Antihypertensive effects of allicin on spontaneously hypertensive rats via vasorelaxation and hydrogen sulfide mechanisms

Hydrogen sulfide mitigates mitochondrial dysfunction and cellular senescence in diabetic patients: Potential therapeutic applications

Diabetes induces a pro-aging state characterized by an increased abundance of senescent cells in various tissues, heightened chronic inflammation, reduced substance and energy metabolism, and a significant increase in intracellular reactive oxygen species (ROS) levels. This condition leads to mitochondrial dysfunction, including elevated oxidative stress, the accumulation of mitochondrial DNA (mtDNA) damage, mitophagy defects, dysregulation of mitochondrial dynamics, and abnormal energy metabolism. These dysfunctions result in intracellular calcium ion (Ca2+) homeostasis disorders, telomere shortening, immune cell damage, and exacerbated inflammation, accelerating the aging of diabetic cells or tissues. Hydrogen sulfide (H2S), a novel gaseous signaling molecule, plays a crucial role in maintaining mitochondrial function and mitigating the aging process in diabetic cells. This article systematically explores the specific mechanisms by which H2S regulates diabetes-induced mitochondrial dysfunction to delay cellular senescence, offering a promising new strategy for improving diabetes and its complications.

ROS-responsive Hydrogel Loaded with Allicin Suppresses Cell Apoptosis for the Treatment of Intervertebral Disc Degeneration in a Rat Model

BACKGROUND

Intervertebral disc degeneration (IVDD) is a common cause of lower back pain, and cell apoptosis plays a key role in its progression. This study explores the therapeutic potential of a reactive oxygen species (ROS)-responsive hydrogel loaded with allicin for treating IVDD.

METHODS

Allicin was encapsulated in an ROS-responsive hydrogel, and its controlled release was studied in vitro. Nucleus pulposus cells were treated with hydrogen peroxide to induce apoptosis, and the effects of the hydrogel were examined using quantitative polymerase chain reaction and Western blotting. An in vivo rat model of IVDD was also established to assess the efficacy of the treatment.

RESULTS

The ROS-responsive hydrogel effectively inhibited apoptosis in nucleus pulposus cells by reducing ROS levels and modulating the expression of apoptotic and antiapoptotic genes. In the rat model, the hydrogel loaded with allicin significantly reduced IVDD, preserving disc morphology and matrix integrity.

CONCLUSIONS

ROS-responsive hydrogel loaded with allicin shows potential as a therapeutic approach for IVDD by inhibiting cell apoptosis and reducing disc degeneration in vivo.

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.

Therapeutic potentials of allicin in cardiovascular disease: advances and future directions

Cardiovascular disease (CVD) remains the predominant cause of mortality and disability worldwide. Against this backdrop, finding effective drugs for the pharmacological treatment of CVD has become one of the most urgent and challenging issues in medical research. Garlic (Allium sativum L.) is one of the oldest plants and is world-renowned for its dietary and medicinal values. Allicin (diallyl thiosulfinate) is one of the primary natural active ingredients in garlic, which has been proven to have powerful cardioprotective effects and mediate various pathological processes related to CVD, such as inflammatory factor secretion, myocardial cell apoptosis, oxidative stress, and more. Therefore, allicin holds a promising application prospect in the treatment of CVD. This review summarized the biological functions of allicin and its potential mechanisms in CVD, including antioxidation, anti-inflammation, and anti-apoptosis effects. Reckoning with these, we delved into recent studies on allicin's cardioprotective effects concerning various CVDs, such as atherosclerosis, hypertension, myocardial infarction, arrhythmia, cardiac hypertrophy, heart failure, and cardiotoxicity. Further, considering the tremendous advancement in nanomedicine, nanotechnology-based drug delivery systems show promise in addressing limitations of allicin's clinical applications, including improving its solubility, stability, and bioavailability. Through this review, we hope to provide a reference for further research on allicin in cardioprotection and drug development.

Construction of diallyltrisulfide nanoparticles for alleviation of ethanol-induced acute gastric injury

Gastric ulcer, a significant health issue characterized by the degradation of the gastric mucosa, often arises from excessive gastric acid secretion and poses a challenge in current medical treatments due to the limited efficacy and side effects of first-line drugs. Addressing this, our study develops a novel therapeutic strategy leveraging gas therapy, specifically targeting the release of hydrogen sulfide (H2S) in the treatment of gastric ulcers. We successfully developed a composite nanoparticle, named BSA·SH-DATS, through a two-step process. Initially, bovine serum albumin (BSA) was sulfhydrated to generate BSA·SH nanoparticles via a mercaptosylation method. Subsequently, these nanoparticles were further functionalized by incorporating diallyltrisulfide (DATS) through a precise Michael addition reaction. This sequential modification resulted in the creation of BSA·SH-DATS nanoparticles. Our comprehensive in vitro and in vivo investigations demonstrate that these nanoparticles possess an exceptional ability for site-specific action on gastric mucosal cells under the controlled release of H2S in response to endogenous glutathione (GSH), markedly diminishing the production of pro-inflammatory cytokines, thereby alleviating inflammation and apoptosis. Moreover, the BSA·SH-DATS nanoparticles effectively regulate critical inflammatory proteins, including NF-κB and Caspase-3. Our study underscores their potential as a transformative approach for gastric ulcer treatment.

