Aged garlic extract preserves cutaneous microcirculation in patients with increased risk for cardiovascular diseases: A double-blinded placebo-controlled study

Investigation of Antiproliferative Effects of Combinations of White and Black Garlic Extracts with 5-Fluorouracil (5-FU) on Caco-2 Colorectal Adenocarcinoma Cells

Garlic is rich in bioactive compounds that are effective against colon cancer cells. This study tests the antioxidant and antiproliferative effects of cold-extracted white and black garlic extracts. Black garlic extracted in water (SSU) exhibits the highest antioxidant activity, phenolic content, and flavonoid content, while black garlic extracted in ethanol (SET) shows the lowest values. Caspase-3 activity is notably higher in the white garlic extracted in methanol (BME), white garlic extracted in methanol combines with 5-FU, black garlic extracted in ethanol (SET), black garlic extracted in ethanol combines with 5-fluorouracil (5-FU), and 5-FU treatments compare to the control group (p > 0.05). BME+5-FU displays the highest caspase-8 activity (p < 0.05). A decrease in NF-κB levels is observed in the SET+5-FU group (p>0.05), while COX-2 activities decrease in the BME, SET+5-FU, SET, and 5-FU groups (p>0.05). Wound healing increases in the BME, BME+5-FU, SET+5-FU, and 5-FU groups (p < 0.05). In conclusion, aqueous black garlic extract may exhibit pro-oxidant activity despite its high antioxidant capacity. It is worth noting that exposure to heat-treated food and increased sugar content may lead to heightened inflammation and adverse health effects. This study is the first to combine garlic with chemo-preventive drugs like 5-FU in Caco-2 cells.

Advances in the study of vascular related protective effect of garlic (Allium sativum) extract and compounds

Garlic (Allium sativum) is a functional food containing multiple bioactive compounds that find widespread applications in culinary and medicinal practices. It consists of multiple chemical components, including allicin and alliin. This article offers a comprehensive review of the protective effects of garlic extracts and their active constituents on the vascular system. In vitro and in vivo experiments have shown that garlic extracts and their active ingredients possess various bioactive properties. These substances demonstrate beneficial effects on blood vessels by demonstrating anti-inflammatory and antioxidant activities, inhibiting lipid accumulation and migration, preventing lipid peroxidation, promoting angiogenesis, reducing platelet aggregation, enhancing endothelial function, and inhibiting endothelial cell apoptosis. In clinical studies, garlic and its extracts have demonstrated their efficacy in managing vascular system diseases, including atherosclerosis, diabetes, and high cholesterol levels. In summary, these studies highlight the potential therapeutic roles and underlying mechanisms of garlic and its constituents in managing conditions like diabetes, atherosclerosis, ischemic diseases, and other vascular disorders.

Garlic against Heart-related Ailments: Chemistry, Pharmacology, and Future Perspective

BACKGROUND

Allium sativum L. (Garlic) is a well-recognized plant of great nutraceutical value with pharmacological evidences. It is full of dietary as well as pharmaceutical properties and has been used in traditional medications for a long time. It is known for good antioxidant, antifungal, antibacterial, anti-diabetic, anti-inflammatory, anticancer, and antiviral effects, along with other therapeutic roles in cardiovascular diseases, anti-atherosclerotic, antihypertensive, anti-thrombotic, blood pressure, bone and skin related problems etc. Objective: Considering the potential of garlic in the treatment of cardiovascular/heart-related diseases, the main objective of this study was to prepare a subject-centric mini-review focusing on its chemistry and pharmacology in heart-related issues.

METHODS

In order to prepare this mini-review article, an extensive online literature search was performed to find out the most recent studies related to this topic. These studies were briefly reviewed, assessed, and discussed to explore the possible capability of garlic for the cure of cardiovascular problems.

RESULT

Several experiments on mice models, rat models as well as on humans show the effective role of various forms of garlic in cardiovascular or heart-related ailments. After reviewing the available publications on garlic in heart-related issues, authors found that garlic and its sulfur (S)-based organic constituents may have advantageous applications in the treatment of cardiovascular diseases.

