Diallyl trisulfide protects against high glucose-induced cardiac apoptosis by stimulating the production of cystathionine gamma-lyase-derived hydrogen sulfide

Characterizations of White Mulberry, Sea-Buckthorn, Garlic, Lily of the Valley, Motherwort, and Hawthorn as Potential Candidates for Managing Cardiovascular Disease-In Vitro and Ex Vivo Animal Studies

Cardiovascular diseases are a broadly understood concept focusing on vascular and heart dysfunction. Lack of physical exercise, type 2 diabetes, obesity, hypertension, dyslipidemia, thromboembolism, and kidney and lung diseases all contribute to the development of heart and blood vessel dysfunction. Although effective and important, traditional treatment with diuretics, statins, beta blockers, calcium inhibitors, ACE inhibitors, and anti-platelet drugs remains a second-line treatment after dietary interventions and lifestyle changes. Scientists worldwide are still looking for an herbal product that would be effective and free from side effects, either taken together with or before the standard pharmacological intervention. Such herbal-originated medication therapy may include Morus alba L. (white mulberry), Elaeagnus rhamnoides (L.) A. Nelson (sea-buckthorn), Allium sativum L. (garlic), Convallaria majalis L. (lily of the valley), Leonurus cardiaca L. (motherwort), and Crataegus spp. (hawthorn). Valuable herbal raw materials include leaves, fruits, seeds, and even thorns. This short review focuses on six herbs that can constitute an interesting and potential therapeutic option in the management of cardiovascular disorders.

The potential role of hydrogen sulfide in cancer cell apoptosis

For a long time, hydrogen sulfide (H2S) has been considered a toxic compound, but recent studies have found that H2S is the third gaseous signaling molecule which plays a vital role in physiological and pathological conditions. Currently, a large number of studies have shown that H2S mediates apoptosis through multiple signaling pathways to participate in cancer occurrence and development, for example, PI3K/Akt/mTOR and MAPK signaling pathways. Therefore, the regulation of the production and metabolism of H2S to mediate the apoptotic process of cancer cells may improve the effectiveness of cancer treatment. In this review, the role and mechanism of H2S in cancer cell apoptosis in mammals are summarized.

Activation of PI3K/Akt mediates the protective effect of diallyl trisulfide on doxorubicin induced cardiac apoptosis

Diallyl trisulfide (DATS), an organosulfide compound derived from garlic, is renowned for its potent antioxidant properties, particularly in countering the generation of reactive oxygen species (ROS). It has also gained recognition as a potential agent for preventing heart-related conditions. Doxorubicin (Dox), a commonly used chemotherapeutic drug, is known to induce severe cardiac complications by promoting ROS production. Therefore, it was imperative to investigate whether DATS possesses cardioprotective capabilities against Dox-induced cardiac apoptosis and elucidate the underlying mechanisms. In this study, we observed that the intracellular ROS levels and cardiac apoptosis were heightened in H9c2 cells exposed to Dox (1 μM). However, treatment with 10 μM DATS effectively mitigated the Dox-induced ROS generation and apoptotic signaling, concurrently activating the PI3K/Akt pathway. Notably, the anti-apoptotic effects of DATS were attenuated when PI3K siRNA and the LY294002 PI3K inhibitor were employed. Furthermore, the TUNEL assay results demonstrated a significant reduction in Dox-induced apoptosis with DATS treatment. In summary, our findings indicate that DATS can activate the PI3K/Akt pathway, reducing ROS production in cardiac cells exposed to Dox, and subsequently rescue cardiac cells from apoptosis.

Effect of Glucose Supplementation on Apoptosis in the Pectoralis major of Chickens Raised under Thermoneutral or Heat Stress Environment

Reduced feed intake during heat stress (HS) disrupts glucose homeostasis, thereby resulting in endoplasmic reticulum (ER) stress and triggering apoptosis in chickens. We hypothesize that glucose supplementation could reduce apoptosis in chickens raised under HS. This study comprised 456 28-day-old broiler chickens randomly assigned to four treatment combinations under glucose supplementation and HS. The treatments were TN0, TN6, HS0, and HS6 with two glucose levels (0% and 6%) and two temperature levels (25 °C (thermoneutral-TN) and 35 °C (8.00 AM to 8.00 PM, (HS)). After 7 days post-HS, the blood glucose level for the HS6 group was higher than for TN0, TN6, and HS0. We studied the mRNA expression of genes and caspase-3 activity in the four experimental groups. The expressions of GCN2, ATF4, CHOP, and FOXO3a increased during HS regardless of glucose supplementation, while PERK and MAFbx increased only under HS with glucose supplementation. We show that under TN conditions, glucose supplementation led to a significant increase in cellular apoptosis in the Pectoralis (P.) major. However, under HS with glucose, the level of apoptosis was similar to that of chickens raised under TN conditions with no glucose supplementation. The utility of glucose to curtail apoptosis under HS should be tested under other intense models of HS.

A review on the effect of garlic on diabetes, BDNF, and VEGF as a potential treatment for diabetic retinopathy

BACKGROUND

Garlic is one of the favorite herbs in traditional medicine that has been reported to have many medicinal features. The aim of the current study is to review the latest documents on the effect of garlic on diabetes, VEGF, and BDNF and, finally, to review the existing studies on the effect of garlic on diabetic retinopathy.

MAIN TEXT

The therapeutic effect of garlic on diabetes has been investigated in various studies. Diabetes, especially in advanced stages, is associated with complications such as diabetic retinopathy, which is caused by the alteration in the expression of molecular factors involved in angiogenesis, neurodegeneration, and inflammation in the retina. There are different in-vitro and in-vivo reports on the effect of garlic on each of these processes. Considering the present concept, we extracted the most related English articles from Web of Science, PubMed, and Scopus English databases from 1980 to 2022. All in-vitro and animal studies, clinical trials, research studies, and review articles in this area were assessed and classified.

RESULT AND CONCLUSION

According to previous studies, garlic has been confirmed to have beneficial antidiabetic, antiangiogenesis, and neuroprotective effects. Along with the available clinical evidence, it seems that garlic can be suggested as a complementary treatment option alongside common treatments for patients with diabetic retinopathy. However, more detailed clinical studies are needed in this field.

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.

Involvement of adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 in diallyl trisulfide-induced cytotoxicity in hepatocellular carcinoma cells

It has been demonstrated that APPL1 (adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1) is involved in the regulation of several growth-related signaling pathways and thus closely associated with the development and progression of some cancers. Diallyl trisulfide (DAT), a garlic-derived bioactive compound, exerts selective cytotoxicity to various human cancer cells through interfering with pro-survival signaling pathways. However, whether and how DAT affects survival of human hepatocellular carcinoma (HCC) cells remain unclear. Herein, we tested the hypothesis of the involvement of APPL1 in DAT-induced cytotoxicity in HCC HepG2 cells. We found that Lys 63 (K63)-linked polyubiquitination of APPL1 was significantly decreased whereas phosphorylation of APPL1 at serine residues remained unchanged in DAT-treated HepG2 cells. Compared with wild-type APPL1, overexpression of APPL1 K63R mutant dramatically increased cell apoptosis and mitigated cell survival, along with a reduction of phosphorylation of STAT3, Akt, and Erk1/2. In addition, DAT administration markedly reduced protein levels of intracellular TNF receptor-associated factor 6 (TRAF6). Genetic inhibition of TRAF6 decreased K63-linked polyubiquitination of APPL1. Moreover, the cytotoxicity impacts of DAT on HepG2 cells were greatly attenuated by overexpression of wild-type APPL1. Taken together, these results suggest that APPL1 polyubiquitination probably mediates the inhibitory effects of DAT on survival of HepG2 cells by modulating STAT3, Akt, and Erk1/2 pathways.

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.

