Pomegranate (Punicagranatum) juice decreases lipid peroxidation, but has no effect on plasma advanced glycated end-products in adults with type 2 diabetes: a randomized double-blind clinical trial

The power of Punica granatum: A natural remedy for oxidative stress and inflammation; a narrative review

ETHNOPHARMACOLOGICAL RELEVANCE

Pomegranate 'Punica granatum' offers multiple health benefits, including managing hypertension, dyslipidemia, hyperglycemia, insulin resistance, and enhancing wound healing and infection resistance, thanks to its potent antioxidant and anti-inflammatory properties. It has been symbolized by life, health, femininity, fecundity, and spirituality.

AIM OF THE STUDY

Although laboratory and animal studies have been conducted on the healing effects of pomegranate, there needs to be a comprehensive review on its anti-oxidative and anti-inflammatory effects in chronic disorders. We aim to provide a comprehensive review of these effects based on in-vitro, in-vivo, and clinical studies conducted in managing various disorders.

MATERIALS AND METHODS

A comprehensive search of in-vitro, in-vivo, and clinical findings of pomegranate and its derivatives focusing on the highly qualified original studies and systematic reviews are carried out in valid international web databases, including Web of Science, PubMed, Scopus, and Cochrane Library.

RESULTS

Relevant studies have demonstrated that pomegranate and its derivatives can modulate the expression and activity of several genes, enzymes, and receptors through influencing oxidative stress and inflammation pathways. Different parts of pomegranate; roots, bark, blossoms, fruits, and leaves contain various bioactive compounds, such as polyphenols, flavonoids, anthocyanins, and ellagitannins, that have preventive and therapeutic effects against many disorders such as cardiovascular diseases, diabetes, neurological diseases, and cancers without any serious adverse effects.

CONCLUSIONS

Most recent scientific evidence indicates that all parts of the pomegranate can be helpful in treating a wide range of chronic disorders due to its anti-oxidative and anti-inflammatory activities. Since the safety of pomegranate fruit, juice, and extracts is established, further investigations can be designed by targeting its active antioxidant and anti-inflammatory constituents to discover new drugs.

Health effects of 100% fruit and vegetable juices: evidence from human subject intervention studies

The health effects of 100% fruit and vegetable juices (FVJ) represent a controversial topic. FVJ contain notable amounts of free sugars, but also vitamins, minerals, and secondary compounds with proven biological activities like (poly)phenols and carotenoids. The review aimed to shed light on the potential impact of 100% FVJ on human subject health, comprehensively assessing the role each type of juice may have in specific health outcomes for a particular target population, as reported in dietary interventions. The effects of a wide range of FVJ (orange, grapefruit, mandarin, lemon, apple, white, red, and Concord grapes, pomegranate, cranberry, chokeberry, blueberry, other minor berries, sweet and tart cherry, plum, tomato, carrot, beetroot, and watermelon, among others) were evaluated on a series of outcomes (anthropometric parameters, body composition, blood pressure and vascular function, lipid profile, glucose homeostasis, biomarkers of inflammation and oxidative stress, cognitive function, exercise performance, gut microbiota composition and bacterial infections), providing a thorough picture of the contribution of each FVJ to a health outcome. Some juices demonstrated their ability to exert potential preventive effects on some outcomes while others on other health outcomes, emphasising how the differential composition in bioactive compounds defines juice effects. Research gaps and future prospects were discussed. Although 100% FVJ appear to have beneficial effects on some cardiometabolic health outcomes, cognition and exercise performance, or neutral effects on anthropometric parameters and body composition, further efforts are needed to better understand the impact of 100% FVJ on human subject health.

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 glycemic indices in adults: A systematic review and meta-analysis

BACKGROUND AND AIM

Epidemiologic studies have shown that type 2 diabetes (T2D) is more prevalent worldwide; therefore, improving glycemic indices to prevent or control T2D is vital. Randomized controlled trials (RCTs) on the effects of pomegranate consumption on glycemic indices have shown inconsistent results. Therefore, we aim to evaluate the impact of pomegranate consumption on fasting blood glucose (FBG), fasting insulin, hemoglobin A1c (HbA1c), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in adults.

METHODS

A systematic literature search was performed using electronic databases, including PubMed, Web of Science, and Scopus, up to May 2023 to identify eligible RCTs evaluating the effect of pomegranate consumption on glycemic indices. 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 1999 records, 32 eligible RCTs were included in the current study. Our meta-analysis of the pooled findings showed that pomegranate consumption significantly reduced FBG (WMD: -2.22 mg/dL; 95 % CI: -3.95 to -0.50; p = 0.012), fasting insulin (WMD: -1.06 μU/ml; 95%CI: -1.79 to -0.33; p = 0.004), HbA1c (WMD: -0.22 %; 95% CI: -0.43 to -0.01; p = 0.037), and HOMA-IR (WMD: -0.30; 95%CI: -0.61 to -0.00; p = 0.046).

CONCLUSION

Overall, the results demonstrated that pomegranate consumption benefits glycemic indices in adults. However, further research with long-term interventions is required.

PROSPERO REGISTRATION CODE

CRD42023422780.

