Catechin-rich grape seed extract supplementation attenuates diet-induced obesity in C57BL/6J mice

The promising roles of medicinal plants and bioactive compounds on hepatic lipid metabolism in the treatment of non-alcoholic fatty liver disease in animal models: molecular targets

Imbalance in hepatic lipid metabolism can lead to an abnormal triglycerides deposition in the hepatocytes which can cause non-alcoholic fatty liver disease (NAFLD). Four main mechanisms responsible for regulating hepatic lipid metabolism are fatty acid uptake, de novo lipogenesis, lipolysis and fatty acid oxidation. Controlling the expression of transcription factors at molecular level plays a crucial role in NAFLD management. This paper reviews various medicinal plants and their bioactive compounds emphasising mechanisms involved in hepatic lipid metabolism, other important NAFLD pathological features, and their promising roles in managing NAFLD through regulating key transcription factors. Although there are many medicinal plants popularly investigated for NAFLD treatment, there is still little information and scientific evidence available and there has been no research on clinical trials scrutinised on this matter. This review also aims to provide molecular information of medicinal plants in NALFD treatment that might have potentials for future scientifically controlled studies.

Targeting Metabolic Syndrome in Hidradenitis Suppurativa by Phytochemicals as a Potential Complementary Therapeutic Strategy

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by the appearance of painful inflamed nodules, abscesses, and pus-draining sinus tracts in the intertriginous skin of the groins, buttocks, and perianal and axillary regions. Despite its high prevalence of ~0.4-1%, therapeutic options for HS are still limited. Over the past 10 years, it has become clear that HS is a systemic disease, associated with various comorbidities, including metabolic syndrome (MetS) and its sequelae. Accordingly, the life expectancy of HS patients is significantly reduced. MetS, in particular, obesity, can support sustained inflammation and thereby exacerbate skin manifestations and the chronification of HS. However, MetS actually lacks necessary attention in HS therapy, underlining the high medical need for novel therapeutic options. This review directs attention towards the relevance of MetS in HS and evaluates the potential of phytomedical drug candidates to alleviate its components. It starts by describing key facts about HS, the specifics of metabolic alterations in HS patients, and mechanisms by which obesity may exacerbate HS skin alterations. Then, the results from the preclinical studies with phytochemicals on MetS parameters are evaluated and the outcomes of respective randomized controlled clinical trials in healthy people and patients without HS are presented.

Three Varieties of Grape Pomace, with Distinctive Extractable:Non-Extractable Polyphenol Ratios, Differentially Reduce Obesity and Its Complications in Rats Fed a High-Fat High-Fructose Diet

Grape pomace is a commonly discarded by-product characterized by high extractable (EPP) and non-extractable (NEPP) polyphenol contents which exhibits anti-obesogenic effects. However, the relevance of each fraction needs to be elucidated. In this work, we examined the effects of three pomaces with different concentrations of EPPs and NEPPs on metabolic alterations associated with obesity. The NEPP:EPP ratio of the grape pomaces was 1.48 for Malbec, 1.10 for Garnacha, and 5.76 for Syrah grape varieties. Rats fed a high-fat high-fructose diet supplemented with Malbec grape pomace (HFFD + MAL) Syrah grape pomace (HFFD + SYR) or Garnacha grape pomace (HFFD + GAR) showed significantly less weight gain: 20%, 15%, and 12% less, respectively, compared to HFFD controls. The adiposity index was also significantly decreased by 20% in the HFFD + MAL and HFFD + SYR groups, and by 13% in the HFFD + GAR group. Serum triglycerides were significantly decreased by 46% in the HFFD + MAL group and by 31% in the HFFD + GAR group, compared to the HFFD group, but not in the HFFD + SYR group. All pomace supplementations regulated postprandial glucose in an oral glucose tolerance test. Therefore, grape pomaces containing both EPPs and NEPPs exert beneficial effects on body weight and glucose homeostasis, while EPPs seem to control triglyceride levels more effectively.

