Polyphenol-rich blackcurrant extract exerts hypocholesterolaemic and hypoglycaemic effects in mice fed a diet containing high fat and cholesterol

A Review on the Protecting Effects and Molecular Mechanisms of Berries Against a Silent Public Health Concern: Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) poses a silent threat to human health, with prevalence rising at an alarming rate. The treatment and prevention of NAFLD depend on novel approaches as no effective treatment options are currently available. Berries are unique sources of phenolic compounds that have proven roles in disease prevention and health promotion. However, a comprehensive review of the effects of different berries on NAFLD and related pathologies is lacking. Thus, the present review aims to summarize the effects of berry extracts, plant parts, and bioactive compounds from twenty-one different berries on NAFLD. The molecular mechanisms involved include the regulation of lipid homeostasis, modulation of oxidative stress and inflammation markers, and activation of different signaling pathways in different in vitro and in vivo NAFLD models. Furthermore, their modulatory effects on the gut microbiota have also been highlighted. Clinical intervention research on the benefits of berries in NAFLD is limited; nonetheless, this paper discusses clinical studies demonstrating the effects of different berries in people with NAFLD. Future research should focus on long-term clinical studies to compare the therapeutic potentials of different berries against NAFLD.

Evaluation of fermented soybean meal by Bacillus subtilis as an alternative to fishmeal on the growth, and physiological status of Nile tilapia Oreochromis niloticus fingerlings

A feeding trial was conducted to investigate the effect of fermented soybean meal with Bacillus subtilis bacteria on growth performance, feed utilization, carcass composition, and hematological, and histological section of the liver and intestine of Nile tilapia Oreochromis niloticus fingerlings. Commercial soybean meal (SBM) containing 44% Crude Protein (CP) was fermented using the solid-state fermentation method which depended on autoclaving of SBM, then bacterial treatment injection by Bacillus subtilis, and finally incubation at 40C for 72 h then autoclaved to stop the growth of bacteria. Five isonitrogenous (25% crude protein) and isocaloric (4.4 kcal\g gross energy) experimental fish meal-free diets were formulated to compare with a common control diet containing fishmeal and unfermented soybean meal. Diets without fish meal contain fermented soybean meal (FSM) as a sole protein, FSM with corn gluten (CG), FSM with free amino acid methionine (Meth), FSM with corn gluten and methionine, and unfermented soybean meal. Eighteen glass aquaria, 80-L net volume, were used to stock 10 fingerlings (10.0 ± 0.1 g/fish) in each aquarium in the replicates group. The feed amount was given three times daily, six days a week throughout the 98 days experimental period. Fish were weighed biweekly and feed amounts were adjusted based on the new fish weight. Bacterial fermentation enhanced the protein content of commercial soybean meals by 6%. The crude protein of fermented soybean meal increased from 43.44% to 50.67%. Used of FSM as a sole dietary protein source resulted in a decrease in growth rate and feed utilization. However, the incorporation of FSM with corn gluten, and/or methionine amino acid led to an improvement in the performance of fish. Finally, the best final body weight, weight gain, specific growth rate, protein efficiency ratio, and protein productive value were recorded by a fish-fed mixed plant protein diet (FSM + CG + Meth). Also, Hematocrit and red blood cells were not significantly affected including the FSM.

Chemical Compounds of Berry-Derived Polyphenols and Their Effects on Gut Microbiota, Inflammation, and Cancer

Berry-derived polyphenols are bioactive compounds synthesized and secreted by several berry fruits. These polyphenols feature a diversity of chemical compounds, including phenolic acids and flavonoids. Here, we report the beneficial health effects of berry-derived polyphenols and their therapeutical application on gut-microbiota-related diseases, including inflammation and cancer. Pharmacokinetic investigations have confirmed the absorption, availability, and metabolism of berry-derived polyphenols. In vitro and in vivo tests, as well as clinical trials, showed that berry-derived polyphenols can positively modulate the gut microbiota, inhibiting inflammation and cancer development. Indeed, these compounds inhibit the growth of pathogenic bacteria and also promote beneficial bacteria. Moreover, berry-derived polyphenols exhibit therapeutic effects against different gut-microbiota-related disorders such as inflammation, cancer, and metabolic disorders. Moreover, these polyphenols can manage the inflammation via various mechanisms, in particular the inhibition of the transcriptional factor Nf-κB. Berry-derived polyphenols have also shown remarkable effects on different types of cancer, including colorectal, breast, esophageal, and prostate cancer. Moreover, certain metabolic disorders such as diabetes and atherosclerosis were also managed by berry-derived polyphenols through different mechanisms. These data showed that polyphenols from berries are a promising source of bioactive compounds capable of modulating the intestinal microbiota, and therefore managing cancer and associated metabolic diseases. However, further investigations should be carried out to determine the mechanisms of action of berry-derived polyphenol bioactive compounds to validate their safety and examinate their clinical uses.