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 Impact of Punica granatum Linn and Its Derivatives on Oxidative Stress, Inflammation, and Endothelial Function in Diabetes Mellitus: Evidence from Preclinical and Clinical Studies

Diabetes mellitus is recognized as the leading contributor to cardiovascular disease and associated mortality rates worldwide. Despite the use of pharmaceutical drugs to treat diabetes, its prevalence continues to rise alarmingly. Therefore, exploring remedies with a lower toxicity profile is crucial while remaining safe and effective in addressing this global public health crisis. Punica granatum Linn (pomegranate), known for its properties and safety profile, has been investigated in applied research and preclinical and clinical trials. However, conflicting reports still exist regarding its effects in diabetes. According to our knowledge, no systematic review has been conducted to critically analyze evidence from preclinical and clinical trials simultaneously, explicitly focusing on oxidative stress, inflammation, and endothelial function in diabetes. Therefore, in this systematic review, we searched for evidence on the impact of pomegranate in diabetes using databases such as PubMed, Scopus, and Google Scholar. Our inclusion criteria were limited to studies published in English. Of the 170 retrieved studies, 46 were deemed relevant and underwent critical analysis. The analyzed evidence suggests that pomegranate has the potential to alleviate oxidative stress, inflammation, and endothelial dysfunction in diabetes. Although a beneficial impact was noted in these markers, the endothelial function evidence still requires validation through further clinical trials with a powered sample size.

An Overview of the Health Benefits, Extraction Methods and Improving the Properties of Pomegranate

Pomegranate (Punica granatum L.) is a polyphenol-rich edible food and medicinal plant of ancient origin, containing flavonols, anthocyanins, and tannins, with ellagitannins as the most abundant polyphenols. In the last decades, its consumption and scientific interest increased, due to its multiple beneficial effects. Pomegranate is a balausta fruit, a large berry surrounded by a thick colored peel composed of exocarp and mesocarp with edible arils inside, from which the pomegranate juice can be produced by pressing. Seeds are used to obtain the seed oil, rich in fatty acids. The non-edible part of the fruit, the peel, although generally disposed as a waste or transformed into compost or biogas, is also used to extract bioactive products. This review summarizes some recent preclinical and clinical studies on pomegranate, which highlight promising beneficial effects in several fields. Although further insight is needed on key aspects, including the limited oral bioavailability and the role of possible active metabolites, the ongoing development of suitable encapsulation and green extraction techniques enabling the valorization of waste pomegranate products point to the great potential of pomegranate and its bioactive constituents as dietary supplements or adjuvants in therapies of cardiovascular and non-cardiovascular diseases.

Effect of fruit on glucose control in diabetes mellitus: a meta-analysis of nineteen randomized controlled trials

Objective

Diabetes mellitus is a worldwide health problem, and it remains unclarified whether fruit is beneficial in glycemic control. This study aimed to analyze evidence from randomized controlled trials evaluating the effect of fruit consumption on glucose control.

Methods

We searched the PubMed, EMBASE, Ovid, Web of Science, and Cochrane Central Register of Controlled Trials databases from the respective database inception dates to December 30, 2022, to identify randomized controlled trials that evaluated the effects of fruit consumption on glucose control. Two researchers independently screened the studies in accordance with the inclusion and exclusion criteria, and performed the literature quality evaluation and data extraction. RevMan 5.4 software was used to perform the data analysis.

Results

Nineteen randomized controlled trials with 888 participants were included. Fruit consumption significantly decreased the fasting blood glucose concentration (MD -8.38, 95% CI -12.34 to -4.43), but it showed no significant difference in the glycosylated hemoglobin (MD -0.17, 95% CI -0.51 to 0.17). Subgroup analyses further suggested that the consumption of both fresh and dried fruit decreased the fasting blood glucose concentration.

Conclusions

Increasing the fruit intake reduced fasting blood glucose concentration. Therefore, we recommend that patients with diabetes eat more fruits while ensuring that their total energy intake remains unchanged.

Reporting of adverse effects of pomegranate in clinical studies: a systematic review

OBJECTIVES

Numerous studies have shown the pharmacological effects of pomegranate, such as: anti-cancer, cholesterol-lowering, anti-diabetic, and antihypertensive features. Pomegranate consumption has also revealed some adverse effects. This systematic review aimed to explore the adverse effects of pomegranate reported in clinical studies.

CONTENT

The keywords "pomegranate", "Punica granatum", "side effect", "clinical trial", and "case report or case series" were searched for in valid databases. Reports about adverse effects of pomegranate were also collected from several international registries.

SUMMARY

This systematic review included a total of 66 clinical articles. Eleven articles have reported side effects of pomegranate. Twenty-one articles have recorded no side effects in the pomegranate group while 34 articles have not mentioned any side effects for this plant. The study also included 7 case report studies. The most common side effects included gastrointestinal problems, flu-like symptoms, and urinary problems. In case report studies, the most significant reported side effect was allergic reaction.

OUTLOOK

In summary, pomegranate and its extract seem to be safe according to the reported adverse effects. Meanwhile, conducting more robust controlled trials with pomegranate products and documentation of any probable side effect is warranted.

Anti-glycation, antiplatelet and antioxidant effects of different pomegranate parts

BACKGROUND

Platelet aggregation and advanced glycation end products (AGEs) and oxidative stress are known as key factors for the development of cardiovascular diseases and diabetic complications. In this context, fruit and vegetable consumption, good sources of antioxidant compounds have been largely reported as an effective way of preventing human against these diseases. The current study focuses on the evaluation of antioxidant, antiplatelet and anti-glycation activities of pomegranate (Punica granatum L.) flowers (PF), leaves (PL), peel (PP) juice (PJ) and seeds oil (PSO).

