Polyphenolic composition of extracts from winery by-products and effects on cellular cytotoxicity and mitochondrial functions in HepG2 cells. (July 2020)

• Record Type: Journal Article
• Authors: Fuchs, Christine; Bakuradze, Tamara; Steinke, Regina; Grewal, Rekha; Eckert, Gunter P.; Richling, Elke
• Is Part Of: Journal of functional foods. Volume 70(2020)
• Publication Date: 2020-07
• Subjects: Polyphenols -- Winery by-products -- Vitis vinifera L. cv. Riesling -- Mitochondrial function; Functional foods -- Analysis -- Periodicals; Food -- Biotechnology -- Periodicals; Nutrition -- Periodicals; 613.2
• DOI: 10.1016/j.jff.2020.103988
• Languages: English
• ISSNs: 1756-4646

Abstract

Graphical abstract: Highlights: Pomace (PE), stem (SE), vine leaf (VLE) and vine shoot extract (VSE) were prepared. All extracts induced cytotoxicity in HepG2 cells in a dose-dependent manner. VSE reduced tert -butyl hydroperoxide-induced intracellular reactive oxygen species. VSE reduced mitochondrial membrane potential and mildly impaired respiration. Abstract: Winery by-products arise in high amounts during winemaking processes. Hence, recovery alternatives are of great interest. In this study, effects of extracts from winery by-products ( Vitis vinifera L. cv. Riesling) on mitochondrial functions in human hepatocellular carcinoma (HepG2) cells were examined. Polyphenolic profiles of pomace (PE), stem (SE), vine leaf (VLE), and vine shoot extracts (VSE) were characterized by HPLC-UV/Vis-ESI-MS/MS. The extracts induced dose-dependent cytotoxic effects (PE > SE > VLE > VSE). VSE showed protective effects regarding modulation of tert -butyl hydroperoxide (TBH)-induced intracellular reactive oxygen species (ROS) levels. PE, SE and VLE increased the mitochondrial membrane potential (MMP), whereas VSE decreased it owing to mildly impaired mitochondrial respiration. Cells may try to compensate reduced respiration chain complex activities by increasing the mitochondrial mass, as indicated by enhanced citrate synthase activity and mRNA expression levels after VSE incubation. Thus, winery by-products represent interesting sources of bioactive compounds that exert positive or negative effects on mitochondrial functions.