Allicin Promotes Glucose Uptake by Activating AMPK through CSE/H2S-Induced S-Sulfhydration in a Muscle-Fiber Dependent Way in Broiler Chickens

SCOPE

Allicin, a product of enzymatic reaction when garlic is injured, plays an important role in maintaining glucose homeostasis in mammals. However, the effect of allicin on glucose homeostasis in the state of insulin resistance remains to be elucidated. This study investigates the effect of allicin on glucose metabolism using different muscle fibers in a chicken model.

METHODS AND RESULTS

Day-old male Arbor Acres broilers are randomly divided into three groups and fed a basal diet supplemented with 0, 150, or 300 mg kg-1 allicin for 42 days. Results show that allicin improves the zootechnical performance of broilers at the finishing stage. The glucose loading test (2 g kg-1 body mass) indicates the regulatory role of allicin on glucose homeostasis. In vitro results demonstrate allicin increases glutathione (GSH) level and the expression of cystathionine γ lyase (CSE), leading to endogenous hydrogen sulfide (H2S) production in M. pectoralis major (PM) muscle-derived myotubes. Allicin stimulates adenosine monophosphate-activated protein kinase (AMPK) S-sulfhydration and AMPK phosphorylation to promote glucose uptake, which is suppressed in the presence of d,l-propargylglycine (PAG, a CSE inhibitor).

CONCLUSION

This study demonstrates that allicin induces AMPK S-sulfhydration and AMPK phosphorylation to promote glucose uptake via the CSE/H2S system in a muscle fiber-dependent manner.

Bioactive components and molecular mechanisms of Salvia miltiorrhiza Bunge in promoting blood circulation to remove blood stasis

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge (SM) is an outstanding herbal medicine with various traditional effects, especially promoting blood circulation to remove blood stasis. It has been widely used for centuries to treat blood stasis syndrome (BSS)-related diseases. BSS is one of the basic pathological syndromes of diseases such as cardiovascular and cerebrovascular diseases in traditional East Asian medicine, which is characterized by disturbance of blood circulation. However, the bioactive components and mechanisms of SM in the treatment of BSS have not been systematically reviewed. Therefore, this article outlines the anti-BSS effects of bioactive components of SM, concentrating on the molecular mechanisms.

AIM OF THE REVIEW

To summarize the bioactive components of SM against BSS and highlight its potential targets and signaling pathways, hoping to provide a modern biomedical perspective to understand the efficacy of SM on enhancing blood circulation to remove blood stasis.

MATERIALS AND METHODS

A comprehensive literature search was performed to retrieve articles published in the last two decades on bioactive components of SM used for BSS treatment from the online electronic medical literature database (PubMed).

RESULTS

Phenolic acids and tanshinones in SM are the main bioactive components in the treatment of BSS, including but not limited to salvianolic acid B, tanshinone IIA, salvianolic acid A, cryptotanshinone, Danshensu, dihydrotanshinone, rosmarinic acid, protocatechuic aldehyde, and caffeic acid. They protect vascular endothelial cells by alleviating oxidative stress and inflammatory damage and regulating of NO/ET-1 levels. They also enhance anticoagulant and fibrinolytic capacity, inhibit platelet activation and aggregation, and dilate blood vessels. Moreover, lowering blood lipids and improving blood rheological properties may be the underlying mechanisms of their anti-BSS. More notably, these compounds play an anti-BSS role by mediating multiple signaling pathways such as Nrf2/HO-1, TLR4/MyD88/NF-κB, PI3K/Akt/eNOS, MAPKs (p38, ERK, and JNK), and Ca2+/K+ channels.

CONCLUSIONS

Both phenolic acids and tanshinones in SM may act synergistically to target different signaling pathways to achieve the effect of promoting blood circulation.

Targeting the NLRP3 inflammasome for the treatment of hypertensive target organ damage: Role of natural products and formulations

BACKGROUND AND AIM

Hypertension is a major global health problem that causes target organ damage (TOD) in the heart, brain, kidney, and blood vessels. The mechanisms of hypertensive TOD are not fully understood, and its treatment is challenging. This review provides an overview of the current knowledge on the role of Nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome in hypertensive TOD and the natural products and formulations that inhibit it.

