Garlic for hypertension: A systematic review and meta-analysis of randomized controlled trials

Valorizing Agro‐Food Waste for Nutraceutical Development: Sustainable Approaches for Managing Metabolic Dysfunction‐Associated Steatotic Liver Disease and Related Co‐Morbidities

This comprehensive investigation delves into the interconnectedness of different features of cardiometabolic syndrome, such as metabolic dysfunction‐associated steatotic liver disease (MASLD), atherosclerotic cardiovascular disease (ASCVD), and gut dysbiosis, highlighting the crucial role of nutraceuticals in their management and prevention. Given the significant overlap in the pathophysiology of these conditions, the treatment with nutraceuticals, especially those derived from agro‐food waste, offers a promising, sustainable, and innovative approach to healthcare. The 2030 Agenda for Sustainable Development and the One Health concept are key frameworks for selecting the most interesting supply chain for the production of nutraceuticals from agro‐food waste, ensuring environmental sustainability, and innovative agricultural practices. In this review, the therapeutic potential of kiwifruit and apples has been explored, detailing how their bioactive compounds, like polyphenols, fiber, pectin, kaempferol, phloretin, and phlorizin, may contribute to the management of MASLD, ASCVD, and gut dysbiosis. Various extraction methods for active ingredients, including chemical, water, and enzyme extractions, are analyzed for their respective benefits and drawbacks. By integrating scientific research, sustainable agricultural practices, and innovative extraction methods, we can develop effective strategies to combat these pervasive health issues. This holistic approach not only enhances individual health outcomes but also supports broader environmental and societal goals, promoting a healthier future for all.

The role of Chinese herbal medicine in the regulation of oxidative stress in treating hypertension: from therapeutics to mechanisms

BACKGROUND

Although the pathogenesis of essential hypertension is not clear, a large number of studies have shown that oxidative stress plays an important role in the occurrence and development of hypertension and target organ damage.

PURPOSE

This paper systematically summarizes the relationship between oxidative stress and hypertension, and explores the potential mechanisms of Chinese herbal medicine (CHM) in the regulation of oxidative stress in hypertension, aiming to establish a scientific basis for the treatment of hypertension with CHM.

METHODS

To review the efficacy and mechanism by which CHM treat hypertension through targeting oxidative stress, data were searched from PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the Chinese National Knowledge Infrastructure, the VIP Information Database, the Chinese Biomedical Literature Database, and the Wanfang Database from their inception up to January 2024. NPs were classified and summarized by their mechanisms of action.

RESULTS

In hypertension, the oxidative stress pathway of the body is abnormally activated, and the antioxidant system is inhibited, leading to the imbalance between the oxidative and antioxidative capacity. Meanwhile, excessive production of reactive oxygen species can lead to endothelial damage and vascular dysfunction, resulting in inflammation and immune response, thereby promoting the development of hypertension and damaging the heart, brain, kidneys, blood vessels, and other target organs. Numerous studies suggested that inhibiting oxidative stress may be the potential therapeutic target for hypertension. In recent years, the clinical advantages of traditional Chinese medicine (TCM) in the treatment of hypertension have gradually attracted attention. TCM, including active ingredients of CHM, single Chinese herb, TCM classic formula and traditional Chinese patent medicine, can not only reduce blood pressure, improve clinical symptoms, but also improve oxidative stress, thus extensively affect vascular endothelium, renin-angiotensin-aldosterone system, sympathetic nervous system, target organ damage, as well as insulin resistance, hyperlipidemia, hyperhomocysteinemia and other pathological mechanisms and hypertension related risk factors.

CONCLUSIONS

CHM display a beneficial multi-target, multi-component, overall and comprehensive regulation characteristics, and have potential value for clinical application in the treatment of hypertension by regulating the level of oxidative stress.

Garlic and Hypertension: Efficacy, Mechanism of Action, and Clinical Implications

Hypertension is a major risk factor for heart disease and stroke. Garlic has a long history of use in traditional medicine for various conditions, including hypertension. This narrative review examined the scientific evidence on the efficacy of garlic in lowering blood pressure. It explores the historical uses of garlic in different cultures for medicinal purposes and delves into the phytochemical composition of garlic, highlighting key components, like allicin and ajoene, that are believed to contribute to its potential health benefits. Clinical studies that investigated the effects of garlic and garlic-based supplements on blood pressure are presented, with the findings suggesting that garlic consumption may modestly reduce blood pressure, particularly in individuals with mild hypertension. Potential mechanisms of action include increased nitric oxide production, improved endothelial function, and antioxidant properties. While garlic may offer some benefits for blood pressure management, it should not be considered a substitute for conventional antihypertensive medications. Further large-scale, long-term clinical trials are warranted to establish the efficacy of garlic in managing hypertension, including the optimal dosage and formulation.

Garlic consumption can reduce the risk of dyslipidemia: a meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

Garlic is used as an important medicinal food for treatment of many diseases, however, the association between garlic consumption and dyslipidemia have yielded inconsistent results. So we carried this meta-analysis to explore the blood lipid-lowering effects of garlic.

METHODS

Databases such as PubMed, Scopus, Web of science, Embase, Cochrane Library were systematically searched until June 2024. Heterogeneity among studies was examined using Q and I2 statistics. Also subgroup analysis were conducted to explore the potential heterogeneity. Combined weighted mean differences (WMD) with their 95% confidence interval (CI) were calculated using a random-effects model. The GRADE approach was used to evaluate the overall certainty of the evidence in the meta-analyses.

RESULTS

A total of 21 RCTs studies involved association between garlic consumption and blood lipids level of dyslipidemia patients were included in the meta-analysis. The pooled results showed that garlic consumption significantly reduced total cholesterol (TC)(WMD = -0.64mmol/L, 95%CI = -0.75 --0.54, P < 0.001), triglyceride (TG)(WMD = -0.17mmol/L, 95%CI = -0.26 --0.09, P < 0.001), low-density lipoprotein(LDL-C)(WMD = -0.44mmol/L, 95%CI = -0.57 --0.31, P < 0.001) while slightly increased high-density lipoprotein (HDL-C)(WMD = 0.04mmol/L, 95%CI = -0.00 - 0.08, P < 0.001). And subgroup analyses showed that TC, TG and LDL-C significantly decreased in patients aged > 50 years compared to those aged ≤ 50 years. And garlic oil greatly reduced TC and LDL-C compared with garlic power. Finally, sensitivity analysis and publication bias showed that the results were reliable.

CONCLUSIONS

Evidence from this meta-analysis suggested that garlic consumption could be effective in reducing the risk of dyslipidemia and preventing CVDs. Particularly the older people were more susceptible to the protective effects of garlic.

