Antiinflammatory Effects of Sesquiterpene Lactones from Eupatorium lindleyanum DC. in Rodent Models

Acute inflammation is a fundamental pathological process involved in many immune-related diseases. Eupatorium lindleyanum DC., a traditional medicinal herb, is rich in sesquiterpene lactones (SLEL), which have been reported to exhibit pharmacological activity; however, their antiinflammatory effects and associated molecular changes remain incompletely characterized. In this study, acute inflammatory responses were induced in a xylene-induced mouse ear edema model and a carrageenan-induced rat paw edema model. Tissue injury and inflammatory infiltration were assessed by hematoxylin and eosin staining. Levels of proinflammatory cytokines (TNF-α, IL-6, and IL-1β) were quantified in serum by ELISA, and their transcriptional expression in inflamed tissues was analyzed by quantitative PCR (qPCR). Changes in NF-κB pathway-associated proteins, including phosphorylated IκBα and p65, were evaluated by western blotting. SLEL treatment reduced ear and paw edema and alleviated histopathological features of acute inflammation, including tissue edema, inflammatory cell infiltration, and vascular congestion. In parallel, SLEL administration was associated with decreased serum levels and tissue mRNA expression of Tnf-α, Il-6, and Il-1β. Western blot analysis demonstrated reduced phosphorylation of IκBα and p65 in inflamed tissues following SLEL treatment, indicating modulation of NF-κB-related signaling events. Together, these findings demonstrate an experimental workflow for evaluating the anti-inflammatory activity of SLEL in acute inflammation models and suggest that its effects are associated with reduced pro-inflammatory cytokine expression and altered NF-κB pathway-related signaling.