METHODS

We searched PubMed, Web of Science, Google Scholar, and CNKI for relevant articles using the keywords "hypertension," "target organ damage," "NLRP3 inflammasome," "natural products," and "formulations." We reviewed the effects of the NLRP3 inflammasome on hypertensive TOD in different organs and discussed the natural products and formulations that modulate it.

KEY RESULTS

In hypertensive TOD, the NLRP3 inflammasome is activated by various stimuli such as oxidative stress and inflammation. Activation of NLRP3 inflammasome leads to the production of pro-inflammatory cytokines that exacerbate tissue damage and dysfunction. Natural products and formulations, including curcumin, resveratrol, triptolide, and allicin, have shown protective effects against hypertensive TOD by inhibiting the NLRP3 inflammasome.

CONCLUSIONS AND IMPLICATIONS

The NLRP3 inflammasome is a promising therapeutic target in hypertensive TOD. Natural products and formulations that inhibit the NLRP3 inflammasome may provide novel drug candidates or therapies for hypertensive TOD. Further studies are needed to elucidate the molecular mechanisms and optimize the dosages of these natural products and formulations and evaluate their clinical efficacy and safety.

Antioxidant and anti-inflammatory effects of allicin in the kidney of an experimental model of metabolic syndrome

Background

Recent studies have suggested that metabolic syndrome (MS) encompasses a group of risk factors for developing chronic kidney disease (CKD). This work aimed to evaluate the antioxidant and anti-inflammatory effects of allicin in the kidney from an experimental model of MS.

Methods

Male Wistar rats (220-250 g) were used, and three experimental groups (n = 6) were formed: control (C), metabolic syndrome (MS), and MS treated with allicin (16 mg/Kg/day, gastric gavage) (MS+A). MS was considered when an increase of 20% in at least three parameters (body weight, systolic blood pressure (SBP), fasting blood glucose (FBG), or dyslipidemia) was observed compared to the C group. After the MS diagnosis, allicin was administered for 30 days.

Results

Before the treatment with allicin, the MS group showed more significant body weight gain, increased SBP, and FBG, glucose intolerance, and dyslipidemia. In addition, increased markers of kidney damage in urine and blood. Moreover, the MS increased oxidative stress and inflammation in the kidney compared to group C. The allicin treatment prevented further weight gain, reduced SBP, FBG, glucose intolerance, and dyslipidemia. Also, markers of kidney damage in urine and blood were decreased. Further, the oxidative stress and inflammation were decreased in the renal cortex of the MS+A compared to the MS group.

Conclusion

Allicin exerts its beneficial effects on the metabolic syndrome by considerably reducing systemic and renal inflammation as well as the oxidative stress. These effects were mediated through the Nrf2 pathway. The results suggest allicin may be a therapeutic alternative for treating kidney injury induced by the metabolic syndrome risk factors.

Hydrogen sulfide in the experimental models of arterial hypertension

Hydrogen sulfide (H₂S) is the third member of gasotransmitter family together with nitric oxide and carbon monoxide. H₂S is involved in the regulation of blood pressure by controlling vascular tone, sympathetic nervous system activity and renal sodium excretion. Moderate age-dependent hypertension and endothelial dysfunction develop in mice with knockout of cystathionine γ-lyase (CSE), the enzyme involved in H₂S production in the cardiovascular system. Decreased H₂S concentration as well as the expression and activities of H₂S-producing enzymes have been observed in most commonly used animal models of hypertension such as spontaneously hypertensive rats, Dahl salt-sensitive rats, chronic administration of NO synthase inhibitors, angiotensin II infusion and two-kidney-one-clip hypertension, the model of renovascular hypertension. Administration of H₂S donors decreases blood pressure in these models but has no major effects on blood pressure in normotensive animals. H₂S donors not only reduce blood pressure but also end-organ injury such as vascular and myocardial hypertrophy and remodeling, hypertension-associated kidney injury or erectile dysfunction. H₂S level and signaling are modulated by some antihypertensive medications as well as natural products with antihypertensive activity such as garlic polysulfides or plant-derived isothiocyanates as well as non-pharmacological interventions. Modifying H₂S signaling is the potential novel therapeutic approach for the management of hypertension, however, more experimental clinical studies about the role of H₂S in hypertension are required.

