Abstract 9575: TOTUM-070 Hypocholesterolemic Effect Linked to Intestinal Cholesterol Absorption Inhibition. An in vivo and in vitro Study

Abstract

TOTUM-070 (T070) is a patented blend of five plant extracts designed to act in combination to prevent hypercholesterolemia. Previous study in dyslipidemic hamster model fed a High Fat High Cholesterol (HFHC) diet for 12 weeks demonstrated that supplementation with T070 at 3,5% to 5% in the diet (n=16 per group) reduced serum non-HDL cholesterol compared to HFHC group (-38%, p<0,001 and -47%, p<0,001, respectively) as well as serum triglyceride levels (-30%, n.s and -46%, p<0,05, respectively). We aimed to decipher the mechanisms of action of T070 both in vivo and in vitro. First, the chemical characterization of T070 by HPLC-UV/MS analyses led to the identification and quantification of 37 biomolecules such as oleuropein, oleanolic acid or chlorogenic acid. Total RNA sequencing analysis of livers from the HFHC and T070 5% supplemented groups highlighted 511 genes with significant different expression level between groups. Among canonical pathways identified, 19 genes implicated in metabolism were differentially regulated with T070. Several functional tests were performed in hamster fed with T070 5% for 12 weeks in comparison to HFHC group (n=14 per group). Dosage of lipoprotein lipase activity ex vivo did not show any difference between groups. Results from hepatic triglyceride production test detected no effect of T070. However, an oral fat tolerance test showed that post-prandial hypertriglyceridemia was significantly reduced by 40% (p<0,01) in T070 group following olive oil gavage compared to the HFHC hamsters. Finally, in vivo intestinal [4- 14 C]-Cholesterol absorption test demonstrated a 12% reduction (n.s) with T070 5% compared to HFHC group. In vitro investigations were assessed on differentiated human enterocyte Caco2 cells. Incubation with T070 at 1g/l for 1h acutely reduced [1,2- 3 H(N)]-cholesterol uptake by 30% in Caco2 cells (p<0.01). Pharmacological inhibition of cholesterol transporter NPC1L1 abolished the effect of T070 on cholesterol uptake. There was no effect of T070 on NPC1L1 protein expression in Caco2 cells, suggesting T070 blocked directly NPC1L1 activity. Altogether, our results demonstrate that hypocholesterolemic effect of T070 is mediated by inhibition of intestinal cholesterol absorption.