Potential Factors Influencing the Effects of Anthocyanins on Blood Pressure Regulation in Humans: A Review

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 blueberry and cranberry supplementation on blood pressure in patients with cardiovascular diseases: A systematic review and meta-analysis of randomized clinical trials

Blueberries and cranberries are berry fruits with the highest number of randomized clinical trials (RCTs) focusing on blood pressure (BP). This systematic review and meta-analysis of RCTs analyzed the effects of blueberry and cranberry supplementation alone and in concert with systolic BP (SBP) and diastolic BP (DBP) in patients with cardiometabolic diseases. The searches were performed until August 2023 in the following databases: PubMed, Scopus, Web of Science, Cochrane, and Embase. Studies that examined the effects of blueberry or cranberry intake/supplementation were included. The risk of bias was evaluated using the Rob 2 scale. A meta-analysis was performed to estimate the effects of blueberry and cranberry supplementation on BP levels in patients with cardiometabolic diseases. A total of 17 articles were included, from which two found significant results from blueberry and/or cranberry supplementation in reducing BP. Pooled results revealed statistically non-significant reductions of -0.81 mm Hg for SBP (95% confidence interval [CI]: -2.26, 0.63; I2  = 0%) and -0.15 mm Hg for DBP (95% CI: -1.36, 1.05; I2  = 27%). Blueberry and/or cranberry supplementation had neutral effects on SBP and DBP in patients with cardiometabolic diseases, regardless of duration or age. Further high-quality studies are needed to firmly establish clinical efficacy.

Higher anthocyanin intake is associated with a lower risk of non-alcoholic fatty liver disease in the United States adult population

Background

Flavonoids are a class of plant chemicals known to have health-promoting properties, including six subclasses. Anthocyanin is one of the subclasses that have anti-inflammatory and antioxidant activities. However, the relationship between flavonoid subclass intake and the risk of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis has not been verified in representative samples of the United States.

Methods

This is a cross-sectional study based on the data from the National Health and Nutrition Examination Survey (NHANES) and the Food and Nutrient Database for Dietary Studies (FNDDS) in 2017-2018. The intake of flavonoid subclasses of the participants was obtained from two 24 h dietary recalls. The NAFLD and liver fibrosis were defined based on the international consensus criteria. The relationship between flavonoid subclass intake and NAFLD and liver fibrosis was evaluated using a multivariate logistic regression model corrected for multiple confounding factors. Subgroup analysis, trend tests, interaction tests and restricted cubic spline were carried out to further explore this relationship. In addition, we also explored the relationship between anthocyanin and liver serum biomarkers, dietary total energy intake and healthy eating index (HEI)-2015 scores.

Results

A total of 2,288 participants were included in the analysis. The intake of anthocyanin was significantly negatively associated with the risk of NAFLD, but not other flavonoid subclasses. A higher anthocyanin intake was significantly associated with a lower risk of NAFLD (quartile 4, OR 0.470, 95% CI 0.275-0.803). The results of subgroup analysis showed that the protective effect of dietary anthocyanin intake on NAFLD was more pronounced in participants of non-Hispanic whites, with hypertension and without diabetes (P for interaction <0.05). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), dietary total energy intake was significantly negatively correlated with dietary anthocyanin intake. We did not find any protective effect of flavonoid subclass intake on liver fibrosis.

Conclusion

Anthocyanin, but not other flavonoid subclasses, can significantly reduce the risk of NAFLD. The protective effect was more pronounced in non-Hispanic whites, participants without diabetes and those with hypertension. Our study provides new evidence that anthocyanin intake has a reverse significant association with the risk for NAFLD.

Resveratrol and beyond: The Effect of Natural Polyphenols on the Cardiovascular System: A Narrative Review

Cardiovascular diseases (CVDs) are among the leading causes of morbidity and mortality worldwide. Unhealthy dietary habits have clearly been shown to contribute to the development of CVDs. Beyond the primary nutrients, a healthy diet is also rich in plant-derived compounds. Natural polyphenols, found in fruits, vegetables, and red wine, have a clear role in improving cardiovascular health. In this review, we strive to summarize the results of the relevant pre-clinical and clinical trials that focused on some of the most important natural polyphenols, such as resveratrol and relevant flavonoids. In addition, we aim to identify their common sources, biosynthesis, and describe their mechanism of action including their regulatory effect on signal transduction pathways. Finally, we provide scientific evidence regarding the cardiovascular benefits of moderate, long-term red wine consumption.