Potential Vasculoprotective Effects of Blackcurrant (Ribes nigrum) Extract in Diabetic KK-Ay Mice

Polyphenols are bioactive compounds found naturally in fruits and vegetables; they are widely used in disease prevention and health maintenance. Polyphenol-rich blackcurrant extract (BCE) exerts beneficial effects on vascular health in menopausal model animals. However, the vasculoprotective effects in diabetes mellitus (DM) and atherosclerotic vascular disease secondary to DM are unknown. Therefore, we investigated whether BCE is effective in preventing atherosclerosis using KK-A^y mice as a diabetes model. The mice were divided into three groups and fed a high-fat diet supplemented with 1% BCE (BCE1), 3% BCE (BCE2), or Control for 9 weeks. The mice in the BCE2 group showed a considerable reduction in the disturbance of elastic lamina, foam cell formation, and vascular remodeling compared to those in the BCE1 and Control groups. Immunohistochemical staining indicated that the score of endothelial nitric oxide synthase staining intensity was significantly higher in both BCE2 (2.9) and BCE1 (1.9) compared to that in the Control (1.1). Furthermore, the score for the percentage of alpha-smooth muscle actin was significantly lower in the BCE2 (2.9%) than in the Control (2.1%). Our results suggest that the intake of anthocyanin-rich BCE could have beneficial effects on the blood vessels of diabetic patients.

Genus Ribes Linn. (Grossulariaceae): A comprehensive review of traditional uses, phytochemistry, pharmacology and clinical applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Ribes Linn., which belongs to the Grossulariaceae family, contains 160 species distributed mainly in temperate and cold regions of the Northern Hemisphere. There are 59 species in southwest, northwest and northeast China. Some species of Ribes have been used as traditional and local medicines for the treatment of glaucoma, cardiovascular disease, stomachache, hepatitis, hyperlipidemia, hypertension and other ailments. However, the data provided in recent years have not been collated and compared.

AIM OF THE STUDY

This review aims to summarize the current status of ethnopharmacological uses, phytochemistry, pharmacology, clinical applications, and pharmacokinetics of the genus Ribes to better understand the therapeutic potential of the genus Ribes in the future and hope to provide a relatively novel perspective for further clinical application on the genus.

MATERIALS AND METHODS

The literature on Ribes was collected through a series of scientific search engines including Elsevier, ACS, Springer, Web of Science, PubMed, Google Scholar, Baidu Scholar, Wiley, China National Knowledge Infrastructure (CNKI) and books.

RESULTS

Ribes species have been used for detoxification, glaucoma, cardiovascular disease, stomachache, hepatitis, hyperlipidemia, hypertension and other ailments. These plants mainly contain phenolic glycosides, flavonoids, proanthocyanidins, polysaccharides, etc. Most traditional uses are related to biological activity and have been confirmed by modern research. Pharmacological studies in vitro and in vivo revealed that the extracts and pure compounds possessed significant hypolipidemic, antioxidant, anti-inflammatory, antitumor, antibacterial, and antiviral activity, eyesight protection and other effects.

CONCLUSIONS

The traditional uses, phytochemistry, pharmacology, pharmacokinetics, and clinical applications described in this article explained that the Ribes species has numerous activities, and these findings will promote further action in the area of mechanism research. However, very few preclinical and clinical studies have focused on the toxicology and pharmacokinetics of crude extracts and pure compounds from the genus Ribes. Moreover, several clinical evidence to support the health benefits of Ribes plants. The development of new medicines based on Ribes species as ingredients may be restricted. The pharmacological activity, clinical efficacy and safety of Ribes species need to be verified by systematic and comprehensive preclinical studies and clinical trials.