In Vivo Evaluation of the Cardiometabolic Potential of Grape Pomace: Effect of Applying Instant Controlled Pressure Drop

Grape pomace (GP) is a source of polyphenols which may be present as free structures or associated with dietary fiber. Instant controlled pressure drop (DIC) is a technology which can modify the association of polyphenols with food matrixes, but how these modifications affect the health benefits associated with GP remains to be elucidated. In this study, in rats fed a high-fat-fructose diet (HFF), we evaluated the in vivo cardiometabolic effects of the modification of polyphenols in GP caused by DIC at 0.2 MPa for 60 s (DIC1) and 0.4 MPa for 120 s (DIC2). These treatments increased anthocyanin and total flavonoid contents, respectively, while all the supplementations caused significant improvements in insulin resistance and plasma triacylglycerols. Thus, the bioactive compounds present in GP (including a major fraction of non-extractable proanthocyanidins) caused these modifications independently of the specific polyphenol profiles which may have resulted from these DIC treatments. Additionally, only intact GP led to an increase in HDL cholesterol, while only DIC2-treated GP improved hepatic steatosis. In conclusion, GP always improves insulin sensitivity in this animal model of obesity, while the different compositions of GP modified by DIC may be associated with other cardiometabolic parameters.

Proanthocyanidins at the gastrointestinal tract: mechanisms involved in their capacity to mitigate obesity-associated metabolic disorders

The prevalence of overweight and obesity is continually increasing worldwide. Obesity is a major public health concern given the multiple associated comorbidities. Finding dietary approaches to prevent/mitigate these conditions is of critical relevance. Proanthocyanidins (PACs), oligomers or polymers of flavan-3-ols that are extensively distributed in nature, represent a major part of total dietary polyphenols. Although current evidence supports the capacity of PACs to mitigate obesity-associated comorbidities, the underlying mechanisms remain speculative due to the complexity of PACs' structure. Given their limited bioavailability, the major site of the biological actions of intact PACs is the gastrointestinal (GI) tract. This review discusses the actions of PACs at the GI tract which could underlie their anti-obesity effects. These mechanisms include: i) inhibition of digestive enzymes at the GI lumen, including pancreatic lipase, α-amylase, α-glucosidase; ii) modification of gut microbiota composition; iii) modulation of inflammation- and oxidative stress-triggered signaling pathways, e.g. NF-κB and MAPKs; iv) protection of the GI barrier integrity. Further understanding of the mechanisms and biological activities of PACs at the GI tract can contribute to develop nutritional and pharmacological strategies oriented to mitigate the serious comorbidities of obesity.

Genetic Variation in the Bitter Receptors Responsible for Epicatechin Detection Are Associated with BMI in an Elderly Cohort

Globally, more than one-third of adults are overweight. Overweight and obesity are complex and multifaceted conditions, associated with an increased risk of chronic illness and early mortality. While there are known risk factors, these alone do not fully explain the varying outcomes between individuals. Recently, taste receptors have been proposed to have a role in the risk for obesity. These receptors are expressed throughout the gastrointestinal tract. In this system, they may be involved in modulating dietary intake and metabolic processes. The taste 2 family of receptors (T2Rs) detects bitter compounds. Receptors T2R4 and T2R5 detect (-)-epicatechin (epicatechin), an antioxidant polyphenol, which may have protective effects against obesity. However, the potential role for taste receptors in this association has not been explored. This study assessed whether polymorphisms in TAS2R4 (rs2233998 and rs2234001) and TAS2R5 (rs2227264) were associated with body mass index (BMI). Genotyping (Taqman qPCR assays) was performed on DNA extracted from blood samples (n = 563) from an elderly cohort. Homozygosity for the minor allele of all polymorphisms was significantly associated with a lower BMI in males. The TAS2R4-rs2233998 CC genotype, the TAS2R4-rs2234001 CC genotype and the TAS2R5-rs2227264 TT genotype were associated with lower BMI (2.1, 2.1 and 2.2 units; p = 0.002, 0.003 and 0.001, respectively). Epicatechin intake was not associated with BMI and genotype was not associated with epicatechin intake. This suggests that the association between TAS2R genotype and elevated BMI risk occurs through altered extra-oral responses and not directly via altered epicatechin intake.

