Cocoa shell ingredients improve their lipid-lowering properties under simulated digestion: In vitro and HepG2 cells...

Cocoa (Theobroma cacao) shell, the main by-product of cocoa industry, is associated with the regulation of several biomarkers of metabolic syndrome. However, there is little information about the digestion effect on the physiological properties of cocoa shell. The aim of this study was to assess the impact of a standardized in vitro digestion protocol on the hypolipidemic capacity of two cocoa shell ingredients, a flour (CSF) and an aqueous extract (CSE), through the evaluation of their in vitro hypolipidemic properties and lipid-lowering effects in HepG2 cells. CSF and CSE digested fractions increased their capacity to bind primary bile acids (16-88 %) and inhibit lipase activity (41-100 %), while their ability to bind secondary bile acids (33-42 %) was maintained. Likewise, the digested fractions of cocoa shell ingredients reduced the solubility of the cholesterol micelles (35-97 %) and inhibited the hydroxymethylglutaryl-Co-enzyme A reductase (HMGCR) activity (18-100 %). The hypolipidemic properties of non-digested fractions further enhanced the CSF potential to decrease lipid absorption. Cocoa shell ingredients demonstrated lipid-lowering properties after simulated digestion by effectively reducing the accumulation of intracellular lipids (78-122 %), triacylglycerides (60-90 %), and cholesterol (100 %) induced by palmitic acid in hepatic cells. These results were confirmed by their ability to stimulate lipolysis, reducing the increase in lipase activity (28-78 %) and increasing glycerol release (27-80 %) with respect to palmitic acid treated cells, and inhibiting HMGCR activity. Phenolic compounds and dietary fiber are significantly associated to the observed hypolipidemic effects of cocoa shell ingredients. These findings demonstrated the potential efficacy of CSF and CSE in reducing lipid absorption and reversing its hepatic accumulation. Hence, these cocoa shell ingredients might prevent diseases related to lipid accumulation by improving overall health status.