Effect of pomegranate extract on blood pressure and anthropometry in adults: a double-blind placebo-controlled randomised clinical trial

Effects of Hyperbaric (Non-Thermal) Sanitization and the Method of Extracting Pomegranate Juice on Its Antioxidant and Antihypertensive Properties

Pomegranate (Punica granatum L.) is considered a functional food due to its polyphenol content that benefits the body. The type of processing the fruit undergoes is important, as this also influences the concentrations of these compounds. The pomegranate juice was extracted by two methods: manual extraction using a manual juicer through heat treatment in a water bath (Man-P), and extraction through mechanical pressing using Good Nature X-1 equipment and hyperbaric sanitization (Mech-Hyp). Bromatological analyses showed significant differences (p ≤ 0.05) between the two treatments. When subjected to hyperbaric sanitization, the juice showed higher concentrations of moisture, soluble solids, protein, and carbohydrates. In an antioxidant analysis, the ABTS radical showed no significant difference in the treatments, with 96.99% inhibition. For the DPPH radical, the sample with the highest inhibition was Man-P with 98.48%. The determination of phenols showed that there was a higher concentration in juice that underwent pasteurization (104.566 mg GAE/mL). However, the Mech-Hyp treatment exhibited a minor concentration of phenols with 85.70 mg GAE/mL. FTIR spectra revealed that the functional groups were mainly associated with carbohydrates. Regarding ACE inhibition, it was observed that the Man-P and Mech-Hyp juices showed greater inhibition of enzyme in hypertensive patients compared to normotensive patients. This activity can be attributed to the mechanisms of action of antioxidant compounds. Both extraction methods manual and mechanical pressing resulted in increased antioxidant and antihypertensive activity. The antioxidant compounds accompanied by adequate sanitation were decisive in an antimicrobial analysis, since no pathogenic microorganisms were observed in the juices.

Effects of Ellagic Acid on Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis

Background

Abnormal glucose and lipid metabolism (GALM) serve as both a cause and an inducer for the development of the disease. Improvement and treatment of GALM are an important stage to prevent the occurrence and development of the disease. However, current clinical treatment for GALM is limited. Ellagic acid (EA), a common polyphenol present in foods, has been shown to improve abnormalities in GALM observed in patients suffering from metabolic diseases.

Objective

This study used a meta-analysis method to systematically assess the effects of EA on GALM.

Method

As of November 8, 2023, a comprehensive search was conducted across 5 databases, namely, PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar to identify randomized controlled trials (RCTs) in which EA served as the primary intervention for diseases related to GALM. The risk of bias within the included studies was assessed according to the Cochrane Handbook. All statistical analyzes were performed using RevMan 5.4 software.

Results

In this study, a total of 482 articles were retrieved, resulting in the inclusion of 10 RCTs in the meta-analysis. The results showed that EA could reduce fasting blood glucose (FBG) (p = 0.008), increase insulin secretion (p = 0.01), improve insulin resistance index (HOMA-IR) (p = 0.003), decrease triglyceride (TG) (p = 0.004), and reduce cholesterol (Chol) (p = 0.04) and low-density lipoprotein (LDL-c) (p = 0.0004). EA had no significant effect on waist circumference (WC), body weight (BW), body mass index (BMI), 2 hours after prandial blood glucose (2 h-PG), total cholesterol (TC), and high-density lipoprotein (HDL-c).

Conclusions

The effect of improvement in glucose and lipids of EA was closely related to the dose and the intervention time. EA can improve GALM caused by diseases. To corroborate the findings of this study and improve the reliability of the results, EA is imperative to refine the research methodology and increase the sample size in future investigations.

Beneficial effects of swimming and pomegranate juice in rats with hypertension: A possible role of serum adropin

Hypertension, characterized by persistent and uncontrolled high blood pressure, is one of the most common significant causes of mortality worldwide. Lifestyle modifications such as exercise and antioxidant intake have showed beneficial effects on hypertensive conditions. Adropin and endothelin-1 (ET-1) have important vasoregulatory functions in the endothelium. However, the underlying mechanisms linking exercise- and/or antioxidant intake-mediated improvement of hypertension are not fully understood. In this study, it was hypothesized that swimming exercise and pomegranate juice (PJ) (as an antioxidant) administration might have protective effects on hypertension development and possible involvements of serum adropin and ET-1. To test the hypothesis, the rats with hypertension, induced by Nω-nitro-L-arginine methyl ester hydrochloride, were subjected to swimming exercise and received PJ for 8 weeks. Weekly systolic and diastolic pressures, serum concentrations of adropin and ET-1, and oxidant/antioxidant parameters in various tissues were measured. The obtained data show that swimming exercise leads to complete protection against hypertension within the 8-week duration, whereas the PJ administration causes an ameliorative effect. In addition, the combination of swimming exercise and PJ administration do not have additive effects in protection against hypertension. Notably, the 8-week swimming exercise restores the diminished serum adropin concentration in rats with hypertension to the control level. Serum adropin significantly correlated with systolic and diastolic pressures, depending on swimming exercise, but not PJ administration. Serum ET-1 concentration inconsistently fluctuates in response to Nω-nitro-L-arginine methyl ester hydrochloride, swimming exercise, and PJ intake. In addition, swimming exercise and/or PJ administration lead to a complete normalization in liver malondialdehyde concentrations of rats with hypertension, whereas these interventions cause slight or no improvements in superoxide dismutase, catalase, and glutathione in the heart, liver, and kidney. In conclusion, 8-week swimming exercise modulates hypertension, possibly by influencing adropin concentration and oxidative stress.

