Research Progress on the Anti-Inflammatory and Antioxidant Effects of Daidzein: Its Mechanisms of Action in Related Diseases, and Related Nanoformulations to Enhance Its Bioavailability

Daidzein is a naturally occurring isoflavone phytoestrogen, mainly found in leguminous plants. This component exerts anti-inflammatory effects by regulating inflammatory cells via multiple targets, blocking core inflammatory pathways, and inhibiting the release of inflammatory factors. It also scavenges reactive oxygen species, activates the antioxidant enzyme system, and regulates antioxidant signaling pathways to achieve antioxidant effects. By regulating these two core pathological processes, it exerts protective effects in diseases such as cancer, cardiovascular disease, and acute kidney injury, based on preclinical evidence. The development of nanodelivery systems has effectively improved the physicochemical properties of daidzein, enhanced its bioavailability, and enabled disease-targeted delivery. Most previous reviews have either focused exclusively on daidzein or broadly covered the pharmacological activities of isoflavones, yet have largely overlooked the dual anti-inflammatory and antioxidant mechanisms specific to daidzein. This review summarizes these mechanisms and their preclinical effects on various diseases, including cancer, cardiovascular diseases, and acute kidney injury. It also reviews the pharmacokinetic limitations of daidzein and recent progress in nanodelivery strategies aimed at enhancing its bioavailability and bioactivity. Overall, this review serves as a reference for the future standardized comparison of nanocarriers, targeted therapies, and clinical applications.