In-Vitro Inhibition of Human Lipase PS by Polyphenols From Kiwi Fruit

Eidenberger Thomas,Fuerst Sigrid,Selg Manuel,Krennhuber Klaus

doi:10.5539/jfr.v3n4p71

Abstract

Polyphenols are widely distributed in higher plants. It is well recognized that they are responsible for many beneficial effects observed in humans after ingestion of vegetables and fruits. Kiwis (Actinidia chinensis) are an increasingly popular fruit in Europe and contain a wide range of polyphenols. Different preparations from kiwi fruits were compared for the content of soluble and condensed polyphenols and tested in-vitro for inhibition of human pancreatic lipase. It is shown that human pancreatic lipase is substantially inhibited by kiwi polyphenols as long as the proportion of condensed polyphenols remains intact. Lipase inhibition is negligible when condensed polyphenols are hydrolysed by acidic treatment. It was also demonstrated that Kiwi polyphenols do not precipitate proteins as described for the tannin class of condensed polyphenols. Hence, the inhibitory effect of condensed Kiwi polyphenols is not considered to be related to unspecific enzyme inactivation by a tannin-like effect.

Highlights

Polyphenols (PPs) are widely distributed in plants and are a major class of secondary plant products
Different preparations from kiwi fruits were compared for the content of soluble and condensed polyphenols and tested in-vitro for inhibition of human pancreatic lipase
It is shown that human pancreatic lipase is substantially inhibited by kiwi polyphenols as long as the proportion of condensed polyphenols remains intact

Summary

Introduction

Polyphenols (PPs) are widely distributed in plants and are a major class of secondary plant products. The occurrence of catechins, gallo- and ellagitannins, which are the principal PPs sources in tea, was demonstrated in fruits, wine and chocolate. The presence of these substances was linked to the inhibition of the angiotensin converting enzyme, the low cardiovascular mortality in countries with high red wine consumption (“French wine paradox”) and anti-platelet activities (Arts, van De Putte, & Hollman, 2000a; Arts, van De Putte, & Hollman, 2000b; Actis-Goretta, Ottaviani, & Fraga, 2006). This study at hand tested the hypothesis that condensed PPs may inhibit LPS activity in-vitro without an anti-nutrional effect due to tannin-like enzyme inactivation

Kiwi Sample Preparation

Determination of Soluble and the Total PPs

LPS Activity Assay

Determination of Protein-Precipitating Tannins

Results and Discussion