Evaluation of cholesterol absorption and biosynthesis by decoctions of Annona cherimola leaves

Ethnopharmacological relevance: Decoctions of the leaves of Annona cherimola Mill. are traditionally used in Azores to treat hypercholesterolemia. Although they are sold and consumed by people in order to improve their health, these are products that cannot be sold with claims for health benefits as they have never been studied scientifically. Materials and methods: The activities of decoctions from Annona cherimola leaves were analysed for the two therapeutic approaches currently used to reduce plasma cholesterol: inhibition of dietary cholesterol uptake and inhibition of HMG-CoA reductase activity. Furthermore, the composition of the decoction was elucidated by LC-MS and the permeability of the active components was analysed using Caco-2 cell monolayers as a model of the intestinal barrier (dietary cholesterol uptake). Results: The chemical composition of the Annona cherimola leaves' extract revealed that rutin was its main component. The in vitro gastrointestinal digestion did not modify the chemical composition of the extract. This extract was able to originate a slight reduction in cholesterol absorption through Caco-2 cells lines and to reduce the HMG-CoA reductase activity in 50% when using 137.3 mu g of the extract/mL. Rutin, when used in the same concentration as that found in the extract, was able to reduce cholesterol absorption through Caco-2 cells monolayer in approximately 47%. This flavonoid had an IC50 of 17.85 mu M relatively to the HMG-CoA reductase activity. Conclusions: The traditional use of decoctions from the leaves of Annona cherimola may be justified, at least by the inhibition of HMG-CoA reductase activity. (C) 2013 Elsevier Ireland Ltd. All rights reserved.