Health Effects of Grape Seed and Skin Extracts and Their Influence on Biochemical Markers

This review is focused on the study of the effects of grape seed and skin extract (GSSE) on human health. GSSE contains high concentrations of important polyphenolic substances with high biological activity. This review is a summary of studies that investigate the effects of GSSE on diabetes mellitus, cardiovascular disease and cancer, its neuroprotective effect, and its effects on the gastrointestinal tract and other health complications related to these diseases. The results of the studies confirm that the anti-inflammatory, antiapoptotic, and pro-proliferative effects of “Vitis vinifera L.” seed extract reduce the level of oxidative stress and improve the overall lipid metabolism.

Proanthocyanidin-rich grape seed extract improves bone loss, bone healing, and implant osseointegration in ovariectomized animals

The purpose of the present study was to confirm if proanthocyanidin-rich grape seed extract (GSE) had the ability to improve bone health such as bone loss, bone healing, and implant osseointegration (defined as the direct connection between bone tissue and an implant) in ovariectomized (OVX) animals. We demonstrated that daily oral administration of GSE prevented bone loss in the lumbar vertebrae and femur in OVX mice. In addition, osteoclastogenesis in the lumbar spine bone of OVX mice, as assessed by histological and histomorphometric analyses, was accelerated but GSE prevented this dynamization, suggesting that GSE could counteract OVX-induced accelerated osteoclastogenic activity. In rats, OVX clearly impaired the healing of defects created on the calvaria, and GSE overcame this OVX-impaired healing. In the same way, osseointegration of a tibial implant in rats was retarded by OVX, and GSE counteracted the OVX-induced poor osseointegration, likely promoting bone healing by preventing imbalanced bone turnover. These results suggest that orally administered GSE improved implant osseointegration by mitigating the impaired bone health induced by OVX as a model of estrogen deficiency.

Solanum nigrum polyphenols reduce body weight and body fat by affecting adipocyte and lipid metabolism

Obesity, being overweight and deposition of body fat are critically associated with metabolic disorders.

Muscat Bailey A grape stalk extract ameliorates high-fat diet‑induced obesity by downregulating PPARγ and C/EPBα in mice

Muscat Bailey A grape stalk is an organic waste produced in marked amounts during the vinification of grapes. Previous studies have indicated that grape stalk is rich in bioactive phenolic compounds, and exhibits antioxidant and UV‑protective activities. However, its effects on obesity and obesity‑associated disorders have not yet been investigated. The effects of grape stalk extract on improving metabolic features were examined using a high‑fat diet (HFD)‑induced obesity mouse model. Oral administration of 200 mg/kg/day grape stalk extract over 16 weeks markedly prevented HFD‑induced obesity, hepatic steatosis, diabetic symptoms and the risk of developing cardiovascular disease. Furthermore, grape stalk extract prevented oxidative stress and inflammation caused by HFD in mice. The beneficial effect may be associated with CCAAT/enhancer‑binding protein α and peroxisome‑proliferator‑activated receptor γ down-regulation in liver tissue. Collectively, the results of the present study indicated that grape stalk extract may be a potent functional food ingredient for preventing obesity, hepatic steatosis and type 2 diabetes.

Protective effect of grape seed and skin extract against high-fat diet-induced dyshomeostasis of energetic metabolism in rat lung

BACKGROUND

Obesity is currently one of the major epidemics of this millennium and affects poeples throughout the world. It causes multiple systemic complications as it significantly interferes with respiratory function.