The effects of pomegranate consumption on blood pressure in adults: A systematic review and meta-analysis

Considering the main component of cardiovascular disease and due to the high prevalence of hypertension, controlling blood pressure is required in individuals with various health conditions. Randomized clinical trials (RCTs) which studied the effects of pomegranate consumption on blood pressure have shown inconsistent findings. As a result, we intended to assess the effects of pomegranate consumption on systolic (SBP) and diastolic (DBP) blood pressure in adults. Systematic literature searches up to January 2024 were carried out using electronic databases, including PubMed, Web of Science, and Scopus, to identify eligible RCTs assessing the effects of pomegranate on blood pressure as an outcome. All the individuals who took part in our research were adults who consumed pomegranate in different forms as part of the study intervention. Heterogeneity tests of the selected trials were performed using the I2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference (WMD) with a 95% confidence interval (CI). Of 2315 records, 22 eligible RCTs were included in the current study. Our meta-analysis of the pooled findings showed that pomegranate consumption significantly reduced SBP (WMD: -7.87 mmHg; 95% CI: -10.34 to -5.39; p < 0.001) and DBP (WMD: -3.23 mmHg; 95% CI: -5.37 to -1.09; p = 0.003). Individuals with baseline SBP > 130 mmHg had a significantly greater reduction in SBP compared to individuals with baseline SBP < 130 mmHg. Also, there was a high level of heterogeneity among studies (SBP: I2 = 90.0% and DBP: I2 = 91.8%). Overall, the results demonstrated that pomegranate consumption lowered SBP and DBP in adults. Although our results suggest that pomegranate juice may be effective in reducing blood pressure in the pooled data, further high-quality studies are needed to demonstrate the clinical efficacy of pomegranate consumption.

The effects of pomegranate consumption on obesity indices in adults: A systematic review and meta-analysis

Evidence supports the potential application of polyphenols as agents against obesity. Pomegranate is one of the fruits that possess a high content of polyphenols. This systematic review and meta-analysis of randomized controlled trials (RCTs) sought to evaluate the effects of pomegranate consumption on obesity indices, including body mass index (BMI), body weight, waist circumference (WC), fat mass (FM), body fat percentage (BFP), and fat-free mass (FFM) in adults. Relevant RCTs were obtained by searching databases, including PubMed, SCOPUS, and Web of Science, up to May 2023. Heterogeneity tests of the included trials were performed using the I 2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference with a 95% confidence interval. Pooled analysis of 28 trials revealed that pomegranate consumption led to a significant reduction in body weight (WMD: -1.97, 95% CI: -2.91, -1.03, p < .05), and a significant decrease in BMI (WMD: -0.48, 95% CI: -0.76, -0.20, p < .05) in comparison with the control group. However, there were no significant effects on WC, FM, FFM, and BFP in comparison with the control group. Pomegranate consumption may yield a beneficial effect on body weight and BMI in adults. However, there were no significant effects on WC, FM, FFM, and BFP, by pomegranate consumption. Also, pomegranate consumption can reduce body weight, BMI, WC, and BFP in obese adults. Long-term trials with different doses of pomegranate are needed.

Prospective Randomized, Double-Blind, Placebo-Controlled Study of a Standardized Oral Pomegranate Extract on the Gut Microbiome and Short-Chain Fatty Acids

Punica granatum L., commonly known as the pomegranate, is an abundant source of polyphenols, including hydrolyzable ellagitannins, ellagic acid, anthocyanins, and other bioactive phytochemicals shown to be effective in defending against oxidative stress, and has immunomodulatory activities. Ellagitannins, and their hydrolyzed product ellagic acid, interact with the gut microbiota to yield secondary metabolites known as urolithins that may have health benefits. The objective of this study was to determine the effects of supplementation with a standardized punicalagin-enriched pomegranate extract, Pomella® (250 mg), on the gut microbiome, circulating short-chain fatty acids, and gut microbial-derived ellagitannin metabolite urolithins. A randomized, double-blind, placebo-controlled study was conducted over 4 weeks on healthy volunteers aged 25-55 years. Subjects were randomly assigned to receive either an oral supplement containing 75 mg of punicalagin or an oral placebo. Stool sample collection and venipuncture were performed to analyze the gut microbiome, SCFAs, and urolithin. There was no significant change in the gut microbial diversity in both cohorts after 4 weeks of intervention, but there was a significantly increased relative abundance of Coprococcus eutectus, Roseburia faecis, Roseburia inullnivorans, Ruminococcus bicirculans, Ruminococcus calidus, and Faecalibacterium prausnitzii. Pomegranate extract (PE) supplementation led to the augmentation of circulating propionate levels (p = 0.02) and an increasing trend for acetate levels (p = 0.12). The pomegranate extract (PE) supplementation group had an increased level of circulating urolithins compared to the placebo group (6.6% vs. 1.1%, p = 0.13). PE supplementation correlated with shifts in the gut microbiome and with higher circulating levels of propionate and acetate. Further studies should explore the implications in larger cohorts and over a longer duration.

