Plant iridoids: Chemistry, dietary sources and potential health benefits

Iridoids, a diverse class of plant food monoterpenoids, are characterized by a cyclopentane-fused pyran ring structure and exhibit extensive structural diversity and functional versatility. This review highlights recent advances in iridoid chemistry, biosynthesis via the methylerythritol phosphate pathway, and advanced extraction techniques such as ultrasound-assisted, microwave-assisted, and supercritical fluid extraction. Analytical methods such as liquid chromatography-mass spectrometry enable precise identification and quantification, advancing the study of their health-promoting properties. Iridoids demonstrate potent antioxidant, anti-inflammatory, neuroprotective, antitumor, antiviral, and hepatoprotective effects suggesting their potential use in functional foods, nutraceuticals, pharmaceuticals, and cosmetics. However, for the successful commercialization of iridoid-based products, future research should aim at the cost-effective production of iridoids using sustainable production systems, biotechnological synthesis, and clinical validation. This review reveals the significant promise of iridoids in enhancing human health through potential product innovation and assessment.