An Updated Insight Into Molecular Mechanism of Hydrogen Sulfide in Cardiomyopathy and Myocardial Ischemia/Reperfusion Injury Under Diabetes

Cardiovascular diseases are the most common complications of diabetes, and diabetic cardiomyopathy is a major cause of people death in diabetes. Molecular, transcriptional, animal, and clinical studies have discovered numerous therapeutic targets or drugs for diabetic cardiomyopathy. Within this, hydrogen sulfide (H₂S), an endogenous gasotransmitter alongside with nitric oxide (NO) and carbon monoxide (CO), is found to play a critical role in diabetic cardiomyopathy. Recently, the protective roles of H₂S in diabetic cardiomyopathy have attracted enormous attention. In addition, H₂S donors confer favorable effects in myocardial infarction, ischaemia-reperfusion injury, and heart failure under diabetic conditions. Further studies have disclosed that multiplex molecular mechanisms are responsible for the protective effects of H₂S against diabetes-elicited cardiac injury, such as anti-oxidative, anti-apoptotic, anti-inflammatory, and anti-necrotic properties. In this review, we will summarize the current findings on H₂S biology and pharmacology, especially focusing on the novel mechanisms of H₂S-based protection against diabetic cardiomyopathy. Also, the potential roles of H₂S in diabetes-aggravated ischaemia-reperfusion injury are discussed.

Diallyl Trisulfide Suppresses High-Glucose-Induced Cardiomyocyte Apoptosis by Targeting Reactive Oxygen Species-Mediated Hypoxia-Inducible Factor-1α/Insulin-like Growth Factor Binding Protein 3 Activation

It has been reported that 80% of diabetic patients die due to cardiovascular diseases. We previously demonstrated that activated hypoxia-inducible factor-1α (HIF-1 α)/insulin-like growth factor binding protein-3 (IGFBP-3) signaling by reactive oxygen species (ROS)-regulated prolyl hydroxylase domain-containing protein (PHD) is involved in high-glucose (HG)-induced cardiac apoptosis. Diallyl trisulfide (DATS), a garlic component, shows the strongest inhibitory effect on diabetic cardiomyopathy. In this study, we investigated whether HIF-1α/IGFBP-3 signaling governs the antiapoptotic effect by DATS on HG-exposed cardiomyocytes. It was observed that significantly increased levels of cell apoptosis and decreased Akt phosphorylation were reversed by DATS in HG-exposed cardiac cells. H₂O₂ and PHD small interfering RNA treatments increased HIF-1α and IGFBP-3 protein levels, which were decreased by DATS treatment. Overexpression of HIF-1α and IGFBP-3 increased HG-induced cell apoptosis, which was suppressed by DATS. The coimmunoprecipitation assay results showed that DATS not only increased the IGF-1 level and reduced IGFBP-3 level but also suppressed their extracellular association for cardiac cells exposed to HG. Experiments using neonatal cardiomyocytes and hearts showed similar results. These findings indicate that the effect of ROS-regulated PHD on the activation of HIF-1α/IGFBP-3 signaling governs the antiapoptotic effect by DATS on HG-exposed cardiomyocytes.

Diet and Hydrogen Sulfide Production in Mammals

Significance: In recent times, it has emerged that some dietary sulfur compounds can act on mammalian cell signaling systems via their propensity to release hydrogen sulfide (H₂S). H₂S plays important biochemical and physiological roles in the heart, gastrointestinal tract, brain, kidney, and immune systems of mammals. Reduced levels of H₂S in cells and tissues correlate with a spectrum of pathophysiological conditions, including heart disease, diabetes, obesity, and altered immune function. Recent Advances: In the last decade, researchers have now begun to explore the mechanisms by which dietary-derived sulfur compounds, in addition to cysteine, can act as sources of H₂S. This research has led to the identified several compounds, organic sulfides, isothiocyanates, and inorganic sulfur species including sulfate that can act as potential sources of H₂S in mammalian cells and tissues. Critical Issues: We have summarised progress made in the identification of dietary factors that can impact on endogenous H₂S levels in mammals. We also describe current research focused on how some sulfur molecules present in dietary plants, and associated chemical analogues, act as sources of H₂S, and discuss the biological properties of these molecules as studied in a range of in vitro and in vivo systems. Future Directions: The identification of sulfur compounds in edible plants that can act as novel H₂S releasing molecules is intriguing. Research in this area could inform future studies exploring the impact of diet on H₂S levels in mammalian systems. Despite recent progress, additional work is needed to determine the mechanisms by which H₂S is released from these molecules following ingestions of dietary plants in humans, whether the amounts of H₂S produced is of physiological significance following the metabolism of these compounds in vivo, and if diet could be used to manipulated H₂S levels in humans. Importantly, this will lead to a better understanding of the biological significance of H₂S generated from dietary sources, and this information could be used in the development of plant breeding initiatives to increase the levels of H₂S releasing sulfur compounds in crops, or inform dietary intervention strategies that could be used to alter the levels of H₂S in humans.

Can diallyl trisulfide, a dietary garlic-derived compound, activate ferroptosis to overcome therapy resistance in prostate cancer?

BACKGROUND

Therapy resistance is the underlying reason for poor outcome in prostate cancer (PCa) patients. Diallyl trisulfide (DATS) is an organosulfur compound present in garlic. DATS has been shown to target PCa cells by induction of apoptosis, increase in the production of reactive oxygen species, degradation of ferritin protein and increase in the labile iron (Fe) pool.

AIM

We hypothesize that DATS could induce ferroptosis, an Fe-dependent, unique non-apoptotic form of regulated cell death to eliminate therapy resistance encountered by PCa patients.

METHODS

In vitro and in vivo studies should be performed to test the hypothesis.

RESULTS

As per the hypothesis, DATS would eliminate apoptotic resistance via inducing ferroptosis.

CONCLUSION

Since apoptosis resistance has been reported to be the underlying mechanism of therapy resistance in PCa, DATS could be used to effectively target PCa cells by overcoming apoptosis resistance and inducing ferroptosis-mediated cell death of PCa cells.

Functional Application of Sulfur-Containing Spice Compounds

Sulfur-containing spice compounds possess diverse biological functions and play an important role in food, chemicals, pharmaceuticals, and agriculture. The development of functional spices has become increasingly popular, especially for medicinal functions for dietary health. Thus, this review focuses on the properties and functions of sulfur-containing spice compounds, including antioxidant, anti-inflammatory, antiobesity, anticancer, antibacterial, and insecticidal functions, among others. Developments over the last five years concerning the properties of sulfur-containing spice compounds are summarized and discussed.

SG1002 and Catenated Divalent Organic Sulfur Compounds as Promising Hydrogen Sulfide Prodrugs

Significance: Sulfur has a critical role in protein structure/function and redox status/signaling in all living organisms. Although hydrogen sulfide (H2S) and sulfane sulfur (SS) are now recognized as central players in physiology and pathophysiology, the full scope and depth of sulfur metabolome's impact on human health and healthy longevity has been vastly underestimated and is only starting to be grasped. Since many pathological conditions have been related to abnormally low levels of H2S/SS in blood and/or tissues, and are amenable to treatment by H2S supplementation, development of safe and efficacious H2S donors deserves to be undertaken with a sense of urgency; these prodrugs also hold the promise of becoming widely used for disease prevention and as antiaging agents. Recent Advances: Supramolecular tuning of the properties of well-known molecules comprising chains of sulfur atoms (diallyl trisulfide [DATS], S8) was shown to lead to improved donors such as DATS-loaded polymeric nanoparticles and SG1002. Encouraging results in animal models have been obtained with SG1002 in heart failure, atherosclerosis, ischemic damage, and Duchenne muscular dystrophy; with TC-2153 in Alzheimer's disease, schizophrenia, age-related memory decline, fragile X syndrome, and cocaine addiction; and with DATS in brain, colon, gastric, and breast cancer. Critical Issues: Mode-of-action studies on allyl polysulfides, benzyl polysulfides, ajoene, and 12 ring-substituted organic disulfides and thiosulfonates led several groups of researchers to conclude that the anticancer effect of these compounds is not mediated by H2S and is only modulated by reactive oxygen species, and that their central model of action is selective protein S-thiolation. Future Directions: SG1002 is likely to emerge as the H2S donor of choice for acquiring knowledge on this gasotransmitter's effects in animal models, on account of its unique ability to efficiently generate H2S without byproducts and in a slow and sustained mode that is dose independent and enzyme independent. Efficient tuning of H2S donation characteristics of DATS, dibenzyl trisulfide, and other hydrophobic H2S prodrugs for both oral and parenteral administration will be achieved not only by conventional structural modification of a lead molecule but also through the new "supramolecular tuning" paradigm.