Hypocholesterolemic Effect of Blackcurrant (Ribes nigrum) Extract in Healthy Female Subjects: A Pilot Study

Blackcurrant extract (BCE) ameliorates dyslipidemia in menopausal model animals and in elderly women at a risk of dyslipidemia. However, it is unknown whether the daily intake of BCE can prevent lipid abnormalities in healthy individuals. Lipids are essential for the body, but they also cause arteriosclerosis. In this noncomparative pilot study, we examined the effects of BCE administered for 29 days on serum lipids in young healthy women. Blood samples were collected before and on days 4 and 29 after BCE intake, and 20 lipoprotein fractions in the serum were separated using a gel-permeation high-performance liquid chromatography method to measure the triacylglycerol and cholesterol levels in lipoproteins. There were no effects on lipids on day 4 of BCE intake, but the total cholesterol level decreased on day 29. Furthermore, the levels of total very-low-density lipoprotein (VLDL) cholesterol, small VLDL cholesterol, and large low-density lipoprotein cholesterol were significantly decreased. These results suggest that the daily intake of BCE has a hypocholesterolemic effect in healthy women, and that it is effective in preventing atherosclerosis.

Potential of Beetroot and Blackcurrant Compounds to Improve Metabolic Syndrome Risk Factors

Metabolic syndrome (MetS) is a group of metabolic abnormalities, which together lead to increased risk of coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM), as well as reduced quality of life. Dietary nitrate, betalains and anthocyanins may improve risk factors for MetS and reduce the risk of development of CHD and T2DM. Beetroot is a rich source of dietary nitrate, and anthocyanins are present in high concentrations in blackcurrants. This narrative review considers the efficacy of beetroot and blackcurrant compounds as potential agents to improve MetS risk factors, which could lead to decreased risk of CHD and T2DM. Further research is needed to establish the mechanisms through which these outcomes may occur, and chronic supplementation studies in humans may corroborate promising findings from animal models and acute human trials.

Going "Green" in the Prevention and Management of Atherothrombotic Diseases: The Role of Dietary Polyphenols

During the 20th century processed and ready-to-eat foods became routinely consumed resulting in a sharp rise of fat, salt, and sugar intake in people's diets. Currently, the global incidence of obesity, raised blood lipids, hypertension, and diabetes in an increasingly aged population contributes to the rise of atherothrombotic events and cardiovascular diseases (CVD) mortality. Drug-based therapies are valuable strategies to tackle and help manage the socio-economic impact of atherothrombotic disorders though not without adverse side effects. The inclusion of fresh fruits and vegetables rich in flavonoids to human diets, as recommended by WHO offers a valuable nutritional strategy, alternative to drug-based therapies, to be explored in the prevention and management of atherothrombotic diseases at early stages. Though polyphenols are mostly associated to color and taste in foods, food flavonoids are emerging as modulators of cholesterol biosynthesis, appetite and food intake, blood pressure, platelet function, clot formation, and anti-inflammatory signaling, supporting the health-promoting effects of polyphenol-rich diets in mitigating the impact of risk factors in atherothrombotic disorders and CVD events. Here we overview the current knowledge on the effect of polyphenols particularly of flavonoid intake on the atherothrombotic risk factors and discuss the caveats and challenges involved with current experimental cell-based designs.

Black Current Anthocyanins Improve Lipid Metabolism and Modulate Gut Microbiota in High-Fat Diet-Induced Obese Mice

SCOPE

This study aimed to explore the anti-obesity potential of blackcurrant anthocyanins (BCA) and investigate the correlation between the gut microbiota and the BCA-induced beneficial effects.

METHODS AND RESULTS

Male C57BL/6J mice (n = 36) are randomly assigned into low-fat diet group (LFD), high-fat diet group (HFD), and BCA group feeding HFD supplemented with BCA for 12 weeks. Body weight and food intake are monitored weekly. Obesity-related biochemical indexes and the expression levels of genes related to lipid metabolism are determined. Amplicon sequencing of the bacterial 16S rRNA gene is conducted to analyze the gut microbiota structure, and spearman correlation analysis is used to determine the correlations between gut microbiota and obesity-related indicators. The results showed that BCA treatment alleviated HFD-induced obesity, hyperlipemia, and hepatic steatosis. Moreover, BCA supplement improved hepatic lipid metabolism by regulating the expression of genes related to the synthesis and degradation of lipids and cholesterols. Microbial analysis revealed that BCA supplementation significantly changed the overall structure and composition of the gut microbiota, and resulted in an enrichment of Akkermansia_muciniphila, which is negatively correlated with the physical biomarkers.