Nutraceutical management of metabolic syndrome as a palliative and a therapeutic to coronavirus disease (COVID) crisis

The global market for medicinal plants and herbs is on the increase due to their desirability, efficacy, and less adverse effects as complementary and alternative medications to the orthodox pharmaceuticals, perhaps due to their natural components and qualities. Metabolic syndromes are managed with changes in diet, exercise, lifestyle modifications and the use of pharmacological agents. Plants are now known to have potent antioxidant and cholinergic activities which are relevant to the management of several metabolic syndromes, which are unfortunately, co-morbidity factors in the coronavirus disease crisis. This review will focus on the biological activities of some plant products used as complementary and alternative medicines in the management of metabolic syndromes, and on their reported antiviral, antithrombotic, angiotensin-converting enzyme inhibitory properties, which are integral to their usage in the management of viral infections and may give an avenue for prophylactic and therapeutics especially in the absence of vaccines/formulated antiviral therapies.

Targeting temperature-sensitive transient receptor potential channels in hypertension: far beyond the perception of hot and cold

Transient receptor potential (TRP) channels are nonselective cation channels and participate in various physiological roles. Thus, changes in TRP channel function or expression have been linked to several disorders. Among the many TRP channel subtypes, the TRP ankyrin type 1 (TRPA1), TRP melastatin type 8 (TRPM8), and TRP vanilloid type 1 (TRPV1) channels are temperature-sensitive and recognized as thermo-TRPs, which are expressed in the primary afferent nerve. Thermal stimuli are converted into neuronal activity. Several studies have described the expression of TRPA1, TRPM8, and TRPV1 in the cardiovascular system, where these channels can modulate physiological and pathological conditions, including hypertension. This review provides a complete understanding of the functional role of the opposing thermo-receptors TRPA1/TRPM8/TRPV1 in hypertension and a more comprehensive appreciation of TRPA1/TRPM8/TRPV1-dependent mechanisms involved in hypertension. These channels varied activation and inactivation have revealed a signaling pathway that may lead to innovative future treatment options for hypertension and correlated vascular diseases.

Endothelial Glycocalyx Preservation-Impact of Nutrition and Lifestyle

The endothelial glycocalyx (eGC) is a dynamic hair-like layer expressed on the apical surface of endothelial cells throughout the vascular system. This layer serves as an endothelial cell gatekeeper by controlling the permeability and adhesion properties of endothelial cells, as well as by controlling vascular resistance through the mediation of vasodilation. Pathogenic destruction of the eGC could be linked to impaired vascular function, as well as several acute and chronic cardiovascular conditions. Defining the precise functions and mechanisms of the eGC is perhaps the limiting factor of the missing link in finding novel treatments for lifestyle-related diseases such as atherosclerosis, type 2 diabetes, hypertension, and metabolic syndrome. However, the relationship between diet, lifestyle, and the preservation of the eGC is an unexplored territory. This article provides an overview of the eGC's importance for health and disease and describes perspectives of nutritional therapy for the prevention of the eGC's pathogenic destruction. It is concluded that vitamin D and omega-3 fatty acid supplementation, as well as healthy dietary patterns such as the Mediterranean diet and the time management of eating, might show promise for preserving eGC health and, thus, the health of the cardiovascular system.

L-arginine and aged garlic extract for the prevention of migraine: a study protocol for a randomised, double-blind, placebo-controlled, phase-II trial (LARGE trial)

Background

Migraine is a common and distressing neurological condition characterised by recurrent throbbing headaches, nausea and heightened sensitivity to light and sound. Accumulating evidence suggests that cerebral arteries dilate during migraine, causing distal microvessels to constrict, which could activate nociceptors and cause onset of headache pain. If so, preventing or attenuating chronic microvascular constriction, and promoting a dilatory phenotype, may reduce frequency and/or severity of migraines. The primary aim of the L-Arginine and Aged Garlic Extract (LARGE) trial is to investigate whether oral treatment with dietary nutraceuticals, L-arginine and aged garlic extract (AGE), both systemic vasodilatory agents, will alleviate migraine frequency, duration and severity in adults with chronic frequent episodic migraines.

