenitor cells in the hippocampal region were analyzed by flow cytometry and in vitro assays. Western blotting and enzyme-linked immunosorbent assays (ELISA) were used to measure the expression levels of NLRP3 inflammasome-related proteins and inflammatory factors in the brain. The effect of nigericin (an agonist of the NLRP3 inflammasome) on Eri and Hom intervention in LPS-induced N9 microglia was examined using a High Content Screening System. (3) Results: Eri and Hom reduced neuronal damage in mouse brain tissue, decreased Aβ levels in the brain, downregulated oxidative stress and apoptosis levels, and improved learning and memory capacity by crossing the blood–brain barrier to exert its effects. Moreover, Eri and Hom inhibited NLRP3 inflammasome activation and ameliorated immune cell disorder. Furthermore, the effect of Eri and Hom on LPS-induced N9 microglia disappeared after the addition of nigericin to agonize NLRP3 receptors. (4) Conclusions: Eri and Hom improved Aβ25–35-induced memory impairment in mice by inhibiting the NLRP3 inflammasome.

Futoquinol improves Aβ25–35‐induced memory impairment in mice by inhibiting the activation of p38MAPK through the glycolysis pathway and regulating the composition of the gut microbiota

“…The animals used and the Aβ 25–35 intracerebroventricular (ICV) injection protocol were as reported in our previous study (Guo et al, 2022). Sixty 7‐week‐old and 40 g male Kunming mice (SCXK [Jing] 2016‐0011, Beijing Vitalstar Biotechnology Co. Ltd.) were randomly divided into the control (Con), model (M), donepezil (Don, 10 mg/kg), Piper kadsura (PK, 1.4 g/kg), low‐dose Futoquinol (Fut‐L, 15 mg/kg), and high‐dose Futoquinol (Fut‐H, 30 mg/kg) groups, with 10 mice per group.…”

“…The order in which the mice entered each arm and the total number of arms (N) was recorded. An alternation is considered if an animal entered three different arms in a row, and the largest arm entry is defined as N‐2; percent alternation (%) = [alternation/(N − 2)] × 100% (Guo et al, 2022).…”

Naringenin and apigenin ameliorates corticosterone-induced depressive behaviors

“…5 μL of AV-FITC and 5 μL of PI were added to the cells and incubated at room temperature in the dark for 15min, and then 400 μL PBS was added to each sample. The flow cytometric analysis was performed within 1 h [ 24 ].…”

“…ROS production was evaluated by the FACS flow cytometer. The level of intracellular ROS was shown as a percentage of non-treated control [ 24 ].…”

A novel strategy for bioactive natural products targeting NLRP3 inflammasome in Alzheimer’s disease

“…Eriodictyol and homoeriodictyol are two dihydroflavonoids that exist widely in plants. Reports have demonstrated that these two molecules can penetrate the blood–brain barrier and ameliorate Aβ25–35-induced memory impairment in AD mice; they also inhibited NLRP3 inflammasome activation and ameliorated immune cell disorder ( Guo et al, 2022 ). Nobiletin is a naturally occurring polymethoxylated flavonoid primarily that exists in citrus peel.…”