Bioactivity-Guided Isolation and Antihypertensive Activity of Citrullus colocynthis Polyphenols in Rats with Genetic Model of Hypertension

Background and Objectives: Citrullus colocynthis belongs to the Cucurbitaceae family and is a wild medicinal plant used in folk literature to treat various diseases. The purpose of the current study was to explore the antihypertensive and antioxidant potentials of Citrullus colocynthis (CC) polyphenol-rich fractions using a spontaneous hypertensive rat (SHR) model. Materials and Methods: The concentrated aqueous ethanol extract of CC fruit was successively fractioned using solvents of increasing polarity, i.e., hexane, chloroform, ethyl acetate and n-butanol. The obtained extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC) and total flavonol content (TOF). Moreover, the CC extracts were further evaluated for radical scavenging capacity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays and antioxidant activity using inhibition of linoleic acid peroxidation and determination of reducing potential protocols. The phytochemical components were characterized by HPLC-MWD-ESI-MS in positive ionization mode. Results: The results showed that ethyl acetate fraction (EAF) exhibited a higher content of phenolic compounds in term of TPC (289 mg/g), TFC (7.6 mg/g) and TOF (35.7 mg/g). EAF showed higher antioxidant and DPPH and ABTS scavenging activities with SC50 values of 6.2 and 79.5 µg/mL, respectively. LCMS analysis revealed that twenty polyphenol compounds were identified in the EAF, including phenolic acids and flavonoids, mainly myricetin and quercetin derivatives. The in vivo antihypertensive activity of EAF of CC on SHR revealed that it significantly decreased the mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressures (DBP) and pulse pressure (PP) as compared to normal and hypertensive control groups. Moreover, EAF of CC significantly reduced the oxidative stress in the animals in a dose-dependent manner by normalizing the levels of superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NOx) and total antioxidant capacity (TAC). Furthermore, the treatment groups, especially the 500 mg of EAF per kg body weight (EA-500) group, significantly (p ≤ 0.05) improved the electrocardiogram (ECG) pattern and pulse wave velocity (PWV). Conclusion: It was concluded that the EAF of CC is a rich source of polyphenols and showed the best antioxidant activity and antihypertensive potential in SHR.

Effects of anthocyanin supplementation on blood lipid levels: a systematic review and meta-analysis

Introduction

Dyslipidemia is a major cardiovascular disease risk factor associated with increased mortality. The intake of plant food-derived bioactive compounds is associated with beneficial cardiovascular effects, including decreased blood lipid levels and cardiovascular risk. We aimed to evaluate the effects of anthocyanin intake on blood lipid levels by analyzing relevant randomized controlled trials.

Methods

We searched the PubMed and Embase databases using the "Patient/Population, Intervention, Comparison, and Outcomes" format to determine whether anthocyanin supplementation intervention affected blood lipid levels compared with placebo supplementation in human participants.

Results

A total of 41 studies with 2,788 participants were included in the meta-analysis. Anthocyanin supplementation significantly reduced triglyceride [standardized mean difference (SMD) = -0.10; 95% confidence interval [CI], -0.18, -0.01) and low-density lipoprotein-cholesterol (SMD = -0.16; 95% CI -0.26, -0.07) levels and increased high-density lipoprotein-cholesterol levels (SMD = 0.42; 95% CI 0.20, 0.65).

Discussion

Anthocyanin supplementation significantly improved blood lipid component levels in the included studies. Larger, well-designed clinical trials are needed to further investigate the effects of anthocyanin intake on blood lipid levels and the safety of anthocyanin supplementation for treating dyslipidemia.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021257087, identifier: CRD42021257087.

Berry Dietary Interventions in Metabolic Syndrome: New Insights

Metabolic Syndrome (MetS) is characterized by a group of dysmetabolic conditions, including abdominal obesity, dyslipidemia, glucose intolerance and/or insulin resistance, and hypertension. Generally, MetS is accompanied by an exacerbation of oxidative stress, inflammation, and vascular dysfunction. Increasing evidence suggests that berries and berry bioactives could play a potential role in the prevention and mitigation of the risk factors associated with MetS. The present systematic review summarizes the more recently available evidence deriving from human intervention studies investigating the effect of berries in subjects with at least three out of five MetS parameters. The PubMed, Scopus, and Embase databases were systematically searched from January 2010 until December 2022. A total of 17 human intervention trials met the inclusion criteria. Most of them were focused on blueberry (n = 6), cranberry (n = 3), and chokeberry (n = 3), while very few or none were available for the other berries. If considering MetS features, the main positive effects were related to lipid profile (low and high-density lipoproteins, cholesterol, and triglycerides) following blueberries and chokeberries, while conflicting results were documented for anthropometric parameters, blood pressure, and fasting blood glucose levels. Other markers analyzed within the studies included vascular function, oxidative stress, and inflammation. Here, the main positive effects were related to inflammation with a reduction in interleukin 6 and tumor necrosis factor-alpha following the intake of different berries. In conclusion, although limited, the evidence seems to support a potential role for berries in the modulation of lipid profile and inflammation in subjects with MetS. Furthermore, high-quality intervention trials are mandatory to demonstrate the role of berries in reducing risk factors for MetS and related conditions. In the future, such a demonstration could bring the adoption of berries as a potential dietary strategy to prevent/counteract MetS and related risk factors.