Methods

The study is a randomised double-blind placebo-controlled phase-II single-site clinical trial conducted in Perth, Australia. The target sample is to recruit 240 participants diagnosed with chronic frequent episodic migraines between 18 and 80 years of age. Participants will be randomised to one of four treatment groups for 14 weeks (placebo induction for 2 weeks, followed by 12 weeks on one of the respective treatment arms): placebo, L-arginine, AGE, or a combination of L-arginine and AGE. The doses of L-arginine and AGE are 1.5 g and 1 g daily, respectively. The primary outcome is to assess migraine response using change in migraine frequency and intensity between baseline and 12 weeks. Secondary outcomes include the impact of L-arginine and/or AGE on photosensitivity, retinal vessel changes, and blood biomarker concentrations of vascular tone, following a 12-week intervention.

Discussion

The protocol describes the oral administration of 2 nutraceutical-based interventions as possible prophylactic treatments for chronic frequent episodic migraines, with potential for direct clinical translation of outcomes. Potential limitations of the study include the fixed-dose design of each treatment arm and that in vivo neuroimaging methods, such as magnetic resonance imaging (MRI), will not be conducted to determine putative cerebro-vasodilatory changes to coincide with the outcome measures. Dose-response studies may be indicated.

Trial registration

The trial was retrospectively registered with the Australian New Zealand Clinical Trials Registry ACTRN12621001476820 (Universal Trial Number: U1111-1268-1117) on 04/08/2021. This is protocol version 1, submitted on 25/11/2022.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-023-03149-y.

Garlic (Allium sativum L.) in diabetes and its complications: Recent advances in mechanisms of action

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia and impaired islet secretion that places a heavy burden on the global health care system due to its high incidence rate, long disease course and many complications. Fortunately, garlic (Allium sativum L.), a well-known medicinal plant and functional food without the toxicity and side effects of conventional drugs, has shown positive effects in the treatment of diabetes and its complications. With interdisciplinary development and in-depth exploration, we offer a clear and comprehensive summary of the research from the past ten years, focusing on the mechanisms and development processes of garlic in the treatment of diabetes and its complications, aiming to provide a new perspective for the treatment of diabetes and promote the efficient development of this field.

Natural Products in Cardiovascular Diseases: The Potential of Plants from the Allioideae Subfamily (Ex-Alliaceae Family) and Their Sulphur-Containing Compounds

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide and, together with associated risk factors such as diabetes, hypertension, and dyslipidaemia, greatly impact patients' quality of life and health care systems. This burden can be alleviated by fomenting lifestyle modifications and/or resorting to pharmacological approaches. However, due to several side effects, current therapies show low patient compliance, thus compromising their efficacy and enforcing the need to develop more amenable preventive/therapeutic strategies. In this scenario, medicinal and aromatic plants are a potential source of new effective agents. Specifically, plants from the Allioideae subfamily (formerly Alliaceae family), particularly those from the genus Allium and Tulbaghia, have been extensively used in traditional medicine for the management of several CVDs and associated risk factors, mainly due to the presence of sulphur-containing compounds. Bearing in mind this potential, the present review aims to gather information on traditional uses ascribed to these genera and provide an updated compilation of in vitro and in vivo studies validating these claims as well as clinical trials carried out in the context of CVDs. Furthermore, the effect of isolated sulphur-containing compounds is presented, and whenever possible, the relation between composition and activity and the mechanisms underlying the beneficial effects are pointed out.

Improved microvascular reactivity after aged garlic extract intake is not mediated by hydrogen sulfide in older adults at risk for cardiovascular disease: a randomized clinical trial

PURPOSE

This study aimed to investigate the effects of AGE on microvascular reactivity, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in older individuals at high risk for cardiovascular disease (CVD). Urinary thiosulfate was also investigated as an indirect marker of endogenous hydrogen sulfide (H₂S) synthesis. The study was conducted in a randomized, double-blind, crossover, and placebo-controlled way.