OBJECTIVE

We aimed in the present work to study the effect of high fat diet (HFD) on lung oxidative stress and energy metabolism alterations, as well as the putative protection afforded by grape seed and skin extract (GSSE).

METHODS

We started by characterizing the GSSE and its composition using gas chromatography coupled to mass spectrometry (GC-MS). We used a rat model of high-fat-diet and we evaluated the effect of GSSE on oxidative stress and energetic disturbances induced by HFD. We analyzed the effect of HFD on lung oxidative status by assessing lipid oxidation level, non-protein thiols (NPSH) and superoxide anion level… We also evaluated the effect of HFD on creatine kinase (CK), malate dehydrogenase (MDH) and mitochondrial complex IV.

RESULTS

HFD induced body weight gain, increased lung weight and lipid content without affecting insulinemia and dropped adiponectemia. HFD also provoked on lung oxidative stress characterized by increased carbonylation (+ 95%; p = 0.0045), decreased of NPSH (- 32%; p = 0.0291) and inhibition of antioxidant enzyme activities such as glutathione peroxidase (- 25%; p = 0.0074). HFD also altered lung intracellular mediators as superoxide anion O2¯ (+ 59%; p = 0.0027) and increased lung xanthine oxidase activity (+ 27%; p = 0.0122). HFD induced copper depletion (- 24%; p = 0.0498) and lead (- 51%: p = 0.0490) from the lung. Correlatively HFD decreased the copper associated enzyme tyrosinase (- 29%; p = 0.0500) and decreased glutamine synthetase activity (- 31%; p = 0.0027). HFD altered also lung energy metabolism by increasing CK activity (+ 22%; p = 0.0108) and decreasing MDH and mitochondrial complex IV activities (- 28%; p = 0.0120, - 31%; p = 0.0086 respectively). Importantly all these alterations were efficiently corrected with GSSE treatment.

CONCLUSION

In conclusion, GSSE has the potential to alleviate the deleterious lipotoxic effect of HFD on lung and it could find potential application in the protection against HFD-induced lung complications.

Vernonia cinerea water extract improves insulin resistance in high-fat diet-induced obese mice

Vernonia cinerea (V cinerea) is a plant distributed in grassy areas in Southeast Asia and has several pharmacological effects, including antidiabetic activity. However, the information available regarding the effect of V cinerea on insulin resistance in high-fat diet (HFD)-induced obese mice is not yet determined. We hypothesized that V cinerea water extract (VC) improves insulin sensitivity in HFD-induced obese mice by modulating both phosphatidylinositol-3-kinase (PI3K) and adenosine monophosphate-activated protein kinase (AMPK) pathways in liver, skeletal muscle, and adipose tissue. Obesity was induced in mice from the Institute for Cancer Research by feeding an HFD 188.28 kJ (45 kcal % lard fat) for 12 weeks. During the last 6 weeks of the HFD, obese mice were treated with VC (250 and 500 mg/kg). We found that VC at both doses significantly reduced the hyperglycemia, hyperinsulinemia, hyperleptinemia, and hyperlipidemia. Obese mice treated with VC could increase serum adiponectin but reduce the proinflammatory cytokines, tumor necrosis factor-α, and monocyte chemoattractant protein-1. The extracts decreased triglyceride storage in liver and skeletal muscle of obese mice. The average size of fat cells was smaller in VC-treated groups than that of the HFD group. The protein expressions of PI3K and AMPK pathways in liver, skeletal muscle, and adipose tissue were upregulated (increased phosphorylation of PI3K, protein kinase B, AMPK, and acetyl-CoA carboxylase) by VC treatment. Furthermore, the glucose transporter 4 was increased in muscle and adipose tissue in obese mice treated with VC. These data indicate that VC treatment stimulates phosphorylation of PI3K and AMPK pathways in liver, muscle, and adipose tissue. Stimulating these pathways may improve impaired glucose and lipid homeostasis in an HFD-induced obesity mouse model. Based on these findings, it appears that VC has potential as a functional food or therapeutic agent in management of insulin resistance related diseases, such as type 2 diabetes mellitus.