Medicinal Plant Extracts against Cardiometabolic Risk Factors Associated with Obesity: Molecular Mechanisms and Therapeutic Targets

Obesity has increasingly become a worldwide epidemic, as demonstrated by epidemiological and clinical studies. Obesity may lead to the development of a broad spectrum of cardiovascular diseases (CVDs), such as coronary heart disease, hypertension, heart failure, cerebrovascular disease, atrial fibrillation, ventricular arrhythmias, and sudden cardiac death. In addition to hypertension, there are other cardiometabolic risk factors (CRFs) such as visceral adiposity, dyslipidemia, insulin resistance, diabetes, elevated levels of fibrinogen and C-reactive protein, and others, all of which increase the risk of CVD events. The mechanisms involved between obesity and CVD mainly include insulin resistance, oxidative stress, inflammation, and adipokine dysregulation, which cause maladaptive structural and functional alterations of the heart, particularly left-ventricular remodeling and diastolic dysfunction. Natural products of plants provide a diversity of nutrients and different bioactive compounds, including phenolics, flavonoids, terpenoids, carotenoids, anthocyanins, vitamins, minerals, fibers, and others, which possess a wide range of biological activities including antihypertensive, antilipidemic, antidiabetic, and other activities, thus conferring cardiometabolic benefits. In this review, we discuss the main therapeutic interventions using extracts from herbs and plants in preclinical and clinical trials with protective properties targeting CRFs. Molecular mechanisms and therapeutic targets of herb and plant extracts for the prevention and treatment of CRFs are also reviewed.

Safety classification of herbal medicine use among hypertensive patients: a systematic review and meta-analysis

Background

The use of herbal medicines (HMs) for the treatment of hypertension (HTN) is increasing globally, but research on the potential adverse effects and safety of HMs in HTN patients is limited. Therefore, this systematic review and meta-analysis aim to determine the global prevalence of HM usage among HTN patients and assess the safety of identified herbs based on current scientific evidence.

Methods

The PubMed/MEDLINE, EMBASE (Ovid), and Cumulated Index to Nursing and Allied Health Literature (CINAHL) databases were searched for cross-sectional studies on the use of HM among HTN patients. Our review includes studies published in English up to the year 2023. After extracting and appraising the data from the studies, a meta-analysis was conducted using the Stata version 16.0 to estimate the pooled prevalence of HM use in patients with HTN (PROSPERO: CRD42023405537). The safety classification of the identified HM was done based on the existing scientific literature.

Results

This study analyzed 37 cross-sectional studies from 21 countries and found that 37.8% of HTN patients used HM to manage their health. The prevalence of HM use varied significantly based on publication year and geographical region. Among the 71 identified herbs, Allium sativum L., Hibiscus sabdariffa L., and Olea europaea L. were the most commonly used. However, four herbs were identified as contraindicated, 50 herbs required caution, and only 11 herbs were considered safe for use.

Conclusion

The study highlights the potential risks of toxicities and adverse effects associated with HM use in the treatment of HTN. Ensuring patient safety involves using safe HMs in appropriate doses and avoiding contraindicated HMs. Future research should focus on identifying commonly used herbs, especially in resource-limited countries with poor HTN management, and additional clinical research is required to assess the toxicity and safety of commonly used HMs.

Moringa oleifera Lam. as a potential plant for alleviation of the metabolic syndrome-A narrative review based on in vivo and clinical studies

The metabolic syndrome (MetS) refers to the co-occurrence of risk factors, including hyperglycaemia, increased body weight, hypertension and dyslipidemia, which eventually lead to diabetes and cardiovascular disease, a common health problem worldwide. Recently, there has been an increasing interest in the use of plant-based products for the management of MetS, because of their less detrimental and more beneficial effects. Moringa oleifera (Moringaceae), commonly known as drumstick, is cultivated worldwide for its nutritional and medicinal properties. This review focuses on the in vivo and human studies concerning the potential of M. oleifera in the alleviation of MetS and its comorbidities. The search for relevant articles was carried out in PubMed and Google Scholar databases. Randomised controlled and clinical trials from the PubMed database were included in this review. The results suggested that the administration of M. oleifera, in vivo, shows clear signs of improvement in MetS indices. Despite fewer human studies, the existing data documented convincing results that uphold the potential of M. oleifera against MetS. Therefore, future research discussing the probable mechanism of action is much needed which could further assure the usage of M. oleifera in the treatment regimen of MetS.

Evidence on the use of alternative substances and therapies in hypertension

OBJECTIVE

Review of some of the best-known biological and non-biological complementary/alternative therapies/medicines (CAM) and their relationship with blood pressure (BP) and hypertension (HT).

SEARCH STRATEGY

Narrative review assessing a recent series of systematic reviews, meta-analyses, and clinical trials published in recent years, focusing on the effects of CAM on BP and HT.

SELECTION OF STUDIES

We searched EMBASE, MEDLINE, Cochrane Library and Google Scholar, obtaining a total of 4336 articles, finally limiting the search to 181 after applying filters.

SYNTHESIS OF RESULTS

Some studies on biological therapies show some usefulness in BP reduction with an adequate benefit-risk balance, although there is a scarcity of high-quality trials that support these results. Some mind-body therapies have shown hypothetical benefit; in contrast, others lack robust evidence.

CONCLUSIONS

Although some therapies present a reasonable risk-benefit ratio, they should in no case replace pharmacological treatment when indicated.

Antihypertensive Effects of an Optimized Aged Garlic Extract in Subjects with Grade I Hypertension and Antihypertensive Drug Therapy: A Randomized, Triple-Blind Controlled Trial

The use of garlic (Allium sativum) for treating arterial hypertension has been recognized as effective for several decades. However, tolerance to treatment is low, and several technological modifications have been developed to improve its tolerability, such as the aging process at controlled temperature and humidity. This study aims to validate the antihypertensive effects of an optimized extract of aged black garlic with low doses of s-allyl-cysteine (SAC) in a Grade I hypertensive population with drug treatment. A randomized, triple-blind, placebo-controlled parallel trial was developed, where a daily supplementation with 0.25 mg/day of SAC for 12 weeks was performed. A reduction in systolic and diastolic blood pressure of 1.8 mmHg (0.7 to 4.1 95% CI) and 1.5 mmHg (0.3 to 3.0 95% CI), respectively, was observed. Similarly, an increase in blood nitric oxide (10.3 µM, 1.1 to 19.5 95% CI) and antioxidant capacity (7 × 10-3 µM TE/min, (1.2 to 13 × 10-3 95% CI) and a reduction in uric acid levels (-0.3 mg/dL, -0.5 to -0.001 95% CI) and ACE activity (-9.3 U/L; -18.4 to -0.4 95% CI) were observed. No changes in endothelial function and inflammatory cytokines were observed. It was concluded that low-dose SAC supplementation in an optimized black-garlic extract allows for an extra-significant reduction in blood pressure in a Grade I hypertensive population receiving drug treatment.

Medicinal and therapeutic properties of garlic, garlic essential oil, and garlic-based snack food: An updated review

Garlic (Allium sativum) is an edible tuber belonging to the family Liliaceae. It has been used since ancient times as a spice to enhance the sensory characteristics of food and as a household remedy for the treatment of a variety of ailments. Garlic has been studied for its medicinal and therapeutic effects in the treatment of various human diseases for a long time. Health benefits associated with the consumption of garlic are attributed to the various sulfur compounds present in it such as allicin, ajoene, vinyl-dithiin, and other volatile organosulfur compounds which are all metabolized from alliin. Several researches in the literature have shown evidence that garlic exhibits antioxidant, antiviral, anti-microbial, anti-fungal, antihypertensive, anti-anemic, anti-hyperlipidemic, anticarcinogenic, antiaggregant, and immunomodulatory properties. The present review identifies and discusses the various health benefits associated with the consumption of garlic, its essential oil, and bioactive constituents, along with exploring the various snack-food products developed by incorporating garlic.

