Purple sweet potato extract and vitamin c increase the proliferation of endothelial progenitor cells from stable coronary artery disease patients

Introduction: Endothelial progenitor cell (EPC) numbers are reduced in stable coronary artery disease (CAD), partly due to oxidative stress. This study aimed to evaluate the effect of different antioxidants, purple sweet potato (PSP) extract and vitamin C, on EPC proliferation in stable CAD patients. Methods: Peripheral blood mononuclear cells were isolated and cultivated on fibronectin-coated plates with the colony-forming unit (CFU)-Hill medium for three days. Non-adherent cells were divided into control, PSP extract (1, 5, 25 μg/ml), and vitamin C (10, 50, 250 μg/ml) groups; then cultured for two days. EPC proliferation was assessed with MTT Cell Proliferation Assay Kit. EPCs were identified by detecting the expression of CD34. Resulted CFU-Hill colonies were counted under an inverted light microscope. Results: EPC proliferation was increased in low, moderate, and high doses of PSP extract and vitamin C compared to control (all groups vs. control, p<0.001). The high dose of PSP extract increased EPC proliferation non significantly compared to the moderate dose (p=0.289). Vitamin C increased EPC proliferation better than PSP extract in moderate and high dose groups (p=0.042 and p<0.01, respectively). Meanwhile, the low dose of both treatments increased the EPC proliferation equally (p=0.353). CFU numbers, representing EPC differentiation capability, were highest in the groups given PSP extract compared to control and vitamin C groups. Conclusions: PSP extract and vitamin C increased EPC proliferation dose-dependently. Vitamin C induced EPC proliferation better than PSP extract. Furthermore, PSP extract was presumably a better EPC differentiation inducer.