Oxidative stress burden inhibits spermatogenesis in adult male rats: testosterone protective effect

In this study, we aimed to investigate the protective effects of androgens, using letrozole (LET; an aromatase inhibitor), grape seed extract (GSE; a naturally occurring aromatase inhibitor and antioxidant), and testosterone propionate (Tp), against methotrexate (MTX)-induced testicular toxicity in adult male rats. MTX has been shown to induce oxidative stress and exhibit antiproliferative effects in the testes. Adult male rats received oral saline gavage (control group with no treatment), the potential protective agents (LET, GSE, or Tp) alone, MTX alone, or a combination of one of the potential protective agents and MTX. The testicular levels of oxidative stress markers and cytokines (tumor necrosis factor-α and interleukin-1β) were measured. Spermatogenesis and sperm viability were microscopically evaluated. Administration of LET and GSE 7 days before MTX improved spermatogenesis and sperm viability, as well as reduced the levels of oxidative stress markers and cellular cytokines. Exogenous testosterone exhibited anti-inflammatory and antioxidant activities, similar to GSE and LET. We also showed that enhancing the endogenous androgenic activity by LET and GSE protected spermatogenesis against MTX-induced testicular toxicity via reduction of inflammation and oxidative stress in the testes. Our data suggest that testosterone protected spermatogenesis owing to its antioxidant and anti-inflammatory properties.

Proanthocyanidin-Rich Grape Seed Extract Modulates Intestinal Microbiota in Ovariectomized Mice

Grape-seed extract (GSE) is rich in proanthocyanidins (polymers of flavan-3-ols). GSE is well known to have various beneficial effects to health. The objective of this study was to examine the effect of dietary GSE on the intestinal microbiota in ovariectomized (OVX) mice as a model of menopause. Phylum-level analyses using 16S rRNA-targeted group-specific polymerase-chain reaction primers in fecal samples collected 8 weeks postoperatively from OVX mice revealed that the proportion of Firmicutes and Bacteroidetes populations became imbalanced as compared with that in sham-operated control mice. That is, the ratio of Firmicutes:Bacteroidetes populations in the OVX group were increased significantly. When OVX animals were given dietary GSE, the imbalanced proportion of Firmicutes and Bacteroidetes populations was normalized to that seen in control mice. In addition, the body weight of OVX animals measured at 6 weeks postoperatively was significantly higher than that in sham-operated control animals. Dietary GSE also prevented OVX animals from increasing body weight. Thus, we postulated that GSE can improve imbalanced populations of intestinal microbiota, leading to prevention of obesity under conditions of not only menopause but morbidity.

PRACTICAL APPLICATION

The GSE has a great potential to be a functional food to improve dysbiosis in post-menopausal women.

Chardonnay Grape Seed Flour Ameliorates Hepatic Steatosis and Insulin Resistance via Altered Hepatic Gene Expression for Oxidative Stress, Inflammation, and Lipid and Ceramide Synthesis in Diet-Induced Obese Mice

To identify differentially expressed hepatic genes contributing to the improvement of high-fat (HF) diet-induced hepatic steatosis and insulin resistance following supplementation of partially defatted flavonoid-rich Chardonnay grape seed flour (ChrSd), diet-induced obese (DIO) mice were fed HF diets containing either ChrSd or microcrystalline cellulose (MCC, control) for 5 weeks. The 2-h insulin area under the curve was significantly lowered by ChrSd, indicating that ChrSd improved insulin sensitivity. ChrSd intake also significantly reduced body weight gain, liver and adipose tissue weight, hepatic lipid content, and plasma low-density lipoprotein (LDL)-cholesterol, despite a significant increase in food intake. Exon microarray analysis of hepatic gene expression revealed down-regulation of genes related to triglyceride and ceramide synthesis, immune response, oxidative stress, and inflammation and upregulation of genes related to fatty acid oxidation, cholesterol, and bile acid synthesis. In conclusion, the effects of ChrSd supplementation in a HF diet on weight gain, insulin resistance, and progression of hepatic steatosis in DIO mice were associated with modulation of hepatic genes related to oxidative stress, inflammation, ceramide synthesis, and lipid and cholesterol metabolism.