METHODS

Antioxidant activities was measured against ABTS radical and lipid peroxidation. Antiglycation activity was determined using the formation of AGE fluorescence intensity in the BSA/ribose system. Antiplatelet activity was measured in platelet rich plasma (PRP) against adenosine diphosphate (ADP), Collagen and arachidonic acid (AA).

RESULTS

PF extract displayed the highest antioxidant activity against ABTS and lipid peroxidation with IC₅₀ values of 0.7 mg/mL and 0.63 mg/mL respectively. For anti-glycation activity, PP, PF and PL inhibited moderately the pentosidine-like AGEs formation compared to positive controls with AGE-IC₅₀ value of 0.4 mg/mL. PJ and PSO haven't any anti-AGE effect. All the extracts selectively inhibited platelet aggregation caused by one, two or three inducers in dose dependent manner. PF was the most potent inhibitor caused by all three inducers, with inhibitory effects ranging from 35.6 to 66.6%. PP and PJ exhibited antiplatelet effect against both ADP and collagen and PL and PSO only against AA.

CONCLUSIONS

These results suggest that some pomegranate extracts exert potential in vitro anti-glycative and antiplatelet activities.

Ameliorative Effect of Pomegranate Peel Extract (PPE) on Hepatotoxicity Prompted by Iron Oxide Nanoparticles (Fe2O3-NPs) in Mice

An evaluation of the ameliorative effect of pomegranate peel extract (PPE) in counteracting the toxicity of iron oxide nanoparticles (Fe₂O₃-NPs) that cause hepatic tissue damage is focused on herein. Forty male albino mice were haphazardly grouped into four groups as follows: the first control group was orally gavage daily with physiological saline; the second group received 100 mg/kg of PPE by the oral route day after day; the third group received 30 mg/kg Fe₂O₃-NPs orally; and the fourth group received both PPE and Fe₂O₃-NPs by the oral route, the same as the second and third sets. Later, after the completion of the experiment, we collected the liver, blood, and bone marrow of bone specimens that were obtained for further laboratory tests. For instance, exposure to Fe₂O₃-NPs significantly altered serum antioxidant biomarkers by decreasing the levels of total antioxidant capacity (TAC), catalase (CAT), and glutathione s-transferase (GST). Additionally, it caused changes in the morphology of hepatocytes, hepatic sinusoids, and inflammatory Kupffer cells. Furthermore, they significantly elevated the number of chromosomal aberrations including gaps, breaks, deletions, fragments, polyploidies, and ring chromosomes. Moreover, they caused a significant overexpression of TIMP-1, TNF-α, and BAX mRNA levels. Finally, the use of PPE alleviates the toxicity of Fe₂O₃-NPs that were induced in the hepatic tissues of mice. It is concluded that PPE extract has mitigative roles against the damage induced by Fe₂O₃-NPs, as it serves as an antioxidant and hepatoprotective agent. The use of PPE as a modulator of Fe₂O₃-NPs' hepatotoxicity could be considered as a pioneering method in the use of phytochemicals against the toxicity of nanoparticles.

Pharmacotherapeutic potential of pomegranate in age-related neurological disorders

Age-related neurological disorders [AND] include neurodegenerative diseases [NDDs] such as Alzheimer's disease [AD] and Parkinson's disease [PD], which are the most prevalent types of dementia in the elderly. It also includes other illnesses such as migraine and epilepsy. ANDs are multifactorial, but aging is their major risk factor. The most frequent and vital pathological features of AND are oxidative stress, inflammation, and accumulation of misfolded proteins. As AND brain damage is a significant public health burden and its incidence is increasing, much has been done to overcome it. Pomegranate (Punica granatum L.) is one of the polyphenol-rich fruits that is widely mentioned in medical folklore. Pomegranate is commonly used to treat common disorders such as diarrhea, abdominal pain, wound healing, bleeding, dysentery, acidosis, microbial infections, infectious and noninfectious respiratory diseases, and neurological disorders. In the current review article, we aimed to summarize the data on the pharmacotherapeutic potentials of pomegranate in ANDs.

Effectiveness and Safety of Ayurvedic Medicines in Type 2 Diabetes Mellitus Management: A Systematic Review and Meta-Analysis

Introduction: Many Ayurvedic medicines have the potential for managing type 2 diabetes mellitus (T2DM), with previous systematic reviews demonstrating effectiveness and safety for specific Ayurvedic medicines. However, many of the reviews need updating and none provide a comprehensive summary of all the Ayurvedic medicines evaluated for managing T2DM.

Objective: The objective of this systematic review was to evaluate and synthesize evidence on the effectiveness and safety of Ayurvedic medicines for managing T2DM.

Inclusion criteria: Published and unpublished RCTs assessing the effectiveness and safety of Ayurvedic medicines for managing T2DM in adults.

Methods: The JBI systematic review methodology was followed. A comprehensive search of sources (including 18 electronic databases) from inception to 16 January 2021 was made. No language restrictions were applied. Data synthesis was conducted using narrative synthesis and random effects meta-analyses, where appropriate. Pooled results are reported as mean differences (MD) with 95% confidence intervals (CI).

