Saffron and its active constituents ameliorate hypercholesterolemia by inhibiting PCSK9 and modulating Sortilin, LDLR, and SREBP-2 signaling in high fat diet induced hypercholesterolemic C57BL/6 mice

Ethnopharmacological relevance: Saffron (Crocus sativus L.) has long been used in Ayurveda, Iranian, and Chinese
traditional medicine as a natural remedy for hypercholesterolemia, obesity, and liver disorders though its
therapeutic mechanism remains unclear.
Aim of the study: This study explores the mechanism by which saffron extract (SE), crocin (CN), and crocetin (CR)
mitigate high fat diet (HFD) induced hypercholesterolemia and hepatic inflammation in C57BL/6 mice, focusing
on their inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9).
Materials and methods: C57BL/6 mice (N = 10/group) were fed either a, normal diet, HFD, or HFD supplemented
with SE, CN, CR, or atorvastatin for 12 weeks. Plasma lipids and inflammatory markers were measured. His­
topathological changes were assessed via H&E and Sudan black staining. Gene expression was analyzed using
qRT-PCR, and ligand-protein interactions were studied using molecular docking, simulation, and
thermophoresis.
Results: HFD-fed mice exhibited dyslipidemia, liver damage, and inflammation, which SE, CN, and CR signifi­
cantly improved. Treatments reduced cholesterol, triglycerides, and reactive oxygen species, reversed fatty liver
degeneration, and downregulated PCSK9 and sortilin expression while upregulating LDLR. They suppressed
transcription factors SREBP-1C and SREBP-2 and reduced inflammatory markers, including TNF-α, while
increasing IL-10 expression. CR reduced plasma PCSK9 secretion by 39.9 % (p < 0.05). Docking and simulation
studies confirmed the strong binding potential of CR and CN to PCSK9.
Conclusion: Saffron and its active components (CN and CR) are novel natural PCSK9 inhibitors that effectively
ameliorate hypercholesterolemia by modulating sortilin, LDLR and SREBP-2 pathway, potentially opening the
way for developing new therapeutic approaches for managing cholesterol related disorders.