Acutely administered grape-seed proanthocyanidin extract acts as a satiating agent

Grape-seed proanthocyanidins' role as stimulators of active GLP-1 in rats suggests that they could be effective as satiating agents. Wistar rats were used to study the effects of proanthocyanidins on food intake with different doses, administration times and proanthocyanidin extract compositions. A dose of 423 mg of phenolics per kg body weight (BW) of grape-seed proanthocyanidin extract (GSPE) was necessary to decrease the 12-hour cumulative food intake by 18.7 ± 3.4%. Proanthocyanidins were effective when delivered directly into the gastrointestinal tract one hour before, or simultaneously at the start of the feeding period. Proanthocyanidins without galloyl forms, such as those from cocoa extract, were not as effective as grape-seed derived forms. GSPE increased the portal levels of active GLP-1 and total ghrelin and decreased the CCK levels, simultaneously with a decrease in gastric emptying. In conclusion, grape-seed proanthocyanidins could be useful as a satiating agent under the conditions defined in this study.

Cytoprotective effects of grape seed extract on human gingival fibroblasts in relation to its antioxidant potential

Cytoprotective effects of short-term treatment with grape seed extract (GSE) upon human gingival fibroblasts (hGFs) were evaluated in relation to its antioxidant properties and compared with those of a water-soluble analog of vitamin E: trolox (Tx). GSE and Tx showed comparable antioxidant potential in vitro against di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH; a stable radical), hydroxyl radical (^•OH), singlet oxygen (¹O₂), and hydrogen peroxide (H₂O₂). Pretreatment or concomitant treatment with GSE for 1 min protected hGFs from oxidative stressors, including H₂O₂, acid-electrolyzed water (AEW), and ¹O₂, and attenuated the intracellular formation of reactive oxygen species induced by H₂O₂ and AEW. Tx also reduced the H₂O₂- and AEW-induced intracellular formation of reactive oxygen species, but showed no cytoprotective effects on hGFs exposed to H₂O₂, AEW, or ¹O₂. These results suggest that the cytoprotective effects of GSE are likely exerted independently of its antioxidant potential.

Functional modification of adipocytes by grape seed extract impairs their pro-tumorigenic signaling on colon cancer stem cells and the daughter cancer cells

With global rise in obesity, it is imperative that we identify obesity-driven factors that increase growth and progression of colorectal cancer (CRC), and also discover and develop agents with anti-CRC efficacy under obese conditions. Here in, we investigated grape seed extract (GSE), a well-defined agent with both preventive and anti-CRC efficacy, for its potential to impair pro-tumorigenic signaling of adipocytes on CRC/colon cancer stem cells (CSCs) and associated molecular mechanisms, to control CRC under obese conditions. GSE treatment significantly decreased the growth and invasion promoting effects of both mouse and human adipocytes on CRC cells. Moreover, GSE exerted a direct inhibitory effect, as well as it strongly reduced the growth promoting signals of adipocytes, on colon CSCs. These GSE effects were associated with a decrease in both mRNA and protein levels of various CSC-associated molecules. Notably, GSE effects on adipocytes were not due to changes in lipid content, but by inducing the ‘browning’ of adipocytes as evidenced by an increase in UCP-1 mRNA level and mitochondriogenesis. Together, these findings, for the first time, suggest the ability of GSE to induce ‘brown remodeling’ of white adipocytes, which causes functional modification of adipocytes thus impairing their pro-tumorigenic signals on colon CSCs/CRC cells.