Results: Out of 32,519 records identified from the searches, 219 articles were included in the systematic review representing 199 RCTs (21,191 participants) of 98 Ayurvedic medicines. Overall, in the studies reviewed the methodology was not adequately reported, resulting in poorer methodological quality scoring. Glycated hemoglobin (HbA1c) was reduced using Aegle marmelos (L.) Corrêa (MD -1.6%; 95% CI −3 to −0.3), Boswellia serrata Roxb. (−0.5; −0.7 to −0.4), Gynostemma pentaphyllum (Thunb.) Makino (−1; −1.5 to −0.6), Momordica charantia L. (−0.3; −0.4 to −0.1), Nigella sativa L. (−0.4; −0.6 to −0.1), Plantago ovata Forssk. (−0.9; −1.4 to −0.3), Tinospora cordifolia (Willd.) Hook.f. and Thomson (−0.5; −0.6 to −0.5), Trigonella foenum-graecum L. (−0.6; −0.9 to −0.4), and Urtica dioica L. (−1.3; −2.4 to −0.2) compared to control. Similarly, fasting blood glucose (FBG) was reduced by 4–56 mg/dl for a range of Ayurvedic medicines. Very few studies assessed health-related quality of life (HRQoL). Adverse events were not reported in many studies, and if reported, these were mostly none to mild and predominately related to the gastrointestinal tract.

Conclusion: The current evidence suggests the benefit of a range of Ayurvedic medicines in improving glycemic control in T2DM patients. Given the limitations of the available evidence and to strengthen the evidence base, high-quality RCTs should be conducted and reported.

Potential Mechanisms of the Improvement of Glucose Homeostasis in Type 2 Diabetes by Pomegranate Juice

Pomegranate is a polyphenol-rich fruit. Studies have shown that extracts prepared from its juice or from different parts of the pomegranate plant have various biological activities including antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, cardioprotective, and antidiabetic. The therapeutic potential has been attributed to various phytochemicals, including ellagic acid, punicic acid, flavonoids, anthocyanidins, anthocyanins, flavonols, and flavones. This review focuses on the scientific evidence of pomegranate juice as hypoglycemic, emphasizing the chemical composition and the possible mechanisms of action associated with this effect. Studies were identified using the PubMed, Scopus, and ISI Web of Science databases to identify relevant articles focused on the hypoglycemic effect of pomegranate juice. The physiological responses to pomegranate juice are reported here, including a decrease of oxidative stress damage, an increase of insulin-dependent glucose uptake, maintenance of β-cell integrity, inhibition of nonenzymatic protein glycation, an increase of insulin sensitivity, modulation of peroxisome proliferator-activated receptor-gamma, inhibition of α-amylase, inhibition of α-glucosidase and dipeptidyl peptidase-4, and decreases in inflammation. Overall, we found a significant hypoglycemic effect of pomegranate in in vitro and in vivo studies and we summarize the potential mechanisms of action.

Ellagic Acid: A Review on Its Natural Sources, Chemical Stability, and Therapeutic Potential

Ellagic acid (EA) is a bioactive polyphenolic compound naturally occurring as secondary metabolite in many plant taxa. EA content is considerable in pomegranate (Punica granatum L.) and in wood and bark of some tree species. Structurally, EA is a dilactone of hexahydroxydiphenic acid (HHDP), a dimeric gallic acid derivative, produced mainly by hydrolysis of ellagitannins, a widely distributed group of secondary metabolites. EA is attracting attention due to its antioxidant, anti-inflammatory, antimutagenic, and antiproliferative properties. EA displayed pharmacological effects in various in vitro and in vivo model systems. Furthermore, EA has also been well documented for its antiallergic, antiatherosclerotic, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties. This review reports on the health-promoting effects of EA, along with possible mechanisms of its action in maintaining the health status, by summarizing the literature related to the therapeutic potential of this polyphenolic in the treatment of several human diseases.

Preventive Effect of Ellagic Acid on Cardiac Dysfunction in Diabetic Mice through Regulating DNA Hydroxymethylation

Ellagic acid (EA) improves mitochondrial dysfunction and protects diabetic hearts. The mitochondrial tricarboxylic acid (TCA) cycle regulates DNA 5-hydroxymethylcytosine (5hmC) levels by affecting activity of 10-11 translocation enzymes (TETs). Therefore, we hypothesized that EA prevents diabetic cardiac dysfunction by modulating DNA 5hmC levels. C57BL/6J mice were fed a high-fat diet to induce diabetes and treated with EA (100 mg kg^-1 day^-1) for 8 weeks. Serum concentrations of glucose, insulin, and triglyceride and aspartate transaminase and creatine kinase activities were significantly lower in the EA group than the diabetes mellitus (DM) group. DNA 5hmC levels of mice hearts were significantly higher in the EA group than the DM group. The protein levels of TET, complexes I/III/V were significantly higher in the EA group than the DM group. The results shows that EA has a preventive effect on diabetic cardiac dysfunction, which may be achieved by upregulating TET activity through improving the TCA cycle, to reshape DNA 5hmC levels of mice hearts.