Toxoplasma gondii infection triggers ongoing inflammation mediated by increased intracellular Cl- concentration in airway epithelium

Toxoplasma gondii is a widespread parasitic protozoan causing toxoplasmosis including pulmonary toxoplasmosis. As the first line of host defense, airway epithelial cells play critical roles in orchestrating pulmonary innate immunity. However, the mechanism underlying the airway inflammation induced by the T. gondii infection remains largely unclear. This study demonstrated that after infection with T. gondii, the major anion channel located in the apical membranes of airway epithelial cells, cystic fibrosis transmembrane conductance regulator (CFTR), was degraded by the parasite-secreted cysteine proteases. The intracellular Cl^- concentration ([Cl^-]_i) was consequently elevated, leading to activation of nuclear factor-κB (NF-κB) signaling via serum/glucocorticoid regulated kinase 1. Furthermore, the heightened [Cl^-]_i and activated NF-κB signaling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP level through NF-κB-mediated up-regulation of phosphodiesterase 4. Conversely, the sulfur-containing compound allicin conferred anti-inflammatory effects on pulmonary toxoplasmosis by decreasing [Cl^-]_i via activation of CFTR. These results suggest that the intracellular Cl^- dynamically modulated by T. gondii mediates sustained airway inflammation, which provides a potential therapeutic target against pulmonary toxoplasmosis.

Regulation of blood pressure by natural sulfur compounds: Focus on their mechanisms of action

Natural sulfur compounds are emerging as therapeutic options for the management of hypertension and prehypertension. They are mainly represented by polysulfides from Alliaceae (i.e., garlic) and isothiocyanates from Brassicaceae (or crucifers). The beneficial cardiovascular effects of these compounds, especially garlic polysulfides, are well known and widely reported both in preclinical and clinical studies. However, only a few authors have linked the ability of natural sulfur compounds to induce vasorelaxation and subsequent antihypertensive effects with their ability to release hydrogen sulfide (H₂S) in biological tissue. H₂S is an endogenous gasotransmitter involved in vascular tone regulation. Some cardiovascular diseases, such as hypertension, are associated with lower plasma H₂S levels. Consequently, exogenous sources of H₂S (H₂S donors) have been designed and synthesized or identified among secondary plant metabolites as potential therapeutic options. In addition to antioxidant effects due to its chemical properties as a reducing agent, H₂S induces vasorelaxation by interacting with a range of molecular targets. The mechanisms of action accounting for H₂S-induced vasodilation include opening of vascular potassium channels (such as ATP-sensitive (K_ATP) and voltage-operated (Kv7) channels), inhibition of 5-phosphodiesterase (5-PDE), and activation of vascular endothelial growth factor receptor-2 (VEGFR-2). These effects may be attributed to H₂S-induced S-persulfidation (or S-sulfhydration), which is a posttranslational modification of cysteine residues of many types of proteins resulting in structural and functional alterations (activation/inhibition). Thus, H₂S donors, such as natural sulfur compounds, are promising antihypertensive agents with novel mechanisms of action.

Cellular Mechanisms Underlying the Cardioprotective Role of Allicin on Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a group of diseases in which the common denominator is the affection of blood vessels, heart tissue, and heart rhythm. The genesis of CVD is complex and multifactorial; therefore, approaches are often based on multidisciplinary management and more than one drug is used to achieve the optimal control of risk factors (dyslipidemia, hypertension, hypertrophy, oxidative stress, endothelial dysfunction, inflammation). In this context, allicin, a sulfur compound naturally derived from garlic, has shown beneficial effects on several cardiovascular risk factors through the modulation of cellular mechanisms and signaling pathways. Effective pharmacological treatments for CVD or its risk factors have not been developed or are unknown in clinical practice. Thus, this work aimed to review the cellular mechanisms through which allicin exerts its therapeutic effects and to show why it could be a therapeutic option for the prevention or treatment of CVD and its risk factors.

The role of adipose tissue-derived hydrogen sulfide in inhibiting atherosclerosis

Hydrogen sulfide (H₂S) is the third gaseous signaling molecule discovered in the body after NO and CO and plays an important organismal protective role in various diseases. Within adipose tissue, related catalytic enzymes (cystathionine-β-synthetase, cystathionine-γ-lyase, and 3-mercaptopyruvate transsulfuration enzyme) can produce and release endogenous H₂S. Atherosclerosis (As) is a pathological change in arterial vessels that is closely related to abnormal glucose and lipid metabolism and a chronic inflammatory response. Previous studies have shown that H₂S can act on the cardiovascular system, exerting effects such as improving disorders of glycolipid metabolism, alleviating insulin resistance, protecting the function of vascular endothelial cells, inhibiting vascular smooth muscle cell proliferation and migration, regulating vascular tone, inhibiting the inflammatory response, and antagonizing the occurrence and development of As.