Pomegranate Extract Administration Reverses Loss of Motor Coordination and Prevents Oxidative Stress in Cerebellum of Aging Mice

The cerebellum is responsible for complex motor functions, like maintaining balance and stance, coordination of voluntary movements, motor learning, and cognitive tasks. During aging, most of these functions deteriorate, which results in falls and accidents. The aim of this work was to elucidate the effect of a standardized pomegranate extract during four months of supplementation in elderly mice to prevent frailty and improve the oxidative state. Male C57Bl/6J eighteen-month-old mice were evaluated for frailty using the "Valencia Score" at pre-supplementation and post-supplementation periods. We analyzed lipid peroxidation in the cerebellum and brain cortex and the glutathione redox status in peripheral blood. In addition, a set of aging-related genes in cerebellum and apoptosis biomarkers was measured via real-time polymerase chain reaction (RT-PCR). Our results showed that pomegranate extract supplementation improved the motor skills of C57Bl/6J aged mice in motor coordination, neuromuscular function, and monthly weight loss, but no changes in grip strength and endurance were found. Furthermore, pomegranate extract reversed the increase in malondialdehyde due to aging in the cerebellum and increased the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio in the blood. Finally, aging and apoptosis biomarkers improved in aged mice supplemented with pomegranate extract in the cerebellum but not in the cerebral cortex.

The effect of pomegranate consumption on cardiovascular risk factors in hemodialysis patients: A systematic review of clinical trials

Patients undergoing maintenance dialysis have a significantly higher incidence of cardiovascular disease (CVD) compared with the general population. CVD is the most common cause of morbidity and mortality among hemodialysis patients, and has been attributed, among other causes, to increased oxidative stress, inflammation, hypertension and dyslipidemia. Pomegranate, a popular fruit worldwide, has demonstrated health benefits such as antioxidative, antidiabetic, antihypertensive, antihyperlipidemic and anti-inflammatory effects. In this systematic review of clinical trials, we aim to summarize the effect of different parts of pomegranate and the effects of its use on CVD risk factors in hemodialysis patients. PubMed/MEDLINE, EMBASE, Scopus, and Web of Science were searched to identify eligible clinical trials up to December 2021. Ultimately, seven clinical trials were included in this study. Different parts of pomegranate used in these trials were pomegranate juice, pomegranate extract and pomegranate peel extract. The duration of the studies varied from one dialysis session to 1 year. Our results showed that different parts of pomegranate may have anti-hypertensive, antioxidant, anti-inflammatory effects and improve lipid profile by decreasing TG (triglycerides) and increasing HDL-C (high-density lipoprotein cholesterol) in hemodialysis patients. However, due to limited number of studies, more clinical trials need to be performed.

The effects of pomegranate consumption on inflammatory and oxidative stress biomarkers in adults: a systematic review and meta-analysis

BACKGROUND

Several studies have shown the effects of pomegranate on oxidative stress and inflammation biomarkers, while some studies showed no effects of pomegranate on these biomarkers. Therefore, we aimed to evaluate the effects of pomegranate consumption on C-reactive protein (CRP), interlukin-6 (IL-6), tumor necrosis factor α (TNF-α), total antioxidant capacity (TAC), and malondialdehyde (MDA) in adults.

METHODS

A systematic literature search was performed using databases, including PubMed, Web of Science, and Scopus, up to May 2023 to identify eligible randomized controlled trials (RCTs). Heterogeneity tests of the included trials were performed using the I2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference with a 95% confidence interval.

RESULTS

Of 3811 records, 33 eligible RCTs were included in the current study. Our meta-analysis of the pooled findings showed that pomegranate consumption significantly reduced CRP (WMD: -0.50 mg/l; 95% CI -0.79 to -0.20; p = 0.001), IL-6 (WMD: -1.24 ng/L 95% CI -1.95 to -0.54; p = 0.001), TNF-α (WMD: -1.96 pg/ml 95%CI -2.75 to -1.18; p < 0.001), and MDA (WMD: -0.34 nmol/ml 95%CI -0.42 to -0.25; p < 0.001). Pooled analysis of 13 trials revealed that pomegranate consumption led to a significant increase in TAC (WMD: 0.26 mmol/L 95%CI 0.03 to 0.49; p = 0.025).

CONCLUSION

Overall, the results demonstrated that pomegranate consumption has beneficial effects on oxidative stress and inflammatory biomarkers in adults. Therefore, pomegranate can be consumed as an effective dietary approach to attenuate oxidative stress and inflammation in patients with cardiovascular diseases.

PROSPERO REGISTRATION CODE

CRD42023406684.

The effects of pomegranate peel added bread on anthropometric measurements, metabolic and oxidative parameters in individuals with type 2 diabetes: a double-blind, randomized, placebo-controlled study

BACKGROUND/OBJECTIVES

The aim of this study was to evaluate the sensory properties of antioxidant-rich bread made by adding pomegranate peels and their effects on anthropometric measurements and metabolic and oxidative parameters of individuals with type 2 diabetes after consumption.

SUBJECTS/METHODS

This randomized, double-blind, placebo-controlled study was conducted with 22 individuals aged between 19 and 64 years who had been diagnosed with type 2 diabetes for at least 5 years, used only metformin, did not lose more than 10% of their body weight in the last 6 months, and had a body mass index of ≥ 25.0 kg/m². While the study group (n = 11) consumed bread containing 500 mg pomegranate peel daily for 8 wk, the control group (n = 11) consumed standard bread. Anthropometric measurements and metabolic and oxidative parameters of individuals were evaluated at the beginning and end of the study.