Effectiveness of anthocyanins rich foods on cardiometabolic factors in individuals with metabolic syndrome: a systematic review and meta-analysis

PURPOSE

The aim of this systematic review with meta-analysis was to determine whether anthocyanin-rich foods are effective to improve cardiometabolic markers in individuals with metabolic syndrome (MetS), compared with placebo or control interventions.

METHODS

We searched MEDLINE, CENTRAL, Embase, LILACS, CINAHL, and Web of Science from their inception up to March 2022. We include clinical trials (randomized clinical trials, controlled clinical trials, and cross-over trials) with anthocyanin-rich foods versus placebo or control intervention that assessment cardiometabolic factors.

RESULTS

We found 14 clinical trials that met the eligibility criteria, and we included 10 studies for the quantitative synthesis. For anthocyanin-rich foods versus control interventions, the mean difference (MD) for low-density lipoprotein (LDL) was - 7.98 mg/dL (CI = - 15.20 to - 0.77, GRADE: Very low). For homeostatic model assessment for insulin resistance (HOMA-IR), the MD was 0.04 (CI = 0.08 to 0.16, GRADE: Moderate). The MD for interleukin 6 was 0.00 pg/mL (CI = - 0.01 to 0.00, GRADE: Low). For tumor necrosis factor alpha (TNF-α), the standardized mean difference (SMD) was - 0.52 pg/mL (CI = 0.85 to 0.19 GRADE: Very low) when compared with the control interventions. The certainty of the evidence for the other outcomes it is very low.

CONCLUSION

Our findings suggest that anthocyanin-rich foods could improve certain cardiometabolic markers (e.g., TC, TG, LDL, and TNF-α) among individuals with MetS (with very low quality evidence according to GRADE), compared with placebo or other control interventions.

PROSPERO REGISTRATION NUMBER

CRD42020187287.

Impact of cyanidin 3-O-glucoside on rat micro-and systemic circulation, possibly thorough angiogenesis

Cyanidin 3-O-glucoside (C3G), an antioxidant, is one of the most abundant anthocyanin in plant foods. Intervention trials and subsequent meta-analyses have suggested that anthocyanins could reduce the risks of cardiovascular diseases. This study investigated hemodynamic alterations following a single intragastric dose of C3G by measuring blood flow in rat cremaster muscle arteriole for 60 min. Next, in excised aortas, we performed western blotting to measure the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS). A single oral dose of C3G significantly increased blood flow soon after ingestion, and it was maintained throughout the experimental period. In addition, aortic Akt phosphorylation increased. Then, we examined the impact of repeated oral administrations of C3G for 14 days. The mean blood pressure was significantly reduced at 7 and 14 days after treatment, with a slight increase in aortic eNOS expression. Immunohistochemical analyses of the soleus showed that the level of CD31, an angiogenesis-marker protein, was significantly increased with C3G. These results suggested that an oral dose of C3G increased blood flow, which promoted angiogenesis within skeletal muscle, and consequently, blood pressure was reduced.

Pharmacological and phytochemical potential of Rubus ellipticus: a wild edible with multiple health benefits

OBJECTIVES

Rubus ellipticus (family Rosaceae) is used for its delicious edible fruits in the Himalayan region and other parts of the globe. However, the full potential of the species is yet to be harnessed. The current review focuses on the phytochemical, traditional uses, morphological, molecular and pharmacological potential of R. ellipticus.

KEY FINDINGS

The review of the literature reveals that many health-promoting compounds of R. ellipticus have been reported from the species along with the different biological properties, such as nephroprotective, anti-inflammatory, analgesic, anti-pyretic, anti-proliferative, cytotoxicity, anti-cancer, wound healing, anti-fertility, anti-plasmodial, anti-microbial and antioxidant. Traditionally, it is used in many formulations, which are validated through primary pharmacological assays. However, several medicinal properties are still need to be validated through detailed pharmacological and clinical studies.

SUMMARY

All the information is available in a scanty form, and the complete information is missing on a single platform. Such type of information will help researchers to better utilize the available data for initiating future research on the species as it has the potential to contribute to the food and pharmaceutical industry. The review highlights the need for further studies on the species to harness its potential in nutraceutical, functional food, energy supplement, and beneficial therapeutic drug development program.