Ellagic Acid Alleviates Oxidative Stress by Mediating Nrf2 Signaling Pathways and Protects against Paraquat-Induced Intestinal Injury in Piglets

The gastrointestinal tract is a key source of superoxide so as to be one of the most vulnerable to oxidative stress damage. Ellagic acid (EA), a polyphenol displays widely biological activities owing to its strong antioxidant properties. Here, we investigated the protective benefits of EA on oxidative stress and intestinal barrier injury in paraquet (PQ)-challenged piglets. A total of 40 weaned piglets were randomly divided into five groups: Control, PQ, 0.005% EA-PQ, 0.01% EA-PQ, and 0.02% EA-PQ. Piglets were intraperitoneally injected with 4 mg/kg (BW) PQ or saline on d-18, and sacrificed on d-21 of experiment. EA treatments eliminated growth-check induced by PQ and increased serum superoxide dismutase (SOD) activity but decreased serum malondialdehyde (MDA) level as compared to PQ group. EA supplementation promoted Nrf2 nuclear translocation and enhanced heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO1) protein abundances of small intestinal mucosa. Additionally, EA improved PQ-induced crypt deepening, goblet cells loss, and villi morphological damage. Consistently, EA increased tight junction protein expression as was evident from the decreased serum diamine oxidase (DAO) levels. EA could ameliorate the PQ-induced oxidative stress and intestinal damage through mediating Nrf2 signaling pathway. Intake of EA-rich food might prevent oxidative stress-mediated gut diseases.

Therapeutic Effects of Punica granatum (Pomegranate): An Updated Review of Clinical Trials

Punica granatum L. belongs to the Punicaceae family which is distributed around the world. Different parts of pomegranate like seed, peel, juice, and leaves are rich in potential bioactive compounds. These plants have found application in traditional medicine such as in treatment of gastrointestinal, cardiovascular, and endocrine diseases, among others. The present review aimed to summarize the current research on the traditional and scientific applications of P. granatum with regard to the phytochemical content and clinical applications that may be useful for future drug development. Information about P. granatum was obtained from local classic herbal literature and electronic databases, such as PubMed, Scopus, and ScienceDirect. Several phytochemical constituents including polyphenolics, flavonoids, anthocyanosides, alkaloids, lignans, and triterpenes have been reported from the plant. Randomized clinical trials have provided evidence as to the pharmacological activities of pomegranate in several diseases including diabetes, cardiovascular disease, oral cavity disorders, endocrine disorders, and cancer. The present review has provided an insight into the traditional applications of the plants, and some of them have been validated by scientific evidence, particularly their applications as treatment of cardiovascular and endocrine diseases.

100% Fruit juice intake and cardiovascular risk: a systematic review and meta-analysis of prospective and randomised controlled studies

PURPOSE

The relationship between 100% fruit juice (100%FJ) consumption and cardiovascular risk is object of debate: indeed, recently published investigations provided new but discrepant evidence on this important question and International dietary guidelines are not in agreement on recommendations about fruit juice consumption. Therefore, we performed a meta-analysis of the prospective studies and the randomised controlled trials (RCTs) that explored the relationship between 100%FJ intake, cardiovascular risk profile and risk of cardiovascular events.

METHODS

We performed a systematic search of publications up to August 2019. Summary relative risks and exploration of linearity of the association were estimated for prospective studies and summary mean differences (MDs) calculated for RCTs.

RESULTS

A total of 21 prospective studies and 35 RCTs met the inclusion criteria. Dose-response analysis detected a significant inverse association between low-moderate 100%FJ consumption and risk of stroke (up to 200 ml/day) or total CV events (up to 170 ml/day) compared with no consumption, with a non-linear relationship (p for non-linearity < 0.05). No significant association was found for coronary heart disease and diabetes risk. In RCTs, a favorable and significant effect of 100%FJ intake was detected on blood pressure (systolic, MD: - 3.14 mmHg; diastolic, MD: - 1.68 mmHg), arterial compliance (carotid-femoral pulse wave velocity, - 0.38 m/s) and endothelial function (flow-mediated dilation, 2.10%). Neutral effects were found on body weight, blood lipids and glucose metabolism.

CONCLUSIONS

The results of these analyses indicate that 100%FJ consumption is not associated with higher CV risk. A non-linear inverse dose-response relationship occurs between 100%FJ consumption and CV disease, in particular for risk of stroke, probably mediated by the decrease in blood pressure.

TRIAL REGISTRATION

PROSPERO registration number (CRD42019135577).

The effects of pomegranate peel extract on the gene expressions of antioxidant enzymes in a rat model of alloxan-induced diabetes

This study was conducted to evaluate the anti-diabetic and antioxidant effects of hydroalcoholic pomegranate peel extract (APE) in alloxan-induced diabetes rat models. We divided 60 rats into the following six equal groups (n = 10): Healthy control; diabetic control (100 mg/kg alloxan); sham + glibenclamide (10 mg/kg); diabetic + glibenclamide (10 mg/kg); sham + APE (200 mg/kg) and diabetic + APE (200 mg/kg). After 8 weeks, kidneys were taken out for biochemical and molecular studies. Following APE treatment, biochemical parameters including malondialdehyde (MDA), and glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) significantly induced in the treated group as compared with the control group (p < 0.05). Also, gene expression of GPx (3-fold), CAT (2.6-fold), and SOD (1.5-fold) were increased as compared to controls (p < 0.05). Overall, our results indicated that pomegranate can be used as an antioxidant agent to reduce complications from diseases associated with oxidative stress.