Therapeutic Potential of Allicin and Aged Garlic Extract in Alzheimer’s Disease

Garlic, Allium sativum, has long been utilized for a number of medicinal purposes around the world, and its medical benefits have been well documented. The health benefits of garlic likely arise from a wide variety of components, possibly working synergistically. Garlic and garlic extracts, especially aged garlic extracts (AGEs), are rich in bioactive compounds, with potent anti-inflammatory, antioxidant and neuroprotective activities. In light of these effects, garlic and its components have been examined in experimental models of Alzheimer’s disease (AD), the most common form of dementia without therapy, and a growing health concern in aging societies. With the aim of offering an updated overview, this paper reviews the chemical composition, metabolism and bioavailability of garlic bioactive compounds. In addition, it provides an overview of signaling mechanisms triggered by garlic derivatives, with a focus on allicin and AGE, to improve learning and memory.

Allicin Facilitates Airway Surface Liquid Hydration by Activation of CFTR

Airway epithelium plays critical roles in regulating airway surface liquid (ASL), the alteration of which causes mucus stasis symptoms. Allicin is a compound released from garlic and harbors the capacity of lung-protection. However, the potential regulatory effects of allicin on airway epithelium remain elusive. This study aimed to investigate the effects of allicin on ion transport across airway epithelium and evaluate its potential as an expectorant. Application of allicin induced Cl⁻ secretion across airway epithelium in a concentration-dependent manner. Blockade of cystic fibrosis transmembrane conductance regulator (CFTR) or inhibition of adenylate cyclase-cAMP signaling pathway attenuated allicin-induced Cl⁻ secretion in airway epithelial cells. The in vivo study showed that inhaled allicin significantly increased the ASL secretion in mice. These results suggest that allicin induces Cl⁻ and fluid secretion across airway epithelium via activation of CFTR, which might provide therapeutic strategies for the treatment of chronic pulmonary diseases associated with ASL dehydration.

Potential Effects of Natural H2S-Donors in Hypertension Management

After the discovery of hydrogen sulfide (H₂S) in the central nervous system by Abe and Kimura in 1996, the physiopathological role of H₂S has been widely investigated in several systems such as the cardiovascular. In particular, H₂S plays a pivotal role in the control of vascular tone, exhibiting mechanisms of action able to induce vasodilation: for instance, activation of potassium channels (KATP and Kv7) and inhibition of 5-phosphodiesterase (5-PDE). These findings paved the way for the research of natural and synthetic exogenous H₂S-donors (i.e., molecules able to release H₂S) in order to have new tools for the management of hypertension. In this scenario, some natural molecules derived from Alliaceae (i.e., garlic) and Brassicaceae (i.e., rocket or broccoli) botanical families show the profile of slow H₂S-donors able to mimic the endogenous production of this gasotransmitter and therefore can be viewed as interesting potential tools for management of hypertension or pre-hypertension. In this article, the preclinical and clinical impacts of these natural H₂S-donors on hypertension and vascular integrity have been reviewed in order to give a complete panorama of their potential use for the management of hypertension and related vascular diseases.

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.

The interactive effects of exercise training and functional feeds on the cardiovascular performance of rainbow trout (Oncorhynchus mykiss) at high temperatures

The cardiovascular performance of salmonids in aquaculture can be impaired by acute climate warming, posing risks for fish survival. Exercise training and functional feeds have been shown to be cardioprotective in mammals but their action on the fish heart and its upper thermal performance has not been studied. To investigate this, rainbow trout were trained at a moderate water velocity of 1 body length per second (bl s⁻¹) for 6 h per day, either alone or in combination with one of two functional feed-supplements, allicin and fucoidan. After 6 weeks of exercise training and feeding, maximum heart rate and the temperature coefficient of heart rate were significantly higher in the trained fish as compared to untrained ones. There was a slight increase in hematocrit in trained control fish reared on a normal diet (TC group) compared to untrained fish fed with the same diet (CC). This implies that exercise training enhanced oxygen delivery to trout tissues via an increase of cardiac blood flow in warm water. However, cardiac thermal tolerance was not affected by exercise training or feeding, except from the temperature of peak heart rate which was higher in the trained group fed with fucoidan supplement (TF) as compared to the untrained group fed with same diet (CF). Allicin supplement caused a significant reduction in the maximum heart rate and the temperature coefficient of heart rate, especially in trained fish, while fucoidan supplement did not cause any effect on heart rate. No differences were observed in growth performance among groups. However, fish fed with fucoidan-supplemented diet had a slight reduction in feed conversion efficiency. We suggest further investigations to understand the antagonistic effect of allicin supplemental feeding and exercise training on cardiovascular performance. More studies are also required to investigate if other exercise training intensities could increase cardiac thermal tolerance.