Peonidin-3-O-Glucoside from Purple Corncob Ameliorates Nonalcoholic Fatty Liver Disease by Regulating Mitochondrial and Lysosome Functions to Reduce Oxidative Stress and Inflammation

A frequent chronic liver condition across the world is nonalcoholic fatty liver disease (NAFLD). Oxidative stress caused by lipid accumulation is generally considered to be the main cause of NAFLD. Anthocyanins can effectively inhibit the production of reactive oxygen species and improve oxidative stress. In this work, six major anthocyanins were separated from purple corncob by semi-preparative liquid chromatography. The effects of the 6 kinds of anthocyanins against NAFLD were investigated using a free fatty acid (FFA)-induced cell model. The results showed that peonidin 3-O-glucoside (P3G) can significantly reduce lipid accumulation in the NAFLD cell model. The treatment with P3G also inhibited oxidative stress via inhibiting the excessive production of reactive oxygen species and superoxide anion, increasing glutathione levels, and enhancing the activities of SOD, GPX, and CAT. Further studies unveiled that treatment with P3G not only alleviated inflammation but also improved the depletion of mitochondrial content and damage of the mitochondrial electron transfer chain developed concomitantly in the cell model. P3G upregulated transcription factor EB (TFEB)-mediated lysosomal function and activated the peroxisome proliferator-activated receptor alpha (PPARα)-mediated peroxisomal lipid oxidation by interacting with PPARα possibly. Overall, this study added to our understanding of the protective effects of purple corn anthocyanins against NAFLD and offered suggestions for developing functional foods containing these anthocyanins.

Dietary Approaches to Stop Hypertension via Indo-Mediterranean Foods, May Be Superior to DASH Diet Intervention

Western-type diet with high salt and sugar, sedentary behavior, obesity, tobacco and alcoholism are important risk factors for hypertension. This review aims to highlight the role of western diet-induced oxidative stress and inflammation in the pathogenesis of hypertension and the role of various types of diets in its prevention with reference to dietary approaches to stop hypertension (DASH) diet. It seems that it is crucial to alter the western type of diet because such diets can also predispose all CVDs. Western diet-induced oxidative stress is characterized by excessive production of reactive oxygen species (ROS) with an altered oxidation-reduction (redox) state, leading to a marked increase in inflammation and vascular dysfunction. Apart from genetic and environmental factors, one important cause for differences in the prevalence of hypertension in various countries may be diet quality, deficiency in functional foods, and salt consumption. The role of the DASH diet has been established. However, there are gaps in knowledge about the role of some Indo-Mediterranean foods and Japanese foods, which have been found to decrease blood pressure (BP) by improving vascular function. The notable Indo-Mediterranean foods are pulses, porridge, spices, and millets; fruits such as guava and blackberry and vegetables, which may also decrease BPs. The Japanese diet consists of soya tofu, whole rice, in particular medical rice, vegetables and plenty of fish rich in fish oil, fish peptides and taurine that are known to decrease BPs. Epidemiological studies and randomized, controlled trials have demonstrated the role of these diets in the prevention of hypertension and metabolic diseases. Such evidence is still meager from Japan, although the prevalence of hypertension is lower (15-21%) compared to other developed countries, which may be due to the high quality of the Japanese diet. Interestingly, some foods, such as berries, guava, pumpkin seeds, carrots, soya beans, and spices, have been found to cause a decrease in BPs. Omega-3 fatty acids, fish peptide, taurine, dietary vitamin D, vitamin C, potassium, magnesium, flavonoids, nitrate and l-arginine are potential nutrients that can also decrease BPs. Larger cohort studies and controlled trials are necessary to confirm our views.

The Role of Berry Consumption on Blood Pressure Regulation and Hypertension: An Overview of the Clinical Evidence

The existence of a relationship between the consumption of dietary berries and blood pressure reduction in humans has been repeatedly hypothesized and documented by an increasing body of epidemiological and clinical evidence that has accumulated in recent years. However, results are mixed and complicated by a number of potentially confounding factors. The objective of this article is to review and summarize the available clinical evidence examining the effects of berry consumption on blood pressure regulation as well as the prevention or treatment of hypertension in humans, providing an overview of the potential contribution of distinctive berry polyphenols (anthocyanins, condensed tannins and ellagic acid), and results of dietary interventions with blueberries, bilberries, cranberries, raspberries, strawberries, chokeberries, cherries, blackcurrants and açai berries. We conclude that, while there is insufficient evidence supporting the existence of a direct blood pressure lowering effect, there is stronger evidence for specific types of berries acting indirectly to normalize blood pressure in subjects that are already hypertensive.

Chokeberry (A. melanocarpa (Michx.) Elliott)—A Natural Product for Metabolic Disorders?

Abnormal metabolism of substances in the body can result in metabolic disorders which include obesity, cardiovascular diseases, diabetes, hypertension, chronic kidney disease, liver disease, or cancer. Foods rich in antioxidants can help to prevent and treat various types of disorders. Chokeberry fruits are rich in polyphenols, especially cyanidins, and therefore, can show a beneficial health effect. The aim of this study was to summarize and systematize reports about the effects of chokeberry on various metabolic parameters. Studies from 2000 to 2021, published in the PubMed and Google Scholar databases, were reviewed. The review of studies shows that chokeberry may have a positive effect in dyslipidemia and hypertension and may increase the body’s antioxidant defense mechanisms. The anti-inflammatory effect, in turn, may translate into a reduction in the risk of metabolic disorders over a longer period of use. Changes in glucose levels were reported by studies in which the intervention lasted more than 10 weeks in patients with carbohydrate metabolism disorders. The effects of protecting the liver, inhibiting platelet aggregation, lowering uric acid levels, and having a protective effect on the kidneys require additional confirmation in human clinical trials. Consumption of chokeberry fruit did not impact on anthropometric measurements; however, it seems that chokeberry fruit can be recommended in many metabolic disorders due to the richness of bioactive ingredients.