Ellagic Acid as a Tool to Limit the Diabetes Burden: Updated Evidence

Oxidative stress contributes not only to the pathogenesis of type 2 diabetes (T2D) but also to diabetic vascular complications. It follows that antioxidants might contribute to limiting the diabetes burden. In this review we focus on ellagic acid (EA), a compound that can be obtained upon intestinal hydrolysis of dietary ellagitannins, a family of polyphenols naturally found in several fruits and seeds. There is increasing research on cardiometabolic effects of ellagitannins, EA, and urolithins (EA metabolites). We updated research conducted on these compounds and (I) glucose metabolism; (II) inflammation, oxidation, and glycation; and (III) diabetic complications. We included studies testing EA in isolation, extracts or preparations enriched in EA, or EA-rich foods (mostly pomegranate juice). Animal research on the topic, entirely conducted in murine models, mostly reported glucose-lowering, antioxidant, anti-inflammatory, and anti-glycation effects, along with prevention of micro- and macrovascular diabetic complications. Clinical research is incipient and mostly involved non-randomized and low-powered studies, which confirmed the antioxidant and anti-inflammatory properties of EA-rich foods, but without conclusive results on glucose control. Overall, EA-related compounds might be potential agents to limit the diabetes burden, but well-designed human randomized controlled trials are needed to fill the existing gap between experimental and clinical research.

Pomegranate juice as a functional food: a comprehensive review of its polyphenols, therapeutic merits, and recent patents

Pomegranate (Punica granatum) is an ancient perennial plant species of the Punicaceae family and is regarded as the 'miracle fruit' for its seeds being consumed as food, juice and as a functional food. Significant modern pharmacological and clinical evidence has highlighted the wide medicinal applications of pomegranate fruit parts and its juice. Pomegranate juice (PJ) that is superior to other fruit juices is a fortified source of dietary polyphenols with potential antioxidant capacity. Polyphenols of PJ include tannins, anthocyanins, and flavonoids. The presence of these beneficial phytochemicals is directly linked to its favourable health benefits viz., obesity and diabetes management and anti-inflammatory effects. This comprehensive review capitalizes on PJ with emphasis on the interrelationship between its holistic chemical composition, metabolism and biological effects. Moreover, the review recapitulates on the diverse health benefits of PJ and related patents in the field of PJ production to ensure the best produced juice quality.

The role of anthocyanins as antidiabetic agents: from molecular mechanisms to in vivo and human studies

Diabetes mellitus is a chronic metabolic disease characterized by high blood glucose concentration. Nowadays, type 2 diabetes or insulin resistant diabetes is the most common diabetes, mainly due to unhealthy lifestyle. Healthy habits like appropriate nutritional approaches or the consumption of certain natural products or food supplements have been suggested as non-pharmacological strategies for the treatment and prevention of type 2 diabetes. Some of the main bioactive compounds from plant foods are polyphenols, important mainly for their antioxidant capacity in oxidative stress conditions and ageing. Anthocyanins are polyphenols of the flavonoid group, which act as pigments in plants, especially in fruits such as berries. A search of in vitro, in vivo and human studies in relation with antidiabetic properties of anthocyanins has been performed in different electronic databases. Results of this review demonstrate that these compounds have the ability to inhibit different enzymes as well as to influence gene expression and metabolic pathways of glucose, such as AMPK, being able to modulate diabetes and other associated disorders, as hyperlipidaemia, overweight, obesity and cardiovascular diseases. Additionally, human interventional studies have shown that high doses of anthocyanins have potential in the prevention or treatment of type 2 diabetes; nevertheless, anthocyanins used in these studies should be standardized and quantified in order to make general conclusions about its use and to claim benefits for the human population.

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).

Effects of green coffee extract on fasting blood glucose, insulin concentration and homeostatic model assessment of insulin resistance (HOMA-IR): a systematic review and meta-analysis of interventional studies

Many studies have investigated the relationship between coffee and diabetes. Evaluation of the current evidence on the effect of coffee intake on diabetes is critical. Therefore, we aimed to investigate the potential association between green coffee extract (GCE) and fasting blood glucose (FBG), insulin and homeostatic model assessment of insulin resistance (HOMA-IR) by pooling together the results from clinical trials. PubMed, Scopus and Google Scholar were searched for experimental studies which have been published up to December 2018. Randomized controlled trials (RCTs) that investigated the effect of GCE supplementation on FBG, insulin and HOMA-IR in adults were included for final analysis. A total of six articles were included in the meta-analysis. Results revealed that GCE supplementation reduced FBG level (SMD: -0.32, 95% CI - 0.59 to - 0.05, P = 0.02) but had no effect on insulin levels (SMD: -0.22, 95% CI -0.53 to 0.09, P = 0.159). Although analysis showed that GCE supplementation cannot change the HOMA-IR status (SMD: -0.30, 95% CI -0.73 to 0.13, P = 0.172), after stratified studies by GCE dosage (< 400 mg/day versus > 400 mg/day) there was a significant decrease in HOMA-IR status in a dose greater than 400 mg. These findings suggest that GCE intake might be associated with FBG improvement.