Effect of garlic powder supplementation on blood pressure and hs-C-reactive protein among nonalcoholic fatty liver disease patients: A randomized, double-blind, placebo-controlled trial

Based on the anti-inflammatory and antihypertensive properties of garlic, the current study was designed to evaluate the garlic powder effects on blood pressure and high-sensitivity C-reactive protein (hs-CRP) among Nonalcoholic Fatty Liver Disease patients (NAFLD). This randomized, double-blind, placebo-controlled trial study was conducted on 110 patients with NAFLD. The patients were randomly divided into 2 groups, receiving two tablets of either 400 mg garlic or placebo daily for 15 weeks. At baseline and the end of the study, blood pressure and hs-CRP were determined. Of 110 patients enrolled in the trial, 98 subjects were included in the final analysis. After the intervention, systolic blood pressures (SBP) (mean: -7.89; 95%CI:‒11.39 to -4.39 mm Hg), diastolic blood pressure (DBP) (mean: -5.38; 95%CI: -7.77 to -3 mm Hg), and Mean Arterial Pressure (MAP) (mean: -6:95%CI: -8.4 to -3.6 mm Hg) decreased significantly in the garlic group as compared to the placebo group. Also, the percentage of reduced hs-CRP was significantly higher in the intervention group compared with the control group (mean: -16.1; 95%CI: -32.7 to -0.53; p = .035). Moreover, a positive correlation was observed between the percentage change in hs-CRP and percentage changes in SBP (r = 0.221; p = .029), DBP (r = 0.166; p = .012), and MAP (r = 0.210; p = .038). Garlic supplementation can be a safe and potentially adjunct treatment to reduce blood pressure and the risk of cardiovascular disorders in patients with NAFLD.

Phytotherapy for Cardiovascular Disease: A Bench-to-Bedside Approach

At present, cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, and global trends suggest that this panorama will persist or worsen in the near future. Thus, optimization of treatment strategies and the introduction of novel therapeutic alternatives for CVD represent key objectives in contemporary biomedical research. In recent years, phytotherapy-defined as the therapeutic use of whole or minimally modified plant components-has ignited large scientific interest, with a resurgence of abundant investigation on a wide array of medicinal herbs (MH) for CVD and other conditions. Numerous MH have been observed to intervene in the pathophysiology of CVD via a myriad of molecular mechanisms, including antiinflammatory, anti-oxidant, and other beneficial properties, which translate into the amelioration of three essential aspects of the pathogenesis of CVD: Dyslipidemia, atherosclerosis, and hypertension. Although the preclinical data in this scenario is very rich, the true clinical impact of MH and their purported mechanisms of action is less clear, as large-scale robust research in this regard is in relatively early stages and faces important methodological challenges. This review offers a comprehensive look at the most prominent preclinical and clinical evidence currently available concerning the use of MH in the treatment of CVD from a bench-to-bedside approach.

Natural Bioactive Compounds Useful in Clinical Management of Metabolic Syndrome

Metabolic syndrome (MetS) is a clinical manifestation characterized by a plethora of comorbidities, including hyperglycemia, abdominal obesity, arterial hypertension, and dyslipidemia. All MetS comorbidities participate to induce a low-grade inflammation state and oxidative stress, typical of this syndrome. MetS is related to an increased risk of cardiovascular diseases and early death, with an important impact on health-care costs. For its clinic management a poly-pharmaceutical therapy is often required, but this can cause side effects and reduce the patient's compliance. For this reason, finding a valid and alternative therapeutic strategy, natural and free of side effects, could represent a useful tool in the fight the MetS. In this context, the use of functional foods, and the assumption of natural bioactive compounds (NBCs), could exert beneficial effects on body weight, blood pressure and glucose metabolism control, on endothelial damage, on the improvement of lipid profile, on the inflammatory state, and on oxidative stress. This review focuses on the possible beneficial role of NBCs in the prevention and in the clinical management of MetS and its comorbidities.

Nursing case management for people with hypertension: A randomized controlled trial protocol

OBJECTIVE

To explore the effect of management of nursing case on blood pressure control in hypertension patients.

METHOD

This is a randomized controlled study which will be carried out from May 2021 to May 2022. The experiment was granted through the Research Ethics Committee of the People's Hospital of Chengyang District (03982808). Our research includes 200 patients. Patients who meet the following conditions will be included in this experiment: the patients aged 18 to 60 years; the patients had the diagnosis of hypertension; and the urban residents. While patients with the following conditions will be excluded: having renal failure, liver failure, heart and respiratory failure; and known pregnancy. Primary result is blood pressure, while secondary results are treatment compliance, waist circumference, body mass index (BMI), type and number of antihypertensive agents used, and the existence of metabolic and cardiovascular comorbidities.

RESULTS

Table 1 shows the clinical outcomes between the two groups.

CONCLUSION

Nursing case management is effective to improve the prognosis of hypertension patients.

Multi-phytochemical determination of polar and non-polar garlic bioactive compounds in different food and nutraceutical preparations

Amongst functional foods, garlic and its by-products stand out given their rich phytochemical profile. A comprehensive analytical approach becomes necessary to fully address garlic preparations health-promoting activities, considering the coexistence of several active ingredients from different chemical families. For this, we developed a multi-phytochemical protocol combining Ultrasound and Dispersive Liquid-Liquid Microextraction, coupled to Liquid Chromatography, for the determination of flavonols, organosulfur compounds, and inulin. Hydrophilic interaction chromatography showed an adequate resolution of flavonols and sugars in a shorter time. The protocol showed a suitable performance and acceptable quantitative yields for garlic powder, cooked garlic, black garlic, and liquid garlic flavouring samples. Additionally, the proposed methodology represented a useful tool to assess how the different garlic products related to functional properties, taking into account the various phytochemical families present in each sample. This is the first time a comprehensive and multi-phytochemical validated analysis of garlic preparations is proposed.

Does Home Remedy Use Contribute to Medication Nonadherence Among Blacks with Hypertension?

Background

Home remedies (HRs) are described as foods, herbs, and other household products used to manage chronic conditions. The objective of this study was to examine home remedy (HR) use among Blacks with hypertension and to determine if home remedy use is correlated with blood pressure and medication adherence.

Methods

Data for this cross-sectional study were obtained from the TRUST study conducted between 2006-2008. Medication adherence was measured using the Morisky Medication Adherence Scale, and HR use was self-reported. Multivariable associations were quantified using ordinal logistic regression.

Results

The study sample consisted of 788 Blacks with hypertension living in the southern region of the United States. HR use was associated with higher systolic (HR users 152.79, nonusers 149.53; P=.004) and diastolic blood pressure (HR users 84.10, nonusers 82.14 P=.005). Use of two or more HRs was associated with low adherence (OR: .55, CI: .36-.83, P= .004).

Conclusion

The use of HR and the number of HRs used may be associated with medication nonadherence, and higher systolic and diastolic blood pressure among Blacks with hypertension. Medication nonadherence is of critical importance for individuals with hypertension, and it is essential that health care providers be aware of health behaviors that may serve as barriers to medication adherence, such as use of home remedies.