RESULTS

Decreases were detected in the waist circumference, waist/hip and waist/height ratios, body fat percentages, blood pressure, and serum insulin, triglyceride, and total cholesterol levels in the individuals in the treatment group, compared with those in the control group (P < 0.05).

CONCLUSIONS

Pomegranate peel consumption by individuals with type 2 diabetes may have positive effects on anthropometric measurements and glycemic and lipid parameters.

Exploring the Potential of Pomegranate Peel Extract as a Natural Food Additive: A Review

PURPOSE OF THE REVIEW

Pomegranate is one of the super fruit and a storehouse of several antioxidants and health-promoting compounds which can act as a natural food additive. The pomegranate processing industry generates huge quantities of by-products, particularly peels (50% of fresh fruit weight), that cause environmental pollution due to improper disposal. In this perspective, the present review article focuses on the chemical composition of pomegranate peel and its application as a natural food additive in different food products such as bakery, dairy, meat/meat products, fish/fish products, edible oils, and packaging materials.

RECENT FINDINGS

There is a continuous demand for processed foods exhibiting natural food additives over foods containing synthetic additives/colorants, which can cause serious health implications such as cancer with regular consumption. The food industry is looking for an alternative to synthetic/artificial food additives. To overcome these problems, pomegranate peel or its extract can be used as a natural biopreservative in food products that are prone to fat oxidation and microbial growth. Pomegranate peel contains bioactive compounds, especially tannins, phenolic acids, and flavonoids, which have nutraceutical value and possess higher antioxidant activity and antimicrobial properties. Due to these properties, pomegranate peel prevents lipid oxidation in fatty foods and can also retard the microbial growth.

A standardized pomegranate fruit extract ameliorates thioacetamide-induced liver fibrosis in rats via AGE-RAGE-ROS signaling

This work aimed to investigate a possible mechanism that may mediate the hepatoprotective effects of pomegranate fruit extract (PFE) against thioacetamide (THIO)-induced liver fibrosis in rats. Male Sprague Dawley rats were randomly allocated into four groups (n = 8 each): control; PFE (150 mg/kg/day, orally); THIO (200 mg/kg, i.p, 3 times a week); and THIO and PFE-treated groups. Oral PFE treatment decreased liver/body weight ratio by 12.4%, diminished serum function levels of ALT, AST, ALP, LDH, and total bilirubin, increased serum albumin, boosted hepatic GSH (by 35.6%) and SOD (by 17.5%), and significantly reduced hepatic levels of ROS, MDA, 4-HNE, AGEs, and RAGE in THIO-fibrotic rats relative to untreated THIO group. Moreover, PFE administration downregulated the hepatic levels of profibrotic TGF-β1 (by 23.0%, P < 0.001) and TIMP-1 (by 41.5%, P < 0.001), attenuated α-SMA protein expression, decreased serum HA levels (by 41.3%), and reduced the hepatic levels of the fibrosis markers hydroxyproline (by 26.0%, P < 0.001), collagen type IV (by 44.3%, P < 0.001) and laminin (by 43.4%, P < 0.001) compared to the untreated THIO group. The histopathological examination has corroborated these findings, where PFE decreased hepatic nodule incidence, attenuated portal necroinflammation and reduced extent of fibrosis. These findings may suggest that oral PFE administration could slow the progression of hepatic fibrogenesis via reducing hepatic levels of AGEs, RAGE, ROS, TGF-β1, and TIMP-1.

Common pregnancy complications and polyphenols intake: an overview

During pregnancy, the body undergoes a great amount of changes in order to support a healthy developing fetus. In this context, maternal dietary supplementation is widely encouraged to provide adequate nutrition for the newborn. In the past few years, studies have emerged highlighting the benefits of polyphenols intake during pregnancy. Indeed, despite differences among reports, such as experimental model, polyphenol employed, dosage and regimen of administration, there is no doubt that the ingestion of these molecules has a protective effect in relation to three pregnancy-associated diseases or conditions: preeclampsia, gestational diabetes and fetal growth restriction. In this review, we describe the effects of different polyphenols and polyphenol-rich extracts or juices on the main outcomes of these common pregnancy-associated complications, obtained in human, animal and in vitro studies. Therefore, this work provides a critical analysis of the literature, and a summary of evidences, from which future research using polyphenols can be designed and evaluated.

Antioxidant Properties and Beneficial Cardiovascular Effects of a Natural Extract of Pomegranate in Healthy Volunteers: A Randomized Preliminary Single-Blind Controlled Study

Pomegranates are known to possess anti-hypertensive, anti-atherogenic and cardioprotective effects mainly due to their pleiotropic effects on various cellular pathways, especially those triggered by oxidative stress. The aim of this study was to investigate the effect of natural standardized pomegranate (PE) extract on cardiovascular risk factors in 24 healthy volunteers who participated in a randomized, single-blind placebo-controlled study. There were 12 subjects in the PE group and 12 in the placebo group. Variables were measured at baseline and after 14 and 28 days of supplementation are anthropometry, BP, pulse wave velocity, fat and lean body mass, salivary and urinary cortisol, and cortisone, total phenolics, antioxidant capacity and lipid peroxidation. Urinary total phenolics excretion and antioxidant capacity were significantly increased after 14 and 28 days of PE intake. At day 28, there were also statistically significant decreases in systolic and diastolic blood pressure (BP), pulse wave velocity, body fat and fat mass, as well as an increase in lean body mass. Significant changes in the placebo group were not found. Glucocorticoid levels showed a significant decrease in saliva cortisol at day 28 (morning) in the PE group, and cortisol/cortisone ratio was significantly decreased following 28 days of PE intake at morning, noon, and evening. Urine free cortisol was significantly reduced at day 14. These findings suggest that pomegranate extract intake may improve antioxidant and oxidative stress status and play a beneficial role in the attenuation of some cardiovascular risk factors. Future studies should concentrate on overweight and older people.