METHODS

Twenty-eight participants (14 male), 67 ± 6 years old with CVD risk factors, ingested 2.4 g of AGE or placebo (PLA). Near-infrared spectroscopy evaluated tissue oxygen saturation (StO₂) during a vascular occlusion test (30 s baseline, 5 min occlusion, and 2 min reperfusion). The upslope of StO₂ signal after cuff release was calculated to measure microvascular reactivity. Urinary thiosulfate levels were measured using a high-performance liquid chromatography system.

RESULTS

The upslope of StO₂ was significantly faster after AGE (1.01 ± 0.37% s^-1) intake compared to PLA (0.83 ± 0.35% s^-1; P < 0.001; d = 0.50). Relative changes in Δ% SBP from pre- to post-AGE intake (- 5.17 ± 5.77%) was significantly different compared to Δ% PLA (0.32 ± 5.99%; P = 0.001; d = 0.93). No significant changes in urinary thiosulfate concentrations were observed between interventions. Moreover, no significant gender effect in any parameter assessed was found.

CONCLUSION

This study demonstrated that a single dose of AGE improved microvascular reactivity in older adults at risk of CVD despite such an effect was not linked with urinary thiosulfate levels. This trial was registered at clinicaltrials.gov as NCT04008693 (May 19, 2020).

Garlic: A systematic review of the effects on cardiovascular diseases

Allium sativum (garlic) certainly is one of the oldest horticultural crops in the world and presents bioactive compounds that are related to the garlic's effects on human health. Several authors have shown beneficial effects on diabetes, hypertension, dyslipidemia, obesity, and cardiovascular diseases (CVD), which are among the most relevant causes of mortality in the world. The aim of this systematic review was to evaluate the effects of garlic in the risk factors of CVD and evaluate its economic importance. MEDLINE-PubMed, COCHRANE, EMBASE, and Google Scholar databases were searched. The included studies showed that the use of garlic can reduce blood pressure, waist circumference, body mass index, LDL-c, non-HDL-c, total cholesterol, triglycerides, and inflammatory markers. It also can increase the levels of HDL-c and can improve cardiovascular parameters such as coronary artery calcium, microcirculation, epicardial and periaortic adipose tissue, post occlusive reactive hyperemia, low attenuation plaque, carotid intima-media thickness; and carotid intima-media thickness. Due to these reasons, garlic can be considered in the prevention and treatment of CVD risk factors.

Efficacy of Oral Administration of Allium sativum Powder "Garlic Extract" on Lipid Profile, Inflammation, and Cardiovascular Indices among Hemodialysis Patients

Background

Inflammation plays a prominent role in the deteriorating cardiovascular risk of hemodialysis patients. Utilization of herbal remedies, especially garlic extract, in these patients has resulted in promising improvement in lipid profile, inflammation, and cardiovascular markers.

Purpose

In this survey, we aimed to determine the effects of oral administration of Allium sativum powder on lipid profile, inflammation, and cardiovascular markers among hemodialysis patients.

Methods

In this interventional double-blinded randomized crossover study, 70 patients were enrolled and assigned in two groups. Each group received 300 mg of garlic powder BID or placebo for eight weeks; after a six-week wash-out period, the agents were switched between two groups so that the group who received garlic powder in the first eight weeks received placebo for the second eight weeks, and vice versa. Venous blood samples were obtained in baseline, wash-out period, and at the end of study. Following obtaining laboratory data, BUN, creatinine, Na, K, Ca, Ph, homocysteine, and lipid profile were compared.

Results

No significant differences were shown at baselines of outcomes between the garlic and placebo group (p value>0.05). However, there was a significant decrease in absolute values of OXLDL (mean placebo = 979.63, mean garlic = 676.54; p value<0.001) and HCY (mean placebo = 36.54, mean garlic = 27.78; p value<0.001). In addition, significant treatment differences were seen in change values of Ca (placebo = 1.17, garlic = 0.21; p value = 0.006), TG (placebo = −6.71, garlic = -24.14; p value = 0.014), OXLDL (placebo = −281.30, garlic = -699.78; p value<0.001), and HCY (placebo = −0.24, garlic = −6.68; p value<0.001).