Nutraceuticals: Reviewing their Role in Chronic Disease Prevention and Management

Over half the adult population in many Western countries consume nutraceuticals because of their purported therapeutic benefits, accessibility and convenience. Several studies have demonstrated that they may also serve as a useful adjunct to pharmaceuticals to better manage chronic conditions or offset negative side effects. Individuals are advised to consult their physician before using nutraceuticals, but this advice is often overlooked. Thus, the community pharmacist plays an increasingly important role in assisting consumers with selecting a nutraceutical that is safe and for which there is evidence of therapeutic efficacy. Therefore, the aim of this review is to summarise the clinical evidence, safety and purported mechanisms of action for selected nutraceuticals in the management of chronic diseases, including obesity, diabetes, hypertension, hypercholesterolemia and inflammatory-based diseases.

Comparison Among Garlic, Berberine, Resveratrol,Hibiscus sabdariffa, GenusZizyphus, Hesperidin, Red Beetroot,Catha edulis,Portulaca oleracea, and Mulberry Leaves in the Treatment of Hypertension and Type 2 DM: A Comprehensive Review

Diabetes mellitus (DM) and hypertension are 2 of the most prevalent diseases with poor impact on health status worldwide. In most cases, they coexist with other metabolic disorders as well as cardiac, micro- and macrovascular complications. Many plants are known for their hypotensive, cardioprotective, and/or antidiabetic activities. Their active ingredients either identified and isolated or still utilized as herbal preparations of certain plant parts. The use of medicinal plants comprises the main basis for most of the traditional medicine (TM) systems and procedures. As conventional medicines seem insufficient to control such progressive diseases, herbal agents from TM could be used as adjuvant with good impact on disease control and progression as well as other concomitant health conditions. The aim of this study is to compare the efficacy of 10 different herbal medicines of botanical origin or herbal preparations in the management of hypertension and its cardiovascular complications and type 2 DM along with various coexisting health disorders. These herbal medicines are garlic, berberine, resveratrol, Hibiscus sabdariffa, Zizyphus ( oxyphylla, mucronate, jujube, rugosa), hesperidin, red beetroot, Catha edulis, mulberry leaves, and Portulaca oleracea.

Therapeutic effects of garlic in cardiovascular atherosclerotic disease

Garlic (Allium sativum) is a widely known medicinal plant, potential of which remains to be fully evaluated. Its wide-range beneficial effects appear to be relevant for treatment and prevention of atherosclerosis and related diseases. It is generally believed that garlic-based preparations are able to improve lipid profile in humans, inhibit cholesterol biosynthesis, suppress low density lipoprotein oxidation, modulate blood pressure, suppress platelet aggregation, lower plasma fibrinogen level and increase fibrinolytic activity, thus providing clinically relevant cardioprotective and anti-atherosclerotic effects. It is important to assess the level of evidence available for different protective effects of garlic and to understand the underlying mechanisms. This information will allow adequate integration of garlic-based preparations to clinical practice. In this review, we discuss the mechanisms of anti-atherosclerotic effects of garlic preparations, focusing on antihyperlipidemic, hypotensive, anti-platelet and direct anti-atherosclerotic activities of the medicinal plant. We also provide an overview of available meta-analyses and a number of clinical trials that assess the beneficial effects of garlic.

The effect of garlic on vascular function: A systematic review of randomized clinical trials

BACKGROUNDS AND AIMS

Atherosclerosis and its associated cardiovascular disease (CVD) represent a major global health problem worldwide and vascular dysfunction is important in its pathogenesis. Clinical trials investigating the effect of garlic on vascular function measured by several non-invasive methods and their results are inconsistent. This study aimed to summarize the current evidence regarding the effectiveness of garlic as one of the world's most ancient medicines on measures of vascular reactivity and/or stiffness in adults.

METHODS

All published RCTs in English were systematically searched on PubMed, Scopus and Google Scholar search engines up to Oct 2019. The exposure and outcome variable of interest were garlic and vascular function measurements. Ten trials which met inclusion criteria were included in this study.

RESULTS

A total of 45 studies were found through search databases. After excluding duplicates, the 25 remaining studies were screened by title and abstract which 15 of them excluded. Finally, ten trials were included in this review study, which were published between 2004 and 2018.

CONCLUSIONS

Findings were inconsistent. However, garlic has the potential to improve vascular function, particularly in subjects with cardiovascular risk factors. Additional human studies on garlic and its constituents should consider the population and the specific type of garlic preparation.

Effect of cinnamon supplementation on blood pressure and anthropometric parameters in patients with type 2 diabetes: A systematic review and meta-analysis of clinical trials

BACKGROUND AND AIMS

The present systematic review and meta-analysis was conducted to investigate the effect of cinnamon supplementation on blood pressure and anthropometric indices in patients with type 2 diabetes.

METHODS

PubMed, Embase, Scopus, Web of Science and Cochrane Library were systematically searched to find relevant records up to 22 August 2019. Standard mean difference (SMD) and 95% confidence interval (CI) were used to evaluate the effect of cinnamon supplementation on the outcomes of this study. In the case of heterogeneity, fixed and random effect models were used. The obtained data were analyzed by Stata 13. After excluding irrelevant records, 9 eligible articles were included.

RESULTS

This meta-analysis found a significant reduction in systolic blood pressure (SBP) (SMD: -0.532, 95% CI: [-1.032, -0.033], P = 0.037) and diastolic blood pressure (DBP) (SMD: -0.681, 95% CI: [-1.297, -0.065], P = 0.030) of patients with type 2 diabetes following cinnamon supplementation. Based on the results of the present study, cinnamon supplementation had no significant effect on the body weight (BW) (SMD: -0.309, 95% CI: [-0.793, 0.175], P = 0.211), body mass index (BMI) (SMD: -0.550, 95% CI: [-1.244, 0.144], P = 0.120). and waist circumference (WC) (SMD: -0.235, 95% CI: [-0.518, 0.047], P = 0.103).

CONCLUSIONS

Cinnamon supplementation significantly decreased SBP and DBP of patients with type 2 diabetes. Although cinnamon intake caused changes in anthropometric parameters, the observed changes were not statistically significant.

Antihypertensive phytocomplexes of proven efficacy and well-established use: Mode of action and individual characterization of the active constituents

Hypertension has become the leading risk factor for worldwide cardiovascular diseases. Conventional pharmacological treatment, after both dietary and lifestyle changes, is generally proposed. In this review, we present the antihypertensive properties of phytocomplexes from thirteen plants, long ago widely employed in ethnomedicines and, in recent years, increasingly evaluated for their activity in vitro and in vivo, also in humans, in comparison with synthetic drugs acting on the same systems. Here, we focus on the demonstrated or proposed mechanisms of action of such phytocomplexes and of their constituents proven to exert cardiovascular effects. Almost seventy phytochemicals are described and scientifically sound pertinent literature, published up to now, is summarized. The review emphasizes the therapeutic potential of these natural substances in the treatment of the 'high normal blood pressure' or 'stage 1 hypertension', so-named according to the most recent European and U.S. guidelines, and as a supplementation in more advanced stages of hypertension, however needing further validation by clinical trial intensification.