Pomegranate Peel as a Source of Bioactive Compounds: A Mini Review on Their Physiological Functions

The production and consumption of pomegranates have always been increasing owing to their taste and nutrition. However, during fruit processing, a large number of by-products are produced, such as peels and seeds, which can lead to environmental pollution problems if not handled properly. The pomegranate peel takes up about 26-30% of the total weight, while it contains abundant bioactive substances. This paper carries out a mini review of the characterization and physiological functions of key bioactive compounds in pomegranate peel, comprehensively assessing their effects on human health. The overview summarizes the main phenolic substances in pomegranate peel, including tannins, flavonoids, and phenolic acids. Dietary fiber and other bioactive substances such as alkaloids, minerals, and vitamins are also mentioned. These components act as antioxidants by improving oxidative biomarkers and scavenging or neutralizing reactive oxygen species, further contributing to their extensive functions like anti-inflammatory, anti-cancer, antibacterial, and cardiovascular protection. Overall, it is envisaged that through the deeper understanding of bioactive compounds in pomegranate peel, the waste sources can be better reused for physiological applications.

Pomegranate (Punica granatum L.) and Metabolic Syndrome Risk Factors and Outcomes: A Systematic Review of Clinical Studies

Pomegranate (Punica granatum L.) can be considered a multipurpose medicinal and dietary plant due to its anti-inflammatory and antioxidant actions. Pomegranate can be used to prevent or treat metabolic syndrome (MetS) risk factors. Although previously published reviews addressed the effects of pomegranate on different diseases, there is no systematic review that exclusively focuses on clinical trials related to all MetS-related risk factors. In view of this limitation, the objective of this up-to-date, comprehensive, and systematic review is to critically evaluate the potential of pomegranate (P. granatum) on various MetS risk factors on the basis of clinical studies. PubMed, EMBASE, MEDLINE, Google Scholar, COCHRANE, and Clinical Trials.gov databases were searched on 15 October 2021. The Preferred Reporting Items for a Systematic Review and Meta-Analysis guidelines were followed, and the bias risk evaluation was performed according to the Cochrane Handbook for Systematic Reviews of Interventions. We identified 5683 studies in the databases. After removing the duplicates, 3418 studies remained. Of these, 147 studies met the eligibility criteria, and finally, only 20 were included in the qualitative analysis. The included studies suggest that pomegranate can be beneficial to reduce body weight, blood pressure, glycemia, triglycerides, total cholesterol, and low-density lipoprotein cholesterol. Moreover, it can augment high-density lipoprotein cholesterol levels and improve insulin resistance. Although relevant effects were observed, additional well-designed clinical trials are needed to determine the correct formulations and doses to be used to prevent or treat MetS components.

Therapeutic Potential of Pomegranate in Metabolic Disorders

Metabolic syndrome and associated disorders have become one of the major challenging health problems over the last decades. Considerable attention has been paid to natural products and herbal medicines for the management of metabolic disorders in recent years. Many studies have investigated the therapeutic effects of different parts (arils, peels, seeds, and flowers) of pomegranate (Punica granatum L.) for the prevention and treatment of this syndrome. This study aims to provide an updated review on the in vitro and in vivo studies as well as clinical trials investigating the effects of pomegranate and its active compounds on different components of metabolic problems such as hyperglycemia, hyperlipidemia, hypertension, as well as obesity over the last two decades. Besides, the key mechanisms by which pomegranate affects these pathogenic conditions are also discussed. The studies show that although pomegranate has promising beneficial effects on diabetes, hypertension, hyperlipidemia, and obesity in various cellular, animal, and clinical models of studies, there are some conflicting results, particularly for hyperglycemic conditions. The main mechanisms include influencing oxidative stress and anti-inflammatory responses. Overall, pomegranate seems to have positive effects on the pathogenic conditions of metabolic syndrome according to the reviewed studies. Although pomegranate is not suggested as the first line of therapy or monotherapy, it could be only used as an adjunctive therapy. Nevertheless, further large and long-term clinical studies are still required.

The effects and mechanisms of pomegranate in the prevention and treatment of metabolic syndrome

Metabolic syndrome, such as obesity, diabetes and cardiovascular disease, is becoming epidemic both in developing and developed countries in recent years. Vegetable and fruit consumptions have been associated with the prevention of metabolic syndrome. Pomegranate is a widely consumed fruit in Middle East and Asia. Currently, accumulating data showed that pomegranate exhibits antioxidant, anti-inflammatory, hypolipidemic and hypoglycemic activities in experimental and clinical studies. The beneficial effects of pomegranate may come from its rich polyphenols and be mediated by increasing the activity of AMPK, upregulating GLUT4, activating PPAR[Formula: see text]- ABCA1/CYP7A1 pathways and improving mitochondrial function. This review provides a systematical presentation of findings on the beneficial effects as well as the possible mechanisms of pomegranate and its major components on prevention and treatment of metabolic syndrome.

