Effect of Diallyl Trisulfide on Ischemic Tissue Injury and Revascularization in a Diabetic Mouse Model

Hydrogen sulfide and sulfaceutic or sulfanutraceutic agents: Classification, differences and relevance in preclinical and clinical studies

Hydrogen sulfide (H2S) has been extensively studied as a signal molecule in the body for the past 30 years. Researchers have conducted studies using both natural and synthetic sources of H2S, known as H2S donors, which have different characteristics in terms of how they release H2S. These donors can be inorganic salts or have various organic structures. In recent years, certain types of sulfur compounds found naturally in foods have been characterized as H2S donors and explored for their potential health benefits. These compounds are referred to as "sulfanutraceuticals," a term that combines "nutrition" and "pharmaceutical". It is used to describe products derived from food sources that offer additional health advantages. By introducing the terms "sulfaceuticals" and "sulfanutraceuticals," we categorize sulfur-containing substances based on their origin and their use in both preclinical and clinical research, as well as in dietary supplements.

Clinical Potential of Hydrogen Sulfide in Peripheral Arterial Disease

Peripheral artery disease (PAD) affects more than 230 million people worldwide. PAD patients suffer from reduced quality of life and are at increased risk of vascular complications and all-cause mortality. Despite its prevalence, impact on quality of life and poor long-term clinical outcomes, PAD remains underdiagnosed and undertreated compared to myocardial infarction and stroke. PAD is due to a combination of macrovascular atherosclerosis and calcification, combined with microvascular rarefaction, leading to chronic peripheral ischemia. Novel therapies are needed to address the increasing incidence of PAD and its difficult long-term pharmacological and surgical management. The cysteine-derived gasotransmitter hydrogen sulfide (H₂S) has interesting vasorelaxant, cytoprotective, antioxidant and anti-inflammatory properties. In this review, we describe the current understanding of PAD pathophysiology and the remarkable benefits of H₂S against atherosclerosis, inflammation, vascular calcification, and other vasculo-protective effects.

Diallyl trisulfide inhibits monosodium urate-induced NLRP3 inflammasome activation via NOX3/4-dependent mitochondrial oxidative stress in RAW 264.7 and bone marrow-derived macrophages

BACKGROUND

Monosodium urate (MSU) crystals are associated with gouty inflammatory diseases. MSU-associated inflammation is majorly triggered by NOD-like receptor protein 3 (NLRP3) inflammasome that promotes interleukin (IL)-1β secretion. Although diallyl trisulfide (DATS) is well-known polysulfide garlic compounds with anti-inflammatory effects, its action in MSU-induced inflammasome activation has not been known yet.

PURPOSE

The objective of the current study was to investigate anti-inflammasome effects and mechanisms of DATS in RAW 264.7 and bone marrow-derived macrophages (BMDM).

METHODS

The concentrations of IL-1β were analyzed with enzyme-linked immunosorbent assay. The MSU-induced mitochondrial damage and reactive oxygen species (ROS) production were detected by fluorescence microscope and flow cytometry. The protein expressions of NLRP3 signaling molecules, NADPH oxidase (NOX) 3/4 were assessed with Western blotting.

RESULTS

DATS suppressed MSU-induced IL-1β and caspase-1 accompanied by decreased inflammasome complex formation in RAW 264.7 and BMDM. In addition, DATS restored mitochondrial damage. DATS downregulated NOX 3/4 that were upregulated by MSU as predicted by gene microarray and confirmed by Western blotting.

CONCLUSION

This study first reports mechanistic finding that DATS alleviates MSU-induced NLRP3 inflammasome by mediating NOX3/4-dependent mitochondrial ROS production in macrophages in vitro and ex vivo, suggesting DATS could be effective therapeutic candidate for gouty inflammatory condition.

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.

Role of hydrogen sulphide in physiological and pathological angiogenesis

The role of hydrogen sulphide (H₂ S) in angiogenesis has been widely demonstrated. Vascular endothelial growth factor (VEGF) plays an important role in H₂ S-induced angiogenesis. H₂ S promotes angiogenesis by upregulating VEGF via pro-angiogenic signal transduction. The involved signalling pathways include the mitogen-activated protein kinase pathway, phosphoinositide-3 kinase pathway, nitric oxide (NO) synthase/NO pathway, signal transducer and activator of transcription 3 (STAT3) pathway, and adenosine triphosphate (ATP)-sensitive potassium (K_ATP ) channels. H₂ S has been shown to contribute to tumour angiogenesis, diabetic wound healing, angiogenesis in cardiac and cerebral ischaemic tissues, and physiological angiogenesis during the menstrual cycle and pregnancy. Furthermore, H₂ S can exert an anti-angiogenic effect by inactivating Wnt/β-catenin signalling or blocking the STAT3 pathway in tumours. Therefore, H₂ S plays a double-edged sword role in the process of angiogenesis. The regulation of H₂ S production is a promising therapeutic approach for angiogenesis-associated diseases. Novel H₂ S donors and/or inhibitors can be developed in the treatment of angiogenesis-dependent diseases.