Conclusion

In this study, Allium sativum powder demonstrated efficacy in lipid profile improvement and renal protective effects among hemodialysis patients.

Aged Garlic Extract Reduces IL-6: A Double-Blind Placebo-Controlled Trial in Females with a Low Risk of Cardiovascular Disease

Background

Chronic inflammation is a risk factor for cardiovascular disease. The aim of the study was to evaluate whether a daily supplementation of aged garlic extract (AGE) could reduce inflammation in females with low risk for cardiovascular disease. The study was conducted at a single center, as a parallel randomized placebo-controlled trial.

Method

63 females with a Framingham risk score over 10 underwent cardiac computed tomography (CT) scan. Of those, patients with a coronary artery calcium (CAC) scores less than 5 (n = 31) met the inclusion criteria and were randomized, in a double-blind manner to an intake of placebo or AGE (2400 mg daily) for 1 year.

Results

Main outcome measure was changes in inflammatory biomarkers, blood pressure, fastening blood glucose, and blood lipids. A total of 29 patients (14 in the AGE group and 15 in the placebo group) completed the study and were analyzed. Females treated with AGE showed lower levels of inflammatory marker IL-6 after 12 months of treatment compared to females receiving placebo (p < 0.05). The blood lipids had a trend towards a lowering effect in females treated with AGE; however, this trend was not significant.

Conclusion

The present study concludes that AGE lowers IL-6 in females with a risk profile of cardiovascular disease. We could also conclude that risk prediction with cardiac CT  scan turned out to be superior in estimating the risk of cardiac disease compared to Framingham risk score. This trial is registered with NCT03860350.

Successful improved peripheral tissue perfusion was seen in patients with atherosclerosis after 12 months of treatment with aged garlic extract

Patients with arteriolosclerosis have impaired microvascular perfusion leading to impaired wound healing. Aged garlic extract has shown to have a positive impact on vascular elasticity. The present study aimed to assess the effect of long‐term treatment with AGE on peripheral tissue perfusion in patients with confirmed atherosclerosis. Ninety three patients with a CT‐scan confirmed coronary artery arteriolosclerosis were randomised in a double‐blind manner to placebo or 2400 mg AGE daily for 1 year. Peripheral tissue perfusion was evaluated at 0‐ and 12‐months using Laser Speckle Contrast Imaging. Measurement of post occlusive reactive hyperemia (PORH) and cutaneous vascular conductance (CVC) using acetylcholine iontophoresis (Ach) was conducted. After 12 months a significant increase of 21.6% (95% CI 3.2%‐40.0%, P < .05) was seen in the relative change of PORH in the AGE compared with the placebo group. The same response was seen for CVC and Ach with an increase of 21.4% (95% CI 3.4%‐39.4%, P < .05) in the AGE group compared with the placebo group. Aged garlic extract regenerated peripheral tissue perfusion and increase microcirculation in patients with arteriolosclerosis. Adequate peripheral tissue perfusion and tissue oxygen tension are important prerequisites for successful tissue repair. Restored microcirculation in patients could hypothetically facilitate wound healing.

S-1-propenylcysteine improves TNF-α-induced vascular endothelial barrier dysfunction by suppressing the GEF-H1/RhoA/Rac pathway

Background

Vascular endothelial barrier function is maintained by cell-to-cell junctional proteins and contributes to vascular homeostasis. Various risk factors such as inflammation disrupt barrier function through down-regulation of these proteins and promote vascular diseases such as atherosclerosis. Previous studies have demonstrated that aged garlic extract (AGE) and its sulfur-containing constituents exert the protective effects against several vascular diseases such as atherosclerosis. In this study, we examined whether AGE and its sulfur-containing constituents improve the endothelial barrier dysfunction elicited by a pro-inflammatory cytokine, Tumor-necrosis factor-α (TNF-α), and explored their mode of action on TNF-α signaling pathway.