CONCLUSION

This study demonstrated that BCA supplement could be a beneficial treatment for preventing HFD-induced obesity by targeting microbiota.

Extraction, Identification, and Health Benefits of Anthocyanins in Blackcurrants (Ribes nigrum L.)

The fruit of the blackcurrant (Ribes nigrum L.) is round-shaped, dark purple, bittersweet, and seed-containing edible berries. The blackcurrant has been used as a traditional medicine in both Asia and European countries. It is known as a rich source of antioxidants, largely due to its high content of phenolic compounds, especially anthocyanins. Studies on anthocyanins from blackcurrants have adopted different extraction methods and a panel of anthocyanins has been identified in them. Research on the health benefits of blackcurrant anthocyanins has also grown. To present a general overview of research in blackcurrant anthocyanins, this review focuses on the extraction methods of anthocyanins from blackcurrants and the molecular mechanisms underlying their health benefits.

Dietary anthocyanins as potential natural modulators for the prevention and treatment of non-alcoholic fatty liver disease: A comprehensive review

Nonalcoholic fatty liver disease (NAFLD) refers to a metabolic syndrome linked with type 2 diabetes mellitus, obesity, and cardiovascular diseases. It is characterized by the accumulation of triglycerides in the hepatocytes in the absence of alcohol consumption. The prevalence of NAFLD has abruptly increased worldwide, with no effective treatment yet available. Anthocyanins (ACNs) belong to the flavonoid subclass of polyphenols, are commonly present in various edible plants, and possess a broad array of health-promoting properties. ACNs have been shown to have strong potential to combat NAFLD. We critically assessed the literature regarding the pharmacological mechanisms and biopharmaceutical features of the action of ACNs on NAFLD in humans and animal models. We found that ACNs ameliorate NAFLD by improving lipid and glucose metabolism, increasing antioxidant and anti-inflammatory activities, and regulating gut microbiota dysbiosis. In conclusion, ACNs have potential to attenuate NAFLD. However, further mechanistic studies are required to confirm these beneficial impacts of ACNs on NAFLD.

Dietary calamondin supplementation slows the progression of non-alcoholic fatty liver disease in C57BL/6 mice fed a high-fat diet

Obesity is associated with an increased risk of metabolic abnormalities. The citrus fruit calamondin contains nobiletin and hesperidin, which are involved in lipid metabolism, and vitamin C, which is an antioxidant. We investigated the metabolic profiles of C57BL/6 mice fed a normal diet, high-fat diet (HFD), HFD + 1% (w/w) calamondin puree (HFD + CL1), or HFD + 5% (w/w) calamondin puree (HFD + CL5). Glucose tolerance was significantly higher in HFD + CL than in HFD-fed mice. Histological analysis revealed less lipid accumulation in the livers of HFD + CL-fed mice than in those of HFD-fed control mice. Hepatocyte ballooning and large lipid droplets - key non-alcoholic fatty liver disease characteristics - were observed in HFD-fed mice after 4 weeks; however, they were nearly absent in HFD + CL-fed mice. The serum expression level of inflammation-associated Ccl2 was lower in HFD + CL-fed mice than in HFD-fed mice. Thus, calamondin may ameliorate HFD-induced metabolic disturbances, including the progression of non-alcoholic fatty liver disease.

