Anti-Neuroinflammatory Effects of the Human Milk Oligosaccharide, 2′-Fucosyllactose, Exerted via Modulation of M2 Microglial Activation in a Mouse Model of Ischemia–Reperfusion Injury

Abstract

Cerebral ischemic stroke is one of the leading causes of death and disability worldwide. 2′-fucosyllactose (2′-FL), a human milk oligosaccharide, exerts anti-inflammatory effects and plays a protective role in arterial thrombosis; however, its role in ischemic stroke remains unclear. This study aimed to investigate the neuroprotective effects of 2′-FL and its potential mechanisms in a mouse model of ischemic stroke. Neurological score and behavior tests revealed that 2′-FL promoted the recovery of neurological deficits and motor function in middle cerebral artery occlusion (MCAO) mice, and that 2′FL led to a reduction in the size of cerebral infarct. Biochemical studies showed that administration of 2′-FL led to a reduction of reactive oxygen species (ROS)-related products in the brain of MCAO mice. 2′-FL upregulated IL-10 and downregulated TNF-α level. In addition, 2′-FL enhanced M2-type microglial polarization and upregulated CD206 expression at 7 days after MCAO. At 3 days after MCAO, 2′-FL increased IL-4 levels and activated STAT6. Our data show that 2′-FL reduced the neurological symptoms of ischemic stroke and ROS accumulation in the brain through IL-4/STAT6-dependent M2-type microglial polarization in MCAO mice. These results demonstrate that 2′-FL is a potentially effective therapeutic agent for ischemic stroke.