The anti-inflammatory effects of iridoid glycosides: a comprehensive review of mechanisms of action and structure-activity relationships

Inflammation plays a crucial role in the onset and progression of various diseases. However, current anti-inflammatory therapies often produce adverse effects that limit their clinical utility. This review focuses on the therapeutic potential of iridoid glycosides, a class of monoterpenoid compounds known for their anti-inflammatory properties. Drawing on literature from PubMed and Google Scholar, this study comprehensively examines eight well-studied iridoid glycosides in terms of their sources, administration methods, dosages, target inflammatory models, and mechanisms of action. The compounds were found to modulate critical signaling pathways, including NF-κB, NLRP3 inflammasome, MAPK, and JAK-STAT, thereby suppressing key inflammatory cytokines such as TNF-α, IL-1β, and IL-6, while also activating antioxidant defenses. Structure–activity relationship analysis suggests that glycosyl, ester, and epoxy groups are essential pharmacophores for their bioactivity. Collectively, these findings underscore the promise of iridoid glycosides as effective and safer alternatives for managing inflammatory diseases.