Combined Ethanol Extract of Grape Pomace and Omija Fruit Ameliorates Adipogenesis, Hepatic Steatosis, and Inflammation in Diet-Induced Obese Mice

Abstract

The aim of this study was to evaluate the long-term effects of grape pomace ethanol extract (GPE) with or without omija fruit ethanol extract (OFE) on adiposity, hepatic steatosis, and inflammation in diet-induced obese mice. Male C57BL/6J mice were fed a high-fat diet (HFD) as the control diet and HFD plus GPE (0.5%, w/w) with or without OFE (0.05%, w/w) as the experimental diet for 12 weeks. GPE alone did not significantly affect adipogenesis and hepatic steatosis. However, the supplementation of GPE + OFE significantly lowered body weight gain, white adipose tissue weight, adipocyte size, and plasma free fatty acid and adipokines (leptin, PAI-1, IL-6, and MCP-1) levels in HFD-fed mice compared to those of the control group. These beneficial effects of GPE + OFE were partly related to the decreased expression of lipogenic and inflammatory genes in white adipose tissue. GPE + OFE supplementation also significantly lowered liver weight and ameliorated fatty liver by inhibiting expression of hepatic genes involved in fatty acid and cholesterol syntheses as well as inflammation and by activating hepatic fatty acid oxidation. These findings suggest that the combined ethanol extract of grape pomace and omija fruit has the potential to improve adiposity and fatty liver in diet-induced obese mice.

Assessment of the effect of grape seed cake inclusion in the diet of healthy fattening‐finishing pigs

“…Interestingly, the grape seed cake diet produced a significant decrease in cholesterol concentration in the plasma of GS pigs, being in accordance with previous studies on laboratory animals and on humans, which demonstrated the protective antihyperlipidemic and antihyperglycemic effect of grape by‐products or (whole fruit) grape (Cho et al., ; Cui et al., ; Han et al., ). Polyphenols like catechin, gallic acid, epicatechin and other active compounds from grape seed reduced cholesterol absorption through the inhibition of pancreatic cholesterol esterase, which reduce the solubility of cholesterol in micelles and blood (Evans, Wilson, & Guthrie, ; Hui & Howles, ; Ngamukote, Makynen, Thilawech, & Adisakwattana, ).…”

“…Cho et al. (Cho et al., ) suggested that the downregulation of NF‐kB, the signalling transcription factor, which activates the transcription of genes encoding for pro‐inflammatory cytokines (Perez‐Cano et al., ) may be one of the mechanisms by which bioactive compounds from grape produce their effects in liver (Cho et al., ). Moreover, other studies demonstrated that the inhibitory mechanism produced by grape compounds involved the inhibition of the entire inflammatory cascade including MAPK (p‐38, ERK, JNK, c‐jun) in the cytoplasm and NF‐kB in the nucleus (Chuang et al., ; Fraga & Oteiza, ; Park et al., ; Rahman, Biswas, & Kirkham, ).…”

“…Wine by‐products including grape pomace (peels, seeds and stems) or grape seed cake are considered special source of such secondary metabolites due to their high levels of polyphenolic compounds, especially anthocyanins, flavonoids and phenolic acids or others (linoleic‐ ω ‐6 fatty acid, fibres, etc.). Many of these compounds have been shown to exert a broad range of beneficial effects on health in humans and rodent models (Cho et al., ; Gessner, Ringseis, & Eder, ; Torres et al., ).…”

Mixture of Ethanol Extract of Grape Pomade and Omija Fruit Prevents Hyperglycemia and Alleviates Oxidative Stress in Mice Fed an Obesogenic Diet

“…C57BL/6J mice fed an HFD develop oxidative stressassociated obesity and diabetes [21]. Supplementation of GPOF amelioratedadipogenesis, hepatic steatosis, and inflammation in DIO mice, and its effects were stronger than those of GP alone as reported by our previous study [12]. In the present study, we have firstly demonstrated that GPOF alleviates hyperglycemia, insulin resistance, and oxidative stress in DIO mice.…”

“…Omija (Schisandrachinensis), another polyphenol-rich plant that has been used in traditional Chinese medicine and pharmacotherapy of European and other countries, plays an important role in lowering blood glucose level and regulating the endocrine and immune systems and antioxidant enzyme activities [10,11]. We previously demonstrated that combined extracts of grape pomace (GP) and GP plus omija fruit (GPOF) showed anti-obesity and anti-inflammatory effects in diet-induced obese (DIO) mice [12] and an anti-diabetes effect in db/db mice [13]. The aims of the present study were to examine whether GPOF has blood glucose-and oxidative stress-lowering effects in mice fed an obesogenic diet and compare its effects with those of GP.…”