Pharmacological modulation of the hydrogen sulfide (H2 S) system by dietary H2 S-donors: A novel promising strategy in the prevention and treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) represents the most common age-related metabolic disorder, and its management is becoming both a health and economic issue worldwide. Moreover, chronic hyperglycemia represents one of the main risk factors for cardiovascular complications. In the last years, the emerging evidence about the role of the endogenous gasotransmitter hydrogen sulfide (H₂ S) in the pathogenesis and progression of T2DM led to increasing interest in the pharmacological modulation of endogenous "H₂ S-system". Indeed, H₂ S directly contributes to the homeostatic maintenance of blood glucose levels; moreover, it improves impaired angiogenesis and endothelial dysfunction under hyperglycemic conditions. Moreover, H₂ S promotes significant antioxidant, anti-inflammatory, and antiapoptotic effects, thus preventing hyperglycemia-induced vascular damage, diabetic nephropathy, and cardiomyopathy. Therefore, H₂ S-releasing molecules represent a promising strategy in both clinical management of T2DM and prevention of macro- and micro-vascular complications associated to hyperglycemia. Recently, growing attention has been focused on dietary organosulfur compounds. Among them, garlic polysulfides and isothiocyanates deriving from Brassicaceae have been recognized as H₂ S-donors of great pharmacological and nutraceutical interest. Therefore, a better understanding of the therapeutic potential of naturally occurring H₂ S-donors may pave the way to a more rational use of these nutraceuticals in the modulation of H₂ S homeostasis in T2DM.

Hydrogen Sulfide Switch Phenomenon Regulating Autophagy in Cardiovascular Diseases

Hydrogen sulfide (H₂S), a novel gaseous signaling molecule, is a vital physiological signal in mammals. H₂S protects the cardiovascular system via modulation of vasodilation, vascular remodeling, and inhibition of vascular calcification, and also has anti-atherosclerosis properties. Autophagy is a lysosomal-mediated intracellular degradation mechanism for excessive or abnormal proteins and lipids. The contribution of autophagy to normal and disease-state cell physiology is extremely complicated. Autophagy acts as a double-edged sword in the cardiovascular system. It can defend against damage to cells caused by environmental changes and it can also induce active cell death under certain conditions. In recent years, accumulating evidence indicates that H₂S can up- or downregulate autophagy in many pathological processes, thereby switching from a harmful to a beneficial role. In this review, we summarize progress on understanding the mechanism by which H₂S regulates autophagy in cardiovascular disease. We also discuss a H₂S switch phenomenon that regulates autophagy and provides protection in cardiovascular diseases.

Andrographolide mitigates cardiac apoptosis to provide cardio-protection in high-fat-diet-induced obese mice

Excessive intake of high fat diet (HFD) and associated obese conditions are critical contributors of cardiac diseases. In this study, an active metabolite andrographolide from Andrographis paniculata was found to ameliorate HFD-induced cardiac apoptosis. C57/BL6 mouse were grouped as control (n = 9), obese (n = 8), low dose (25 mg/kg/d) andrographolide treatment (n = 9), and high dose (50 mg/kg/d) andrographolide treatment (n = 9). The control group was provided with standard laboratory chow and the other groups were fed with HFD. Andrographolide was administered through oral gavage for 1 week. Histopathological analysis showed increase in apoptotic nuclei and considerable cardiac-damages in the obese group signifying cardiac remodeling effects. Further, Western blot results showed increase in pro-apoptotic proteins and decrease in the proteins of IGF-1R-survival signaling. However, feeding of andrographolide significantly reduced the cardiac effects of HFD. The results strongly suggest that andrographolide supplementation can be used for prevention and treatment of cardiovascular disease in obese patients.

Induction of caveolin-3/eNOS complex by nitroxyl (HNO) ameliorates diabetic cardiomyopathy

Nitroxyl (HNO), one-electron reduced and protonated sibling of nitric oxide (NO), is a potential regulator of cardiovascular functions. It produces positive inotropic, lusitropic, myocardial anti-hypertrophic and vasodilator properties. Despite of these favorable actions, the significance and the possible mechanisms of HNO in diabetic hearts have yet to be fully elucidated. H9c2 cells or primary neonatal mouse cardiomyocytes were incubated with normal glucose (NG) or high glucose (HG). Male C57BL/6 mice received intraperitoneal injection of streptozotocin (STZ) to induce diabetes. Here, we demonstrated that the baseline fluorescence signals of HNO in H9c2 cells were reinforced by both HNO donor Angeli's salt (AS), and the mixture of hydrogen sulfide (H₂S) donor sodium hydrogen sulfide (NaHS) and NO donor sodium nitroprusside (SNP), but decreased by HG. Pretreatment with AS significantly reduced HG-induced cell vitality injury, apoptosis, reactive oxygen species (ROS) generation, and hypertrophy in H9c2 cells. This effect was mediated by induction of caveolin-3 (Cav-3)/endothelial nitric oxide (NO) synthase (eNOS) complex. Disruption of Cav-3/eNOS by pharmacological manipulation or small interfering RNA (siRNA) abolished the protective effects of AS in HG-incubated H9c2 cells. In STZ-induced diabetic mice, administration of AS ameliorated the development of diabetic cardiomyopathy, as evidenced by improved cardiac function and reduced cardiac hypertrophy, apoptosis, oxidative stress and myocardial fibrosis without affecting hyperglycemia. This study shed light on how interaction of NO and H₂S regulates cardiac pathology and provide new route to treat diabetic cardiomyopathy with HNO.

Tetramethylpyrazine reverses high-glucose induced hypoxic effects by negatively regulating HIF-1α induced BNIP3 expression to ameliorate H9c2 cardiomyoblast apoptosis

Background

Diabetic patients are highly vulnerable to hypoxic injury, which is associated with hypoxia induced BNIP3 expression that subsequently activate apoptosis. Our previous research show that Tetramethylpyrazine (TMP), a food flavoring agent, represses the hypoxia induced BNIP3 expression attenuate myocardial apoptosis. In this study, we evaluate the effect of TMP to provide protection against hypoxia aggravated high-glucose associated cellular apoptosis.

Methods

The cytoprotective effect of TMP against high glucose induced cellular damages was determined on embryo derived H9c2 cardiomyoblast cells that were subjected to 5% hypoxia for 24 h and subjected to different duration of 33 mM high glucose challenge. Further, the involvement of HIF-1α and BNIP3 in cellular damage and the mechanism of protection of TMP were determined by overexpression and silencing HIF-1α and BNIP3 protein expression.

Results

The results show that hypoxic effects on cell viability aggravates with high glucose challenge and this augmentative effect is mediated through BNIP3 in H9c2 cardiomyoblast cells. However, TMP administration effectively reversed the augmented HIF-1α levels and BNIP3 elevation. TMP improved the survival of H9c2 cells and effectively suppressed apoptosis in H9c2 cells. Further comparison on the effects of TMP on H9c2 cells challenged with high glucose and those challenged with hypoxia show that TMP precisely regulated the hypoxic intensified apoptotic effects in high-glucose condition.

Conclusion

The results clearly show that flavoring agent-TMP attenuates cytotoxicity amplified by hypoxia challenge in high glucose condition by destabilizing HIF-1α.

