Taurine Supplementation Lowers Blood Pressure and Improves Vascular Function in Prehypertension: Randomized, Double-Blind, Placebo-Controlled Study

Taurine administration ablates sepsis induced diaphragm weakness

Infection induced diaphragm weakness is a major contributor to death and prolonged mechanical ventilation in critically ill patients. Infection induced muscle dysfunction is associated with activation of muscle proteolytic enzymes, and taurine is known to suppress proteolysis. We therefore postulated that taurine administration may prevent infection induced diaphragm dysfunction. The purpose of this study was to test this hypothesis using a clinically relevant animal model of infection, i.e. cecal ligation puncture induced sepsis (CLP). Studies were performed on (n = 5-7 mice/group): (a) sham operated controls, (b) animals with sepsis induced by CLP, (c) sham operated animals given taurine (75 mg/kg/d, intraperitoneally), and (d) CLP animals given taurine. At intervals after surgery animals were euthanized, diaphragm force generation measured in vitro, and diaphragm calpain, caspase and proteasomal activity determined. CLP elicited a large reduction in diaphragm specific force generation at 24 h (1-150 Hz, p < 0.001) and taurine significantly attenuated CLP induced diaphragm weakness at all stimulation frequencies (p < 0.001). CLP induced significant increases in diaphragm calpain, caspase and proteasomal activity; taurine administration prevented increases in the activity of all three pathways. In additional time course experiments, diaphragm force generation remained at control levels over 72 h in CLP animals treated with daily taurine administration, while CLP animals demonstrated severe, sustained reductions in diaphragm strength (p < 0.01 for all time points). Our results indicate that taurine administration prevents infection induced diaphragm weakness and reduces activation of three major proteolytic pathways. Because this agent is has been shown to be safe, non-toxic when administered to humans, taurine may have a role in treating infection induced diaphragm weakness. Future clinical studies will be needed to assess this possibility.

Oral taurine improves critical power and severe-intensity exercise tolerance

This study investigated the effects of acute oral taurine ingestion on: (1) the power-time relationship using the 3-min all-out test (3MAOT); (2) time to exhaustion (TTE) 5% > critical power (CP) and (3) the estimated time to complete (T_lim) a range of fixed target intensities. Twelve males completed a baseline 3MAOT test on a cycle ergometer. Following this, a double-blind, randomised cross-over design was followed, where participants were allocated to one of four conditions, separated by 72 h: TTE + taurine; TTE + placebo; 3MAOT + taurine; 3MAOT + placebo. Taurine was provided at 50 mg kg^-1, whilst the placebo was 3 mg kg^-1 maltodextrin. CP was higher (P < 0.05) in taurine (212 ± 36 W) than baseline (197 ± 40 W) and placebo (193 ± 35 W). Work end power was not affected by supplement (P > 0.05), yet TTE 5% > CP increased (P < 0.05) by 1.7 min after taurine (17.7 min) compared to placebo (16.0 min) and there were higher (P < 0.001) estimated T_lim across all work targets. Acute supplementation of 50 mg kg^-1 of taurine improved CP and estimated performance at a range of severe work intensities. Oral taurine can be taken prior to exercise to enhance endurance performance.

Characteristics of Selected Antioxidative and Bioactive Compounds in Meat and Animal Origin Products

Meat and meat products have a high nutritional value. Besides major components, meat is rich in bioactive components, primarily taurine, l-carnitine, choline, alpha-lipoic acid, conjugated linoleic acid, glutathione, creatine, coenzyme Q10 and bioactive peptides. Many studies have reported their antioxidant and health-promoting properties connected with their lipid-lowering, antihypertensive, anti-inflammatory, immunomodulatory activity and protecting the organism against oxidative stress. The antioxidant activity of meat components results, among others, from the capability of scavenging reactive oxygen and nitrogen species, forming complexes with metal ions and protecting cells against damage. This review is focused to gather accurate information about meat components with antioxidant and biological activity.