An Appraisal of Developments in Allium Sulfur Chemistry: Expanding the Pharmacopeia of Garlic

Alliums and allied plant species are rich sources of sulfur compounds that have effects on vascular homeostasis and the control of metabolic systems linked to nutrient metabolism in mammals. In view of the multiple biological effects ascribed to these sulfur molecules, researchers are now using these compounds as inspiration for the synthesis and development of novel sulfur-based therapeutics. This research has led to the chemical synthesis and biological assessment of a diverse array of sulfur compounds representative of derivatives of S-alkenyl-l-cysteine sulfoxides, thiosulfinates, ajoene molecules, sulfides, and S-allylcysteine. Many of these synthetic derivatives have potent antimicrobial and anticancer properties when tested in preclinical models of disease. Therefore, the current review provides an overview of advances in the development and biological assessment of synthetic analogs of allium-derived sulfur compounds.

Raw garlic consumption is inversely associated with prehypertension in a large-scale adult population

Previous studies have shown that allicin can lower blood pressure (BP) by reducing oxidative stress and inflammation. However, the association between habitual raw garlic intake (as allicin source) and prehypertension are unclear. The aim of this study was to investigate how raw garlic consumption is associated with prehypertension in an adult population. A cross-sectional study was conducted with 22,812 adults (mean [standard deviation] age: 39.4 [10.7] years; males, 47.7%) in Tianjin, China. Raw garlic consumption was assessed using a validated food frequency questionnaire. BP was measured at least twice by trained nurses using an automatic device. Prehypertension was defined as systolic BP of 120-139 mmHg and/or diastolic BP of 80-89 mmHg without taking antihypertensive medication. Multiple logistic regression models were used to assess the association between raw garlic consumption and prehypertension. The prevalence of prehypertension was 49.9%. After fully adjusting for potential confounders, the ORs (95% confidence intervals) of having prehypertension by increasing frequency of raw garlic consumption were 1.00 (reference) for ≤3 times/week, 0.96 (0.87, 1.06) for 4 times/week to 1 time/day, and 0.69 (0.52, 0.90) for ≥2 times/day (p for trend = 0.06). In contrast, no associations were observed between other kinds of allium vegetables consumption and prehypertension. In conclusion, our results suggested that a more frequent consumption of raw garlic was inversely associated with prehypertension. This is the first large-scale study on the association between raw garlic consumption and prehypertension in the general population.

Role of Nutrition and Exercise Programs in Reducing Blood Pressure: A Systematic Review

The combined effect of diet and strength training (ST) on blood pressure (BP) seems to be very important for the treatment of prehypertension and hypertension (HT). Therefore, the aim of this study was to determine whether ST alone or combined with nutrition or supplementation has an impact on the arterial pressure reduction in normotensive and hypertensive populations. A systematic computerized literature search was performed according to the PRISMA guidelines using PubMed, Scopus and Google Scholar; only English language studies published from 1999 until 2018 were included. This systematic search identified the results of 303 individuals from nine studies. The ST program alone had a similar effectiveness as the nutrition program (NP) alone; however, their combination did not result in increased effectiveness in terms of a high BP reduction. The consumption of L-citrulline had a similar effect as ST on lowering BP; on the other hand, caffeine led to an increase in BP during the ST session. Our data suggest that a combination of ST 2-3 times a week at moderate intensity and a NP seems to be equally effective in terms of lowering BP (systolic and diastolic) as ST and NP alone.

Efficacy and safety of Chinese herbal medicine Xiao Yao San in hypertension: A systematic review and meta-analysis

BACKGROUND

Xiao Yao San (XYS) is thought to be beneficial for the treatment of hypertension in China.

PURPOSE

A systematic review and meta-analysis was performed to evaluate the efficacy and safety of XYS in hypertension.

STUDY DESIGN

A comprehensive literature search was conducted in 7 electronic databases for randomized controlled trials from their inception until January 7, 2019.

METHODS

Methodological quality was assessed independently using the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

A total of 17 trials including 1460 hypertensive patients met the selection criteria. Pooled analysis favored XYS plus antihypertensive drugs on blood pressure (BP), Hamilton anxiety scale, self-rating anxiety scale, self-rating depression scale, 9-item patient health questionnaire scale, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, homocysteine, and C-reactive protein. No significant difference between XYS plus antihypertensive drugs and antihypertensive drugs on major cardiovascular and cerebrovascular events was identified. XYS was well tolerated in the treatment of hypertension.

CONCLUSION

XYS adjuvant to antihypertensive drugs maybe beneficial for hypertensive patients in lowering BP, improving depression, regulating blood lipids, and inhibiting inflammation. However, the efficacy and safety of XYS are still uncertain due to methodological shortcomings. More long-term, randomized, double-blinded clinical trials are needed in future studies.

Allium vegetable consumption and health: An umbrella review of meta-analyses of multiple health outcomes

Previously, our meta-analysis and other studies have suggested that allium vegetable consumption is beneficial for health, but no umbrella review has been conducted to assess the evidence of the various health benefits of allium vegetable consumption. Therefore, we conducted this umbrella review on this topic. This umbrella review included a total of 16 meta-analyses with 50 unique outcomes. The most beneficial cancer-related outcome was shown for gastric cancer (risk ratio 0.78; 95% confidence interval [CI] 0.67-0.91). In addition, only 8 weeks of garlic consumption significantly decreased serum total cholesterol (weighted mean differences -17.20 mg/dl; 95% CI -23.10 to -11.30), and patients with dyslipidemia who consumed garlic experienced more benefits than the whole population. Diabetic patients with longer durations of garlic intake experienced more benefits in terms of fasting blood glucose (FBG), HbA1c, and serum fructosamine than healthy participants, and garlic intake was associated with blood pressure reduction in hypertensive patients but not in normotensive participants. Limited side effects of garlic, such as garlic odor and gastrointestinal complaints, were reported among the included meta-analyses. Our results suggested that allium vegetables might be beneficial for cancer prevention. In particular, garlic was comparatively safe and is recommended as a long-term dietary component for patients with dyslipidemia, diabetes, and hypertension.

The mechanisms of pharmacokinetic food-drug interactions - A perspective from the UNGAP group

The simultaneous intake of food and drugs can have a strong impact on drug release, absorption, distribution, metabolism and/or elimination and consequently, on the efficacy and safety of pharmacotherapy. As such, food-drug interactions are one of the main challenges in oral drug administration. Whereas pharmacokinetic (PK) food-drug interactions can have a variety of causes, pharmacodynamic (PD) food-drug interactions occur due to specific pharmacological interactions between a drug and particular drinks or food. In recent years, extensive efforts were made to elucidate the mechanisms that drive pharmacokinetic food-drug interactions. Their occurrence depends mainly on the properties of the drug substance, the formulation and a multitude of physiological factors. Every intake of food or drink changes the physiological conditions in the human gastrointestinal tract. Therefore, a precise understanding of how different foods and drinks affect the processes of drug absorption, distribution, metabolism and/or elimination as well as formulation performance is important in order to be able to predict and avoid such interactions. Furthermore, it must be considered that beverages such as milk, grapefruit juice and alcohol can also lead to specific food-drug interactions. In this regard, the growing use of food supplements and functional food requires urgent attention in oral pharmacotherapy. Recently, a new consortium in Understanding Gastrointestinal Absorption-related Processes (UNGAP) was established through COST, a funding organisation of the European Union supporting translational research across Europe. In this review of the UNGAP Working group "Food-Drug Interface", the different mechanisms that can lead to pharmacokinetic food-drug interactions are discussed and summarised from different expert perspectives.