Involvement of endocannabinoid system, inflammation and apoptosis in diabetes induced liver injury: Role of 5-HT3 receptor antagonist

Confident relationships between diabetes andliver damagehave previously been established. This study was designed to evaluate hepaticinflammation, apoptosis, and endocannabinoid system alterations in diabetes with or withouttropisetrontreatment. Rats were assigned to five equal groups: control, tropisetron, diabetes, tropisetron+diabetes, and glibenclamide+diabetes (n = 7 in each group). Rats were treated with tropisetron (3 mg/kg) and glibenclamide (1 mg/kg) as a positive control for two weeks after type 1 diabetes induction.Inflammatory cytokines tumor necrosis factor-alpha and interleukin 6 (TNF-α and IL-6) levels, apoptotic cells, and fatty acid amide hydrolase (FAAH) enzyme, at both transcriptional and protein levels increased, while the gene expression of cannabinoid receptor 1 (CB1) and its protein level decreased in the diabetic liver compared to the control. Treatment with tropisetron reversed TNF-α, apoptotic index, and endocannabinoid system components. These effects were equipotent with glibenclamide, indicating that tropisetroncan protect liver tissue against diabetic disturbances. These findings strongly support the idea that diabetes-induced liver abnormality is mediated by inflammatory reactions, apoptosis, and endocannabinoid system, and that these effects can be alleviated by using tropisetron as an antioxidant and anti-inflammatory agent.

Effects of phytochemicals on cellular signaling: reviewing their recent usage approaches

Most of the previous studies in last three decades report evidence of interactions between the different phytochemicals and the proteins involved in signal transduction pathways using in silico, in vitro, ex vivo, and in vivo analyses. However, extrapolation of these findings for clinical purposes has not been that fruitful. The efficacy of the phytochemicals in vivo studies is limited by parameters such as solubility, metabolic degradation, excretion, etc. Various approaches have now been devised to circumvent these limitations. Recently, chemical modification of the phytochemicals are demonstrated to reduce some of the limitations and improve their efficacy. Similar to traditional medicines several combinatorial phytochemical formulations have shown to be more efficient. Further, phytochemicals have been reported to be even more efficient in the form of nanoparticles. However, systematic evaluation of their efficacy, mode of action in pathway modulation, usage and associated challenges is required to be done. The present review begins with basic understanding of how signaling cascades regulate cellular response and the consequences of their dysregulation further summarizing the developments and problems associated with the dietary phytochemicals and also discuss recent approaches in strengthening these compounds in pharmacological applications. Only context relevant studies have been reviewed. Considering the limitations and scope of the article, authors do not claim inclusion of all the early and recent studies.

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.

Aqueous garlic extract supresses experimental gentamicin induced renal pathophysiology mediated by oxidative stress, inflammation and Kim-1

BACKGROUND

Gentamicin (Gent) has rapid & high bactericidal action in addition to its cheap price. Nevertheless, 30% of gentamicin-treated patients develop nephrotoxicity.

OBJECTIVE

To explore the probable nephroprotective effects of the aqueous garlic extract (AGE) & to elucidate its underlying mechanisms via monitoring proinflammatory cytokines as tumer necrosis factor (TNF-α), interleukin 6 (IL-6) and interferon-γ (INF-γ), oxidative stess markers as malondialdehyde (MDA) & superoxide dismutase (SOD) & kidney injury molecule (Kim-1) as a promising early specific biomarker of renal dysfunction.

METHODS

32 adult male rats were divided into 4 equal groups treated for 21 days as: normal control group received normal saline orally, AGE-treated group received AGE at 250 mg/kg/day orally, Gent-treated group received Gent-sulphate intraperitoneal injection at 80 mg/kg /day, and AGE & Gent cotreated group received AGE and Gent concomitantly in the same previous doses. Serum urea, creatinine, glomerular filteration rate (GFR), systolic (SBP) and diastolic blood pressure (DBP), TNF-α, IL-6, INF-γ, MDA and SOD and Kim-1 mRNA expression were evaluated in kidney tissue homogenate. Renal cortex sections stained with Haematoxylin & eosin (H&E) were examined.

RESULTS

AGE is nephroprotective through significantly reducing serum urea, creatinine, SBP and DBP, TNF-α, IL-6, INF-γ and MDA (the main product of lipid peroxidation), decreasing expression of Kim-1 mRNA in renal tissue and increasing level of GFR, the natural antioxidant SOD and improving renal histological features of Gent-treated rats.

CONCLUSION

AGE normalizes Gent-induced renal dysfunction. Their co-administration is a plausible advice, although the therapeutic efficiency of Gent was not investigated.

Combination effect of voluntary exercise and garlic (Allium sativum) on oxidative stress, cholesterol level and histopathology of heart tissue in type 1 diabetic rats

Introduction: This study aimed to evaluate the combination effect of voluntary exercise and garlic on oxidative markers, cholesterol level and histological alterations in streptozotocin (STZ)- induced diabetes in rat heart.

Methods: Thirty-five male Wistar rats were randomly assigned into five experimental groups (n=7): Control, Diabetes, Diabetes+Garlic, Diabetes+Exercise, Diabetes+Garlic+Exercise groups. Diabetes was induced by STZ (ip, 50 mg/kg) in animals. Animals received garlic homogenate (250 mg/kg) by oral gavage or subjected to voluntary exercise alone or together for 6 weeks. At the end of intervention blood and heart tissue samples were obtained and used for measurement of glycosylated haemoglobin (HbA1c), cholesterol, total antioxidant capacity (TAC), malondialdehyde (MDA) levels and histological analysis.

Results: Improved blood glucose, cholesterol, total antioxidant capacity, and MDA levels were established in both Diabetes+Garlic and Diabetes+Exercise groups. Additionally, staining with Hematoxylin and Eosin (H&E) revealed that voluntary exercise and garlic alone and together reduced interstitial edema, leukocyte infiltration, and myonecrosis. Furthermore, simultaneous treatment of diabetic rats with garlic and exercise training had an additive effect on these parameters.

Conclusion: The findings indicated that combination therapy with garlic and voluntary exercise may present more beneficial effects in heart histological remodeling in diabetic rats than the use of garlic or voluntary exercise alone and that these beneficial effects might be associated with enhancement in cholesterol, total antioxidant capacity, and MDA levels.

Controllable thioester-based hydrogen sulfide slow-releasing donors as cardioprotective agents

Hydrogen sulfide (H₂S) is an important signaling molecule with promising protective effects in many physiological and pathological processes.

Homocysteine, Thioretinaco Ozonide, and Oxidative Phosphorylation in Cancer and Aging: A Proposed Clinical Trial Protocol

The objective of the proposed clinical interventional trial is to demonstrate the efficacy of a novel therapeutic strategy in subjects with cancer and hyperhomocysteinemia. Following discovery of abnormal homocysteine thiolactone metabolism in cultured malignant cells, thioretinamide, the amide synthesized from retinoic acid and homocysteine thiolactone, and thioretinaco, the complex formed from cobalamin and thioretinamide, were demonstrated to have antineoplastic, anticarcinogenic, and anti-atherogenic properties in animal models. Retinol, ascorbate, and homocysteine thiolactone are necessary for biosynthesis of thioretinamide and thioretinaco by cystathionine synthase and for formation of thioretinaco ozonide from thioretinamide, cobalamin, and ozone. Thioretinaco ozonide is required for prevention of abnormal oxidative metabolism, aerobic glycolysis, suppressed immunity, and hyperhomocysteinemia in cancer.The pancreatic enzyme therapy of cancer promotes catabolism of proteins, nucleic acids, and glycosaminoglycans with excess homocysteinylated amino groups resulting from abnormal accumulation of homocysteine thiolactone in malignant cells. Dietary deficiencies of pyridoxal, folate, cobalamin, and nitriloside contribute to hyperhomocysteinemia in cancer, and in protein energy malnutrition. A deficiency of dietary sulfur amino acids downregulates cystathionine synthase, causing hyperhomocysteinemia.The organic sulfur compound diallyl trisulfide increases hydrogen sulfide production from homocysteine in animal models, inhibits Stat3 signaling in cancer stem cells, and produces apoptosis of malignant cells. The furanonaphthoquinone compound napabucasin inhibits Stat3 signaling and causes mitochondrial dysfunction, decreased oxidative phosphorylation, and apoptosis of malignant cells. The protocol of the proposed clinical trial in subjects with myelodysplasia consists of thioretinamide and cobalamin as precursors of thioretinaco ozonide, combined with pancreatic enzyme extracts, diallyl trisulfide, napabucasin, nutritional modification to minimize processed foods, vitamin supplements, essential amino acids, and beneficial dietary fats and proteins.