Favourable effects of grape seed extract on intestinal epithelial differentiation and barrier function in IL10-deficient mice

The impairment in the rate of cell proliferation and differentiation leads to a negative consequence on the renewal of the intestinal epithelium, which is the aetiological factor of a number of digestive diseases. Grape seed extract (GSE), a rich source of proanthocyanidins, is known for its beneficial health effects. The present study evaluated the beneficial effects of GSE on colonic cell differentiation and barrier function in IL10-deficient mice. Female mice aged 6 weeks were randomised into two groups and given drinking-water containing 0 or 0·1 % GSE (w/v) for 12 weeks. GSE supplementation decreased serum TNF-α level and intestinal permeability, and increased the colonic goblet cell density that was associated with increased mRNA expression of mucin (Muc)-2. Immunohistochemical analyses showed lower accumulation of β-catenin in the crypts of colon tissues of the GSE-supplemented mice, which was associated with a decreased mRNA expression of two downstream effectors of Wingless and Int (Wnt)/catenin signalling, myelocytomatosis oncogene protein (Myc) and cyclin D1 (Ccnd1). Consistently, GSE supplementation decreased the number of colonic proliferating cell nuclear antigen-positive cells, a well-known cell proliferation marker, and a weakened extracellular signal-regulated kinases 1 and 2 (ERK1/2) signalling. In summary, these data indicate that supplementation of 0·1 % GSE for 12 weeks improved gut barrier function and colonic cell differentiation in the IL10-deficient mice probably via inhibiting Wnt/β-catenin pathway.

Dietary supplementation of chardonnay grape seed flour reduces plasma cholesterol concentration, hepatic steatosis, and abdominal fat content in high-fat diet-induced obese hamsters

The mechanisms for the hypocholesterolemic and antiobesity effects of grape seed flours derived from white and red winemaking processing were investigated using male Golden Syrian hamsters fed high-fat (HF) diets supplemented with 10% partially defatted grape seed flours from Chardonnay (ChrSd), Cabernet Sauvignon (CabSd), or Syrah (SyrSd) pomace as compared to a HF control diet for 3 weeks. Hamsters fed the ChrSd diet had significantly lowered plasma total-, VLDL-, and LDL-cholesterol concentrations compared to the CabSd, SyrSd, and control diets. The improved plasma cholesterol after ChrSd was correlated with the up-regulation of hepatic genes related to cholesterol (CYP51) and bile acid (CYP7A1) synthesis as well as LDL-cholesterol uptake (LDLR). A reduction of hepatic lipid content was associated with altered expression of the genes related to lipid metabolism. However, fecal total lipid content was not changed. Expression of ileal apical sodium bile acid transporter (ASBT) was not affected by ChrSd, indicating unchanged ileal bile acid reabsorption. The antiobesity effect of the ChrSd diet appears to be related to expression of adipogenesis- and inflammation-related genes in adipose tissue. These findings suggest that flavonoid-rich Chardonnay grape seed flour induced cholesterol-lowering, antiobesity, and anti-inflammatory health benefits and attenuation of hepatic steatosis via regulation of gene expression related to cholesterol, bile acid, and lipid metabolism in liver and adipose tissue.