Current Knowledge on Intestinal Absorption of Anthocyanins

Anthocyanins are flavonoid compounds that are natural color pigments occurring in various colored plants, such as berry fruits, vegetables, and grapes. With the elucidation of their various physiological effects, anthocyanins have been identified as promising functional food ingredients. However, findings on the bioavailability of anthocyanins, which are present in various chemical structures in foods, are limited; their intestinal absorption behaviors, including their transport route(s), have not been fully explained. This perspective overviews the current knowledge and issues and discusses advanced techniques, such as in situ matrix-assisted laser desorption/ionization mass spectrometry imaging, and future perspectives on the study of the bioavailability of anthocyanins.

Roselle for hypertension in adults

BACKGROUND

Hypertension is considered to be a serious health problem worldwide. Controlling and lowering blood pressure are of significant benefit to people with hypertension because hypertension is a risk factor for stroke, heart disease, and cardiovascular disease. Roselle, the tropical plant Hibiscus sabdariffa, also commonly called sour tea or red tea, has been used as both a thirst-quenching drink and for medicinal purposes.

OBJECTIVES

To assess the effect of Roselle on blood pressure in people with primary hypertension.

SEARCH METHODS

For this update, the Cochrane Hypertension Information Specialist searched the following databases and trials registers for randomised controlled trials (RCTs): the Cochrane Hypertension Specialised Register (to 6 August 2021), Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 7), MEDLINE Ovid (1946 to 5 August 2021), Embase Ovid (1974 to 5 August 2021), ProQuest Dissertations & Theses (to 6 August 2021), Web of Science Clarivate (to 7 August 2021), Food Science and Technology Abstracts Clarivate (to 7 August 2021), the WHO International Clinical Trials Registry Platform (to 6 August 2021), and the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (to 6 August 2021). We searched Google Scholar and OpenSIGLE. We also handsearched local and regional Chinese databases: CBM, CMCC, TCMLARS, CNKI, CMAC, and the Index to Chinese Periodical Literature (to 14 September 2020), as well as Thai databases (ThaiJO, CUIR, TDC, CMU e-Theses, TCTR) (to 3 October 2020). There were no language or publication date restrictions.

SELECTION CRITERIA

We sought RCTs evaluating the use of any forms of Roselle with placebo or no treatment in adults with hypertension. Our primary outcome was change in trough and/or peak systolic and diastolic blood pressure (SBP, DBP). Secondary outcomes were withdrawals due to adverse effects, change in pulse pressure, and change in heart rate.

DATA COLLECTION AND ANALYSIS

All search results were managed using Covidence and re-checked for the number of records, inclusion and exclusion of studies with Mendeley reference management software. We used standard methodological procedures expected by Cochrane. Two review authors worked independently in parallel for screening (titles and abstracts, and full reports), data extraction, risk of bias assessment, and assessment of the certainty of the evidence using the GRADE approach. Any disagreements were resolved by discussion or by consultation with the third review author if necessary. We presented mean difference (MD) of change in SBP and DBP with their corresponding 95% confidence interval (CI).

MAIN RESULTS

For this update, only one RCT with a parallel-group design involving 60 participants with type 2 diabetes mellitus fulfilled the inclusion criteria. This study investigated the effect of Roselle extract capsules (total dose of 5600 mg) compared with placebo (lactose) at eight weeks. The study was at low risk of selection bias, performance bias, and detection bias. Conversely, it was at high risk of attrition bias, reporting bias, and other bias (baseline imbalance). We have very little confidence in the effect estimate of Roselle on change-from-baseline in both SBP and DBP between the two groups. The MD of change in SBP was 1.65, 95% CI -7.89 to 11.19 mmHg, 52 participants, very low-certainty evidence. The MD of change in DBP was 4.60, 95% CI -1.38 to 10.58 mmHg, 52 participants, very low-certainty evidence. Our secondary outcomes of withdrawals due to adverse effects, change in pulse pressure, and change in heart rate were not reported. Due to the limited available data, no secondary analyses were performed (subgroup and sensitivity analysis).

AUTHORS' CONCLUSIONS

The evidence is currently insufficient to determine the effectiveness of Roselle compared to placebo for controlling or lowering blood pressure in people with hypertension. The certainty of evidence was very low due to methodological limitations, imprecision, and indirectness. There is a need for rigorous RCTs that address the review question.