A diet rich in taurine, cysteine, folate, B12 and betaine may lessen risk for Alzheimer's disease by boosting brain synthesis of hydrogen sulfide

The gaseous physiological modulator hydrogen sulfide (H₂S) has recently been shown to exert a variety of neuroprotective effects. In particular, the treatment of transgenic mouse models of Alzheimer's disease (AD) with agents that release H₂S aids preservation of cognitive function, suppresses brain production of amyloid beta, and decreases tau phosphorylation. The possible physiological relevance of these findings is suggested by the finding that brain and plasma levels of H₂S are markedly lower in AD patients than matched controls. Hence, nutraceutical strategies which boost brain synthesis or levels of H₂S may have potential for prevention of AD. The chief enzyme which synthesizes H₂S in brain parenchyma, cystathionine beta-synthase (CBS), employs cysteine as its rate-limiting substrate, and is allosterically activated by S-adenosylmethionine (SAM). Supplemental taurine has been shown to boost expression of this enzyme, as well as that of another H₂S source, cystathionine gamma-lyase, in vascular tissue, and to enhance plasma H₂S levels; in rats subjected to hemorrhagic stroke, co-administration of taurine has been shown to blunt a marked reduction in brain CBS expression. Brain levels of SAM are about half as high in AD patients as in controls, and this is thought to explain the reduction of brain H₂S in these patients. These considerations suggest that supplementation with cysteine, taurine, and agents which promote methyl group availability - such as SAM, folate, vitamin B₁₂, and betaine - may have potential for boosting brain synthesis of H₂S and thereby aiding AD prevention. Indeed, most of these agents have already demonstrated utility in mouse AD models - albeit the extent to which increased H₂S synthesis contributes to this protection remains unclear. Moreover, prospective epidemiology has associated low dietary or plasma levels of folate, B12, and taurine with increased dementia risk. Rodent studies suggest that effective nutraceutical strategies for boosting brain H₂S synthesis may in fact have broad neuroprotective utility, possibly aiding prevention and/or control not only of AD but also Parkinson's disease and glaucoma, while diminishing the neuronal damage associated with brain trauma or stroke.

Taurine and its analogs in neurological disorders: Focus on therapeutic potential and molecular mechanisms

Taurine is a sulfur-containing amino acid and known as semi-essential in mammals and is produced chiefly by the liver and kidney. It presents in different organs, including retina, brain, heart and placenta and demonstrates extensive physiological activities within the body. In the several disease models, it attenuates inflammation- and oxidative stress-mediated injuries. Taurine also modulates ER stress, Ca2+ homeostasis and neuronal activity at the molecular level as part of its broader roles. Different cellular processes such as energy metabolism, gene expression, osmosis and quality control of protein are regulated by taurine. In addition, taurine displays potential ameliorating effects against different neurological disorders such as neurodegenerative diseases, stroke, epilepsy and diabetic neuropathy and protects against injuries and toxicities of the nervous system. Several findings demonstrate its therapeutic role against neurodevelopmental disorders, including Angelman syndrome, Fragile X syndrome, sleep-wake disorders, neural tube defects and attention-deficit hyperactivity disorder. Considering current biopharmaceutical limitations, developing novel delivery approaches and new derivatives and precursors of taurine may be an attractive option for treating neurological disorders. Herein, we present an overview on the therapeutic potential of taurine against neurological disorders and highlight clinical studies and its molecular mechanistic roles. This article also addresses the neuropharmacological potential of taurine analogs.

Impact of High Volume Energy Drink Consumption on Electrocardiographic and Blood Pressure Parameters: A Randomized Trial