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Exercise training at 1 bl s⁻¹ increased the hematocrit values of rainbow trout.

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Exercise training at 1 bl s⁻¹ increased the maximum heart rate and temperature coefficient of rainbow trout.

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Exercise training at 1bl s⁻¹ did not enhance the cardiac thermal tolerance of rainbow trout.

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Functional feeds, allicin and fucoidan, did not improve the cardiovascular system of rainbow trout at high temperatures.

Protective Effects of Allicin on Acute Myocardial Infarction in Rats via Hydrogen Sulfide-mediated Regulation of Coronary Arterial Vasomotor Function and Myocardial Calcium Transport

Acute myocardial infarction (AMI) is a condition with high morbidity and mortality, for which effective treatments are lacking. Allicin has been reported to exert therapeutic effects on AMI, but the underlying mechanisms of its action have not been fully elucidated. To investigate this, a rat model of AMI was generated by ligating the left anterior descending branch of the coronary artery. DL-propargylglycine (PAG), a specific hydrogen sulfide (H₂S) synthetase inhibitor, was used to examine the effects of allicin on H₂S production. Isolated coronary arteries and cardiomyocytes were assessed for vascular reactivity and cellular Ca²⁺ transport using a multiwire myography system and a cell-contraction-ion detection system, respectively. Allicin administration improved cardiac function and myocardial pathology, reduced myocardial enzyme levels, and increased H₂S and H₂S synthetase levels. Allicin administration resulted in concentration-dependent effects on coronary artery dilation, which were mediated by receptor-dependent Ca²⁺ channels, ATP-sensitive K⁺ channels, and sarcoplasmic reticulum (SR) Ca²⁺ release induced by the ryanodine receptor. Allicin administration improved Ca²⁺ homeostasis in cardiomyocytes by increasing cardiomyocyte contraction, Ca²⁺ transient amplitude, myofilament sensitivity, and SR Ca²⁺ content. Allicin also enhanced Ca²⁺ uptake via SR Ca²⁺-ATPase and Ca²⁺ removal via the Na⁺/Ca²⁺ exchanger, and it reduced SR Ca²⁺ leakage. Notably, the protective effects of allicin were partially attenuated by blockade of H₂S production with PAG. Our findings provide novel evidence that allicin-induced production of H₂S mediates coronary artery dilation and regulation of Ca²⁺ homeostasis in AMI. Our study presents a novel mechanistic insight into the anti-AMI effects of allicin and highlights the therapeutic potential of this compound.

Hydrogen sulfide: A new therapeutic target in vascular diseases

Hydrogen sulfide (H₂S) is one of most important gas transmitters. H₂S modulates many physiological and pathological processes such as inflammation, oxidative stress and cell apoptosis that play a critical role in vascular function. Recently, solid evidence show that H₂S is closely associated to various vascular diseases. However, specific function of H₂S remains unclear. Therefore, in this review we systemically summarized the role of H₂S in vascular diseases, including hypertension, atherosclerosis, inflammation and angiogenesis. In addition, this review also outlined a novel therapeutic perspective comprising crosstalk between H₂S and smooth muscle cell function. Therefore, this review may provide new insight inH₂S application clinically.

Allicin, an Antioxidant and Neuroprotective Agent, Ameliorates Cognitive Impairment

Allicin (diallylthiosulfinate) is a defense molecule produced by cellular contents of garlic (Allium sativum L.). On tissue damage, the non-proteinogenic amino acid alliin (S-allylcysteine sulfoxide) is converted to allicin in an enzyme-mediated process catalysed by alliinase. Allicin is hydrophobic in nature, can efficiently cross the cellular membranes and behaves as a reactive sulfur species (RSS) inside the cells. It is physiologically active molecule with the ability to oxidise the thiol groups of glutathione and between cysteine residues in proteins. Allicin has shown anticancer, antimicrobial, antioxidant properties and also serves as an efficient therapeutic agent against cardiovascular diseases. In this context, the present review describes allicin as an antioxidant, and neuroprotective molecule that can ameliorate the cognitive abilities in case of neurodegenerative and neuropsychological disorders. As an antioxidant, allicin fights the reactive oxygen species (ROS) by downregulation of NOX (NADPH oxidizing) enzymes, it can directly interact to reduce the cellular levels of different types of ROS produced by a variety of peroxidases. Most of the neuroprotective actions of allicin are mediated via redox-dependent pathways. Allicin inhibits neuroinflammation by suppressing the ROS production, inhibition of TLR4/MyD88/NF-κB, P38 and JNK pathways. As an inhibitor of cholinesterase and (AChE) and butyrylcholinesterase (BuChE) it can be applied to manage the Alzheimer's disease, helps to maintain the balance of neurotransmitters in case of autism spectrum disorder (ASD) and attention deficit hyperactive syndrome (ADHD). In case of acute traumatic spinal cord injury (SCI) allicin protects neuron damage by regulating inflammation, apoptosis and promoting the expression levels of Nrf2 (nuclear factor erythroid 2-related factor 2). Metal induced neurodegeneration can also be attenuated and cognitive abilities of patients suffering from neurological diseases can be ameliorates by allicin administration.