The antihypertensive potential of flavonoids from Chinese Herbal Medicine: A review

With the coming of the era of the aging population, hypertension has become a global health burden to be dealt with. Although there are multiple drugs and procedures to control the symptoms of hypertension, the management of it is still a long-term process, and the side effects of conventional drugs pose a burden on patients. Flavonoids, common compounds found in fruits and vegetables as secondary metabolites, are active components in Chinese Herbal Medicine. The flavonoids are proved to have cardiovascular benefits based on a plethora of animal experiments over the last decade. Thus, the flavonoids or flavonoid-rich plant extracts endowed with anti-hypertension activities and probable mechanisms were reviewed. It has been found that flavonoids may affect blood pressure in various ways. Moreover, despite the substantial evidence of the potential for flavonoids in the control of hypertension, it is not sufficient to support the clinical application of flavonoids as an adjuvant or core drug. So the synergistic effects of flavonoids with other drugs, pharmacokinetic studies, clinical trials and the safety of flavonoids are also incorporated in the discussion. It is believed that more breakthrough studies are needed. Overall, this review may shed some new light on the explicit recognition of the mechanisms of anti-hypertension actions of flavonoids, pointing out the limitations of relevant research at the current stage and the aspects that should be strengthened in future researches.

The influence of tart cherries (Prunus Cerasus) on vascular function and the urinary metabolome: a randomised placebo-controlled pilot study

Montmorency tart cherries (MC) have been found to modulate indices of vascular function with interventions of varying duration. The objective of this preliminary study was to identify the chronic effects of MC supplementation on vascular function and the potential for urinary metabolomics to provide mechanistic evidence. We performed a placebo-controlled, double-blind, randomised study on 23 healthy individuals (18M, 7F) that consumed 30 ml MC or a placebo twice daily for 28 days. Whole body measures of vascular function and spot urine collections were taken at baseline and after supplementation. There were no significant changes to vascular function including blood pressure and arterial stiffness. Urinary metabolite profiling highlighted significant changes (P < 0⋅001) with putative discriminatory metabolites related to tryptophan and histidine metabolism. Overall, MC supplementation for 28 days does not improve indices of vascular function but changes to the urinary metabolome could be suggestive of potential mechanisms.

Higher habitual dietary flavonoid intake associates with lower central blood pressure and arterial stiffness in healthy older adults

Flavonoids have shown anti-hypertensive and anti-atherosclerotic properties: the impact of habitual flavonoid intake on vascular function, central haemodynamics and arterial stiffness may be important. We investigated the relationship between habitual flavonoid consumption and measures of central blood pressure and arterial stiffness. We performed cross-sectional analysis of 381 non-smoking healthy older adults (mean age 66·0 (sd 4·1) years; BMI, 26·4 (sd 4·41) kg/m2; 41 % male) recruited as part of the Australian Research Council Longevity Intervention study. Flavonoid intake (i.e. flavonols, flavones, flavanones, anthocyanins, isoflavones, flavan-3-ol monomers, proanthocyanidins, theaflavins/thearubigins and total consumption) was estimated from FFQ using the US Department of Agriculture food composition databases. Measures of central haemodynamics and arterial stiffness included systolic blood pressure (cSBP), diastolic blood pressure (cDBP), mean arterial pressure (cMAP) and augmentation index (cAIx). After adjusting for demographic and lifestyle confounders, each sd/d higher intake of anthocyanins ((sd 44·3) mg/d) was associated with significantly lower cDBP (-1·56 mmHg, 95 % CI -2·65, -0·48) and cMAP (-1·62 mmHg, 95 % CI -2·82, -0·41). Similarly, each sd/d higher intake of flavanones ((sd 19·5) mg/d) was associated with ~1 % lower cAIx (-0·93 %, 95 % CI -1·77, -0·09). These associations remained significant after additional adjustment for (1) a dietary quality score and (2) other major nutrients that may affect blood pressure or arterial stiffness (i.e. Na, K, Ca, Mg, n-3, total protein and fibre). This study suggests a possible benefit of dietary anthocyanin and flavanone intake on central haemodynamics and arterial stiffness; these findings require corroboration in further research.

Review of Functional and Pharmacological Activities of Berries

Functional plant-based foods (such as fruits, vegetables, and berries) can improve health, have a preventive effect, and diminish the risk of different chronic diseases during in vivo and in vitro studies. Berries contain many phytochemicals, fibers, vitamins, and minerals. The primary phytochemicals in berry fruits are phenolic compounds including flavonoids (anthocyanins, flavonols, flavones, flavanols, flavanones, and isoflavonoids), tannins, and phenolic acids. Since berries have a high concentration of polyphenols, it is possible to use them for treating various diseases pharmacologically by acting on oxidative stress and inflammation, which are often the leading causes of diabetes, neurological, cardiovascular diseases, and cancer. This review examines commonly consumed berries: blackberries, blackcurrants, blueberries, cranberries, raspberries, black raspberries, and strawberries and their polyphenols as potential medicinal foods (due to the presence of pharmacologically active compounds) in the treatment of diabetes, cardiovascular problems, and other diseases. Moreover, much attention is paid to the bioavailability of active berry components. Hence, this comprehensive review shows that berries and their bioactive compounds possess medicinal properties and have therapeutic potential. Nevertheless, future clinical trials are required to study and improve the bioavailability of berries' phenolic compounds and extend the evidence that the active compounds of berries can be used as medicinal foods against various diseases.