Blackcurrant (Ribes nigrum) Extract Prevents Dyslipidemia and Hepatic Steatosis in Ovariectomized Rats

Estrogen is involved in lipid metabolism. Menopausal women with low estrogen secretion usually gain weight and develop steatosis associated with abnormal lipid metabolism. A previous study showed that blackcurrant (Ribes nigrum L.) extract (BCE) had phytoestrogen activity. In this study, we examined whether BCE improved lipid metabolism abnormalities and reduced liver steatosis in ovariectomized rats, as a menopausal animal model. Twelve-week-old ovariectomized (OVX) rats were fed a regular diet (Ctrl) or a 3% BCE supplemented diet while sham rats were fed a regular diet for three months. Body weight, visceral fat weight, levels of serum triglycerides, total cholesterol, and LDL cholesterol decreased in the BCE-treated OVX and sham rats, but not in OVX Ctrl rats. The results of hematoxylin and eosin staining revealed that BCE decreased the diameters of adipocytes and the nonalcoholic fatty liver disease activity score. Furthermore, quantitative RTPCR indicated a decreased expression of hepatitis-related genes, such as tumor necrosis factor-α, IL-6, and IL-1β in OVX rats after BCE treatment. This is the first study that reported improvement of lipid metabolism abnormalities in OVX rats by BCE administration. These results suggest that the intake of BCE alleviated dyslipidemia and prevented nonalcoholic steatohepatitis during menopause in this animal model.

Blackcurrant (Ribes nigrum) Extract Exerts an Anti-Inflammatory Action by Modulating Macrophage Phenotypes

Macrophages are polarized into different phenotypes depending on tissue microenvironment where they reside. In obesity-associated inflammation, M1-type macrophages are predominant in the inflamed tissue, exerting pro-inflammatory responses. Our previous studies demonstrate that blackcurrant consumption attenuates hepatic inflammation and lipopolysaccharide-stimulated inflammatory responses of splenocytes in obese mice. In this study, we determined whether blackcurrant modulates macrophage phenotypes to exert its anti-inflammatory action. Mouse bone marrow-derived macrophages (BMDM) and human THP-1 macrophages were polarized into M1 macrophages in the presence or absence of blackcurrant extract (BCE). BCE repressed M1 polarization of both murine and human macrophages. Also, to gain insight into the role of blackcurrant metabolites produced in vivo in the regulation of macrophage phenotypes, BMDM were treated with serum obtained from lean or obese mice fed blackcurrant. While serum from lean mice fed blackcurrant did not exert either anti-inflammatory actions or suppressive effects on M1 polarization, serum from obese mice fed blackcurrant reduced the expression of pro-inflammatory genes in BMDM. Our data demonstrate that BCE suppresses M1 polarization, with reduced pro-inflammatory responses. Moreover, this study suggests that blackcurrant metabolites may not exert their anti-inflammatory effect directly by altering macrophage phenotypes, but possibly by inhibiting the production of obesity-associated inflammatory factors.

Enzymatic acylation of blackcurrant (Ribes nigrum) anthocyanins and evaluation of lipophilic properties and antioxidant capacity of derivatives

Anthocyanin-rich fractions isolated from blackcurrant (Ribes nigrum L.) including delphinidin-3-O-glucoside, delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside were enzymatically acylated with lauric acid. All the four anthocyanins were successfully monoacylated, and their relative proportions did not affect the conversion yield. The acylation occurred at the 6″-OH position of the glucosides and at the rhamnose 4‴-OH of the rutinosides. The rutinoside moieties of the anthocyanins were successfully acylated for the first time, and the corresponding acylation sites were verified by NMR analysis. The acylation enhanced the lipophilicity. The hydrophilic anthocyanin rutinosides were more lipophilic after acylation. Introducing lauric acid into the anthocyanins significantly improved the thermostability and capacity to inhibit lipid peroxidation and maintained UV-vis absorbance and antioxidant activity. This research provides important insights into acylation of mixed anthocyanins with different glycosyl moieties.

Blackcurrant (Ribes nigrum) Prevents Obesity-Induced Nonalcoholic Steatohepatitis in Mice

OBJECTIVE

With increasing prevalence of nonalcoholic steatohepatitis (NASH), effective strategies to prevent NASH are needed. This study investigated whether the consumption of blackcurrant (Ribes nigrum) can prevent the development of obesity-induced NASH in vivo.

METHODS

Male C57BL/6J mice were fed a low-fat control diet, a low-fat diet with 6% whole blackcurrant powder, an obesogenic high-fat/high-sucrose control diet (HF), or a high-fat/high-sucrose diet containing 6% whole blackcurrant powder (HF-B) for 24 weeks.