Plant Phenolics and Extracts in Animal Models of Preeclampsia and Clinical Trials-Review of Perspectives for Novel Therapies

The current health requirements set the direction in pharmacological research, especially as regards diseases that require improvement of existing therapeutic regimens. Such diseases include preeclampsia, which is a hypertensive disorder of pregnancy during which there occurs progressive increasing activation of the immune system through elevation of pro-inflammatory cytokines and antiangiogenic factors, which is dangerous for the mother and fetus. A promising field of research for new drugs to treat this disease is the study of natural phenolic compounds of plant origin and herbal extracts, which are complex matrices of chemical compounds with broad biological activities. Many plant substances with anti‑inflammatory and anti‑hypertensive properties are known, but studies in animal models of preeclampsia and clinical trials concerning this disease constitute a new and developing research trend of significant medical importance. The aim of our research review was to identify and analyze the results of already available studies on baicalin, curcumin, epigallocatechin gallate, punicalagin, quercetin, resveratrol, salvianolic acid A (danshensu), silibinin, and vitexin, as well as plant extracts from Brassica oleracea L., Euterpe oleracea Mart., Moringa oleifera Lam., Punica granatum L., Silybum marianum (L.) Gaertner, Thymus schimperi Ronniger, Uncaria rhynchophylla (Miq.) Miq. ex Havil., and Vitis vinifera L., which are potential and promising candidates for further research and for potential new therapies.

Antioxidant Food Components for the Prevention and Treatment of Cardiovascular Diseases: Effects, Mechanisms, and Clinical Studies

Cardiovascular diseases (CVDs) have gained increasing attention because of their high prevalence and mortality worldwide. Epidemiological studies revealed that intake of fruits, vegetables, nuts, and cereals could reduce the risk of CVDs, and their antioxidants are considered as the main contributors. Moreover, experimental studies showed that some antioxidant natural products and their bioactive compounds exerted beneficial effects on the cardiovascular system, such as polyphenols, polysaccharides, anthocyanins, epigallocatechin gallate, quercetin, rutin, and puerarin. The mechanisms of action mainly included reducing blood pressure, improving lipid profile, ameliorating oxidative stress, mitigating inflammation, and regulating gut microbiota. Furthermore, clinical trials confirmed the cardiovascular-protective effect of some antioxidant natural products, such as soursop, beetroot, garlic, almond, and green tea. In this review, we summarized the effects of some antioxidant natural products and their bioactive compounds on CVDs based on the epidemiological, experimental, and clinical studies, with special attention paid to the relevant mechanisms and clinical trials.

Effects of flavonoid-rich fruits on hypertension in adults: a systematic review

OBJECTIVE

The objective of this systematic review was to synthesize the best available research evidence on the effectiveness of flavonoid-rich fruits in the treatment of hypertension.

INTRODUCTION

Hypertension is a serious public health concern as it contributes to a significant burden of disease, leading to millions of deaths globally. Complementary therapies including flavonoids have generated interest in assisting the treatment of hypertension. Flavonoids are a type of polyphenol abundant in fruits and a growing body of evidence suggests antihypertensive effects of the flavonoids due to their antioxidant properties. To date, no systematic review has been performed to collate the evidence on the effects of flavonoid-rich fruits on hypertension in adults.

INCLUSION CRITERIA

This systematic review included randomized controlled trials (RCTs) that compared the administration of any type of flavonoid-rich fruit or equivalent supplement with a placebo or other intervention in adults with hypertension. Trials that measured blood pressure using objective outcome measures such as a manual mercury sphygmomanometer were included. Studies that did not specify the flavonoid component of the fruit or fruit supplement were excluded from the review. Secondary outcomes, including change in weight, blood glucose level, triglycerides and total blood cholesterol levels, were also assessed.

METHODS

A three-step search was undertaken, including a comprehensive search of the MEDLINE, Embase, Cochrane Trials (CENTRAL) and CINAHL databases, in September 2018. We also searched Dissertation Abstracts International, ProQuest Dissertations and Theses, MedNar and ClinicalTrials.gov to identify unpublished studies. The title and abstracts of the studies were reviewed by two independent reviewers against the inclusion/exclusion criteria. The methodological quality of the potential studies for inclusion were assessed using the critical appraisal checklist for randomized controlled trials as recommended by JBI. Data were pooled in a statistical meta-analysis model. Subgroup-analysis according to type of intervention and length of intervention period was performed. Where statistical pooling was not possible, the findings have been presented in a narrative form.

RESULTS

Fifteen randomized controlled trials involving 572 participants were included in the review. The subclasses of flavonoids assessed included: anthocyanins, naringin, narirutin and flavan-3-ols. The overall methodological quality of the trials was high. Six trials investigated the effect of the flavonoid intervention on blood pressure within four weeks. Meta-analysis of four of the trials demonstrated no effect of flavonoids on systolic or diastolic blood pressure when compared to placebo (systolic mean difference = -1.02, 95% confidence interval [CI] -3.12, 1.07; p = 0.34, I = 0%; diastolic mean difference = -0.90, 95% CI -2.10, 0.31; p = 0.15, I = 0%). Similarly, pooled results from two crossover RCTs with two-timed dosed interventions in a 24-hour period demonstrated no effect on a reduction in diastolic blood pressure (p = 0.38) but did reveal evidence of a reduction in systolic blood pressure (p = 0). Six trials assessed blood pressure following the flavonoid intervention at more than four weeks follow-up. Meta-analysis of five of the trials demonstrated evidence of no effect on either systolic blood pressure (mean difference = -0.95, 95%CI -3.58, 1.68; p = 0.478, I = 0%) or diastolic blood pressure (mean difference = 0.86, 95%CI -1.11, 2.82; p = 0.393, I = 0%).