Garlic Supplementation Reduces Circulating C-reactive Protein, Tumor Necrosis Factor, and Interleukin-6 in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Conflicting findings on the effects of garlic supplementation on inflammatory biomarkers have been observed in randomized clinical trials (RCTs).

OBJECTIVES

The aim of this study was to summarize study results regarding the effects of garlic supplementation on serum inflammatory biomarkers in adults.

METHODS

We searched Scopus, PubMed, Google Scholar and Cochrane library databases for relevant papers published until April 2018, using keywords such as "garlic" and "inflammatory biomarker." We included RCTs that 1) were conducted in adults, 2) examined the effects of garlic supplementation on inflammatory biomarkers compared to a control group, and 3) reported sufficient data on inflammatory biomarkers. Results were reported as weighted mean differences (WMD) with 95% CI using random effects models. Cochrane's Q and I-squared (I2) tests were used to determine heterogeneity among studies. Funnel plots and Egger's regression test were used to assess publication bias.

RESULTS

Sixteen RCTs were included. Garlic doses ranged from 12 to 3600 mg/d, and intervention duration ranged from 2 to 52 wk. Garlic administration significantly reduced serum C-reactive protein (CRP) (n = 13) (WMD: -0.61 mg/L, 95% CI: -1.12, -0.11, P = 0.018, I2 = 76.9%), IL-6 (n = 5) (WMD: -0.73 ng/L, 95% CI: -1.06, -0.40, P < 0.001, I2 = 0%), and TNF (n = 7) (WMD: -0.26 ng/L, 95% CI: -0.41, -0.12, P < 0.001, I2 = 0.0%), compared to controls. However, the effect of garlic supplementation on serum adiponectin (n = 3) (WMD: 0.18 µg/L, 95% CI: -0.21, 0.57, P = 0.35, I2 = 60.7%) and leptin (n = 2) (WMD: -1.25 µg/L, 95% CI: -2.64, 0.14, P = 0.07, I2 = 0.0%) concentrations were not significant.

CONCLUSION

In this meta-analysis of RCTs, we found that garlic supplementation reduced serum concentrations of CRP, TNF, IL-6, but did not affect serum adiponectin and leptin in adults. More RCTs are needed to test the effects of garlic supplementation on inflammation.

Efficacy and safety of Chinese herbal medicine for patients with postmenopausal hypertension: A systematic review and meta-analysis

Chinese herbal medicine has been increasingly used for patients with postmenopausal hypertension in China. A comprehensive literature search was performed in 7 electronic databases from their inception up to December 17, 2017 to examine the efficacy and safety of Chinese herbal medicine for postmenopausal hypertension. Thirty-nine randomized controlled trials involving 3, 823 participants were included. Meta-analyses favored Chinese herbal medicine plus antihypertensive drugs on blood pressure, blood pressure variability, postmenopausal symptoms, quality of life, and hormone levels compared with antihypertensive drugs. No severe adverse effects were identified. Er-xian decoction was the most frequently prescribed herbal formula, while Rehmannia glutinosa Libosch. was the most commonly used single herb. Chinese herbal medicine as complementary therapy maybe beneficial for postmenopausal hypertension. However, the effectiveness and safety of the decoction are still uncertain due to methodological shortcomings. Well-conducted trials are warranted to resolve the issue.

Biomarkers of food intake for Allium vegetables

Allium vegetables are widely consumed around the world and are known for their potential bioactive components improving human health. These effects have been extensively investigated; however, the results were inconsistent in human studies. Biomarkers of food intake (BFIs) could provide objective measurements of food intake in observational studies and assess compliance in intervention studies. Therefore, the discovery and application of BFIs for Allium vegetables would facilitate the exploring and understanding of the health benefit of Allium vegetables. In this manuscript, we reviewed the currently used and potential candidate BFIs for Allium vegetables and evaluated their levels of validation. S-Allylmercapturic acid (ALMA), allyl methyl sulfide (AMS), allyl methyl sulfoxide (AMSO), allyl methyl sulfone (AMSO2), and S-allylcysteine (SAC), which are derived from organosulfur compounds, were shown to be promising candidate BFIs for garlic consumption. Further validation is needed to assess their robustness and concordance with other measures. Their applicability for the whole food group should be evaluated as well. N-Acetyl-S-(2-carboxypropyl)cysteine (CPMA) was detected in high levels in urine after both garlic and onion intake, suggesting that it may be used for the assessment of intake of Allium food group. The available information regarding its kinetics, robustness, and analytical performance is limited and needs to be assessed in further studies. No candidate BFIs specific to intake of onion, leek, chives, shallots, or ramsons were found. Untargeted metabolomics studies and further validation studies should be performed to discover more reliable BFIs for individual Allium vegetables and the whole food group. This paper serves as an example of Biomarker of Food Intake Reviews (BFIRev) and biomarker of food intake validation procedures.

Antimicrobial genes from Allium sativum and Pinellia ternata revealed by a Bacillus subtilis expression system

Antimicrobial genes are found in all classes of life. To efficiently isolate these genes, we used Bacillus subtilis and Escherichia coli as target indicator bacteria and transformed them with cDNA libraries. Among thousands of expressed proteins, candidate proteins played antimicrobial roles from the inside of the indicator bacteria (internal effect), contributing to the sensitivity (much more sensitivity than the external effect from antimicrobial proteins working from outside of the cells) and the high throughput ability of screening. We found that B. subtilis is more efficient and reliable than E. coli. Using the B. subtilis expression system, we identified 19 novel, broad-spectrum antimicrobial genes. Proteins expressed by these genes were extracted and tested, exhibiting strong external antibacterial, antifungal and nematicidal activities. Furthermore, these newly isolated proteins could control plant diseases. Application of these proteins secreted by engineered B. subtilis in soil could inhibit the growth of pathogenic bacteria. These proteins are thermally stable and suitable for clinical medicine, as they exhibited no haemolytic activity. Based on our findings, we speculated that plant, animal and human pathogenic bacteria, fungi or even cancer cells might be taken as the indicator target cells for screening specific resistance genes.

Blood-Letting Therapy for Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the efficacy and safety of blood-letting therapy (BLT) in treatment of hypertension.

METHODS

A comprehensive electronic and manual bibliographic searches were performed in Cochrane Central Register of Controlled Trials, Excerpt Medica Database (EMBASE), PubMed, China National Knowledge Infrastructure, Chinese Scientific Journal Database, Chinese Biomedical Literature Database, and Wanfang Database to identify randomized controlled trials (RCTs) in which hypertensive patients were treated with BLT or BLT plus antihypertensive drugs (BPAD) against placebo, no treatment or antihypertensive drugs. The Cochrane Risk Assessment Tool was used to assess the methodological quality of trials. The Review Manager 5.3 software was used for meta-analysis.

