Center for Human Nutrition, David Geffen School of Medicine at UCLA, Los Angeles, CA, 1083390095, USA.
Department of Medicine, VA Greater Los Angeles Health Care System, Los Angeles, CA, 90073, USA.
Mol Nutr Food Res. 2023 Nov;67(21):e2300224. doi: 10.1002/mnfr.202300224. Epub 2023 Sep 6.
Four weeks' of concentrated grape powder (GP) consumption reduces circulating cholesterol in healthy free-living subjects consuming a low-fiber/low-polyphenol diet. Here, the study aims to investigate the underlying mechanisms for cholesterol reduction by evaluating biomarkers of cholesterol de novo biosynthesis, intestinal absorption, miRNA involved in transcriptional regulation of cholesterol metabolism, as well as cholesterol oxidation.
Fasting plasma samples collected from 19 healthy free-living subjects at baseline and week 4 of GP consumption are used in this study. Gas chromatography-mass (GC-MS) analysis of plasma samples shows that lathosterol, a precursor of cholesterol synthesis, is significantly decreased after GP consumption indicating reduced cholesterol de novo biosynthesis. Markers of intestinal absorption, campesterol, and β-sitosterol are not changed. Realtime PCR shows that plasma exosomal miRNA-1 is increased after GP consumption. GC-MS also shows that GP consumption reduces the plasma cholesterol oxidation product 27-hydroxycholesterol (27-HC).
This study enhances the understanding of the mechanisms of the cholesterol lowering effects of GP, and provides new insights into the potential health benefits of grape consumption.
四周集中摄入葡萄粉（GP）可降低食用低纤维/低多酚饮食的健康自由生活受试者的循环胆固醇。在此，本研究旨在通过评估胆固醇从头生物合成、肠道吸收、参与胆固醇代谢转录调控的 miRNA 以及胆固醇氧化的生物标志物，来研究胆固醇降低的潜在机制。
本研究使用了 19 名健康自由生活受试者在基线和 GP 摄入第 4 周时采集的空腹血浆样本。对血浆样本进行气相色谱-质谱（GC-MS）分析显示，胆固醇合成的前体麦角甾醇在 GP 摄入后显著降低，表明胆固醇从头生物合成减少。肠道吸收标志物坎培醇和β-谷甾醇没有变化。实时 PCR 显示 GP 摄入后血浆外泌体 miRNA-1 增加。GC-MS 还显示 GP 摄入可降低血浆胆固醇氧化产物 27-羟胆固醇（27-HC）。
本研究增强了对 GP 降低胆固醇作用机制的理解，并为葡萄消费的潜在健康益处提供了新的见解。
