Alzheimer's disease (AD) is characterized by memory impairment and existence of amyloid-β (Aβ) plaques and neuroinflammation. Due to the pivotal role of oxidative damage in AD, natural antioxidative agents, such as polyphenol-rich fungi, have garnered scientific scrutiny. Here, the aqueous extract of mixed medicinal mushroom mycelia (MMMM)-Phellinus linteus, Ganoderma lucidum, and Inonotus obliquus-cultivated on a barley medium was assessed for its anti-AD effects. Neuron-like PC12 cells, which were subjected to Zn2+, an Aβ aggregator, were employed as an in vitro AD model. The cells pretreated with or without MMMM were assayed for Aβ immunofluorescence, cell viability, reactive oxygen species (ROS), apoptosis, and antioxidant enzyme activity. Then, 5XFAD mice were administered with 30 mg/kg/day MMMM for 8 weeks and underwent memory function tests and histologic analyses. In vitro results demonstrated that the cells pretreated with MMMM exhibited attenuation in Aβ immunofluorescence, ROS accumulation, and apoptosis, and incrementation in cell viability and antioxidant enzyme activity. In vivo results revealed that 5XFAD mice administered with MMMM showed attenuation in memory impairment and histologic deterioration such as Aβ plaque accumulation and neuroinflammation. MMMM might mitigate AD-associated memory impairment and cerebral pathologies, including Aβ plaque accumulation and neuroinflammation, by impeding Aβ-induced neurotoxicity.
Keywords: 5XFAD; Alzheimer’s disease; amyloid β; medicinal mushroom; zinc.