Pentacyclic Triterpenoids as Multitarget Ligands Bridging Inflammation, Metabolic Dysfunction, and Cancer: Mechanistic Insights and Translational Perspectives

Pentacyclic Triterpenoids (PTs) such as oleanolic acid, ursolic acid, and betulinic acid are a large family of natural products with considerable diversity and have excellent therapeutic potential in the treatment of inflammatory and metabolic diseases. PTs have substantial efficacy against both critical pathways in inflammation and glucose regulation. The anti-inflammatory effects are mainly achieved by inhibiting nuclear factor-κB (NF-κB) activation, downregulating pro-inflammatory cytokines, and attenuating oxidative stress. At the same time, the anti-diabetic effects are related to the regulation/modulation of insulin signaling, activation of AMP-activated protein kinase (AMPK), modulation of peroxisome proliferator-activated receptor-gamma (PPAR-γ), and improvement of glucose homeostasis. Cross-talk between inflammation and metabolism explains the dual biological effects of PTs on inflammation and on patients with metabolic disorders. The Structure-Activity Relationship (SAR) studies show that certain structural modifications could improve each activity, indicating potential for rational drug design. The clinical translation of these agents, although supported by encouraging data in preclinical models, has been limited by issues regarding bioavailability, standardization, and the full assessment of safety. This review discusses the role of PTs in distinct pathological conditions (inflammation, diabetes, and cancer) and the integrated examination of inflammation-metabolism crosstalk via common molecular mediators (e.g., NF-κB, Nrf2, PPAR-γ, and PTP1B). This analysis bridges Structure-Activity Relationship (SAR) trends with translational and clinical insights. The resulting framework provides a mechanistically unified, forward-looking perspective designed to guide targeted therapeutic development. In contrast to single-target synthetic drugs, PTs simultaneously drive complexity in multifactorial diseases, including diabetes, metabolic syndrome, and inflammation-associated cancer, by modulating inflammatory, metabolic, and oxidative pathways.