Britanin is a sesquiterpene lactone natural product isolated from the traditional medicinal plant *Inula japonica* (Japanese elecampane). It is a white crystalline powder with a molecular formula of C20H26O6. Its structure features a characteristic α-methylene-γ-lactone moiety, which is common to many bioactive sesquiterpene lactones. Extensive pharmacological studies have identified Britanin as a compound with significant anti-inflammatory and anti-tumor activities. Its primary mechanisms of action involve the inhibition of the NF-κB signaling pathway and the suppression of pro-inflammatory cytokine production (e.g., TNF-α, IL-6). These properties underpin its research applications in models of inflammatory diseases and various cancers, positioning it as a promising lead compound for drug development, particularly in the oncology and immunology fields. As a plant-derived natural product, Britanin serves as a valuable chemical probe for studying inflammatory pathways and as a reference standard in the quality control of herbal medicines containing *Inula* species. Its research use is primarily in academic and pharmaceutical discovery settings.