Antioxidant and hypolipidemic activities of pectin isolated from citrus canning processing water

In order to make full use of the citrus resource, antioxidant and hypolipidemic activities of pectin isolated from citrus fruit canning processing water were investigated. The crude citrus pectin (CLCP) and its three separated fractions (LCP0, LCP1 and LCP3) possessed considerable DPPH, hydroxyl and ABTS radical scavenging ability. These were also found to effectively decrease ROS level and improve SOD activity in the H2O2-induced oxidative stress HepG2 cell model. In an in vitro simulated gastrointestinal environment, all the four pectins showed remarkable bile acid-binding ability. CLCP, LCP1 and LCP3 exhibited appreciable activity in reducing total cholesterol (TC) and triglyceride (TG) levels in an oleic acid-induced high-fat HepG2 cell model. RT-qPCR assays revealed that pectins effectively down-regulated the mRNA expression level of fatty acid synthetase (FAS) and sterol regulatory element-binding protein (SREBP)-1c. Thus, down-regulation of mRNA expression FAS and SREBP-1c could be important mechanism of the pectins to lower blood lipids. The citrus pectins investigated in this work have potential as ingredients of functional foods due to the antioxidant and hypolipidemic activities.

Automated summary

This study investigated the antioxidant and hypolipidemic activities of pectin extracted from citrus fruit canning processing water. The pectins showed significant ability to scavenge free radicals and bind bile acids, effectively reducing oxidative stress and blood lipid levels. Furthermore, they down-regulated the expression of relevant genes associated with lipid metabolism. Therefore, these citrus pectins have potential as ingredients for functional foods.