Anthocyanins: Promising Natural Products with Diverse Pharmacological Activities

Anthocyanins are natural products that give color to plants. As natural plant pigments, anthocyanins also have a series of health-promoting benefits. Many researchers have proved that anthocyanins have therapeutic effects on diseases, such as circulatory, nervous, endocrine, digestive, sensory, urinary and immune systems. Additionally, a large number of studies have reported that anthocyanins have an anticancer effect through a wide range of anti-inflammatory and antioxidant effects. The anti-disease impact and mechanism of anthocyanins are diverse, so they have high research value. This review summarizes the research progress of anthocyanins on the pharmacological agents of different diseases to provide references for subsequent research.

The Influence of Tart Cherry (Prunus cerasus, cv Montmorency) Concentrate Supplementation for 3 Months on Cardiometabolic Risk Factors in Middle-Aged Adults: A Randomised, Placebo-Controlled Trial

BACKGROUND

Tart Montmorency cherries (MC) have been shown to be rich in anthocyanins and other phytochemicals known to have anti-inflammatory properties and influence pathways that might improve cardiometabolic health. However, there is limited evidence for the longer-term use of tart cherries on these indices. The aim of the current study was to investigate the influence of MC concentrate on cardiometabolic health indices following a 3-month supplementation period.

METHODS

Fifty middle-aged adults (34 males and 16 females; mean ± SD age: 48 ± 6 years and BMI: 27.6 ± 3.7 kg/m2) completed a randomised, placebo-controlled parallel study in which they either received MC or an isocaloric placebo. Participants drank 30 mL of their allocated treatment twice per day for 3 months. Vascular function (blood pressure [BP], heart rate [HR], pulse wave velocity and analysis [PWV/A], and flow mediated dilation [FMD]) as well as indices of metabolic health (insulin, glucose, lipid profiles, and high sensitivity C reactive protein) were measured following an overnight fast before and after the 3 months.

RESULTS

No effect of the intervention between the groups was observed for vascular function or metabolic health variables following the intervention (p > 0.05). However, MC concentrate was shown to be safe and well-tolerated and, importantly, did not have any deleterious effects on these outcomes. In conclusion, MC has no influence on cardiometabolic indices in middle-aged adults.

Matrix-assisted laser desorption/ionization mass spectrometry-guided visualization analysis of intestinal absorption of acylated anthocyanins in Sprague-Dawley rats

It is unknown whether intestinal absorption of acylated anthocyanins occurs in their intact or metabolized form. In this study, with the aid of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging, intestinal absorption of acylated anthocyanins was visually investigated. Anthocyanin extracts from purple carrots were orally administered to Sprague-Dawley rats. Acylated cyanidins were absorbed into portal and circulating blood systems in their intact form, and aglycon; cyanidin 3-O-(6-O-feruloyl-β-d-glucopyranosyl)-(1 → 6)-[β-d-xylopyranosyl-(1 → 2)]-β-d-galactopyranoside (Cy3XFGG), and showed a high absorption of 39.3 ± 0.1 pmol/mL-plasma at 60 min after administration. MALDI-MS imaging analysis of the rat jejunum membranes showed that an organic anion transporting polypeptide (OATP) transporter was involved in Cy3XFGG transport, while deacylated anthocyanins were incorporated through both the glucose transporter 2 and OATP routes. In conclusion, acylated anthocyanin, Cy3XFGG, can be absorbed in its intact form through intestinal OATP.

Insights to potential antihypertensive activity of berry fruits

Hypertension is one of the main risk factors for cardiovascular disease and causes widespread morbidity and mortality worldwide. Although several antihypertensive drugs have been proposed for management of high blood pressure, changing lifestyle, including diet, has attracted interest recently. In this sense, consumption of fruits and vegetables, which are rich in vitamins, minerals, and phytochemicals, has been assigned as an efficient therapeutics. Berry fruits contain various bioactive compounds with potential health implications such as antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. The main mechanisms responsible for antihypertensive activity mainly arise from the activity of flavonoids, minerals, and vitamins, as well as fibers. The objective of this review is to provide a summary of studies regarding the effect of berry fruits on the hypertensive animals and humans. The mechanisms involved in reducing blood pressure by each group of compounds have been highlighted. It can be concluded that berries' bioactive compounds are efficient in mitigation of hypertension through improvement of vascular function, angiotensin-converting enzyme's (ACE) inhibitory activity, increasing endothelial nitric oxide synthase (eNOS) activity, and nitric oxide (NO) production, besides anti-oxidative and anti-inflammatory activities. These fruits can be considered as potential sources of invaluable compounds for development of antihypertensive foods and pharmaceuticals.