Methods

Human umbilical vein endothelial cells (HUVECs) were treated with test substances in the presence of TNF-α for various time periods. The endothelial permeability was measured by using a transwell permeability assay. The localization of cell-to-cell junctional proteins and actin cytoskeletons were visualized by immunostaining. RhoA and Rac activities were assessed by using GTP-binding protein pulldown assay. Gene and protein expression levels of signaling molecules were analyzed by real-time PCR and western blotting, respectively.

Results

We found that AGE and its major sulfur-containing constituent, S-1-propenylcysteine (S1PC), reduced hyperpermeability elicited by TNF-α in HUVECs. In addition, S1PC inhibited TNF-α-induced production of myosin light chain (MLC) kinase and inactivation of MLC phosphatase through the suppression of the Rac and RhoA signaling pathways, respectively, which resulted in the dephosphorylation of MLC2, a key factor of actin remodeling. Moreover, S1PC inhibited the phosphorylation and activation of guanine nucleotide exchange factor-H1 (GEF-H1), a common upstream key molecule and activator of Rac and RhoA. These effects of S1PC were accompanied by its ability to prevent the disruption of junctional proteins on the cell–cell contact regions and the increase of actin stress fibers induced by TNF-α.

Conclusions

The present study suggested that AGE and its major constituent, S1PC, improve endothelial barrier disruption through the protection of junctional proteins on plasma membrane.

Aged garlic extract rescues ethephon-induced kidney damage by modulating oxidative stress, apoptosis, inflammation, and histopathological changes in rats

Ethephon is an organophosphorus plant growth regulator used to accelerate the ripening process and decrease the duration of cultivation. Here, the potential protective role of aged garlic extract (AGE) was investigated against ethephon-mediated nephrotoxicity. Four experimental groups were established (n = 15), including control, AGE (250 mg/kg), ethephon (200 mg/kg), and AGE + ethephon. In the current work, kidney function parameters (urea, creatinine, and KIM-1) along with oxidative stress biomarkers, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, glutathione, and its related enzymes, superoxide dismutase, catalase, malondialdehyde, and nitric oxide, were determined. The expression of inflammatory mediators namely tumor necrosis factor alpha, interleukin 1 beta, nuclear factor kappa B, and apoptotic markers (caspase 3, Bax, and Bcl2) were determined in the renal tissue. Additionally, the histopathological alterations in response to treatments were examined. Ethephon exposure increased the levels of kidney function markers along with relative kidney weight coupled with histological changes in the kidney tissue. Additionally, ethephon increased the levels of the tested pro-oxidant markers and decreased the antioxidant indices, resulting in oxidative damage to renal tissues. An elevation in the pro-inflammatory mediators was also recorded following ethephon intoxication. Furthermore, renal cell loss was observed through histological examinations and biochemical measurements upon ethephon administration. On the other hand, AGE significantly ameliorated the molecular, biochemical, and structural changes elicited by ethephon. These findings suggest that AGE may be used to decrease or prevent the side effects of ethephon exposure in kidneys, through the activation of Nrf2 and inhibition of inflammation and apoptotic response.

Herbal therapy as a promising approach for regulation on lipid profiles: A review of molecular aspects

Impaired lipid profile is defined as abnormal plasma levels of low-density lipoprotein, triglycerides, and total cholesterol. This disease state is associated with the development and progression of various disorders, such as diabetes mellitus, cardiovascular diseases, and acute myocardial infarction. Globally, all of these disorders are related to a significant rate of death. Therefore, finding a suitable approach for the prevention and treatment of lipid profile-related disorders is in the spotlight. Recently, herbal therapy has been considered a promising therapeutic approach for the treatment of hyperlipidemia or its related disorders due to its safety and efficacy. Hereby, we address the potential benefits of some of these herbal compounds on different aspects of lipid profile and its abnormalities with a special focus on their underlying mechanisms. Using herbal products, such as teas and mushrooms, or their derivatives, Rosmarinus officinalis Linn, Curcuma longa, Green tea, Lippia triphylla, Lippia citriodora, Plantago asiatica L, Vine tea, and Grifola frondosa have been proved to exert several therapeutic impacts on lipid profile and its related disorders, and we would provide a brief review on them in this literature.