Background Energy drinks have been linked to an increase in emergency room visits and deaths. We aim to determine the impact of energy drinks on electrocardiographic and hemodynamic parameters in young healthy volunteers. Methods and Results A randomized, double-masked, placebo-controlled, crossover study was conducted in healthy volunteers. Participants consumed 32 oz of either energy drink A, energy drink B, or placebo within 60 minutes on 3 study days with a 6-day washout period in between. The primary end point of QT c interval and secondary end points of QT interval, PR interval, QRS duration, heart rate, and brachial and central blood pressures were measured at baseline, and every 30 minutes for 240 minutes. A repeated-measures 2-way analysis of variance was performed with the main effects of intervention, time, and an interaction of intervention and time. Thirty-four participants were included (age 22.1±3.0 years). The interaction term of intervention and time was statistically significant for Bazett's corrected QT interval, Fridericia's corrected QT interval, QT , PR , QRS duration, heart rate, systolic blood pressure, diastolic blood pressure, central systolic blood pressure, and central diastolic blood pressure (all P<0.001). The maximum change from baseline in Bazett's corrected QT interval for drinks A, B, and placebo were +17.9±13.9, +19.6±15.8, and +11.9±11.1 ms, respectively ( P=0.005 for ANOVA ) ( P=0.04 and <0.01, respectively compared with placebo). Peripheral and central systolic and diastolic blood pressure were statistically significantly different compared with placebo (all P<0.001). Conclusion Energy drinks significantly prolong the QT c interval and raise blood pressure. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT03196908.

Risk assessment of energy drinks with focus on cardiovascular parameters and energy drink consumption in Europe

To assess the possible cardiovascular risks associated with energy drink (ED) consumption in Europe, a comprehensive literature research was performed in regard to (i) possible ED-induced dose-dependent cardiovascular outcomes, (ii) ED consumption patterns in Europe and (iii) the risks of EDs in combination with alcohol. The identified intervention studies primarily investigated acute ED effects in young healthy adults. Moderate consumption of EDs corresponding to an acute caffeine intake of up to 200 mg did not result in clinically relevant cardiovascular changes in young healthy adults. However, high intake of EDs (about 1 L) was associated with moderate to severe adverse effects in some participants (i.a. prolonged QTc interval, palpitations). Studies have indicated that on some occasions, a substantial proportion of ED consuming children and adolescents (12% in 16 EU Member States) drink EDs in high quantities (≥1 L). This could pose a possible health risk to this group since adverse effects by such high ED consumption have been observed already in young healthy adults. Among further measures that might be considered to minimize this identified risk, policy makers could develop information and educational programs with the aim of raising public awareness.

Pharmacological correction of endothelial dysfunction using ademethionin and taurine

Introduction: Рharmacological correction of endothelial dysfunction is a urgent problem of modern medicine.

Materials and methods: Endothelial dysfunction was simulated in male rats using the e-NOS inhibitor L-NAME (25 mg/kg/day intraperitoneally, for 7 days). Simulation of ADMA-like preeclampsia was performed by intraperitoneal injection of L-NAME to females in the same doses for 7 days (14-20th days of pregnancy). These pathologies were corrected by administering ademethionine in dose 150 mg/kg and taurine at a dose of 260 mg/kg, as well as their combination at the same doses, intragastrically, through an atraumatic probe, once a day.

Results: In the group with use of taurine at a dose of 260 mg/kg the coefficient of endothelial dysfunction decreased to the level of intact animals. Use of ademethionine at a dose of 150 mg/kg and taurine at a dose of 260 mg/kg combined resulted in the most pronounced endothelioprotective effect on the ADMA-like preeclampsia model. The coefficient of endothelial dysfunction decreased more than when using monotherapy of these drugs. Morphological studies of myocardiocytes showed that the combination of ademethionine at a dose of 150 mg/kg and taurine at a dose of 260 mg/kg prevented an increase in the cross-section of cardiomyocytes.

Discussion: Possibly, ademethionine and taurine have an endothelioprotective effect because of their ability to decrease hyperhomocysteinemia.

Conclusion: The investigated drugs showed pronounced endothelioprotective activity and can be recommended for further pre-clinical studies.