CONCLUSIONS

The findings of this systematic review should be interpreted with caution, given that the results are obtained from single-center trials with small sample sizes. Flavonoids have no effect on systolic and diastolic blood pressure. Further robust RCTs using sample sizes based on power calculations are needed to provide evidence for the use of flavonoid-rich fruits for the management of hypertension.

The effect of synbiotics pomegranate juice on cardiovascular risk factors in PCOS patients: a randomized, triple-blinded, controlled trial

PURPOSE

Polycystic ovarian syndrome (PCOS) is one of the most common metabolic and endocrine disorders. Functional foods like pomegranate and probiotics are those that are considered to have beneficial effects on metabolic diseases beyond their basic nutritional value. So, we aimed to evaluate the effect of synbiotic pomegranate juice (SPJ) on cardiovascular risk factors on PCOS patients.

METHODS

This was a randomized, triple-blinded, 8-week trial. Participants were randomly assigned to receive 300 mL/day of pomegranate juice (PJ), synbiotic beverage (SB), synbiotic pomegranate juice (SPJ), or placebo beverage (PB). Biochemical indices (lipid profile, Total Antioxidant Capacity (TAC), Malondialdehyde (MDA), high sensitive C-Reactive Protein (hs-CRP)) and blood pressure were assessed before and after the intervention.

RESULTS

Participants in the PJ, SB, and SPJ groups experienced improvement in their lipid profile, oxidative stress, inflammation, and blood pressure during the time. Compared to placebo, Total Cholesterol (TC) was lower in the SB group (P < 0.01), LDL-c was lower in the SPJ and SB groups (P < 0.01), and HDL-c was higher in the SPJ and PJ groups (P < 0.01). With regards to oxidative stress and inflammation, when compared with placebo, MDA was lower in the SPJ, SB, and PJ groups (P < 0.001), TAC was increased in the SPJ and PJ groups (P[Formula: see text] 0.001), and hs-CRP was decreased in the PJ group (P = 0.02). Blood pressure (BP) was lower in the SPJ and PJ groups compared to placebo (P < 0.001; P < 0.01, respectively).

CONCLUSIONS

Consuming daily SPJ for 8 weeks improved metabolic, oxidative, inflammatory, and BP outcomes in females with PCOS. This trial was registered in the Iranian Registry of Clinical Trials (IRCT20170207032439N2).

Pomegranate juice improves cardiometabolic risk factors, biomarkers of oxidative stress and inflammation in hemodialysis patients: a randomized crossover trial

BACKGROUND

Pomegranate has antioxidant, cardioprotective and anti-inflammatory properties. We designed a crossover study aimed at determining if consumption of pomegranate juice (PJ) improves lipid profile and oxidative and inflammatory biomarkers of hemodialysis patients. Forty-one hemodialysis patients were randomly assigned to one of two groups: PJ-treated group receiving 100 mL of natural PJ immediately after their dialysis session three times a week and the control group receiving the usual care. After 8 weeks, a 4-week washout period was established and then the role of the groups was exchanged. Lipid profile, blood pressure and oxidative and inflammatory biomarkers were measured before and after each sequence.

RESULTS

Based on the results of intention-to-treat analysis, triglycerides were decreased in PJ condition and increased in the controls. Conversely, high-density lipoprotein cholesterol was increased in PJ and decreased in the control group. Total and low-density lipoprotein cholesterol did not significantly change in either condition. Systolic and diastolic blood pressure significantly decreased in PJ condition. Total antioxidant capacity increased in PJ condition (P < 0.001) and decreased in the controls (P < 0.001). Conversely, malondialdehyde and interleukin-6 decreased in PJ (P < 0.001) and increased in the control group (P ≤ 0.001). The changes of these biomarkers were significantly different between the two conditions.

CONCLUSIONS

Eight-week PJ consumption showed beneficial effects on blood pressure, serum triglycerides, high-density lipoprotein cholesterol, oxidative stress and inflammation in hemodialysis patients. © 2019 Society of Chemical Industry.

Short-term Effect of Fresh Pomegranate Juice on Serum Cortisol and Thyroxine in Patients with type 2 Diabetes

BACKGROUND

The effect of pomegranate juice on type 2 diabetic conditions has been determined in various occasions. However, such an effect on cortisol and thyroxine hormones, which are major controllers of energy metabolism, is not yet revealed.

OBJECTIVES

In this study, we intended to measure the short-term effect of fresh pomegranate juice on serum cortisol and thyroxine in patients with type 2 diabetes.

MATERIALS AND METHODS

This study was a randomized clinical trial in which 89 fasted patients with type 2 diabetes were supplemented with fresh pomegranate juice at a dose of 1.5 mL kg-1. Blood specimens were then collected before and at 1 and 3 hours after juice administration. Serum cortisol and thyroxine were assessed using commercial chemiluminescent-immunoassay kits.