A review of some common African spices with antihypertensive potential

Hypertension is the most common non-communicable disease, with about 1.28 billion hypertensive people worldwide. It is more prevalent in men than women and more common in the elderly. Hereditary, age, obesity, lifestyle, diet, alcohol, and chronic metabolic diseases are the major risk factors of hypertension. Treating hypertension is a complex process as there are several mechanisms responsible for its pathogenesis; hence, a combination of several drugs is used for managing hypertension. Drugs used in managing hypertension are expensive and often come with associated side effects; thus, there is need for alternative means of managing this life-threatening disease. These drugs do not achieve the recommended blood pressure target in most people; more so majority of people with hypertension do not follow the treatment regimen religiously. Some Africans have been reported to become normotensive as a result of dietary consumption of spices. Several spices have been used over the years in Africa to manage hypertension. The aim of this review is to evaluate the ethnomedicinal use, bioactive phytochemical composition, bioactive compounds present, and pharmacological applications of spices commonly used in Africa for managing hypertension. Most of the plants used contained polyphenols, flavonoids, tannins, anthraquinone, flavonoids, cardiac glycosides, and saponins. Dietary supplementation of Xylopia aethiopica and other spices in diet have been proven to significantly reduced plasma angiotensin-I-converting enzyme (ACE) than simvastatin (the reference drug). Toxicological, histological, and hematological evaluation revealed that acute and chronic consumption of most of these spices are safe. Studies have also revealed that some of the spices can be used as alternative therapy alongside usual antihypertensive medications. PRACTICAL IMPLICATION: The prevalent rate of hypertension is on the increase in both the developed and developing countries. People often skip medication due to their busy schedule and anti-hypertensive potential side effects; however, this is not the case with food/spices as most people consumed them daily. Deliberate, right combinations and consistent incorporation of spices with proven anti-hypertensive potential into our diet may be of great benefit in normalizing blood pressure and mitigate other complications on the heart and vital organs.

Vascular Health Triad in Humans With Hypertension-Not the Usual Suspects

Hypertension (HTN) affects more than one-third of the US population and remains the top risk factor for the development of cardiovascular disease (CVD). Identifying the underlying mechanisms for developing HTN are of critical importance because the risk of developing CVD doubles with ∼20 mmHg increase in systolic blood pressure (BP). Endothelial dysfunction, especially in the resistance arteries, is the primary site for initiation of sub-clinical HTN. Furthermore, inflammation and reactive oxygen and nitrogen species (ROS/RNS) not only influence the endothelium independently, but also have a synergistic influence on each other. Together, the interplay between inflammation, ROS and vascular dysfunction is referred to as the vascular health triad, and affects BP regulation in humans. While the interplay of the vascular health triad is well established, new underlying mechanistic targets are under investigation, including: Inducible nitric oxide synthase, hydrogen peroxide, hydrogen sulfide, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor activated T cells. This review outlines the role of these unusual suspects in vascular health and function in humans. This review connects the dots using these unusual suspects underlying inflammation, ROS and vascular dysfunction especially in individuals at risk of or with diagnosed HTN based on novel studies performed in humans.

The Antiviral Roles of Hydrogen Sulfide by Blocking the Interaction between SARS-CoV-2 and Its Potential Cell Surface Receptors

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is posing a great threat to the global economy and public health security. Together with the acknowledged angiotensin-converting enzyme 2, glucose-regulated protein 78, transferrin receptor, AXL, kidney injury molecule-1, and neuropilin 1 are also identified as potential receptors to mediate SARS-CoV-2 infection. Therefore, how to inhibit or delay the binding of SARS-CoV-2 with the abovementioned receptors is a key step for the prevention and treatment of COVID-19. As the third gasotransmitter, hydrogen sulfide (H2S) plays an important role in many physiological and pathophysiological processes. Recently, survivors were reported to have significantly higher H2S levels in COVID-19 patients, and mortality was significantly greater among patients with decreased H2S levels. Considering that the beneficial role of H2S against COVID-19 and COVID-19-induced comorbidities and multiorgan damage has been well-examined and reported in some excellent reviews, this review will discuss the recent findings on the potential receptors of SARS-CoV-2 and how H2S modulates the above receptors, in turn blocking SARS-CoV-2 entry into host cells.