Hydrogen Sulfide (H2S)-Releasing Compounds: Therapeutic Potential in Cardiovascular Diseases

Cardiovascular disease is the main cause of death worldwide, but its pathogenesis is not yet clear. Hydrogen sulfide (H₂S) is considered to be the third most important endogenous gasotransmitter in the organism after carbon monoxide and nitric oxide. It can be synthesized in mammalian tissues and can freely cross the cell membrane and exert many biological effects in various systems including cardiovascular system. More and more recent studies have supported the protective effects of endogenous H₂S and exogenous H₂S-releasing compounds (such as NaHS, Na₂S, and GYY4137) in cardiovascular diseases, such as cardiac hypertrophy, heart failure, ischemia/reperfusion injury, and atherosclerosis. Here, we provided an up-to-date overview of the mechanistic actions of H₂S as well as the therapeutic potential of various classes of H₂S donors in treating cardiovascular diseases.

Garlic (Allium sativum) exhibits a cardioprotective effect in experimental chronic renal failure rat model by reducing oxidative stress and controlling cardiac Na+/K+-ATPase activity and Ca2+ levels

Gentamicin (GNT)-induced nephrotoxicity culminates into renal failure with a possible cardiovascular impact. Garlic extract (GE) is a cardiovascular protectant with limited mechanistic data. Therefore, we assessed the disturbance in specific cardiac parameters and the potential protective effect of GE supplementation against them in a rat model of GNT-induced chronic renal failure (CRF). Adult male rats (n = 24) were randomly assigned into four groups (n = 6 each): normal controls (CON), garlic extract controls (GE; 250 mg kg-1, orally), GNT-induced CRF (GNT; 100 mg kg-1, i.p.), and GNT + GE (GNT and GE in the same previous doses) groups. GNT and GE were given daily for 3 weeks. Animals co-treated with GNT and GE exhibited improved renal functions, body weight (BW), and heart weight (HW)/BW ratio; declined blood pressure; lowered plasma levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and total peroxides (TP); and elevated total antioxidant capacity (TAC) levels. Moreover, the heart tissue contained raised levels of TAC and Na+/K+-ATPase activity and lowered levels of TP and Ca2+. Findings provide evidence that administration of GE in experimental CRF model helped protect the heart through reducing oxidative stress and controlling cardiac Na+/K+-ATPase activity and Ca2+ levels.

Pkcδ Activation is Involved in ROS-Mediated Mitochondrial Dysfunction and Apoptosis in Cardiomyocytes Exposed to Advanced Glycation End Products (Ages)

Diabetic patients exhibit serum AGE accumulation, which is associated with reactive oxygen species (ROS) production and diabetic cardiomyopathy. ROS-induced PKCδ activation is linked to mitochondrial dysfunction in human cells. However, the role of PKCδ in cardiac and mitochondrial dysfunction caused by AGE in diabetes is still unclear. AGE-BSA-treated cardiac cells showed dose- and time-dependent cell apoptosis, ROS generation, and selective PKCδ activation, which were reversed by NAC and rotenone. Similar tendency was also observed in diabetic and obese animal hearts. Furthermore, enhanced apoptosis and reduced survival signaling by AGE-BSA or PKCδ-WT transfection were reversed by kinase-deficient (KD) of PKCδ transfection or PKCδ inhibitor, respectively, indicating that AGE-BSA-induced cardiomyocyte death is PKCδ-dependent. Increased levels of mitochondrial mass as well as mitochondrial fission by AGE-BSA or PKCδ activator were reduced by rottlerin, siPKCδ or KD transfection, indicating that the AGE-BSA-induced mitochondrial damage is PKCδ-dependent. Using super-resolution microscopy, we confirmed that PKCδ colocalized with mitochondria. Interestingly, the mitochondrial functional analysis by Seahorse XF-24 flux analyzer showed similar results. Our findings indicated that cardiac PKCδ activation mediates AGE-BSA-induced cardiomyocyte apoptosis via ROS production and may play a key role in the development of cardiac mitochondrial dysfunction in rats with diabetes and obesity.

Activation of autophagic flux and the Nrf2/ARE signaling pathway by hydrogen sulfide protects against acrylonitrile-induced neurotoxicity in primary rat astrocytes

Hydrogen sulfide (H₂S), the third gasotransmitter, has been shown to act as a neuroprotective factor in numerous pathological processes; however, its underlying mechanism(s) of action remain unclear. It is widely accepted that activation of moderate autophagy and the Nrf2/ARE signaling pathway play important roles in the biological self-defense systems. In the present study, we investigated whether exogenous H₂S protects against the cytotoxicity of acrylonitrile (AN), a neurotoxin, in primary rat astrocytes. We found that pretreatment for 1 h with sodium hydrosulfide (NaHS), a donor of H₂S (200-800 µM), significantly attenuated the AN-induced decrease in cell viability, increase in lactate dehydrogenase release and morphological changes. Furthermore, NaHS significantly attenuated AN-induced oxidative stress by reducing reactive oxygen species (ROS) levels and increasing glutathione (GSH) concentration. Moreover, NaHS activated the autophagic flux, detectable as a change in autophagy-related proteins (Beclin-1, Atg5 and p62), the formation of acidic vesicular organelles and LC3B aggregation, confirmed by adenoviral expression of mRFP-GFP-LC3. Additionally, NaHS stimulated translocation of Nrf2 into the nucleus and increased expression of heme oxygenase-1 and γ-glutamylcysteine synthetase, downstream targets of Nrf2. Notably, the autophagy inhibitor 3-methyladenine and Beclin-1, or Nrf2-targeted siRNA, significantly attenuated the neuroprotective effects of NaHS against AN-induced neurotoxicity. In conclusion, we identified a crucial role of  autophagy and the Nrf2/ARE signaling pathway in H₂S-mediated neuroprotection against AN-induced toxicity in primary rat astrocytes. Our findings provide novel insights into the mechanisms of H₂S-mediated neuroprotection, and suggest that H₂S-based donors may serve as potential new candidate drugs to treat AN-induced neurotoxicity.

Garlic and Gaseous Mediators

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

Diallyl trisulfide ameliorates myocardial ischemia-reperfusion injury by reducing oxidative stress and endoplasmic reticulum stress-mediated apoptosis in type 1 diabetic rats: role of SIRT1 activation

Diallyl trisulfide (DATS) protects against apoptosis during myocardial ischemia-reperfusion (MI/R) injury in diabetic state, although the underlying mechanisms remain poorly defined. Previously, we and others demonstrated that silent information regulator 1 (SIRT1) activation inhibited oxidative stress and endoplasmic reticulum (ER) stress during MI/R injury. We hypothesize that DATS reduces diabetic MI/R injury by activating SIRT1 signaling. Streptozotocin (STZ)-induced type 1 diabetic rats were subjected to MI/R surgery with or without perioperative administration of DATS (40 mg/kg). We found that DATS treatment markedly improved left ventricular systolic pressure and the first derivative of left ventricular pressure, reduced myocardial infarct size as well as serum creatine kinase and lactate dehydrogenase activities. Furthermore, the myocardial apoptosis was also suppressed by DATS as evidenced by reduced apoptotic index and cleaved caspase-3 expression. However, these effects were abolished by EX527 (the inhibitor of SIRT1 signaling, 5 mg/kg). We further found that DATS effectively upregulated SIRT1 expression and its nuclear distribution. Additionally, PERK/eIF2α/ATF4/CHOP-mediated ER stress-induced apoptosis was suppressed by DATS treatment. Moreover, DATS significantly activated Nrf-2/HO-1 antioxidant signaling pathway, thus reducing Nox-2/4 expressions. However, the ameliorative effects of DATS on oxidative stress and ER stress-mediated myocardial apoptosis were inhibited by EX527 administration. Taken together, these data suggest that perioperative DATS treatment effectively ameliorates MI/R injury in type 1 diabetic setting by enhancing cardiac SIRT1 signaling. SIRT1 activation not only upregulated Nrf-2/HO-1-mediated antioxidant signaling pathway but also suppressed PERK/eIF2α/ATF4/CHOP-mediated ER stress level, thus reducing myocardial apoptosis and eventually preserving cardiac function.