Diallyl trisulfide modulated autophagy in isoproterenol induced acute myocardial infarction

Background

Acute myocardial infarction (AMI) is the most serious manifestation of coronary artery disease. The initial ischemia in AMI causes biochemical and metabolic alterations in cardiomyocytes.

Objectives

The present study aimed to investigate the biomolecular mechanisms underlying cardioprotective effects of diallyl trisulfide (DATS) as well as captopril (CAP) in isoproterenol (ISO) induced AMI focusing on autophagy & PI3K/Akt signaling.

Methods

Seventy male Albino rats were divided into seven groups as follows: Normal control, ISO, ISO + LY294002 (PI3K inhibitor), DATS+ISO, CAP+ISO, DATS+LY294002 + ISO, and CAP+LY294002 + ISO. All treatments (40 mg/kg DATS, 50 mg/kg CAP & 0.3 mg/kg LY294002) were given daily for two weeks before ISO injection (85 mg/kg for 2 days). At the end of the experiment, serum and cardiac tissues were collected. Serum cardiac troponin I (cTnI), and creatine kinase MB (CK-MB) were measured. Cardiac glutathione peroxidase (GSH-px), malondialdehyde (MDA), hypoxia-inducible factor 1 alpha (HIF-1α), autophagy proteins (P62 & LC3IIB) and gene expression of PI3K, Akt, FOXO-1, and eNOS were assessed. Histopathological examination of heart tissue was performed.

Results

DATS and CAP significantly (p < 0.01) decreased serum CK-MB and cTnI, cardiac levels of MDA, HIF-1α, p62 and LC3IIB along with an increase in GSH-px activity compared with ISO group. Moreover, DATS and CAP significantly up-regulated PI3K, Akt, and eNOS gene expression but down-regulated FOXO-1 expression compared to ISO group. However, LY294002 reversed DATS and CAP cardioprotective effects.

Conclusion

DATS and CAP prior treatment proved cardioprotective effects via modulation of autophagy, PI3K/Akt signaling, eNOS and FOXO-1 downregulation in ISO induced AMI rat model.

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.

Diallyl Trisulfide Enhances the Survival of Multiterritory Perforator Skin Flaps

The multiterritory perforator flap is one of the widest flap patterns used to repair tissue defects. However, flap necrosis of the distal part is still a challenging issue for plastic surgeons. Diallyl trisulfide (DATS) is an efficient ingredient extracted from garlic, exerting many important effects on different diseases. Our experiment aims to reveal whether DATS has a beneficial effect on the survival of perforator flaps and to explore its mechanism of action. The results showed that DATS enhanced angiogenesis and autophagy and reduced cell apoptosis and oxidative stress, thereby improving the survival rate of skin flaps. After co-administration with autophagy inhibitor 3-methyladenine (3MA), perforator flap survival was further improved. Mechanistically, we showed that PI3K/Akt and AMPK-HIF-1α signaling pathways in flap were activated under DATS treatment. All in all, DATS promoted the survival of multiterritory perforator flaps via the synergistic regulation of PI3K/Akt and AMPK-HIF-1α signaling pathways, and inhibition of DATS-induced autophagy further improves flap survival.

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.

Inhibitory Activities of Sulfur Compounds in Garlic Essential Oil against Alzheimer's Disease-Related Enzymes and Their Distribution in the Mouse Brain

Alzheimer's disease (AD) is the most common neurodegenerative disease. Garlic reportedly has various physiological effects, including a role in protecting against dementia. However, the action mechanisms of garlic on AD are not entirely clear. In this study, we investigated the inhibitory activity of garlic essential oil (GEO) against AD-related enzymes and evaluated the distribution of active substances in GEO to the brain. We found that several sulfur compounds in GEO significantly inhibited AD-related enzymes. Sulfur compounds were detected in the serum and brain 6 h post administration. The ratios of allyl mercaptan (24.0 ± 3.9%) and allyl methyl sulfide (49.8 ± 15.6%) in the brain were significantly higher than those in GEO, while those of dimethyl trisulfide (0.89 ± 34.8%), allyl methyl trisulfide (0.41 ± 19.0%), and diallyl trisulfide (0.43 ± 72.8%) in the brain were significantly lower than those in GEO. Similar results were observed in the serum, suggesting that the organosulfur compounds were converted to allyl mercaptan or allyl methyl sulfide in the body. Although allyl mercaptan and allyl methyl sulfide are not the main components of GEO, they might be key molecules to understand the bioactivities of GEO in the body.

