Eriodictyol Attenuates LPS-Induced Neuroinflammation, Amyloidogenesis, and Cognitive Impairments via the Inhibition of NF-kappa B in Male C57BL/6J Mice and BV2 Microglial Cells

Eriodictyol, a natural flavonoid mainly distributed in citrus fruits and peanut, has been well-documented with possession of excellent anti-inflammatory, antioxidant, and anticancer bioactivities. This work focus on the protective effects of eriodictyol on LPS-induced neuroinflammation, amyloidogenesis, cognitive impairment, and the potential mechanisms involved. Behavioral tests and histological examinations showed that eriodictyol significantly prevented the memory and neuronal damage triggered by LPS. Consistently, eriodictyol (100 mg/kg) reduced the formation of A beta(1-42) by 28.37 +/- 16.71 pg/mL compared to the LPS group. In addition, high dose eriodictyol (100 mg/kg) also equilibrated the cholinergic system via suppressing AChE activity (0.1996 +/- 0.0831 U/mgprot) and elevating ChAT activity (41.81 +/- 24.72 U/g) as well as ACh level (5.093 +/- 3.531 mu g/mgprot) compared to the LPS group. Western blot results indicated that compared to the LPS group, eriodictyol suppressed LPS-induced filial overactivation (84.29% +/- 27.21%) and regulated inflammatory mediators and cytokines by inhibiting the NE-kappa B and MAPK pathways. These results indicated that eriodictyol alleviated amyloidogenesis and memory impairment triggered by LPS via inhibiting TLR4, MAPKs, and PI3K/Akt, and activating Sirt1 pathways and thus blocking downstream translocation of NF-kappa B, which offers a potential nutritional preventive strategy for neuroinflammation diseases such as Alzheimer's disease (AD).