Impact of hyperglycemia on cystathionine-γ-lyase expression during resuscitated murine septic shock

BACKGROUND

Cystathionine-γ-lyase (CSE) was shown to have a regulatory role in glucose metabolism. Circulatory shock can induce metabolic stress, thereby leading to hyperglycemia and mitochondrial dysfunction. In vitro data suggest an effect of high glucose on CSE expression. Therefore, the aim of this study was to investigate the effects of hyperglycemia on CSE expression in resuscitated murine septic shock.

METHODS

Normo- (80-150 mg/dl) and hyperglycemic (>200 mg/dl) male C57/BL6J mice (n = 5-6 per group) underwent cecal ligation and puncture (CLP)-induced polymicrobial sepsis or sham procedure (n = 6 per group) and, 15 h afterwards, were anesthetized again, surgically instrumented and received intensive care treatment, including antibiotics, lung protective mechanical ventilation, circulatory support, and intravenous (i.v.) glucose infusion (50% as stable-isotope labeled 1,2,3,4,5,6-13C6 glucose). Blood and breath gas were sampled hourly to quantify parameters of glucose metabolism. 5 h later, mice were sacrificed and organs were harvested. The liver mitochondrial respiratory activity was determined via high resolution respirometry; CSE, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), and adipocyte differentiation-related protein (ADRP) expression was immunohistochemically investigated.

RESULTS

In sepsis combined with hyperglycemia the least CSE and PGC1α expression could be detected, along with reduced mitochondrial respiratory activity, and enhanced ADRP expression, a marker of lipid droplet formation, in the liver. A novel in vivo finding is the CSE translocation from the cytosol to the nucleus triggered by metabolic stress.

CONCLUSIONS

A relationship between CSE and glucose metabolism was established, which, when dysregulated, may contribute to fatty liver disease and hepatic steatosis.

Short-term hypoxia upregulated Mas receptor expression to repress the AT1 R signaling pathway and attenuate Ang II-induced cardiomyocyte apoptosis

Hypertension-stimulated cardiac hypertrophy and apoptosis play critical roles in the progression of heart failure. Our previous study suggested that hypertensive angiotensin II (Ang II) enhanced insulin-like growth factor receptor II (IGF-IIR) expression and cardiomyocyte apoptosis, which are involved JNK activation, sirtuin1 (SIRT1) degradation, and heat-shock transcription factor 1 (HSF1) acetylation. Moreover, previous studies have implied that short-term hypoxia (STH) might exert cardioprotective effects. However, the effects of STH on Ang II-induced cardiomyocyte apoptosis remain unknown. In this study, we found that STH reduced myocardial apoptosis caused by Ang II via upregulation of the Mas receptor (MasR) to inhibit the AT₁ R signaling pathway. STH activates MasR to counteract the Ang II pro-apoptotic signaling cascade by inhibiting IGF-IIR expression via downregulation of JNK activation and reduction of SIRT1 degradation. Hence, HSF could remain deacetylated, and repress IGF-IIR expression. These effects decrease the activation of downstream pro-apoptotic and hypertrophic cascades and protect cardiomyocytes from Ang II-induced injury. In addition, we also found that silencing MasR expression enhanced Ang II-induced cardiac hypertrophy and the apoptosis signaling pathway. These findings suggest a critical role for MasR in cardiomyocyte survival. Altogether, our findings indicate that STH protects cardiomyocytes from Ang II-stimulated apoptosis. The protective effects of STH are associated with the upregulation of MasR to inhibit AT₁ R signaling. STH could be a potential therapeutic strategy for cardiac diseases in hypertensive patients.

Regulation mechanism of oxidative stress induced by high glucose through PI3K/Akt/Nrf2 pathway in juvenile blunt snout bream (Megalobrama amblycephala)

This study was conducted to investigate the effects of oral administration of a high concentration of glucose on the respiratory burst, antioxidant status, and hepatic gene expression of heme oxygenase-1 (ho1) and PI3K/Akt/Nrf2-related signaling molecules in juvenile blunt snout bream (Megalobrama amblycephala). Blunt snout bream juveniles with an initial body weight of 19.94 ± 0.58 g were orally fed with a high concentration of glucose (3 g/kg body weight). The results indicated that plasma glucose exhibited a biphasic response. Acute and persistent hyperglycemia due to the oral glucose administration significantly reduced (P < 0.05) the white blood cell count, red blood cell count, and hemoglobin content and caused oxidative stress (significantly increased alanine aminotransferase, aspartate transaminase, alkaline phosphatase, and glucose levels) and early apoptosis of hepatocytes in the fish. Hepatic superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities increased rapidly (P < 0.05) as protection from oxidative stress and were downregulated (P < 0.05) because of persistent hyperglycemia. Blood respiratory burst was significantly reduced (P < 0.05) because of hyperglycemia and showed a trend that was opposite to that of plasma glucose. Slight upregulation of nrf2 mRNA and antioxidants acts as a compensative protection mechanism, and the downregulated PI3K/Akt pathway blocked this function of Nrf2. In conclusion, the PI3K/Akt pathway and Nrf2 mediated the antioxidative mechanism independently in the blunt snout bream juveniles subjected to the oral administration of a high glucose concentration.

Hyperhomocysteinemia, Suppressed Immunity, and Altered Oxidative Metabolism Caused by Pathogenic Microbes in Atherosclerosis and Dementia

Many pathogenic microorganisms have been demonstrated in atherosclerotic plaques and in cerebral plaques in dementia. Hyperhomocysteinemia, which is a risk factor for atherosclerosis and dementia, is caused by dysregulation of methionine metabolism secondary to deficiency of the allosteric regulator, adenosyl methionine. Deficiency of adenosyl methionine results from increased polyamine biosynthesis by infected host cells, causing increased activity of ornithine decarboxylase, decreased nitric oxide and peroxynitrate formation and impaired immune reactions. The down-regulation of oxidative phosphorylation that is observed in aging and dementia is attributed to deficiency of thioretinaco ozonide oxygen complexed with nicotinamide adenine dinucleotide and phosphate, which catalyzes oxidative phosphorylation. Adenosyl methionine biosynthesis is dependent upon thioretinaco ozonide and adenosine triphosphate (ATP), and the deficiency of adenosyl methionine and impaired immune function in aging are attributed to depletion of thioretinaco ozonide from mitochondrial membranes. Allyl sulfides and furanonaphthoquinones protect against oxidative stress and apoptosis by increasing the endogenous production of hydrogen sulfide and by inhibiting electron transfer to the active site of oxidative phosphorylation. Diallyl trisulfide and napabucasin inhibit the signaling by the signal transducer and activator of transcription 3 (Stat3), potentially enhancing immune function by effects on T helper lymphocytes and promotion of apoptosis. Homocysteine promotes endothelial dysfunction and apoptosis by the unfolded protein response and endoplasmic reticulum stress through activation of the N-methyl D-aspartate (NMDA) receptor, causing oxidative stress, calcium influx, apoptosis and endothelial dysfunction. The prevention of atherosclerosis and dementia may be accomplished by a proposed nutritional metabolic homocysteine-lowering protocol which enhances immunity and corrects the altered oxidative metabolism in atherosclerosis and dementia.