Acute taurine supplementation enhances thermoregulation and endurance cycling performance in the heat

This study investigated the effects of oral taurine supplementation on cycling time to exhaustion at a fixed-intensity and thermoregulation in the heat. In a double-blind, randomised crossover design, 11 healthy males participated in a time to exhaustion test in the heat (35°C, 40% RH), cycling at the power output associated with ventilatory threshold, 2 h after ingesting: Taurine (50 mg kg^-1) or placebo (3 mg kg^-1 maltodextrin). Core and mean skin temperature, mean sweat rate, heart rate, rating of perceived exertion (RPE), thermal comfort and thermal sensation were measured during exercise and blood lactate concentration (B[La]) was measured after exercise. Taurine supplementation increased time to exhaustion by 10% (25.16 min vs. 22.43 min, p = 0.040), end sweat rate by 12.7% (687 nL min^-1 vs. 600 nL min^-1, p = 0.034) and decreased B[La] by 16.5% (5.75 mmol L^-1 vs. 6.85 mmol L^-1, p = 0.033). Core temperature was lower in the final 10% of the time to exhaustion (38.5°C vs. 38.1°C, p = 0.049). Taurine supplementation increased time to exhaustion and local sweating, while decreasing RPE and core temperature in the later stages of exercise, as well as reducing post-exercise B[La]. This study provides the evidence of taurine's role in thermoregulatory processes. These findings have implications for the short-term preparation strategies of individuals exercising in the heat. Based on these findings, a single dose of taurine 2 h prior to training or competition would provide an ergogenic and thermoregulatory effect.

Effects of Taurine Supplementation on Vascular Endothelial Function at Rest and After Resistance Exercise

High-intensity resistance exercise has been shown to increase arterial stiffness and reduce vascular endothelial function. Taurine supplementation has a favorable effect on maintaining vascular function. We had previously reported that taurine supplementation attenuated increases in resistance exercise-induced arterial stiffness. In the present study, we further investigate the effects of taurine supplementation on vascular endothelial function at rest and after resistance exercise.Twenty-nine healthy men were recruited and randomly assigned to either the placebo supplement group (n = 14) or the taurine supplement group (n = 15) in a double-blinded manner. Subjects were required to ingest 6 g of either a placebo or the taurine supplement for 2 weeks prior to and 3 days following the exercise. Two weeks after the commencement of supplementation, the subjects were asked to perform 2 sets of 20 repetitive unilateral maximal-effort resistance exercise of the elbow flexors on a Biodex isokinetic dynamometer, with each contraction lasting 3 s, with 1 repetition performed every 9 s and 4 min rest in between sets. We evaluated the changes in brachial artery flow-mediated dilation (FMD) in the non-exercised arm as an index of vascular endothelial function. Relative and absolute FMDs were measured prior to supplementation, before exercise, and 24, 48, and 96 h after exercise.Two weeks of taurine supplementation significantly increased both relative and absolute FMDs. Baseline diameter significantly increased at 96 h following the exercise in both groups. However, there was no change in the peak diameter. Consequently, both relative and absolute FMDs were significantly reduced at 96 h after the exercise in both groups. Taurine supplementation does not affect resistance exercise-induced reduction in FMD.Two weeks of taurine supplementation (6 g/day) significantly increased vascular endothelial function at rest; however, taurine supplementation did not improve resistance exercise-induced reduction in FMD.

Cod Residual Protein Prevented Blood Pressure Increase in Zucker fa/fa Rats, Possibly by Inhibiting Activities of Angiotensin-Converting Enzyme and Renin

Hypertension is the leading risk factor for cardiovascular disease, and prevention of high blood pressure through diet and lifestyle should be a preferred approach. High intake of fish is associated with lower blood pressure, possibly mediated through the proteins since peptides with angiotensin-converting enzyme (ACE) inhibiting capacities have been identified in fish skin, backbone, and fillet. The effects of cod meals made from residual materials and fillet on blood pressure were investigated in obese Zucker fa/fa rats which spontaneously develop high blood pressure. Rats were fed diets containing water-soluble (stickwater) or water-insoluble (presscake) fractions of protein-rich meals from cod residual materials (head, gut, backbone with muscle residuals, skin, trimmings) or fillet. Rats were fed diets containing 25% of total protein from cod meal and 75% of protein from casein, or casein as the sole protein source (control group) for four weeks. Results show that a diet containing residual presscake meal with high gut content prevented blood pressure increase, and this cod residual meal also showed the strongest in vitro inhibitions of ACE and renin activities. In conclusion, a diet containing water-insoluble proteins (presscake meal) with high gut content prevented increase in blood pressure in obese Zucker fa/fa rats.