RESULTS

A total of 7 RCTs with 637 hypertensive patients from 1989 to 2017 were identified. Compared with antihypertensive drugs, blood pressure was significantly reduced by BLT (RR=1.21, 95% CI: 1.01 to 1.44, P=0.03; heterogeneity: P=0.06, I²=60%) and BPAD (RR=1.25, 95% CI, 1.02 to 1.53, P=0.03; heterogeneity: P= 0.01, I²=71%). Moreover, a significant improvement in Chinese medicine syndrome by BLT (RR=1.32; 95% CI: 1.14 to 1.53, P=0.0002; heterogeneity: P=0.53, I²=0%) and BPAD (RR=1.47; 95% CI: 1.06 to 2.04, P=0.02; heterogeneity: P=0.13, I²=56%) was identified. The reported adverse effects were well tolerated.

CONCLUSION

Although some positive findings were identified, no definite conclusions regarding the efficacy and safety of BLT as complementary and alternative approach for treatment of hypertension could be drew due to the generally poor methodological design, significant heterogeneity, and insufficient clinical data. Further rigorously designed trials are warranted to confirm the results.

Cholesterol-Lowering Nutraceuticals Affecting Vascular Function and Cardiovascular Disease Risk

PURPOSE OF REVIEW

The aim of this review is to provide an update on the effects of the dietary supplementation with cholesterol-lowering nutraceuticals and nutraceutical combinations affecting vascular function and CV risk in clinical interventional studies.

RECENT FINDINGS

Current evidence supports the mild-to-moderate cholesterol-lowering efficacy of red yeast rice, berberine, plant sterols, fibers, and some nutraceutical combinations whereas data on the individual cholesterol-lowering action of other nutraceuticals are either less striking or even inconclusive. There is also promising evidence on the vascular protective effects of some of the aforementioned nutraceuticals. However, except for red yeast rice, clinical interventional studies have not investigated their impact on CV outcomes. Evidence of both cholesterol-lowering and vascular protection is a prerogative of few single nutraceuticals and nutraceutical combinations, which may support their clinical use; however, caution on their uncontrolled adoption is necessary as they are freely available on the market and, therefore, subject to potential misuse.

Garlic and Gaseous Mediators

Garlic (Allium sativum) and allied plant species are rich sources of sulfur compounds. Major roles for garlic and its sulfur constituents include the regulation of vascular homeostasis and the control of metabolic systems linked to nutrient metabolism. Recent studies have indicated that some of these sulfur compounds, such as diallyl trisulfide (DATS), alter the levels of gaseous signalling molecules including nitric oxide (NO), hydrogen sulfide (H₂S), and perhaps carbon monoxide (CO) in mammalian tissues. These gases are important in cellular processes associated with the cardiovascular system, inflammation, and neurological functions. Importantly, these studies build on the known biological effects of garlic and associated sulfur constituents. This review highlights our current understanding of the health benefits attributed to edible plants like garlic.

Effects of Avocado (Persea americana) on Metabolic Syndrome: A Comprehensive Systematic Review

Metabolic syndrome (MetS) is a clustering of risk factors including high blood glucose, dyslipidemia, hypertension, and obesity that lead to the increased risk of type 2 diabetes mellitus and cardiovascular diseases (CVDs), which are among leading causes of death in the world. Metabolic syndrome increases the risk of type 2 diabetes mellitus and CVDs by approximately five and three folds, respectively. Therefore, it is of vital importance to manage such conditions with herbal options which have less undesirable adverse effects and may be more efficacious in comparison with synthetic options. Avocado is a well-known source of carotenoids, minerals, phenolics, vitamins, and fatty acids. The lipid-lowering, antihypertensive, antidiabetic, anti-obesity, antithrombotic, antiatherosclerotic, and cardioprotective effects of avocado have been demonstrated in several studies. In this review, we aimed to find out avocado's pharmacological effects on different components of MetS. Moreover, this review report is performed on the MetS effects of peel, seed, flesh, and leaves of avocado. Copyright © 2017 John Wiley & Sons, Ltd.

Complementary and Alternative Medicine Use in Hypertension

Thirty six percent of people in USA and Canada regularly use complementary and alternative medicine (CAM) for the prevention and treatment of different diseases, including hypertension. Generally, majority of the hypertensive patients do not disclose the use of such remedies, and also health care providers do not usually ask their hypertensive patients if they use CAM. The widespread consumption of CAM in hypertension requires clear understanding of their underlying mechanism of action, efficacy and safety. This chapter will provide a comprehensive list of CAM commonly used by Americans for the prevention and treatment of hypertension as well as their postulated mechanism of action. Modulation of drug metabolizing enzymes and their safety will also be covered along with the clinical consequences, i.e. drug-herb or herb-disease interactions. patients and healthcare providers should also be careful with using CAM therapies, because not only is there minimal evidence that several CAM products work to treat hypertension, but their safety hasn't been well-established.

Antihypertensive effect of allicin in dexamethasone-induced hypertensive rats

BACKGROUND

Glucocorticoid is among the most commonly prescribed medicine. Unfortunately, Excess glucocorticoid level leads hypertension in 80-90% patients. Garlic (Allium sativum) has been used since ancient times and even nowadays as a part of popular medicine for various ailments and physiological disorders. Hence this study was undertaken to investigate the antihypertensive activity of allicin in dexamethasone induced hypertension in wistar rats.

METHODS

The animals were randomly divided into four groups comprising of six rats per group. Hypertension was induced by subcutaneous injection of dexamethasone (10 μg/rat/day) in hypertensive rats. Two hypertensive group animals were treated with nicorandil (6 mg/kg/day, po) and allicin (8 mg/kg/day, po) respectively for 8 weeks. While systolic blood pressure (SBP) was measured by the tail-cuff method weekly up to 8 weeks.

RESULTS

Dexamethasone treatment resulted in significant increase in SBP while allicin treatment significantly decreases the SBP. Thus, this study confirmed that allicin treatment for 8 weeks partially reverse dexamethasone induced hypertension in rats. Allicin treatment also attenuated dexamethasone-induced anorexia and loss of total body weight.

CONCLUSION

This result suggests antihypertensive effects of allicin in dexamethasone induced hypertension. However, further studies are needed to explore the detailed mechanism of antihypertensive effect of allicin.

An umbrella review of garlic intake and risk of cardiovascular disease

PURPOSE

To gain further insight into the strength of evidence and extent of possible biases in the scope of studies investigating the impact of garlic and garlic supplement intake on biomarkers of cardiovascular disease, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials.

METHODS

Electronic database PubMed (between 1966 and June 2015) was searched for systematic reviews and meta-analyses using following search terms: ("garlic" OR "allium sativum" OR "allicin" OR "organosulfur") AND ("cardiovascular" OR "coronary" OR "cholesterol" OR "triglyceride" OR "atherosclerosis" OR "blood pressure" OR "hypertension" OR "blood glucose") AND ("systematic review" OR "meta-analysis"), with no restriction to calendar data and language. Hand-search of reference lists and relevant clinical guidelines was performed as well.

RESULTS

Nine systematic reviews investigated the effects of garlic on lipid parameters and eight systematic reviews analyzed the effects on blood pressure parameters were identified. Eight of nine meta-analyses synthesizing the effect of garlic on blood lipids reported significantly decreased total cholesterol levels. Inconsistent results could be detected for HDL-cholestrol, LDL-cholesterol, and triacylglycerols. The effect of garlic on systolic blood pressure showed consistent results across publications with 7 out of 8 meta-analyses demonstrating a substantial decrease in systolic blood pressure. Similar results could be reported regarding the effect of garlic on diastolic blood pressure, i.e. 6 out of 8 meta-analyses detected significant reductions in diastolic blood pressure levels following interventions with garlic.