H2S as a Bridge Linking Inflammation, Oxidative Stress and Endothelial Biology: A Possible Defense in the Fight against SARS-CoV-2 Infection?

The endothelium controls vascular homeostasis through a delicate balance between secretion of vasodilators and vasoconstrictors. The loss of physiological homeostasis leads to endothelial dysfunction, for which inflammatory events represent critical determinants. In this context, therapeutic approaches targeting inflammation-related vascular injury may help for the treatment of cardiovascular disease and a multitude of other conditions related to endothelium dysfunction, including COVID-19. In recent years, within the complexity of the inflammatory scenario related to loss of vessel integrity, hydrogen sulfide (H₂S) has aroused great interest due to its importance in different signaling pathways at the endothelial level. In this review, we discuss the effects of H₂S, a molecule which has been reported to demonstrate anti-inflammatory activity, in addition to many other biological functions related to endothelium and sulfur-drugs as new possible therapeutic options in diseases involving vascular pathobiology, such as in SARS-CoV-2 infection.

Phytochemicals as Therapeutic Interventions in Peripheral Artery Disease

Peripheral artery disease (PAD) affects over 200 million people worldwide, resulting in significant morbidity and mortality, yet treatment options remain limited. Among the manifestations of PAD is a severe functional disability and decline, which is thought to be the result of different pathophysiological mechanisms including oxidative stress, skeletal muscle pathology, and reduced nitric oxide bioavailability. Thus, compounds that target these mechanisms may have a therapeutic effect on walking performance in PAD patients. Phytochemicals produced by plants have been widely studied for their potential health effects and role in various diseases including cardiovascular disease and cancer. In this review, we focus on PAD and discuss the evidence related to the clinical utility of different phytochemicals. We discuss phytochemical research in preclinical models of PAD, and we highlight the results of the available clinical trials that have assessed the effects of these compounds on PAD patient functional outcomes.

Endothelium as a Source and Target of H2S to Improve Its Trophism and Function

The vascular endothelium consists of a single layer of squamous endothelial cells (ECs) lining the inner surface of blood vessels. Nowadays, it is no longer considered as a simple barrier between the blood and vessel wall, but a central hub to control blood flow homeostasis and fulfill tissue metabolic demands by furnishing oxygen and nutrients. The endothelium regulates the proper functioning of vessels and microcirculation, in terms of tone control, blood fluidity, and fine tuning of inflammatory and redox reactions within the vessel wall and in surrounding tissues. This multiplicity of effects is due to the ability of ECs to produce, process, and release key modulators. Among these, gasotransmitters such as nitric oxide (NO) and hydrogen sulfide (H₂S) are very active molecules constitutively produced by endotheliocytes for the maintenance and control of vascular physiological functions, while their impairment is responsible for endothelial dysfunction and cardiovascular disorders such as hypertension, atherosclerosis, and impaired wound healing and vascularization due to diabetes, infections, and ischemia. Upregulation of H₂S producing enzymes and administration of H₂S donors can be considered as innovative therapeutic approaches to improve EC biology and function, to revert endothelial dysfunction or to prevent cardiovascular disease progression. This review will focus on the beneficial autocrine/paracrine properties of H₂S on ECs and the state of the art on H₂S potentiating drugs and tools.

From the distinctive smell to therapeutic effects: Garlic for cardiovascular, hepatic, gut, diabetes and chronic kidney disease

Garlic, a member of the Allium family, widely used in cooking for many centuries, displays well described antioxidant and anti-inflammatory properties, as a result of its constituent organosulfur compounds, such as alliin, allicin, ajoene S-allyl-cysteine, diallyl sulfide and diallyl disulfide, among others. Although garlic has demonstrated beneficial effects in cardiovascular disease, diabetes, and cancer, its efficacy as a therapeutic intervention in chronic kidney disease remains to be proven. This review thus focuses on the potential benefits of garlic as a treatment option in chronic kidney disease. and its ability to mitigate associated cardiovascular complications and gut dysbiosis.