International Union of Basic and Clinical Pharmacology. CII: Pharmacological Modulation of H2S Levels: H2S Donors and H2S Biosynthesis Inhibitors

Over the last decade, hydrogen sulfide (H2S) has emerged as an important endogenous gasotransmitter in mammalian cells and tissues. Similar to the previously characterized gasotransmitters nitric oxide and carbon monoxide, H2S is produced by various enzymatic reactions and regulates a host of physiologic and pathophysiological processes in various cells and tissues. H2S levels are decreased in a number of conditions (e.g., diabetes mellitus, ischemia, and aging) and are increased in other states (e.g., inflammation, critical illness, and cancer). Over the last decades, multiple approaches have been identified for the therapeutic exploitation of H2S, either based on H2S donation or inhibition of H2S biosynthesis. H2S donation can be achieved through the inhalation of H2S gas and/or the parenteral or enteral administration of so-called fast-releasing H2S donors (salts of H2S such as NaHS and Na2S) or slow-releasing H2S donors (GYY4137 being the prototypical compound used in hundreds of studies in vitro and in vivo). Recent work also identifies various donors with regulated H2S release profiles, including oxidant-triggered donors, pH-dependent donors, esterase-activated donors, and organelle-targeted (e.g., mitochondrial) compounds. There are also approaches where existing, clinically approved drugs of various classes (e.g., nonsteroidal anti-inflammatories) are coupled with H2S-donating groups (the most advanced compound in clinical trials is ATB-346, an H2S-donating derivative of the non-steroidal anti-inflammatory compound naproxen). For pharmacological inhibition of H2S synthesis, there are now several small molecule compounds targeting each of the three H2S-producing enzymes cystathionine-β-synthase (CBS), cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase. Although many of these compounds have their limitations (potency, selectivity), these molecules, especially in combination with genetic approaches, can be instrumental for the delineation of the biologic processes involving endogenous H2S production. Moreover, some of these compounds (e.g., cell-permeable prodrugs of the CBS inhibitor aminooxyacetate, or benserazide, a potentially repurposable CBS inhibitor) may serve as starting points for future clinical translation. The present article overviews the currently known H2S donors and H2S biosynthesis inhibitors, delineates their mode of action, and offers examples for their biologic effects and potential therapeutic utility.

Diallyl trisulfide, a garlic polysulfide protects against As-induced renal oxidative nephrotoxicity, apoptosis and inflammation in rats by activating the Nrf2/ARE signaling pathway

BACKGROUND

Arsenic (As) contamination is an extremely dangerous global environmental problem as it can enter into the food chain and become bio-accumulated, endangering human health. Chronic As intoxication leads to undesirable toxic effects in various organ systems of the body, especially the kidney. Diallyl trisulfide (DATS) is an organosulfur compound which has been widely known for its uses as antibacterial, antitumorogenic, antioxidant agent and has been also reported to have anti-apoptotic and anti-inflammatory properties.

PURPOSE

In the present work, we intend to investigate the protective role of DATS, a garlic organosulfur compound in preventing the As-induced oxidative stress mediated renal injury in rats. Study design The activity of DATS to antagonize As-induced renal oxidative toxicity was analyzed using rats as an in vivo model.

METHODS

We investigated the nephroprotective effect of DATS on As treated rats by performing various serological, biochemical, molecular and histological studies. The activation of Nrf2 was investigated using western blot.

RESULTS

The data showed that As exposure significantly increased the serum and urine nephritic, oxidative stress, apoptosis and inflammatory markers in the renal tissue of rats. As intoxication also decreased the antioxidant status of the renal tissue along with the disturbances in the membrane bound ATPases. As nephrotoxicity was further confirmed with the altered morphological and ultrastructural changes in the renal tissue. Conversely, the DATS pre-administration effectively recuperate the altered renal variables by As, which has been further supported by the histological and ultrastructural observations. This counteraction was achieved partially via the activation of Nrf2-ARE pathway through the activation of Akt.

CONCLUSION

These findings explicate the prospective use of DATS as a promising organosulfur compound against As-induced renal oxidative dysfunction in rats.

A possible mechanism of inhibition of U87MG and SH-SY5Y cancer cell proliferation by diallyl trisulfide and other aspects of its activity

The study was conducted to elucidate the mechanism of antiproliferative and antioxidative action of diallyl trisulfide (DATS), a garlic-derived organosulfur compound. Changes in the l-cysteine desulfuration, and the levels of cystathionine and non-protein thiols in DATS-treated human glioblastoma (U87MG) and neuroblastoma (SH-SY5Y) cells were investigated. The inhibition of proliferation of the investigated cells by DATS was correlated with an increase in the inactivated form of Bcl-2. In U87MG cells, an increased level of sulfane sulfur and an increased activity of 3-mercaptopyruvate sulfurtransferase (MPST) and rhodanese, the enzymes involved in sulfane sulfur generation and transfer, suggest that DATS can function as a donor of sulfane sulfur atom, transferred by sulfurtransferases, to sulfhydryl groups of cysteine residues of Bcl-2 and in this way lower the level of active form of Bcl-2 by S-sulfuration. Diallyl trisulfide antioxidative effects result from an increased level of cystathionine, a precursor of cysteine, and an increased glutathione level. MPST and rhodanese, the level of which is increased in the presence of DATS, can serve as antioxidant proteins.

Diallyl trisulfide exerts cardioprotection against myocardial ischemia-reperfusion injury in diabetic state, role of AMPK-mediated AKT/GSK-3β/HIF-1α activation

Diallyl trisulfide (DATS), the major active ingredient in garlic, has been reported to confer cardioprotective effects. However, its effect on myocardial ischemia-reperfusion (MI/R) injury in diabetic state and the underlying mechanism are still unknown. We hypothesize that DATS reduces MI/R injury in diabetic state via AMPK-mediated AKT/GSK-3β/HIF-1α activation. Streptozotocin-induced diabetic rats received MI/R surgery with or without DATS (20mg/kg) treatment in the presence or absence of Compound C (Com.C, an AMPK inhibitor, 0.25mg/kg) or LY294002 (a PI3K inhibitor, 5mg/kg). We found that DATS significantly improved heart function and reduced myocardial apoptosis. Additionally, in cultured H9c2 cells, DATS (10μM) also attenuated simulated ischemia-reperfusion injury. We found that AMPK and AKT/GSK-3β/HIF-1α signaling were down-regulated under diabetic condition, while DATS markedly increased the phosphorylation of AMPK, ACC, AKT and GSK-3β as well as HIF-1α expression in MI/R-injured myocardium. However, these protective actions were all blunted by Com.C administration. Additionally, LY294002 abolished the stimulatory effect of DATS on AKT/GSK-3β/HIF-1α signaling without affecting AMPK signaling. While 2-methoxyestradiol (a HIF-1α inhibitor) reduced HIF-1α expression without affecting AKT/GSK-3β signaling. Taken together, these data showed that DATS protected against MI/R injury in diabetic state by attenuating cellular apoptosis via AMPK-mediated AKT/GSK-3β/HIF-1α signaling. Its cardioprotective effect deserves further study.