Pomegranate Juice Increases Sirtuin1 Protein in Peripheral Blood Mononuclear Cell from Patients with Type 2 Diabetes: A Randomized Placebo Controlled Clinical Trial

BACKGROUND

Few studies have examined anti-inflammatory effects of pomegranate juice (PJ). The present study aimed to evaluate the effect of PJ on nuclear factor kappa B (NF-κB) p65 and sirtuin1 in peripheral blood mononuclear cell (PBMC), and plasma vascular inflammation biomarkers.

METHODS

Patients with type 2 diabetes were randomly assigned to either the PJ (n = 22) or the placebo group (n = 22). The patients in the PJ group received 250 mL of PJ daily for 12 weeks, whereas the placebo group received corresponding control beverages of similar color and energy content. At baseline and at the end of week 12, fasting plasma concentrations of soluble intercellular adhesion molecule type 1 (sICAM-1), soluble vascular cell adhesion molecule type 1 (sVCAM-1), and soluble E-selectin (sE-selectin) were measured. NF-κB p65 and SIRT1 were measured in the PBMC.

RESULTS

Plasma sE-selectin concentration decreased significantly in the PJ group at the end of week 12 compared to baseline (P < 0.001 for treatment effect), and the reduction was significant in comparison with the placebo group (P < 0.05 for treatment effect). There were no significant differences between the two groups in plasma sICAM-1 and sVCAM-1. At the end of the study, compared with the placebo group, NF-κB p65 in PBMC was significantly lower (P < 0.01 for treatment effect) and SIRT1 was significantly higher (P < 0.0001 for treatment effect) in the PJ group.

CONCLUSION

This study supports the PJ consumption as a food with potential benefits in individuals with type 2 diabetes as evidenced by improvements in NF-κB and SIRT1 levels in PBMC of study participants.

100 % Fruit juice and measures of glucose control and insulin sensitivity: a systematic review and meta-analysis of randomised controlled trials

Studies on the effects of consuming 100 % fruit juice on measures of glycaemic control are conflicting. The purpose of the present study was to systematically review and quantitatively summarise results from randomised controlled trials (RCT) examining effects of 100 % fruit juice on glucose-insulin homeostasis. Eligible studies were identified from a systematic review of PubMed and EMBASE and hand searches of reference lists from reviews and relevant papers. Using data from eighteen RCT, meta-analyses evaluated the mean difference in fasting blood glucose (sixteen studies), fasting blood insulin (eleven studies), the homeostatic model assessment of insulin resistance (HOMA-IR; seven studies) and glycosylated Hb (HbA1c; three studies) between the 100 % fruit juice intervention and control groups using a random-effects model. Compared with the control group, 100 % fruit juice had no significant effect on fasting blood glucose (-0·13 (95 % CI -0·28, 0·01) mmol/l; P = 0·07), fasting blood insulin (-0·24 (95 % CI -3·54, 3·05) pmol/l; P = 0·89), HOMA-IR (-0·22 (95 % CI -0·50, 0·06); P = 0·13) or HbA1c (-0·001 (95 % CI -0·38, 0·38) %; P = 0·28). Results from stratified analyses and univariate meta-regressions also largely showed no significant associations between 100 % fruit juice and the measures of glucose control. Overall, findings from this meta-analysis of RCT suggest a neutral effect of 100 % fruit juice on glycaemic control. These findings are consistent with findings from some observational studies suggesting that consumption of 100 % fruit juice is not associated with increased risk of diabetes.

Pomegranate juice, but not an extract, confers a lower glycemic response on a high-glycemic index food: randomized, crossover, controlled trials in healthy subjects

Background: Low-glycemic index diets have demonstrated health benefits associated with a reduced risk of developing type 2 diabetes.Objectives: We tested whether pomegranate polyphenols could lower the glycemic response of a high-glycemic index food when consumed together and the mechanism by which this might occur.Design: We compared the acute effect of a pomegranate juice and a polyphenol-rich extract from pomegranate (supplement) on the bread-derived postprandial blood glucose concentration in 2 randomized, crossover, controlled studies (double-blinded for the supplements), each on 16 healthy volunteers. An additional randomized, crossover, controlled study on 16 volunteers consuming constituent fruit acids in a pH-balanced solution (same pH as pomegranate) and bread was conducted to determine any contributions to postprandial responses caused by acidic beverages.Results: As primary outcome, the incremental area under the curve for bread-derived blood glucose (-33.1% ± 18.1%, P = 0.000005) and peak blood glucose (25.4% ± 19.3%, P = 0.0004) were attenuated by pomegranate juice, compared with a control solution containing the equivalent amount of sugars. In contrast, the pomegranate supplement, or a solution containing the malic and citric acid components of the juice, was ineffective. The pomegranate polyphenol punicalagin was a very effective inhibitor of human α-amylase in vitro, comparable to the drug acarbose. Neither the pomegranate extract nor the individual component polyphenols inhibited ¹⁴C-D-glucose transport across differentiated Caco-2/TC7 cell monolayers, but they inhibited uptake of ¹⁴C-glucose into Xenopus oocytes expressing the human glucose transporter type 2. Further, some of the predicted pomegranate gut microbiota metabolites modulated ¹⁴C-D-glucose and ¹⁴C-deoxy-D-glucose uptake into hepatic HepG2 cells.Conclusions: These data indicate that pomegranate polyphenols, when present in a beverage but not in a supplement, can reduce the postprandial glycemic response of bread, whereas microbial metabolites from pomegranate polyphenols exhibit the potential to further modulate sugar metabolism much later in the postprandial period. This trial was registered at clinicaltrials.gov as NCT02486978, NCT02624609, and NCT03242876.

