Using bismuth selenide nanoparticles to combat methylmercury-induced neurodegeneration

Neurodegenerative diseases bring heavy burden to our society. Methylmercury (MeHg) is a potent neurotoxin and causes neurodegenerative diseases like Minamata Disease. Therefore, finding ways to combat MeHg-induced neurodegeneration may shed light on the treatment of neurodegenerative diseases. This study investigated the efficacy of bismuth selenide nanoparticles (Bi₂Se₃NPs, nBS) in treating MeHg-induced neurodegeneration. MeHg-poisoned rats were orally given nBS (4 mg/kg) every other day for 21 days and then sacrificed. It was found that nBS improved neurobehavioral performance, alleviated hippocampus damage and intestinal barrier damage, reduced Hg accumulation, and promoted MeHg demethylation in MeHg-poisoned rats. In addition, nBS up-regulated the abundance of gut microbes such as Faecalibacterium, Bifidobacterium and Akkermansiaceae, and increased the levels of butyric acid in feces while reduced the concentration of isobutyric acid in the brains. At the same time, nBS reduced the secretion of inflammatory factors IL-6 and TNF-α in the brains, guts and serum, and regulated AHR/IDO expression in the guts and brains. In all, nBS treatment improved the health status of MeHg-poisoned rats through enhancing Hg excretion and MeHg demethylation, reshaping gut microbiota, and reducing neuroinflammation. These findings suggested that nBS supplementation is a promising approach to treat MeHg-induced neurodegeneration, which may shed lights on the treatment of neurodegenerative diseases.