Crocus Sativusand Its Active Compound, Crocin Inhibits the Endothelial Activation and Monocyte-Endothelial Cells Interaction in Stimulated Human Coronary Artery Endothelial Cells

Abstract

21 Crocus sativus L. or saffron has been shown to have anti-atherogenic effects. However, its 22 effects on key events in atherogenesis such as endothelial activation and monocyte-2 23 endothelial cell binding in lipolysaccharides (LPS)-stimulated in vitro model have not been 24 extensively studied. Objectives: To investigate the effects of saffron and its bioactive 25 derivative crocin on the gene and protein expressions of biomarkers of endothelial activation 26 in LPS stimulated human coronary artery endothelial cells (HCAECs). Methodology: 27 HCAECs were incubated with different concentrations of aqueous ethanolic extracts of 28 saffron and crocin together with LPS. Protein and gene expressions of endothelial activation 29 biomarkers were measured using ELISA and qRT-PCR, respectively. Adhesion of monocytes 30 to HCAECs was detected by Rose Bengal staining. Methyl-thiazol-tetrazolium assay was 31 carried out to assess cytotoxicity effects of saffron and crocin. Results: Saffron and crocin up 32 to 25.0 and 1.6 μg/ml respectively exhibited >85% cell viability. Saffron treatment reduced 33 sICAM-1, sVCAM-1 and E-selectin proteins (concentrations: 3.13, 6.25, 12.5 and 25.0 μg/ml; 34 3.13, 12.5 and 25.0 μg/ml; 12.5 and 25.0, respectively) and gene expressions (concentration: 35 12.5 and 25.0μg/ml; 3.13, 6.25 and 25.0 μg/ml; 6.25, 12.5 25.0; respectively). Similarly, 36 treatment with crocin reduced protein expressions of sICAM-1, sVCAM-1 and E-selectin 37 (concentration: 0.2, 0.4, 0.8 and 1.6 μg/ml; 0.4, 0.8 and 1.6 μg/ml; 0.8 and 1.6 μg/ml;38 respectively] and gene expression (concentration: 0.8 and 1.6 μg/ml; 0.4, 0.8 and 1.6 μg/ml; 39 and 1.6 μg/ml, respectively). Monocyte-endothelial cell interactions were reduced following 40 saffron treatment at concentrations 6.3, 12.5 and 25.00 μg/ml. Similarly, crocin also 41 suppressed cellular interactions at concentrations 0.04, 0.08, 1.60 μg/ml. Conclusion: Saffron 42 and crocin exhibits potent inhibitory action for endothelial activation and monocyte-43 endothelial cells interaction suggesting its potential anti-atherogenic properties. 44 45