RESULTS

HF significantly increased, whereas HF-B markedly decreased, liver weights and triglyceride. Furthermore, blackcurrant attenuated obesity-induced infiltration of macrophages in the liver, in particular, the M1 type, and also suppressed the hepatic expression of fibrogenic genes and fibrosis. Flow cytometric analysis showed that HF significantly increased the percentages of monocytes of total splenocytes, which was markedly attenuated by blackcurrant. HF-B decreased lipopolysaccharide-stimulated mRNA expression of interleukin 1β and tumor necrosis factor α in splenocytes, compared with those from HF controls. Moreover, the levels of circulating and hepatic miR-122-5p and miR-192-5p, known markers for nonalcoholic fatty liver disease, were significantly increased by HF but decreased by HF-B.

CONCLUSIONS

The study's findings indicate that blackcurrant consumption prevents obesity-induced steatosis, inflammation, and fibrosis in the liver.

The effect of anthocyanin supplementation in modulating platelet function in sedentary population: a randomised, double-blind, placebo-controlled, cross-over trial

The anti-thrombotic properties of anthocyanin (ACN) supplementation was evaluated in this randomised, double-blind, placebo (PBO) controlled, cross-over design, dietary intervention trial in sedentary population. In all, sixteen participants (three males and thirteen females) consumed ACN (320 mg/d) or PBO capsules for 28 d followed by a 2-week wash-out period. Biomarkers of thrombogenesis and platelet activation induced by ADP; platelet aggregation induced by ADP, collagen and arachidonic acid; biochemical, lipid, inflammatory and coagulation profile were evaluated before and after supplementation. ACN supplementation reduced monocyte-platelet aggregate formation by 39 %; inhibited platelet endothelial cell adhesion molecule-1 expression by 14 %; reduced platelet activation-dependant conformational change and degranulation by reducing procaspase activating compound-1 (PAC-1) (↓10 %) and P-selectin expression (↓14 %), respectively; and reduced ADP-induced whole blood platelet aggregation by 29 %. Arachidonic acid and collagen-induced platelet aggregation; biochemical, lipid, inflammatory and coagulation parameters did not change post-ACN supplementation. PBO treatment did not have an effect on the parameters tested. The findings suggest that dietary ACN supplementation has the potential to alleviate biomarkers of thrombogenesis, platelet hyperactivation and hyper-aggregation in sedentary population.

Blackcurrant anthocyanins stimulated cholesterol transport via post-transcriptional induction of LDL receptor in Caco-2 cells

PURPOSES

We previously showed that polyphenol-rich blackcurrant extract (BCE) showed a hypocholesterolemic effect in mice fed a high fat diet. As direct cholesterol removal from the body via the intestine has been recently appreciated, we investigated the effect of BCE on the modulation of genes involved in intestinal cholesterol transport using Caco-2 cells as an in vitro model.

METHODS

Caco-2 cells were treated with BCE to determine its effects on mRNA and protein expression of genes important for intestinal cholesterol transport, low-density lipoprotein (LDL) uptake, cellular cholesterol content, and cholesterol transport from basolateral to apical membrane of Caco-2 cell monolayers. Cells were also treated with anthocyanin-rich or -poor fraction of BCE to determine the role of anthocyanin on BCE effects.

RESULTS

BCE significantly increased protein levels of LDL receptor (LDLR) without altering its mRNA, which consequently increased LDL uptake into Caco-2 cells. This post-transcriptional induction of LDLR by BCE was markedly attenuated in the presence of rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1). In addition, BCE altered genes involved in cholesterol transport in the enterocytes, including apical and basolateral cholesterol transporters, in such a way that could enhance cholesterol flux from the basolateral to apical side of the enterocytes. Indeed, BCE significantly increased the flux of LDL-derived cholesterol from the basolateral to the apical chamber of Caco-2 monolayer. LDLR protein levels were markedly increased by anthocyanin-rich fraction, but not by anthocyanin-free fraction.

CONCLUSION

mTORC1-dependent post-transcriptional induction of LDLR by BCE anthocyanins drove the transport of LDL-derived cholesterol to the apical side of the enterocytes. This may represent a potential mechanism for the hypocholesterolemic effect of BCE.