Grape seed and skin extract mitigates heart and liver oxidative damage induced by a high-fat diet in the rat: gender dependency

Obesity is a public health problem contributing to morbidity and mortality from metabolic syndrome. It has long been recognized that there is a gender dependency in several obesity-related health risks. Using a high fat diet (HFD) to induce obesity in Wistar rats, we studied the gender dependency of fat-induced oxidative stress in the heart and liver, with a special emphasis on the distribution of transition metals, as well as the protective effects of grape seed and skin extract (GSSE). HFD induced obesity in both male and female rats, characterized by increased body weight as well as relative liver mass in both genders, and increased relative heart mass in the males only. HFD also provoked the accumulation of triglycerides and total cholesterol into the male hearts, and into the livers of both genders. HFD induced oxidative stress in the male hearts and also in the livers of both genders. Furthermore, HFD affected cardiac levels of copper in the males, and hepatic levels of copper and zinc in both genders, whereas HFD affected free iron in the male hearts and female livers, specifically. In conclusion, HFD treatment altered transition metal homeostasis more drastically in the male heart than in the female liver, and GSSE efficiently protected these organs against fat-induced disturbances, regardless of gender.

Low doses of grape seed procyanidins reduce adiposity and improve the plasma lipid profile in hamsters

OBJECTIVE

Procyanidins are polyphenolic compounds with beneficial effects on health in relation to cardiovascular disease and metabolic syndrome. In this study, we evaluated the potential beneficial effects of low doses of a grape seed procyanidin extract (GSPE) on body weight and fat deposition.

DESIGN

Four groups of hamsters were fed either a standard diet (STD) or a high-fat diet (HFD) for 30 days and supplemented with either GSPE at 25 mg per kg of body weight per day (STD-GSPE and HFD-GSPE groups) or vehicle (STD and HFD groups) during the last 15 days of the study.

RESULTS

A significant decrease in body weight gain was observed in both GSPE-treated animals at the end of the experiment. GSPE treatment significantly reduced the adiposity index and the weight of all the white adipose tissue depots studied (retroperitoneal (RWAT), mesenteric (MWAT), epididymal (EWAT) and inguinal (IWAT)) in both GSPE-treated groups. GSPE administration reversed the increase in plasma phospholipids induced by the HFD feeding. In the RWAT, GSPE treatment increased the mRNA expression of genes related to β-oxidation and the glycerolipid/free fatty acid (GL/FFA) cycle, mainly in HFD-GSPE animals. In the MWAT, the effects of GSPE at the transcriptional level were not as evident as in the RWAT. Moreover, GSPE treatment induced heparin-releasable lipoprotein lipase activity in the RWAT and MWAT depots. The alterations in the lipid metabolic pathways induced by GSPE were accompanied by lower FFA levels in the plasma and decreased lipid and triglyceride accumulation in the MWAT.

CONCLUSION

The use of GSPE at low doses protects against fat accumulation and improves the plasma lipid profile in hamsters. We suggest that GSPE exerts these effects in part through the activation of both β-oxidation and the GL/FFA cycle, mainly in the RWAT.

Grape seed and skin extract mitigates garlic-induced oxidative stress in rat liver

Garlic is a commonly used spice in folk medicine that can exert adverse health effects when given at a high dose. Grape seed and skin extract (GSSE) exhibits a variety of beneficial effects even at a high dose. In the present study we evaluated the toxicity of high-dose garlic treatment on liver and the protective effect of GSSE. Rats were intraperitoneally administered either with garlic extract (5 g·(kg body weight)–1) or GSSE (500 mg·(kg body weight)–1) or a combination of garlic and GSSE at the same doses daily for 1 month. Plasma and hepatic levels of cholesterol, triacylglycerol, and transaminases and liver antioxidant status were evaluated. Data showed that a high garlic dose induced liver toxicity and a pro-oxidative status characterized by increased malondialdehyde and decreased antioxidant enzyme activities as catalase, peroxidase, and superoxide dismutase. Garlic increased intracellular H2O2but decreased free iron and Ca2+. GSSE alone or in co-treatment with garlic had the reverse effect and counteracted almost all garlic-induced deleterious impacts to near control levels. In conclusion, a high garlic dose induced a pro-oxidative state characterized by the Fenton reaction between H2O2and free iron, inducing Ca2+depletion, while GSSE exerted antioxidant properties and Ca2+repletion.