Abstract

Fine dust, known as PM2.5, has emerged as a significant global environmental issue as it can cause problems throughout the human body via respiratory pathways. Numerous studies have established a link between fine dust and neuro-psychiatric disorders, particularly highlighting certain fine dust particles' ability to penetrate the brain and trigger inflammation, oxidative stress, and other responses. Therefore, measures to address this issue are necessary. In this study, we investigated the effects of a mixed extract of Liriope Tuber, Angelicae Gigantis Radix, and Backhousia Citriodora Leaf (LAB) on memory decline and brain inflammation caused by fine dust. When administered nasally for 7 d, PM2.5 led to a significant decline in cognitive abilities, as observed in object recognition and Y-maze tests. However, this cognitive decline was suppressed by oral administration of the extracts. Furthermore, an increase in the main inflammatory cells, microglia, and astrocytes, related to brain inflammation, was observed in the PM2.5- exposed group, which was effectively suppressed by the administration of the extracts. These results indicate that the administration of the compound extract can suppress brain inflammation and cognitive decline induced by fine dust.