Prolonging healthy aging: Longevity vitamins and proteins

It is proposed that proteins/enzymes be classified into two classes according to their essentiality for immediate survival/reproduction and their function in long-term health: that is, survival proteins versus longevity proteins. As proposed by the triage theory, a modest deficiency of one of the nutrients/cofactors triggers a built-in rationing mechanism that favors the proteins needed for immediate survival and reproduction (survival proteins) while sacrificing those needed to protect against future damage (longevity proteins). Impairment of the function of longevity proteins results in an insidious acceleration of the risk of diseases associated with aging. I also propose that nutrients required for the function of longevity proteins constitute a class of vitamins that are here named "longevity vitamins." I suggest that many such nutrients play a dual role for both survival and longevity. The evidence for classifying taurine as a conditional vitamin, and the following 10 compounds as putative longevity vitamins, is reviewed: the fungal antioxidant ergothioneine; the bacterial metabolites pyrroloquinoline quinone (PQQ) and queuine; and the plant antioxidant carotenoids lutein, zeaxanthin, lycopene, α- and β-carotene, β-cryptoxanthin, and the marine carotenoid astaxanthin. Because nutrient deficiencies are highly prevalent in the United States (and elsewhere), appropriate supplementation and/or an improved diet could reduce much of the consequent risk of chronic disease and premature aging.

Nutrients in Fish and Possible Associations with Cardiovascular Disease Risk Factors in Metabolic Syndrome

Non-communicable diseases (NSDs) are responsible for two-thirds of all deaths globally, whereas cardiovascular disease (CVD) alone counts for nearly half of them. To reduce the impact of CVD, targeting modifiable risk factors comprised in metabolic syndrome (e.g., waist circumference, lipid profile, blood pressure, and blood glucose) is of great importance. Beneficial effects of fish consumption on CVD has been revealed over the past decades, and some studies suggest that fish consumption may have a protective role in preventing metabolic syndrome. Fish contains a variety of nutrients that may contribute to health benefits. This review examines current recommendations for fish intake as a source of various nutrients (proteins, n-3 fatty acids, vitamin D, iodine, selenium, and taurine), and their effects on metabolic syndrome and the CVD risk factors. Fatty fish is recommended due to its high levels of n-3 fatty acids, however lean fish also contains nutrients that may be beneficial in the prevention of CVD.

Magnesium taurate attenuates progression of hypertension and cardiotoxicity against cadmium chloride-induced hypertensive albino rats

The present study was designed to evaluate the antihypertensive activity and cardioprotective effects of magnesium taurate against cadmium chloride (CdCl₂)-intoxicated albino rats. Sprague Dawley male albino rats (120-150 g) were divided into five groups having six animals in each group. Hypertension and cardiotoxicity were induced in animals by administration of CdCl₂ (0.5 mg/kg/day, i.p.) for four weeks. Magnesium taurate (2 and 4 mg/kg/day) was administered orally after induction of hypertension (after two weeks) in their respective groups concurrently with CdCl₂ for next two weeks. Amlodipine (3 mg/kg/day, p.o.) was used as a standard and administered after induction of hypertension. Blood pressure was monitored biweekly by using non-invasive blood pressure system and biochemical parameters and histopathology of the heart were evaluated after four weeks of the experimental protocol. During the four weeks of the experimental protocol, the toxic control group showed significant elevation of systolic and diastolic blood pressure concomitant with augmentation of cardiotoxicity as indicated by reduction in myocardial antioxidants including glutathione peroxidase, catalase, superoxide dismutase, reduced glutathione and increased malondialdehyde level in heart as compared to the normal group. The oral administrations of magnesium taurate significantly restored the blood pressure, myocardial antioxidants and malondialdehyde level as compared to toxic control group. In addition, histopathological examination showed that magnesium taurate treatments substantially reduced the myocardial damages against CdCl₂ treatment. The results suggest that magnesium taurate has prominent antihypertensive and cardioprotective activity via its potent antioxidant activity and can be used as a nutrition supplement to improve the cardiovascular health.