CONCLUSION

According to the data summarized in the present umbrella review, garlic preparations as well as garlic exerted some positive effects on indicators and biomarkers of cardiovascular disease, typically without causing any serious side effects. However, with regard to the substantial heterogeneities between the different trials enrolled in the various meta-analyses of this review, a conservative interpretation of the outcome seems to be appropriate.

Potential of Food and Natural Products to Promote Endothelial and Vascular Health

Endothelial dysfunction is now well established as a pivotal early event in the development of major cardiovascular diseases including hypertension, atherosclerosis, and diabetes. The alteration of the endothelial function is often triggered by an imbalance between the endothelial formation of vasoprotective factors including nitric oxide (NO) and endothelium-dependent hyperpolarization, and an increased level of oxidative stress involving several prooxidant enzymes such as NADPH oxidase and, often also, the appearance of cyclooxygenase-derived vasoconstrictors. Preclinical studies have indicated that polyphenol-rich food and food-derived products such as grape-derived products, black and red berries, green and black teas and cocoa, and omega-3 fatty acids can trigger activating pathways in endothelial cells promoting an increased formation of nitric oxide and endothelium-dependent hyperpolarization. Moreover, intake of such food-derived products has been associated with the prevention and/or the improvement of an established endothelial dysfunction in several experimental models of cardiovascular diseases and in humans with cardiovascular diseases. This review will discuss both experimental and clinical evidences indicating that different types of food and natural products are able to promote endothelial and vascular health, as well as the underlying mechanisms.

Quantitative ethnomedicinal survey of medicinal plants given for cardiometabolic diseases by the non-institutionally trained siddha practitioners of Tiruvallur district, Tamil Nadu, India

ETHNOBOTANICAL RELEVANCE

The burden of cardiometabolic diseases such as dyslipidemia, hyperglycemia, hypertension, visceral obesity and atherosclerotic cardiovascular diseases and the use of traditional medicine for the management of such diseases are high in India; hence there is a need to document and analyze such therapies.

AIM OF THE STUDY

This study documented and analyzed the medicinal plants prescribed for cardiometabolic diseases by the non-institutionally trained siddha practitioners of Tiruvallur district of Tamil Nadu, India.

METHODOLOGY

The field survey was conducted between December 2014 to November 2015. Successive free listing assisted with field-walks was used to interview the informants. After assessing the sampling sufficiency using rarefaction curve analysis, indices such as Informant Consensus Factor (Fic) and Index of Agreement on Remedies (IAR) were calculated for the data. The indicators of informant's medicinal plant knowledge such as Shannon's index, equitability index, etc., were regressed with the demographic profile of the informants.

RESULTS

For this study 70 non-institutionally trained Siddha medical practitioners were approached; the data from 36 practitioners who were treating cardiometabolic diseases were documented. This study recorded the use of 188 species which were used to prepare 368 formulations to treat illnesses categorized under cardiometabolic diseases. In this, 53.04% claims were singletons. Regression analysis showed that single species dominance was reduced and the diversity of medicinal plants was increased with the increase in the age and experience. Increase in the years of formal education increased the equitability in the uses. The plants such as Nelumbo nucifera Gaertn. (cardiovascular diseases), Allium sativum L. (dyslipidemia), Cuminum cyminum L. (hypertension), Macrotyloma uniflorum Verdc. (obesity) and Azadirachta indica A. Juss. (type 2 diabetes) were the highly cited medicinal plants.

CONCLUSION

This survey has identified the plants most commonly used by Siddha practitioners of Tiruvallur district, Tamil Nadu, India for cardiometabolic diseases. The prevalence of chronic, non-communicable metabolic illnesses such as type 2 diabetes, hypertension and obesity are increasing worldwide due to the rapid changes in the lifestyle. These ailments require a life-long care and in such instances, people tend to use complementary therapies in most cases, alongside with conventional therapies. In view of the high use of traditional therapies for treating cardiometabolic illnesses, this study supports the need for more research to evaluate the potential benefits of the treatments and to identify any safety concern.

Garlic oil polysulfides: H2S- and O2-independent prooxidants in buffer and antioxidants in cells

The health benefits of garlic and other organosulfur-containing foods are well recognized and have been attributed to both prooxidant and antioxidant activities. The effects of garlic are surprisingly similar to those of hydrogen sulfide (H2S), which is also known to be released from garlic under certain conditions. However, recent evidence suggests that polysulfides, not H2S, may be the actual mediator of physiological signaling. In this study, we monitored formation of H2S and polysulfides from garlic oil in buffer and in human embryonic kidney (HEK) 293 cells with fluorescent dyes, 7-azido-4-methylcoumarin and SSP4, respectively and redox activity with two redox indicators redox-sensitive green fluorescent protein (roGFP) and DCF. Our results show that H2S release from garlic oil in buffer requires other low-molecular-weight thiols, such as cysteine (Cys) or glutathione (GSH), whereas polysulfides are readily detected in garlic oil alone. Administration of garlic oil to cells rapidly increases intracellular polysulfide but has minimal effects on H2S unless Cys or GSH are also present in the extracellular medium. We also observed that garlic oil and diallyltrisulfide (DATS) potently oxidized roGFP in buffer but did not affect DCF. This appears to be a direct polysulfide-mediated oxidation that does not require a reactive oxygen species intermediate. Conversely, when applied to cells, garlic oil became a significant intracellular reductant independent of extracellular Cys or GSH. This suggests that intracellular metabolism and further processing of the sulfur moieties are necessary to confer antioxidant properties to garlic oil in vivo.

A Critical Approach to Evaluating Clinical Efficacy, Adverse Events and Drug Interactions of Herbal Remedies

Systematic reviews and meta-analyses represent the uppermost ladders in the hierarchy of evidence. Systematic reviews/meta-analyses suggest preliminary or satisfactory clinical evidence for agnus castus (Vitex agnus castus) for premenstrual complaints, flaxseed (Linum usitatissimum) for hypertension, feverfew (Tanacetum partenium) for migraine prevention, ginger (Zingiber officinalis) for pregnancy-induced nausea, ginseng (Panax ginseng) for improving fasting glucose levels as well as phytoestrogens and St John's wort (Hypericum perforatum) for the relief of some symptoms in menopause. However, firm conclusions of efficacy cannot be generally drawn. On the other hand, inconclusive evidence of efficacy or contradictory results have been reported for Aloe vera in the treatment of psoriasis, cranberry (Vaccinium macrocarpon) in cystitis prevention, ginkgo (Ginkgo biloba) for tinnitus and intermittent claudication, echinacea (Echinacea spp.) for the prevention of common cold and pomegranate (Punica granatum) for the prevention/treatment of cardiovascular diseases. A critical evaluation of the clinical data regarding the adverse effects has shown that herbal remedies are generally better tolerated than synthetic medications. Nevertheless, potentially serious adverse events, including herb-drug interactions, have been described. This suggests the need to be vigilant when using herbal remedies, particularly in specific conditions, such as during pregnancy and in the paediatric population. Copyright © 2016 John Wiley & Sons, Ltd.