Potential role of hydrogen sulfide in diabetes-impaired angiogenesis and ischemic tissue repair

Diabetes is one of the most prevalent metabolic disorders and is estimated to affect 400 million of 4.4% of population worldwide in the next 20 year. In diabetes, risk to develop vascular diseases is two-to four-fold increased. Ischemic tissue injury, such as refractory wounds and critical ischemic limb (CLI) are major ischemic vascular complications in diabetic patients where oxygen supplement is insufficient due to impaired angiogenesis/neovascularization. In spite of intensive studies, the underlying mechanisms of diabetes-impaired ischemic tissue injury remain incompletely understood. Hydrogen sulfide (H₂S) has been considered as a third gasotransmitter regulating angiogenesis under physiological and ischemic conditions. Here, the underlying mechanisms of insufficient H₂S-impaired angiogenesis and ischemic tissue repair in diabetes are discussed. We will primarily focuses on the signaling pathways of H₂S in controlling endothelial function/biology, angiogenesis and ischemic tissue repair in diabetic animal models. We summarized that H₂S plays an important role in maintaining endothelial function/biology and angiogenic property in diabetes. We demonstrated that exogenous H₂S may be a theraputic agent for endothelial dysfunction and impaired ischemic tissue repair in diabetes.

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

BACKGROUND

Allicin, the principle active constituent in garlic, has been reported to have antihypertensive effects on drug-induced hypertension or renal hypertension in rats, but reports on spontaneously hypertensive rats (SHRs) are rare. Allicin is comprised of a variety of sulfur-containing compounds, and hydrogen sulfide (H₂S) has been shown to have specific vasomotor effects. We therefore hypothesize that allicin may exert a vasorelaxant activity by inducing H₂S production, and this eventually result in a reduction in blood pressure in SHRs.

METHODS

The in vivo antihypertensive effect of allicin was assessed using a tail-cuff method on SHRs. The in vitro vasorelaxant effect and in-depth mechanisms of allicin were explored on rat mesenteric arterial rings (RMARs) isolated from SD rats.

RESULTS

In the in vivo study, administration of allicin (7 mg/kg and 14 mg/kg, 4 weeks, i.g) dramatically decreased the blood pressure in SHRs, which was also shown to be attenuated by H₂S synthase inhibitor (PAG, 32 mg/kg, i.g). In in vitro studies, allicin (2.50-15.77 mM) produced a concentration-dependent vasorelaxation on RMARs, which was obviously reduced by preincubation with PAG. The removal of endothelium led to a decline in allicin's vasorelaxation, which was almost completely mitigated when treatment was followed with PAG. Inhibitors of nitric oxide (NO) and prostaglandin (PGI₂) pathways separately suppressed the vasorelaxation induced by allicin to a certain degree. When the RMARs incubated with PAG were treated with or without the above inhibitors in separate groups, the relaxations caused by allicin were almost identical under both these conditions. Moreover, allicin treatment increased cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) levels (downstream products of NO and PGI₂ pathways), which was decreased by PAG. Additionally, allicin increased the acetylcholine-induced endothelium-derived hyperpolarizing factor (EDHF) -mediated relaxation, which was unaffected by PAG.

CONCLUSION

Allicin exhibits a potent antihypertensive effect through vasodilatory properties and H₂S mechanisms. Moreover, the vasodilation of allicin is partially dependent on endothelium. The endothelium-dependent vasodilation of allicin is mediated by the NO-sGC-cGMP, PGI₂-AC-cAMP and EDHF pathways, of which H₂S participates in the first two but not the third one. The endothelium independent vasodilation can be predominantly attributed to H₂S production.

Diallyl trisulfide attenuates hyperglycemia-induced endothelial apoptosis by inhibition of Drp1-mediated mitochondrial fission

AIMS

Hyperglycemia induces endothelial cell apoptosis and blood vessel damage, while diallyl trisulfide (DATS) has shown cardiovascular protection in animal models and humans. The aim of this study was to investigate the effects of DATS on inhibition of high glucose-induced endothelial cell apoptosis and the underlying molecular events.

METHODS

Human umbilical vein endothelial cells (HUVECs) were incubated with DATS (100 μM) for 30 min and then cultured in high-glucose medium (HG, 33 mM) for 24 h for assessment of apoptosis, glutathione (GSH), reactive oxygen species (ROS), superoxide dismutase (SOD), and gene expression using the terminal deoxyuridine triphosphate nick end labeling (TUNEL), flow cytometry, caspase-3 activity, ROS, SOD, and western blot assays as well as JC-1 and MitoTracker Red staining, respectively.

RESULTS

DATS treatment significantly inhibited high glucose-induced HUVEC apoptosis by blockage of intracellular and mitochondrial ROS generation, maintenance of the mitochondrial membrane potential, and suppression of high glucose-induced dynamin-related protein 1 (Drp1) expression. Furthermore, DATS blockage of high glucose-induced mitochondrial fission and apoptosis was through adenosine monophosphate-activated protein kinase (AMPK) activation-inhibited Drp1 expression in HUVECs.

CONCLUSIONS

DATS demonstrated the ability to inhibit high glucose-induced HUVEC apoptosis via suppression of Drp1-mediated mitochondrial fission in an AMPK-dependent fashion.