Determination of Luteolin 7-Glucuronide in (L.) Britt. Leaf Extracts from Different Regions of China and Republic of Korea and Its Cholesterol-Lowering Effect.

Lowering blood cholesterol levels is crucial for reducing the risk of cardiovascular disease in patients with familial hypercholesterolemia. To develop (L.) Britt. leaves as a functional food with a cholesterol-lowering effect, in this study, we collected (L.) Britt. leaves from different regions of China and Republic of Korea. On the basis of the extraction yield (all components; g/kg), we selected (L.) Britt. leaves from Hebei Province, China with an extract yield of 60.9 g/kg. After evaluating different concentrations of ethanol/water solvent for (L.) Britt. leaves, with luteolin 7-glucuronide as the indicator component, we selected a 30% ethanol/water solvent with a high luteolin 7-glucuronide content of 0.548 mg/g in (L.) Britt. leaves. Subsequently, we evaluated the cholesterol-lowering effects of (L.) Britt. leaf extract and luteolin 7-glucuronide by detecting total cholesterol in HepG2 cells. The 30% ethanol extract lowered cholesterol levels significantly by downregulating 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase expression. This suggests that (L.) Britt leaves have significant health benefits and can be explored as a potentially promising food additive for the prevention of hypercholesterolemia-related diseases.