Protective Effect of Luteolin Isolated from Taraxacum coreanum Against Neuroinflammatory Responses Induced by Lipopolysaccharide: Involvement of Gut–Brain Axis

Neuroinflammation can be brought on by intestinal inflammatory agents and metabolites generated by the gut microbiota that can pass across the blood-brain barrier. Taraxacum coreanum is rich in the bioactive compound luteolin (LT), a molecule known for its potent antioxidant and anti-inflammatory activities. The current research investigated whether LT prevents inflammatory responses and barrier dysfunction in the brain and gut of lipopolysaccharide (LPS)-injected mice. LT (10 and 20 mg/kg/day) effectively lowered the brain levels of pro-inflammatory mediators and cytokines triggered by LPS stimulation. Moreover, occludin and ZO-1 are two tight junction proteins whose expression was markedly elevated by LT. In the intestine, LT not only attenuated the levels of inflammatory mediators but also markedly upregulated tight junction protein expression relative to the LPS-treated group. LT markedly reversed LPS-induced dysbiosis by increasing beneficial taxa such as Bacteroidota, Actinobacteriota, Murivaculaceae, and Lactobacillus. In addition, LT reduced the relative abundance of Firmicutes and Desulfovibrio. Collectively, LT from Taraxacum coreanum may attenuate neuroinflammation and maintain blood-brain barrier integrity by suppressing inflammatory responses, protecting the gut barrier, and modulating the gut microbiome.