Physiological and thermoregulatory effects of oral taurine supplementation on exercise tolerance during forced convective cooling.

AbstractWe investigated the effects of taurine supplementation on cycling time to exhaustion in cold conditions. Eleven males cycled to exhaustion at a power output equivalent to the mid-point between ventilatory threshold and maximum aerobic power following 15-min rest in the cold (apparent temperature of ∼ 4°C; air flow of 4.17 m s-1). Two hours before, participants ingested taurine (50 mg·kg-1) or placebo beverage. Pulmonary gases, carbohydrate (CHO) and fat oxidation, body temperatures, mean local sweat rate, heart rate, rate of perceived exertion (RPE) and thermal comfort were recorded. Time to exhaustion was not different between trials (taurine = 14.6 ± 4.7 min; placebo = 13.4 ± 5.6 min, P = 0.061, d = 0.27). There were no effects (P > 0.05) of taurine on core temperature, mean skin temperature or local sweat rates. However, the placebo condition showed greater (P < 0.05) reductions in arm-to-finger temperature gradient (i.e. vasodilation) across pre-exercise passive cold exposure and increased CHO oxidation (P < 0.05). Participants also reached a thermally 'comfortable' level quicker in the taurine condition (P < 0.05). A 50 mg·kg-1 dose of taurine did not statistically benefit endurance exercise after moderate cold exposure but conferred some potential vascular and metabolic effects.

Taurine and Camel Milk Modulate Neurobehavioral and Biochemical Changes in Aluminum Chloride-Induced Alzheimer's Disease in Rats.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease associated with deficiency in motor coordination, cognitive impairment, and excessive reactive oxygen species production in the brain. OBJECTIVE: The study evaluated effects of taurine and camel milk (CM) on neurobehavior, amyloid-beta peptide 1-42 (Aß) expression, acetylcholinesterase, and superoxide dismutase activities in aluminum chloride (AlCl3) model of Alzheimer's disease in rats. METHODS: Thirty-five female Wistar rats were divided into seven groups (n = 5): Normal saline (0.2 mL/kg body weight); AlCl3 (100 mg/kg) (AD); CM (33 mL/kg); Taurine (50 mg/kg); AlCl3 (100 mg/kg) + CM (33 mL/kg); AlCl3 (100 mg/kg) + Taurine (50 mg/kg); and AlCl3 (100 mg/kg) + CM (33 mL/kg) + Taurine (50 mg/kg). The administration lasted for eight weeks via oral gavage. After the eighth week, neurobehavior assessments were performed. Rats were sacrificed, and brain and blood samples collected for analysis. RESULTS: There was a significant (p < 0.0001) increase in the duration of motor endurance in AD + CM rats, compared to AD rats. Duration of forced swimming time was lowest (p < 0.0001) in AlCl3 + Taurine rats, compared to that of AD rats. Concentration of Aß peptide decreased (p < 0.05) in AD rats, treated with CM and/or combination. In taurine-treated rats, superoxide dismutase activity was significantly (p < 0.05) higher than in AD rats. Treatment with taurine + CM increased (p < 0.05) acetylcholinesterase activity compared to controls. CONCLUSION: Taurine and CM enhanced cognition and sensorimotor activity by decreasing Aß peptide concentration and increasing superoxide dismutase and acetylcholinesterase activities in AD rats.

The nephroprotective properties of taurine-amikacin treatment in rats are mediated through HSP25 and TLR-4 regulation.

Amikacin (AMK) is one of the most effective aminoglycoside antibiotics. However, nephrotoxicity is a major deleterious and dose-limiting side effect associated with its clinical use especially in high dose AMK-treated patients. The present study assessed the ability of taurine (TAU) to alleviate or prevent AMK-induced nephrotoxicity if co-administrated with AMK focusing on inflammation, apoptosis, and fibrosis. Male Sprague Dawley rats were assigned to six equal groups. Group 1: rats received saline (normal control), group 2: normal rats received 50 mg kg-1 TAU intraperitoneally (i.p.). Groups 3 and 4: received AMK (25 or 50 mg kg-1; i.p.). Groups 5 and 6: received TAU (50 mg kg-1; i.p.) concurrently with AMK (25 or 50 mg kg-1; i.p.) for 3 weeks. AMK-induced nephrotoxicity is evidenced by elevated levels of serum creatinine (CRE), blood urea nitrogen (BUN), and uric acid (UA). Histopathological investigations provoked damaging changes in the renal tissues. Heat shock proteins (HSP)25 and Toll-like receptor-4 (TLR-4) elevated levels were involved in the induction of inflammatory reactions and focal fibrosis. The improved activation of TLR-4 may stimulate monocytes to upgrade Interleukin (IL)-18 production rather than IL-10. TAU proved therapeutic effectiveness against AMK-induced renal toxicity through downregulation of HSP25, TLR-4, caspase-3, and IL-18 with up-regulation of IL-10 levels.

Taurine supplementation in conjunction with exercise modulated cytokines and improved subcutaneous white adipose tissue plasticity in obese women.