-1-Propenylcysteine, a sulfur compound in aged garlic extract, alleviates cold-induced reduction in peripheral blood flow in rat via activation of the AMPK/eNOS/NO pathway

Aged garlic extract (AGE) has been shown to improve peripheral circulatory disturbances in both clinical trials and experimental animal models. To investigate the effect of S-1-propenylcysteine (S1PC), a characteristic sulfur compound in AGE, on cold-induced reduction in tail blood flow of rat, Wistar rats were individually placed in a restraint cage and given the treatment with cold water (15˚C) after the oral administration of AGE or its constituents S1PC, S-allylcysteine (SAC) and S-allylmercaptocysteine (SAMC). After the cold-treatment the tail blood flow of rats was measured at the indicated times. The pretreatment with AGE (2 g/kg BW) and S1PC (6.5 mg/kg BW) significantly alleviated the reduction of rat tail blood flow induced by cold treatment. The effect of S1PC was dose-dependent and maximal at the dose of 6.5 mg/kg BW, whereas SAC and SAMC were ineffective. To gain insight into the mechanism of S1PC action, the concentration of nitrogen oxide metabolites (NOx) in the plasma and the levels of phosphorylated endothelial nitric oxide synthase (eNOS) and 5'-AMP-activated protein kinase (AMPK) in the aorta were measured. The pretreatment with S1PC significantly increased the plasma concentration of NOx as well as the level of phosphorylated form of AMPK and eNOS in the aorta after cold-treatment. The present findings suggest that S1PC is a major constituent responsible for the effect of AGE to alleviate the cold-induced reduction of peripheral blood flow in rat by acting on the AMPK/eNOS/NO pathway in the aorta.

Potential Health Benefit of Garlic Based on Human Intervention Studies: A Brief Overview

Garlic is a polyphenolic and organosulfur enriched nutraceutical spice consumed since ancient times. Garlic and its secondary metabolites have shown excellent health-promoting and disease-preventing effects on many human common diseases, such as cancer, cardiovascular and metabolic disorders, blood pressure, and diabetes, through its antioxidant, anti-inflammatory, and lipid-lowering properties, as demonstrated in several in vitro, in vivo, and clinical studies. The present review aims to provide a comprehensive overview on the consumption of garlic, garlic preparation, garlic extract, and garlic extract-derived bioactive constituents on oxidative stress, inflammation, cancer, cardiovascular and metabolic disorders, skin, bone, and other common diseases. Among the 83 human interventional trials considered, the consumption of garlic has been reported to modulate multiple biomarkers of different diseases; in addition, its combination with drugs or other food matrices has been shown to be safe and to prolong their therapeutic effects. The rapid metabolism and poor bioavailability that have limited the therapeutic use of garlic in the last years are also discussed.

Aged garlic extract preserves cutaneous microcirculation in patients with increased risk for cardiovascular diseases: A double-blinded placebo-controlled study

Laser Doppler velocimetry estimates tissue perfusion providing a record of microvascular blood flow. Patients with heart disease or diabetes mellitus have impaired microvascular perfusion leading to impaired wound healing. Aged garlic extract (AGE) has a positive effect on vascular elasticity. This study aimed to assess the effect of long-term treatment with AGE on cutaneous tissue perfusion. A total of 122 patients with Framingham Risk Score ≥ 10 were randomised in a double-blinded manner to placebo or 2400 mg AGE daily for 1 year and monitored. Cutaneous microcirculation was measured at 0 and 12 months using laser Doppler velocimetry. A repeated measures analysis of variance (ANOVA) with a Greenhouse-Geisser correction determined that mean post-occlusive reactive hyperaemia differed significantly between time points. The mean percent change between the two time points 0 and 12 months was 102, 64 (174, 15)% change for AGE and 78, 62 (107, 92)% change for the placebo group (F[1, 120] = 5. 95, P < 0.016), 12 months of AGE increases the microcirculation in patients with an increased risk for cardiovascular events estimated using the Framingham risk score. Increased microcirculation could hypothetically facilitate wound healing.