Ameliorative effect of allicin on vascular calcification via inhibiting endoplasmic reticulum stress

OBJECTIVES

Vascular calcification (VC) is an independent predictor for cardiovascular events and mortality. However, there are currently no effective methods to reverse or prevent it. The present study aimed to determine the ameliorative effect of allicin on VC.

METHODS

VC model of rats was induced by high-dose vitamin D₃, which was valued by Alizarin Red staining, calcium contents, and alkaline phosphatase in the aorta. Systolic blood pressure, pulse pressure, and pulse wave velocity were measured to determine aortic stiffness. Protein levels were detected by Western blot.

RESULTS

Allicin treatment rescued aortic VC and stiffness. The increased protein levels of RUNX2 and BMP2, two markers of osteoblastic phenotype of vascular smooth muscle cells, in the calcified aorta were attenuated by allicin, whereas the decreased levels of calponin and SM22α induced by calcification were improved. Allicin treatment significantly attenuated the increased protein levels of GRP78, GRP94, and CHOP, which are key markers of endoplasmic reticulum stress, in the calcified aorta. The activation of PERK/eIF2α/ATF4 cascades was also prevented by allicin.

CONCLUSIONS

Allicin could ameliorate aortic VC and stiffness. The ameliorative effect of allicin on VC might be mediated by inhibiting PERK/eIF2α/ATF4 cascades. Our results might provide a new proof for VC treatment.

Hydrogen Sulfide Metabolism and Pulmonary Hypertension

Pulmonary hypertension (PH) is a severe and multifactorial disease characterized by a progressive elevation of pulmonary arterial resistance and pressure due to remodeling, inflammation, oxidative stress, and vasoreactive alterations of pulmonary arteries (PAs). Currently, the etiology of these pathological features is not clearly understood and, therefore, no curative treatment is available. Since the 1990s, hydrogen sulfide (H₂S) has been described as the third gasotransmitter with plethoric regulatory functions in cardiovascular tissues, especially in pulmonary circulation. Alteration in H₂S biogenesis has been associated with the hallmarks of PH. H₂S is also involved in pulmonary vascular cell homeostasis via the regulation of hypoxia response and mitochondrial bioenergetics, which are critical phenomena affected during the development of PH. In addition, H₂S modulates ATP-sensitive K⁺ channel (K_ATP) activity, and is associated with PA relaxation. In vitro or in vivo H₂S supplementation exerts antioxidative and anti-inflammatory properties, and reduces PA remodeling. Altogether, current findings suggest that H₂S promotes protective effects against PH, and could be a relevant target for a new therapeutic strategy, using attractive H₂S-releasing molecules. Thus, the present review discusses the involvement and dysregulation of H₂S metabolism in pulmonary circulation pathophysiology.

Effects of Allicin on Late Sodium Current Caused by ΔKPQ-SCN5A Mutation in HEK293 Cells

Aim

The aim was to study the effect of Allitridum (Allicin) on the heterologous expression of the late sodium current on the ΔKPQ-SCN5A mutations in HEK293 cells, with a view to screening new drugs for the treatment of long QT syndrome type 3 (LQT3).

Methods and Results

The ΔKPQ-SCN5A plasmid was transiently transferred into HEK293 cells by liposome technology and administered by extracellular perfusion, and the sodium current was recorded by whole-cell patch-clamp technology. Application of Allicin 30 μM reduced the late sodium current (I_Na,L) of the Nav1.5 channel current encoded by ΔKPQ-SCN5A from 1.92 ± 0.12 to 0.65 ± 0.03 pA/pF (P < 0.01, n = 15), which resulted in the decrease of I_Na,L/I_Na,P (from 0.94% ± 0.04% to 0.32% ± 0.02%). Furthermore, treatment with Allicin could move the steady-state inactivation of the channel to a more negative direction, resulting in an increase in channel inactivation at the same voltage, which reduced the increase in the window current and further increased the inactivation of the channel intermediate state. However, it had no effect on channel steady-state activation (SSA), inactivation mechanics, and recovery dynamics after inactivation. What’s more, the Nav1.5 channel protein levels of membrane in the ΔKPQ-SCN5A mutation were enhanced from 0.49% ± 0.04% to 0.76% ± 0.02% with the effect of 30 mM Allicin, close to 0.89% ± 0.02% of the WT.

Conclusion

Allicin reduced the late sodium current of ΔKPQ-SCN5A, whose mechanism may be related to the increase of channel steady-state inactivation (SSI) and intermediate-state inactivation (ISI) by the drug, thus reducing the window current.