A review on extraction techniques, biological mechanisms, and functional food applications of safflower (Carthamus tinctorius L.) bioactives

Safflower (Carthamus tinctorius L.) is rich in bioactive compounds with strong potential for functional foods, but translating this potential into evidence-based applications requires comprehensive insights into extraction, biological mechanisms, and safety. This review consolidates recent advances in four green extraction technologies—ultrasound-assisted, microwave-assisted, supercritical fluid, and enzyme-assisted extraction—with emphasis on their efficiency, selectivity, and environmental sustainability. The dose-dependent effects and molecular mechanisms of key bioactives, including hydroxysafflor yellow A, kaempferol, and quercetin, are examined, highlighting their regulation of immune, oxidative, and metabolic pathways via Nrf2 and AMPK/SIRT1/NF-κB signaling. Analysis of 306 approved health food products and toxicological data assesses the current application landscape and safety profiles. By integrating these dimensions, the review identifies critical bottlenecks—notably the lack of standardized protocols and well-defined dose–response relationships—and provides a strategic framework to guide the evidence-based development of safflower functional foods, ultimately facilitating the transition from traditional use to rigorously validated health products.