Nutrient digestibility, hindgut metabolites and antioxidant status of dogs supplemented with pomegranate peel extract

The present study assessed the effect of dietary supplementation of pomegranate peel (methanolic) extract (PPE) on the nutrient digestibility, faecal fermentative metabolites and antioxidant status of dogs. Six medium-sized dogs of mixed breeds were allocated to two groups in a replicated cross-over design and fed a basal diet with and without supplementation of PPE at 50 mg/kg body weight. Each of the experimental periods consisted of 30 d, with a 21 d washout period in between. Results indicated that PPE supplementation led to no significant changes in nutrient digestibility except a trend of improvement (P = 0·070) in crude fibre digestibility. PPE supplementation significantly (P < 0·001) influenced faecal pH, ammonia and lactate production, indicative of positive effects of PPE polyphenols. PPE supplementation further increased faecal SCFA concentration accompanied by a reduction (P < 0·01) in branched-chain fatty acids. PPE supplementation also improved (P < 0·05) indices of erythrocytic antioxidants, namely reduced glutathione, catalase, glutathione peroxidase and glutathione S-transferase together with an improvement in lipid peroxidation. Overall, it can be concluded that dietary supplementation with PPE at 50 mg/kg body weight had a positive impact on hindgut fermentation and antioxidant status in dogs, thereby demonstrating its potential as a gut health-promoting nutraceutical.

Deep sea water improves hypercholesterolemia and hepatic lipid accumulation through the regulation of hepatic lipid metabolic gene expression

A high‑fat diet or high‑cholesterol diet (HCD) is a major cause of metabolic diseases, including obesity and diabetes; vascular diseases, including hypertension, stroke and arteriosclerosis; and liver diseases, including hepatic steatosis and cirrhosis. The present study aimed to evaluate the effects of deep sea water (DSW) on rats fed a HCD. DSW decreased HCD‑induced increases in total cholesterol and low‑density lipoprotein (LDL) cholesterol in the blood, and recovered high‑density lipoprotein cholesterol. In addition, DSW decreased levels of liver injury markers, which were increased in response to HCD, including glutamate‑oxaloacetate transaminase, glutamate‑pyruvate transferase and alkaline phosphatase. Lower lipid droplet levels were observed in the livers of rats fed a HCD and treated with DSW at a hardness of 1,500, as compared with those in the HCD only group. Semi‑quantitative reverse transcription‑polymerase chain reaction (RT‑PCR) revealed that mRNA expression levels of fatty acid synthase and sterol regulatory element binding protein‑1c (SREBP‑1c) in rats fed a HCD with DSW were lower compared with the HCD only group. Furthermore, quantitative RT‑PCR revealed that DSW enhanced LDL receptor (LDLR) mRNA expression in a hardness‑dependent manner. Combined, the results of the present study indicated that DSW may reduce HCD‑induced increases in blood and liver lipid levels, indicating that DSW may protect against hypercholesterolemia and non‑alcoholic hepatic steatosis. In addition, the present study demonstrated that DSW‑induced downregulation of lipids in the blood and hepatic lipid accumulation was mediated by enhancement of LDLR expression and suppression of fatty acid synthase and SREBP‑1c.

Current evidence on the health-beneficial effects of berry fruits in the prevention and treatment of metabolic syndrome

PURPOSE OF REVIEW

Berries belong to the best dietary sources of bioactive compounds, which exert a synergistic and cumulative effect on promotion of human health and prevention of diseases. The present review presents the most recent findings of animal and human studies regarding the health benefits of berries in terms of prevention and treatment of obesity, hypertension, type 2 diabetes, dyslipidemia, and nonalcoholic fatty liver disease.

RECENT FINDINGS

In the last years, there was a growing number of evidence from human epidemiological and interventional studies, which emphasized the role of berries in the management of metabolic diseases. Based on the results from recent clinical trials, it can be established that a berry diet rich in antioxidants and bioactive phytochemicals has beneficial effects on hepatic function, increase of insulin sensitivity and high-density lipoprotein-cholesterol, decrease of serum glucose and low-density lipoprotein-cholesterol, and finally is inversely associated with the incidence of type 2 diabetes.

SUMMARY

Numerous recent studies have shown that berries provide great benefits in preventing or mitigating metabolic disorders. The results of this review indicate that regular long-term consumption of different berries could potentially delay the progression of metabolic syndrome and comorbidities.