Protective effect of pomegranate juice on retinal oxidative stress in streptozotocin-induced diabetic rats

AIM

To investigate the effect of pomegranate juice (PJ) intake on overall oxidation status in retinas of diabetic rats.

METHODS

Twenty-seven rats were divided into four groups as control (CO), diabetic (DM), control treated with PJ (CO-PJ), and diabetic treated with PJ (DM-PJ).The retina tissues were used to determine 8-hydroxy-2'-deoxyguanosine (8OHdG), malondialdehyde (MDA), reduced glutathione (GSH) levels, and the enzyme activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px).

RESULTS

The levels of 8OHdG and MDA were significantly increased in the retina of DM group compared to CO group (P=0.001, P<0.001 respectively). Both 8OHdG and MDA levels were decreased in PJ-DM group compared to DM group (P=0.004, P<0.001 respectively). The activities of antioxidant enzymes GSH, SOD, and GDH-Px were significantly decreased in the retina of DM group compared to CO group (P≤0.01). GSH and GSH-Px activities were higher in PJ-DM group compared with DM group (P=0.010, P=0.042, respectively) but SOD activity was not statistically different (P=0.938).

CONCLUSION

PJ intake is found to be effective in decreasing oxidative end products, and in increasing the activities of antioxidant enzymes in diabetic retinas of rats, which suggests it may be effective against oxidative stress in diabetic retinas.

Pomegranate juice prevents development of non-alcoholic fatty liver disease in rats by attenuating oxidative stress and inflammation

BACKGROUND

The effects of pomegranate juice (PJ) on the risk factors of non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) have been reported previously; however, the effects on NAFLD and its prevention have not yet been clarified. The present study aimed to evaluate the effects of PJ consumption with respect to the prevention of NAFLD/NASH development. Sprague-Dawley rats were fed either a high-fat, high sugar diet (model group); a high-fat, high sugar diet plus PJ (model+PJ); or a chow diet ad libitum for 7 weeks. Serum levels of fasting glucose, triglyceride, cholesterol, liver enzymes, insulin and hepatic tumor necrosis factor-α and tissue growth factor-β gene expression were determined. Hepatic histology was examined by hemotoxylin and eosin staining.

RESULTS

The model+PJ group had significantly lower hepatic steatosis, ballooning, lobular inflammation and portal inflammation (P < 0.001); lower hepatic pro-inflammatory and pro-fibrotic gene expression (P < 0.001); and lower plasma levels of alanine aminotransferase (P = 0.026), aspartate aminotransferase (P = 0.041), insulin (P < 0.001), triglycerides (P = 0.041) and glucose (P = 0.009) compared to the model group; however, weight gain, food intake and plasma high-density lipoprotein levels were not significantly different between these two groups.

CONCLUSION

The data obtained in the present study indicate that the regular consumption of PJ can prevent NAFLD even in the presence of the other risk factors such as obesity, hypercholesterolemia, and high energy, fat and sugar intakes. © 2016 Society of Chemical Industry.

Current concepts regarding developmental mechanisms in diabetic retinopathy in Taiwan

Diabetic retinopathy (DR) is one of the most feared complications of diabetes and is a leading cause of acquired blindness in working adults. The prevalence of undiagnosed diabetes in Taiwan is about 4%, and the annual incidence of T2D (Type 2 Diabetes) in Taiwan is 1.8% following the 1985 WHO criteria. Multiple mechanisms have been shown in T2DR with some signaling pathways, including the polyol pathway, PKC pathway, AGEs pathway, and MAPK pathway. However, the cause of vision loss in diabetic retinopathy is complex and remains incompletely understood. Herein, we try to fully understand the new concepts regarding hyperglycemia-induced biochemical pathways contributing to DR pathophysiology. Our work may be able to provide new strategies for the prevention and treatment of diabetic vascular complications.

Impact of Natural Juice Consumption on Plasma Antioxidant Status: A Systematic Review and Meta-Analysis

Background: Oxidative stress may lead to overproduction of reactive species and a decrease in antioxidant defenses, resulting in chronic diseases such as diabetes and cancer. The consumption of natural compounds with an antioxidant profile may be a preventive alternative. Therefore, we aimed to obtain evidence regarding the potential antioxidant activity of juices in human plasma. Methods: A systematic review and meta-analysis was performed, which included randomized controlled trials that compared the use of fruit or vegetable juices vs. placebo or other beverages. An electronic search was conducted in PubMed, Scopus, International Pharmaceutical Abstracts, and SciELO. The outcome measures extracted were related to antioxidant status, e.g., vitamin C, superoxide dismutase (SOD), and catalase (CAT) levels and reduction in malondialdehyde (MDA) and antioxidant capacity measured as TEAC. Results: Twenty-eight trials were identified (n = 1089), of which 16 were used for meta-analysis. No significant differences were observed between juices and placebo with regard to TEAC, SOD, and CAT. However, juices were superior to control in enhancing vitamin C and reducing MDA. Conclusions: Natural juices are possible candidates for the management of oxidative stress. The effects of juices should be further investigated by conducting larger and well-defined trials of longer duration.