Effects of a Myrciaria jaboticaba peel extract on starch and triglyceride absorption and the role of cyanidin-3-O-glucoside

Abstract

The purpose of this study was to perform a parallel and comparative investigation of the effects of a Myrciaria jaboticaba (common name jabuticaba) peel extract and of its constituent cyanidin-3-O-glucoside on the overall process of starch and triglyceride intestinal absorption. The peel extract inhibited both the porcine pancreactic α-amylase and the pancreatic lipase but was 13.6 times more potent on the latter (IC50 values of 1963 and 143.9 μg mL-1, respectively). Cyanidin-3-O-glucoside did not contribute significantly to these inhibitions. The jabuticaba peel extract inhibited starch absorption in mice at doses that were compatible with its inhibitory action on the α-amylase. No inhibition of starch absorption was found with cyanidin-3-O-glucoside doses compatible with its content in the extract. The extract also inhibited triglyceride absorption, but at doses that were considerably smaller than those predicted by its strength in inhibiting the pancreatic lipase (ID50 = 3.65 mg kg-1). In this case, cyanidin-3-O-glucoside was also strongly inhibitory, with 72% inhibition at the dose of 2 mg kg-1. When oleate + glycerol were given to mice, both the peel extract and cyanidin-3-O-glucoside strongly inhibited the appearance of triglycerides in the plasma. The main mechanism seems, thus, not to be the lipase inhibition but rather the inhibition of one or more steps (e.g., transport) in the events that lead to the transformation of free fatty acids in the intestinal tract into triglycerides. Due to the low active doses, the jabuticaba peel extract presents many favourable perspectives as an inhibitor of fat absorption and cyanidin-3-O-glucoside seems to play a decisive role.