RESULTS

Serum cortisol, but not thyroxine, was significantly (P < 0.0001) lower in patients with type 2 diabetes after ingesting fresh pomegranate juice. In addition, no significant correlation (r2 = 0.00003, P = 0.9569) was observed between cortisol response to fresh pomegranate juice and the level of fasting serum glucose in the recruited patients. Moreover, no significant difference (P = 0.9118) in cortisol response to fresh pomegranate juice was found between recruited males and females.

CONCLUSIONS

In conclusion, fresh pomegranate juice decreased serum cortisol, 1 hour after juice ingestion, but not serum thyroxine 3 hours after juice ingestion, in patients with type 2 diabetes. In addition, cortisol response to fresh pomegranate juice was found not to be affected by patients' gender and the level of fasting serum glucose.

Does pomegranate consumption affect weight and body composition? A systematic review and meta-analysis of randomized controlled clinical trials

Pomegranate is rich in tannins, polyphenols, flavonoids, and several other types of antioxidant compounds whose role in weight loss has been shown in previous studies. However, the results have been mixed regarding the effects of pomegranate consumption on weight loss. Electronic databases such as PubMed, Scopus, ISI Web of Science, and Google Scholar were systematically searched up to May 2018 for controlled clinical trials assessing the effect of pomegranate consumption on weight loss. A random effects model was used to calculate the weighted mean difference (WMD) and 95% confidence interval (CI) as the difference between the mean for the intervention and control groups. Thirteen randomized controlled trials (including 513 participants) were included in the present meta-analysis. Compared with the control groups, there was no significant reduction in bodyweight, body mass index, waist circumference, and body fat percentage after pomegranate consumption (WMD = -0.23 kg, 95% CI: -0.94, 0.47, P = 0.515; WMD = -0.12 kg/m² , 95% CI: -0.29, 0.03, P = 0.132; WMD = -0.08 cm, 95% CI: -0.33, 0.17, P = 0.534; WMD = -0.05, 95% CI: -1.66, 1.55, P = 0.947, respectively). According to the results of the present systematic review and meta-analysis, there was no significant effect of pomegranate consumption on weight and body composition indices.

Supplementation with Hydroxytyrosol and Punicalagin Improves Early Atherosclerosis Markers Involved in the Asymptomatic Phase of Atherosclerosis in the Adult Population: A Randomized, Placebo-Controlled, Crossover Trial

Hydroxytyrosol (HT) and Punicalagin (PC) exert cardioprotective and anti-atherosclerotic effects. This study evaluates the effect of oral supplementation with HT and PC (SAx) on early atherosclerosis markers in middle-aged, seemingly healthy adults. A randomized, double-blinded, placebo-controlled, crossover trial was performed for 20 weeks. There were two treatment sequences (Placebo/SAx, n = 41; SAx/Placebo, n = 43) for which the intervention periods (Placebo and SAx) were 8 weeks long, followed by a 4-week wash out period. The supplement was composed of 9.9 mg of HT and 195 mg of PC, and the placebo was composed of maltodextrin. SAx increased endothelial function (Flow-mediated dilatation [FMD]: 2.36%; p < 0.001) in the endothelial dysfunction subgroup compared to the placebo (2.36 ± 3.9 vs. 0.76 ± 3.5%, p < 0.05). SAx also reduced oxLDL by -28.74 ng/mL (p < 0.05) in subjects with higher levels of oxLDL, which was an improvement compared with the placebo (-28.74 ± 40.2 vs. 25.64 ± 93.8 ng/mL, p < 0.001). The prehypertension and hypertension subgroups exhibited decreased systolic (-15.75 ± 9.9 mmHg; p < 0.001) and diastolic (-6.36 ± 8.7 mmHg; p < 0.001) blood pressure after SAx consumption. Moreover, the systolic prehypertension and hypertension subgroups presented significant differences in systolic blood pressure compared to the placebo (-15.75 ± 9.9 vs. -2.67 ± 12.0 mmHg, p < 0.05). In conclusion, the supplement exerted anti-atherosclerotic effects by improving endothelial function, blood pressure, and levels of circulating oxLDL, especially for persons in whom these parameters were altered.

Enhancement of the gut barrier integrity by a microbial metabolite through the Nrf2 pathway

The importance of gut microbiota in human health and pathophysiology is undisputable. Despite the abundance of metagenomics data, the functional dynamics of gut microbiota in human health and disease remain elusive. Urolithin A (UroA), a major microbial metabolite derived from polyphenolics of berries and pomegranate fruits displays anti-inflammatory, anti-oxidative, and anti-ageing activities. Here, we show that UroA and its potent synthetic analogue (UAS03) significantly enhance gut barrier function and inhibit unwarranted inflammation. We demonstrate that UroA and UAS03 exert their barrier functions through activation of aryl hydrocarbon receptor (AhR)- nuclear factor erythroid 2–related factor 2 (Nrf2)-dependent pathways to upregulate epithelial tight junction proteins. Importantly, treatment with these compounds attenuated colitis in pre-clinical models by remedying barrier dysfunction in addition to anti-inflammatory activities. Cumulatively, the results highlight how microbial metabolites provide two-pronged beneficial activities at gut epithelium by enhancing barrier functions and reducing inflammation to protect from colonic diseases.

Urolithins are microbial metabolites derived from food polyphenols. Here, Singh et al. show that urolithin A and a synthetic analogue enhance gut barrier function via Nrf2-dependent pathways and mitigate inflammation and colitis in mice, highlighting a potential application for inflammatory bowel diseases.