Liraglutide relieves myocardial damage by promoting autophagy via AMPK-mTOR signaling pathway in zucker diabetic fatty rat

Liraglutide, a glucose-lowering agent used to treat type 2 diabetic mellitus is reported to exert cardioprotective effects in clinical trials and animal experiments. However, the cardioprotective mechanism of liraglutide on diabetic cardiomyopathy has not been fully illustrated. The present study was performed to investigate whether liraglutide alleviates diabetic myocardium injury by promoting autophagy and its underlying mechanisms. Our results show that liraglutide significantly reduced the levels of creatine kinase (CK) and lactate dehydrogenase (LDH), improved left ventricular functional status and alleviated myocardial fibrosis in the Zucker diabetic fatty (ZDF) rat model. Liraglutide also mitigated high glucose-induced injury in NRCs. However these effects were partly reversed by the autophagic inhibitor chloroquine (CQ). Liraglutide promoted myocardial autophagy in the vivo and in the vitro models. Furthermore, liraglutide-induced enhancement of autophagy was related to increased AMPK phosphorylation and decreased mTOR phosphorylation, which was partially abolished by the AMPK inhibitor compound C (Comp C). Collectively, our data provide evidence that liraglutide mediated diabetic myocardium injury by promoting AMPK-dependent autophagy.

A Long-Term and Slow-Releasing Hydrogen Sulfide Donor Protects against Myocardial Ischemia/Reperfusion Injury

Hydrogen sulfide (H2S) has been recognized as an important gasotransmitter exerting various physiological effects, especially in the cardiovascular system. Herein we investigated the cardioprotective effects of a novel long-term and slow-releasing H2S donor, DATS-MSN, using in vivo myocardial ischemia/reperfusion (I/R) models and in vitro hypoxia/reoxygenation cardiomyocyte models. Unlike the instant-releasing pattern of sodium hydrosulphide (NaHS), the release of H2S from DATS-MSN was quite slow and continuous both in the cell culture medium and in rat plasma (elevated H2S concentrations during 24 h and 72 h reperfusion). Correspondingly, DATS-MSN demonstrated superior cardioprotective effects over NaHS in I/R models, which were associated with greater survival rates, reduced CK-MB and troponin I levels, decreased cardiomyocyte apoptosis index, increased antioxidant enzyme activities, inhibited myocardial inflammation, greater reduction in the infarct area and preserved cardiac ejection fraction. Some of these effects of DATS-MSN were also found to be superior to classic slow-releasing H2S donor, GYY4137. In in vitro experiments, cardiomyocytes injury was also found to be relived with the use of DATS-MSN compared to NaHS after the hypoxia/reoxygenation processes. The present work provides a novel long-term and slow-releasing H2S donor and an insight into how the release patterns of H2S donors affect its physiological functionality.

Cross-talk of MicroRNA and hydrogen sulfide: A novel therapeutic approach for bone diseases

Bone homeostasis requires a balance between the bone formation of osteoblasts and bone resorption of osteoclasts to maintain ideal bone mass and bone quality. An imbalance in bone remodeling processes results in bone metabolic disorders such as osteoporosis. Hydrogen sulfide (H₂S), a gasotransmitter, has attracted the focus of many researchers due to its multiple physiological functions. It has been implicated in anti-inflammatory, vasodilatory, angiogenic, cytoprotective, anti-oxidative and anti-apoptotic mechanisms. H₂S has also been shown to exert osteoprotective activity through its anti-inflammatory and anti-oxidative effects. However, the underlying molecular mechanisms by which H₂S mitigates bone diseases are not completely understood. Experimental evidence suggests that H₂S may regulate signaling pathways by directly influencing a gene in the cascade or interacting with some other gasotransmitter (carbon monoxide or nitric oxide) or both. MicroRNAs (miRNAs) are short non-coding RNAs which regulate gene expression by targeting, binding and suppressing mRNAs; thus controlling cell fate. Certainly, bone remodeling is also regulated by miRNAs expression and has been reported in many studies. MicroRNAs also regulate H₂S biosynthesis. The inter-regulation of microRNAs and H₂S opens a new possibility for exploring the H₂S-microRNA crosstalk in bone diseases. However, the relationship between miRNAs, bone development, and H₂S is still not well explained. This review focuses on miRNAs and their roles in regulating bone remodeling and possible mechanisms behind H₂S mediated bone loss inhibition, H₂S-miRNAs crosstalk in relation to the pathophysiology of bone remodeling, and future perspectives for miRNA-H₂S as a therapeutic agent for bone diseases.

Protective effect of Co-enzyme Q10 On doxorubicin-induced cardiomyopathy of rat hearts

Q10 is a powerful antioxidant often used in medical nutritional supplements for cancer treatment. This study determined whether Q10 could effectively prevent cardio-toxicity caused by doxorubicin treatment. Four week old SD rats were segregated into groups namely control, doxorubicin group (challenged with doxorubicin), Dox + Q10 group (with doxorubicin challenge and oral Q10 treatment), and Q10 group (with oral Q10 treatment). Doxorubicin groups received IP doxorubicin (2.5 mg/kg) every 3 days and Q10 groups received Q10 (10 mg/kg) every day. Three weeks of doxorubicin challenge caused significant reduction in heart weight, disarray in cardiomyocyte arrangement, elevation of collagen accumulation, enhancement of fibrosis and cell death associated proteins, and inhibition of survival proteins. However, Q10 effectively protected cardiomyocytes and ameliorated fibrosis and cell death induced by doxorubicin. Q10 is, therefore, evidently a potential drug to prevent heart damage caused by doxorubicin. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 679-689, 2017.

A hydrogen sulfide probe activates Nrf2, inhibits cancer cell growth and induces cell apoptosis

Application of a probe for hydrogen sulfide, HF-NBD.

Andrographis paniculata extract attenuates pathological cardiac hypertrophy and apoptosis in high-fat diet fed mice

ETHNOPHARMACOLOGICAL RELEVANCE

Andrographis paniculata (Burm. f.) Nees (Acanthaceae) has a considerable medicinal reputation in most parts of Asia as a potent medicine in the treatment of Endocrine disorders, inflammation and hypertension.

AIM OF THE STUDY

Water extract of A. paniculata and its active constituent andrographolide are known to possess anti-inflammatory and anti-apoptotic effects. Our aim is to identify whether A. paniculata extract could protect myocardial damage in high-fat diet induced obese mice.

MATERIALS AND METHODS

The test mice were divided into three groups fed either with normal chow or with high fat diet (obese) or with high fat diet treated with A. paniculata extract (2g/kg/day, through gavage, for a week).

RESULTS

We found that the myocardial inflammation pathway related proteins were increased in the obese mouse which potentially contributes to cardiac hypertrophy and myocardial apoptosis. But feeding with A. paniculata extract showed significant inhibition on the effects of high fat diet.

CONCLUSION

Our study strongly suggests that supplementation of A. paniculata extract can be used for prevention and treatment of cardiovascular disease in obese patients.

Activation of Na+/K+-ATPase attenuates high glucose-induced H9c2 cell apoptosis via suppressing ROS accumulation and MAPKs activities by DRm217

Hyperglycemia is one of the major factors responsible for the myocardial apoptosis and dysfunction in diabetes. Many studies have proved that there is a close relationship between decreased Na⁺/K⁺-ATPase activity and diabetic cardiomyopathy. However, the effect of directly activated Na⁺/K⁺-ATPase on high glucose-induced myocardial injury is still unknown. Here we found that DRm217, a Na⁺/K⁺-ATPase's DR-region specific monoclonal antibody and direct activator, could prevent high glucose-induced H9c2 cell injury, reactive oxygen species (ROS) release, and mitochondrial dysfunction. High glucose-treatment decreased Na⁺/K⁺-ATPase activity and increased intracellular Ca²⁺ level, whereas DRm217 increased Na⁺/K⁺-ATPase activity and alleviated Ca²⁺ overload. Inhibition of Ca²⁺ overload or closing sodium calcium exchanger (NCX channel) could reverse high glucose-induced ROS increasing and cell injury. In addition, DRm217 could significantly attenuate high glucose-induced p38, JNK and ERK1/2 phosphorylation, which were involved in high glucose-induced cell injury and ROS accumulation. Our findings suggest that DRm217 may protect against the deleterious effects of high glucose in the heart. Prevention of high glucose-induced myocardial cell injury by specific Na⁺/K⁺-ATPase activator may be an attractive therapeutic option.