Effects and Mechanisms of Taurine as a Therapeutic Agent

Taurine is an abundant, β-amino acid with diverse cytoprotective activity. In some species, taurine is an essential nutrient but in man it is considered a semi-essential nutrient, although cells lacking taurine show major pathology. These findings have spurred interest in the potential use of taurine as a therapeutic agent. The discovery that taurine is an effective therapy against congestive heart failure led to the study of taurine as a therapeutic agent against other disease conditions. Today, taurine has been approved for the treatment of congestive heart failure in Japan and shows promise in the treatment of several other diseases. The present review summarizes studies supporting a role of taurine in the treatment of diseases of muscle, the central nervous system, and the cardiovascular system. In addition, taurine is extremely effective in the treatment of the mitochondrial disease, mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and offers a new approach for the treatment of metabolic diseases, such as diabetes, and inflammatory diseases, such as arthritis. The review also addresses the functions of taurine (regulation of antioxidation, energy metabolism, gene expression, ER stress, neuromodulation, quality control and calcium homeostasis) underlying these therapeutic actions.

Regulation of vascular tone homeostasis by NO and H2S: Implications in hypertension

Nitric oxide (NO) and hydrogen sulfide (H2S) are two gasotransmitters that are produced in the vasculature and contribute to the regulation of vascular tone. NO and H2S are synthesized in both vascular smooth muscle and endothelial cells; NO functions primarily through the sGC/cGMP pathway, and H2S mainly through activation of the ATP-dependent potassium channels; both leading to relaxation of vascular smooth muscle cells. A deficit in the NO/H2S homeostasis is involved in the pathogenesis of various cardiovascular diseases, especially hypertension. It is now becoming increasingly clear that there are important interactions between NO and H2S and that have a profound impact on vascular tone and this may provide insights into the new therapeutic interventions. The aim of this review is to provide a better understanding of individual and interactive roles of NO and H2S in vascular biology. Overall, available data indicate that both NO and H2S contribute to vascular (patho)physiology and in regulating blood pressure. In addition, boosting NO and H2S using various dietary sources or donors could be a hopeful therapeutic strategy in the management of hypertension.

Randomised clinical study: the effects of oral taurine 6g/day vs placebo on portal hypertension

BACKGROUND

The amino sulphonic acid taurine reduces oxidative endoplasmatic reticulum stress and inhibits hepatic stellate cell activation, which might lead to reduction of portal pressure in cirrhosis.

AIM

To assess the haemodynamic effects of taurine supplementation in patients with cirrhosis and varices.

METHODS

Patients with hepatic venous pressure gradient (HVPG) ≥12 mm Hg were included in this prospective proof of concept study. Concomitant nonselective beta-blockers therapy was not allowed. Patients received either 4 weeks of oral taurine (6 g/day), or placebo, prior to evaluation of HVPG response.

RESULTS

Thirty patients were screened and 22 included in the efficacy analysis (12 taurine/10 placebo; 64% male, mean age: 52 ± 11 years, Child A: 9%, B:64%, C:27%, ascites:68%). In the taurine group, mean HVPG dropped from 20 mm Hg (±4) at baseline to 18 mm Hg (±4) on day 28 (mean relative change: -12%, P = .0093). In the placebo group, mean HVPG increased from 20 mm Hg (±5) at baseline to 21 mm Hg (±5) on day 28 (mean relative change:+2%, P = .4945). Taurine had no significant effects on systemic haemodynamics. Seven of 12 patients (58%) on taurine achieved a HVPG response >10%, compared to none in the placebo group (P = .0053). In a multivariate linear model, HVPG reduction was significantly larger in the taurine group compared to placebo group (P = .0091 and P = .0109 for absolute and relative change respectively). Treatment-related adverse events included gastrointestinal discomfort and fatigue, and were usually mild and comparable between treatment groups.

CONCLUSION

Taurine is safe and may reduce portal pressure in cirrhotic patients. More studies on the underlying mechanisms of action and long-term effects of taurine supplementation are warranted.

