Phytochemistry, Biological Activities, Molecular Mechanisms, and Toxicity of Saffron (Crocus sativus L.): A Comprehensive Overview

Saffron (<i>Crocus sativus</i> L.), known as the world's most valuable spice, has long been appreciated for its culinary, medicinal, and cultural significance. In recent years, increasing scientific attention has been directed toward its unique phytochemical profile and wide-ranging therapeutic potential. This review provides a comprehensive synthesis of current evidence regarding saffron's chemical composition, molecular mechanisms of action, pharmacological activities, and safety aspects. The stigmas of saffron contain a rich array of bioactive constituents, notably crocin, crocetin, picrocrocin, and safranal, which collectively contribute to its antioxidant, anti-inflammatory, immunomodulatory, cardioprotective, hepatoprotective, neuroprotective, anti-obesity, antidiabetic, and anticancer properties. Evidence from in vitro and in vivo models, as well as clinical studies, suggests that saffron primarily exerts its beneficial effects through the modulation of oxidative stress, apoptosis, autophagy, lipid metabolism, and the regulation of key molecular pathways, including the NF-κB, PI3K/Akt/mTOR, and Nrf2/HO-1 pathways. Furthermore, recent advances in nanotechnology-based formulations have demonstrated improved bioavailability and enhanced therapeutic efficacy, thereby opening up promising avenues for clinical applications. While saffron is generally regarded as safe, challenges remain concerning its high cost, limited availability, and variability in quality due to geographic and environmental factors. Collectively, the accumulated body of evidence highlights saffron as a promising natural agent for the prevention and management of chronic diseases. However, further translational and large-scale clinical investigations are needed to fully establish its therapeutic value and optimize its integration into modern pharmacological and nutraceutical strategies.