Dietary supplementation with Ceriporia lacerata improves learning and memory in a scopolamine-induced amnesia mouse model

Oral Administration of Euonymus alatus Leaf Extract Ameliorates Alzheimer's Disease Phenotypes in 5xFAD Transgenic Mice

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease and is frequently characterized by progressive and irreversible impairment of cognitive functions. However, its etiology remains poorly understood, limiting therapeutic interventions. Our previous study showed that the ethanol extract of Euonymus alatus leaves (EA) positively affected scopolamine-induced hypomnesia in the normal mouse model by promoting nuclear factor E2-related factor 2 (Nrf2) activation. Herein, we examined whether EA administration could ameliorate major AD phenotypes that are manifested in 5xFAD transgenic mice. Two-month-old mice were orally administered with EA at a dose of 50, 100, or 150 mg/kg body weight/day thrice a week for 14 weeks. We observed that EA administration improved behavioral deficits as assessed by the passive avoidance, Morris water maze, and Y-maze tasks; decreased the plasma levels of pro-inflammatory cytokines, including TNFα and IL-1β; decreased the protein expression levels of inflammatory mediators in the hippocampus; and attenuated histological damage and amyloid beta plaques in the hippocampal region of 5xFAD mouse brain. Interestingly, our data demonstrated that the effectiveness was partially attributed to quercetin, which was noted to be a component of EA. Hence, these findings suggest that a long-term administration of EA could alleviate AD symptoms and delay its progression.

Wasp Venom Ameliorates Scopolamine-Induced Learning and Memory Impairment in Mice

This study investigated the effects of wasp venom (WV) from the yellow-legged hornet, Vespa velutina, on scopolamine (SCO)-induced memory deficits in mice, as well as the antioxidant activity in HT22 murine hippocampal neuronal cells in parallel comparison with bee venom (BV). The WV was collected from the venom sac, freeze-dried. Both venoms exhibited free radical scavenging capabilities in a concentration-dependent manner. In addition, the venom treatment enhanced cell viability at the concentrations of ≤40 µg/mL of WV and ≤4 µg/mL of BV in glutamate-treated HT22 cells, and increased the transcriptional activity of the antioxidant response element (ARE), a cis-acting enhancer which regulates the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)-downstream antioxidant enzymes. Concurrently, WV at 20 µg/mL significantly increased the expression of a key antioxidant enzyme heme oxygenase 1 (HO-1) in HT22 cells despite no significant changes observed in the nuclear level of Nrf2. Furthermore, the intraperitoneal administration of WV to SCO-treated mice at doses ranged from 250 to 500 µg/kg body weight ameliorated memory impairment behavior, reduced histological injury in the hippocampal region, and reduced oxidative stress biomarkers in the brain and blood of SCO-treated mice. Our findings demonstrate that WV possess the potential to improve learning and memory deficit in vivo while further study is needed for the proper dose and safety measures and clinical effectiveness.