Potential Lipid-lowering Effects of Northern Thai Vegetable Extracts on Inhibition of Cholesterol Absorption: Emerging In vitro and in vivo models

Abstract

Obesity has emerged as a major health issue which caused by the alteration of lipid profiles including hypercholesterolemia, hypertriglyceridemia, and dyslipidemia. Thus, prevention of hyperlipidemia is urgently needed. Several local Thai vegetables have been recognized for their potent antioxidant properties. However, there is limited information regarding their lipid-lowering effects. Therefore, this study aims to investigate and identify the mechanisms involved in cholesterol-reducing effects of functional ingredients derived from seven local Thai vegetables aqueous extracts using in vitro, ex vivo, and in vivo models. These findings suggest that antioxidant-rich in the extracts have potential to be functional ingredients due to their ability to inhibit cholesterol absorption in intestinal colorectal adenocacinoma (Caco-2) cells. Among these, the aqueous extracts from Piper sarmentosum Roxb. (PSRAE), Solanum torvum Sw. (STSAE), and Acmella oleracea L. (APAE) revealed their most potent lipid-lowering effects through increasing cholesterol micelle size and interfering its formation. Moreover, these extracts modulated lipid homeostasis through distinct mechanisms, including inhibition of cholesterol synthesis and absorption, and stimulation of lipid secretion. The lipid-lowering effects were further confirmed in intact jejunal loops, where PSRAE and STSAE demonstrated the highest cholesterol lowering efficacies. However, a single oral administration in rats revealed that PSRAE solely decreased the cholesterol levels in serum, intestinal, and hepatic tissues. Therefore, PSRAE represented as the most potent lipid-lowering candidate. Nonetheless, long-term efficacy and safety of these extracts required further investigation. Thus, promising set of functional ingredients derived from local Thai vegetables could serve as future foods for controlling hyperlipidemia and preventing non-communicable diseases.