Taurine supplementation reduces neuroinflammation and protects against white matter injury after intracerebral hemorrhage in rats

Intracerebral hemorrhage (ICH) initiates a neuroinflammatory cascade that contributes to substantial neuronal damage and neurological deterioration. Taurine, an abundant amino acid in the nervous system, is reported to reduce inflammatory injury in various central nervous system diseases, but its role and the possible underlying mechanisms in the pathology following ICH remains unclear. This study was designed to evaluate the effect of taurine supplementation on neurological deficits, acute inflammatory responses and white matter injury in a model of ICH in rats. Adult male Sprague-Dawley (SD) rats subjected to collagenase-induced ICH injury were injected intravenously with different concentrations of taurine or vehicle 10 min after ICH and subsequently daily for 3 days. Behavioral studies, brain water content, and assessments of hemorrhagic lesion volume were quantified at day 1 and day 3 post-ICH. Neuronal damage, peri-hematomal inflammatory responses, and white matter injury were determined at 24 h, meanwhile, the content of hydrogen sulfide (H₂S) along with the expression of cystathionine-β-synthase (CBS) and P2X7 receptor (P2X7R) in peri-hematomal tissues was analyzed to investigate the possible anti-inflammatory mechanism of taurine. Treatment with a high dosage of taurine (50 mg/kg) significantly attenuated functional deficits and reduced brain edema and hemorrhagic lesion volume after ICH. Taurine administration also resulted in significant amelioration of neuronal damage and white matter injury. These changes were associated with marked reductions in neutrophil infiltration, glial activation, and expression levels of inflammatory mediators. Moreover, the anti-inflammatory effect of taurine was accompanied by increased H₂S content, enhanced CBS expression, and less expression of P2X7R. Our study demonstrated that the high dosage of taurine supplementation effectively mitigated the severity of pathological inflammation and white matter injury after ICH, and the mechanism may be related to upregulation of H₂S content and reduced P2X7R expression.

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.

Integrative Medicine for Cardiovascular Disease and Prevention

Cardiovascular disease (CVD) is traditionally treated through medications and lifestyle modifications, yet adherence to these treatments is often poor. The use of complementary therapies is increasing, and it is vital for physicians to be aware of the risks and benefits of these options. This article summarizes the current evidence base on integrative therapies for the prevention and treatment of CVD, including hypertension, hyperlipidemia, coronary artery disease, heart failure, and arrhythmias. Where applicable, recommendations are included for therapies that may be used as an adjunct to traditional medical care to improve cardiovascular health and quality of life.

Enhanced Mitochondrial Transient Receptor Potential Channel, Canonical Type 3-Mediated Calcium Handling in the Vasculature From Hypertensive Rats

BACKGROUND

Mitochondrial Ca2+ homeostasis is fundamental to the regulation of mitochondrial reactive oxygen species (ROS) generation and adenosine triphosphate production. Recently, transient receptor potential channel, canonical type 3 (TRPC3), has been shown to localize to the mitochondria and to play a role in maintaining mitochondrial calcium homeostasis. Inhibition of TRPC3 attenuates vascular calcium influx in spontaneously hypertensive rats (SHRs). However, it remains elusive whether mitochondrial TRPC3 participates in hypertension by increasing mitochondrial calcium handling and ROS production.

METHODS AND RESULTS

In this study we demonstrated increased TRPC3 expression in purified mitochondria in the vasculature from SHRs, which facilitates enhanced mitochondrial calcium uptake and ROS generation compared with Wistar-Kyoto rats. Furthermore, inhibition of TRPC3 by its specific inhibitor, Pyr3, significantly decreased the vascular mitochondrial ROS production and H2O2 synthesis and increased adenosine triphosphate content. Administration of telmisartan can improve these abnormalities. This beneficial effect was associated with improvement of the mitochondrial respiratory function through recovering the activity of pyruvate dehydrogenase in the vasculature of SHRs. In vivo, chronic administration of telmisartan suppressed TRPC3-mediated excessive mitochondrial ROS generation and vasoconstriction in the vasculature of SHRs. More importantly, TRPC3 knockout mice exhibited significantly ameliorated hypertension through reduction of angiotensin II-induced mitochondrial ROS generation.