Food processing and risk of hypertension: Cohort of Universities of Minas Gerais, Brazil (CUME Project)

Objective:

To analyse the association between food consumption according to the degree of processing and incidence of hypertension in CUME project participants.

Design:

Longitudinal study in which food consumption was evaluated according to the percentage contribution of daily energetic intake (%/d) of each NOVA classification group (unprocessed/minimally processed foods and culinary preparations (U/MPF&CP); processed foods and ultra-processed foods (UPF)). Hypertension was defined according to American College of Cardiology/American Heart Association (ACC/AHA) criteria. Adjusted relative risks (RR) and their 95% confidence intervals (95 % CI) were estimated by Poisson regression models with robust variances.

Setting:

Brazil.

Participants:

1221 graduates classified as non-hypertensive at baseline and monitored for 2 years.

Results:

Daily energetic percentage from each group according to degree of processing was 64·3 (sd 12) % for U/MPF&CP; 9·9 (sd 5·8) % for processed foods and 25·8 (sd 11) % for UPF. Incidence of hypertension was high (152/1000 person-years; n 113, 193/1000 person-years in males and n 257, 138/1000 person-years in females). After adjusting for potential confounders, participants in the upper quintile of daily energetic intake of U/MPF&CP presented a reduced risk of hypertension (RR: 0·72; 95 % CI 0·52, 0·98), while those in the upper quintile of daily energetic intake of UPF presented an increased risk of the outcome (RR: 1·35; 95 % CI 1·01, 1·81).

Conclusions:

In this prospective cohort of Brazilian middle-aged adult university graduates, the highest consumptions of U/MPF&CP and UPF were associated with, respectively, reduced and increased risk of hypertension. Additional longitudinal studies are needed to confirm our results.

Dietary Anthocyanins and Human Health

Anthocyanins may contribute to the inverse relationship between fruit and vegetable intake and chronic disease. Anthocyanins are pigments found in plant structures that consist of an anthocyanidin (aglycone) attached to sugar moieties. Anthocyanins may be beneficial for health through effects on cellular antioxidant status and inflammation; however, their underlying mechanisms of action in their protection of chronic diseases are likely complex and require further elucidation. This Special Issue comprises 8 peer-reviewed papers (including 6 original research articles) which highlight the diverse bioactivities of anthocyanins and anthocyanin-rich foods in the protection against chronic disease.

Roselle for hypertension in adults

BACKGROUND

Hypertension is considered a serious health problem worldwide. Controlling and lowering blood pressure have a significant benefit to the hypertensive patients because hypertension is a risk factor for stroke, heart disease and cardiovascular disease. A tropical plant called Roselle, or Red Sorrel in English-speaking countries, has been used both as a thirst-quenching drink and for medical purposes.

OBJECTIVES

To explore the effect of Roselle on blood pressure in hypertensive adult patients.

SEARCH STRATEGY

The following databases were searched (Date of most recent search was September 2009): - Cochrane Database of Systematic Reviews (2nd Quarter 2009) - DARE (2nd Quarter 2009) - Ovid MEDLINE (1950 to Present with Daily Update) - EMBASE (1980 to 2009 Week 22) - AMED (1985 to May 2009) - EBSCO CINAHL - BIOSIS (1969 to 2008) - AGRICOLA (1970 to May 2009) - Food Science and Technology Abstract (1969 to 2009 June Week 1) - International Pharmaceutical Abstracts - International Bibliographic Information on Dietary Supplements - Clinical Trials.gov and Current Controlled Trials - OpenSIGLE - Hand searching of journals - ISI Web of Knowledge

SELECTION CRITERIA

We sought randomised control trials (RCTs) evaluating use of any forms of Roselle with placebo or no treatment in hypertensive patients. Change in trough and/or peak systolic and diastolic blood pressure were primary outcomes. Secondary outcomes were withdrawals due to adverse effects, change of pulse pressure and change of heart rate.

DATA COLLECTION AND ANALYSIS

Two review authors (C Ngamjarus, CN and P Pattanittum, PP) independently scanned titles and abstracts, as well as independently screened the full reports of the potentially relevant studies. At each stage, the results were compared and disagreements were solved by discussion.

MAIN RESULTS

No studies were identified that met the inclusion criteria. However, one abstract of an ongoing study is likely to meet the inclusion criteria, when completed.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support the benefit of Roselle for either controlling or lowering blood pressure in patients with hypertension. Based on the information of this review, there is a clear need to develop well-designed studies to assess the efficacy of Roselle on hypertensive patients.