CONCLUSIONS

Together, we give experimental evidence for a potential mechanism by which enhanced TRPC3 activity at the cytoplasmic and mitochondrial levels contributes to redox signaling and calcium dysregulation in the vasculature from SHRs. Angiotensin II or telmisartan can regulate [Ca2+]mito, ROS production, and mitochondrial energy metabolism through targeting TRPC3.

Association of amine biomarkers with incident dementia and Alzheimer's disease in the Framingham Study

INTRODUCTION

The identification of novel biomarkers associated with Alzheimer's disease (AD) could provide key biological insights and permit targeted preclinical prevention. We investigated circulating metabolites associated with incident dementia and AD using metabolomics.

METHODS

Plasma levels of 217 metabolites were assessed in 2067 dementia-free Framingham Offspring Cohort participants (mean age = 55.9 ± 9.7 years; 52.4% women). We studied their associations with future dementia and AD risk in multivariate Cox models.

RESULTS

Ninety-three participants developed incident dementia (mean follow-up = 15.6 ± 5.2 years). Higher plasma anthranilic acid levels were associated with greater risk of dementia (hazard ratio [HR] = 1.40; 95% confidence interval [CI] = [1.15-1.70]; P = 8.08 × 10^-4). Glutamic acid (HR = 1.38; 95% CI = [1.11-1.72]), taurine (HR = 0.74; 95% CI = [0.60-0.92]), and hypoxanthine (HR = 0.74; 95% CI = [0.60-0.92]) levels also showed suggestive associations with dementia risk.

DISCUSSION

We identified four biologically plausible, candidate plasma biomarkers for dementia. Association of anthranilic acid implicates the kynurenine pathway, which modulates glutamate excitotoxicity. The associations with hypoxanthine and taurine strengthen evidence that uric acid and taurine may be neuroprotective.

Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications

Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.

Preclinical and Clinical Studies on Antioxidative, Antihypertensive and Cardioprotective Effect of Marine Proteins and Peptides-A Review

High seafood consumption has traditionally been linked to a reduced risk of cardiovascular diseases, mainly due to the lipid lowering effects of the long chained omega 3 fatty acids. However, fish and seafood are also excellent sources of good quality proteins and emerging documentation show that, upon digestion, these proteins are sources for bioactive peptides with documented favorable physiological effects such as antioxidative, antihypertensive and other cardioprotective effects. This documentation is mainly from in vitro studies, but also animal studies are arising. Evidence from human studies evaluating the positive health effects of marine proteins and peptides are scarce. In one study, a reduction in oxidative stress after intake of cod has been documented and a few human clinical trials have been performed evaluating the effect on blood pressure. The results are, however, inconclusive. The majority of the human clinical trials performed to investigate positive health effects of marine protein and lean fish intake, has focused on blood lipids. While some studies have documented a reduction in triglycerides after intake of lean fish, others have documented no effects.

Homocysteine and hydrogen sulfide in epigenetic, metabolic and microbiota related renovascular hypertension

Over the past several years, hydrogen sulfide (H₂S) has been shown to be an important player in a variety of physiological functions, including neuromodulation, vasodilation, oxidant regulation, inflammation, and angiogenesis. H₂S is synthesized primarily through metabolic processes from the amino acid cysteine and homocysteine in various organ systems including neuronal, cardiovascular, gastrointestinal, and kidney. Derangement of cysteine and homocysteine metabolism and clearance, particularly in the renal vasculature, leads to H₂S biosynthesis deregulation causing or contributing to existing high blood pressure. While a variety of environmental influences, such as diet can have an effect on H₂S regulation and function, genetic factors, and more recently epigenetics, also have a vital role in H₂S regulation and function, and therefore disease initiation and progression. In addition, new research into the role of gut microbiota in the development of hypertension has highlighted the need to further explore these microorganisms and how they influence the levels of H₂S throughout the body and possibly exploiting microbiota for use of hypertension treatment. In this review, we summarize recent advances in the field of hypertension research emphasizing renal contribution and how H₂S physiology can be exploited as a possible therapeutic strategy to ameliorate kidney dysfunction as well as to control blood pressure.