Interventions that can modulate subcutaneous white adipose tissue (scWAT) function, such as exercise training and nutritional components, like taurine, modulate the inflammatory process, therefore, may represent strategies for obesity treatment. We investigated the effects of taurine supplementation in conjunction with exercise on inflammatory and oxidative stress markers in plasma and scWAT of obese women. Sixteen obese women were randomized into two groups: Taurine supplementation group (Tau, n = 8) and Taurine supplementation + exercise group (Tau + Exe, n = 8). The intervention was composed of daily taurine supplementation (3 g) and exercise training for 8 weeks. Anthropometry, body fat composition, and markers of inflammatory and oxidative stress were determined in plasma and scWAT biopsy samples before and after the intervention. We found that, although taurine supplementation increased taurine plasma levels, no changes were observed for the anthropometric characteristics. However, Tau alone decreased interleukin-6 (IL-6), and in conjunction with exercise (Tau + Exe), increased anti-inflammatory interleukins (IL-15 and IL10), followed by reduced IL1ß gene expression in the scWAT of obese women. Tau and Tau + Exe groups presented reduced adipocyte size and increased connective tissue and multilocular droplets. In conclusion, taurine supplementation in conjunction with exercise modulated levels of inflammatory markers in plasma and scWAT, and improved scWAT plasticity in obese women, promoting protection against obesity-induced inflammation. TRN NCT04279600 retrospectively registered on August 18, 2019.

Taurine supplementation protects lens against glutathione depletion.

OBJECTIVE: Cataract which is defined as opacification of eye lens forms approximately 40% of total blindness causes all through the world. Age is the biggest risk factor for cataracts and oxidative stress is known to be one of the most important factors causing cataract formation. Age-related nuclear cataract (ARN) is associated with a loss of glutathione in the center of the lens. Taurine is an important antioxidant in lens tissue. Although, there is a high amount of taurine in lenses in early life, its concentration declines with age. In this study, we aimed to investigate the effects of supplemental taurine in lens tissues in an in vivo oxidative stress model which is induced by glutathione depletion to mimic ARN. MATERIALS AND METHODS: Glutathione depletion was induced in rabbits subcutaneously with l-Buthionine -(S,R)-sulfoximine (BSO)- a glutathione inhibitor and the rabbits were treated with taurine. Total GSH, reduced GSH, GSH/GSSG ratio and MDA levels were measured. RESULTS: BSO lowered the reduced GSH and total GSH levels and GSH/GSSG ratio. Taurine reversed these effects. On the other hand, BSO enhanced MDA level which is normalized by taurine. CONCLUSIONS: These findings suggest that glutathione depletion with BSO may be a useful model to mimic ARN and dietary intake of taurine, may have an important role in decelerating the process of cataract formation.

Prevention of tunneled cuffed catheter dysfunction with prophylactic use of a taurolidine urokinase lock: A randomized double-blind trial.

BACKGROUND: The efficacy and cost-effectiveness of prophylactic thrombolytic locks in hemodialysis patients at high-risk of thrombotic dialysis catheter dysfunction is uncertain. We investigated this question in a double-blinded randomized controlled study. METHODS: Prevalent hemodialysis patients from 8 Belgian hemodialysis units, with ≥2 separate episodes of thrombotic dysfunction of their tunneled cuffed catheter during the 6 months before inclusion, were randomized to either: taurolidine heparin locks thrice weekly (control arm) or the same locks twice a week combined with taurolidine urokinase locks once a week before the longest interval without HD (TaurolockU arm). The primary efficacy outcome was the incidence rate of catheter thrombotic dysfunction requiring thrombolytic locks to restore function. RESULTS: 68 hemodialysis patients (32 controls, 36 urokinase) were followed during 9875 catheter days between May 2015 and June 2017. Incidence rate of thrombotic catheter dysfunction was 4.8 in TaurolockU vs 12.1/1000 catheter days in control group (rate ratio 0.39; 95%CI 0.23-0.64). 15/36 (42%) catheters in the treatment group required at least one therapeutic urokinase lock vs 23/32 (72%) in the control group (P = 0.012). The two groups did not differ significantly in catheter-related bloodstream infection and combined cost of prophylactic and therapeutic catheter locks. The TaurolockU group had a numerically higher number of episodes of refractory thrombosis. CONCLUSIONS: Prophylactic use of urokinase locks is highly effective in reducing the number of thrombotic catheter dysfunctions in catheters with a history of recurring dysfunction. Prophylactic use of urokinase locks did not reduce the overall costs associated with catheter locks and was associated with a numerically higher number of episodes of refractory thrombosis. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02036255.

Taurine in sports and exercise.

BACKGROUND: Taurine has become a popular supplement among athletes attempting to improve performance. While the effectiveness of taurine as an ergogenic aid remains controversial, this paper summarizes the current evidence regarding the efficacy of taurine in aerobic and anaerobic performance, metabolic stress, muscle soreness, and recovery. METHODS: Google Scholar, Web of Science, and MedLine (PubMed) searches were conducted through September 2020. Peer-reviewed studies that investigated taurine as a single ingredient at dosages of < 1 g - 6 g, ranging from 10 to 15 min-to-2 h prior to exercise bout or chronic dose (7 days- 8 weeks) of consumption were included. Articles were excluded if taurine was not the primary or only ingredient in a supplement or food source, not published in peer-reviewed journals, if participants were older than 50 years, articles published before 1999, animal studies, or included participants with health issues. A total of 19 studies met the inclusion criteria for the review. RESULTS: Key results include improvements in the following: VO2max, time to exhaustion (TTE; n = 5 articles), 3 or 4 km time-trial (n = 2 articles), anaerobic performance (n = 7 articles), muscle damage (n = 3 articles), peak power (n = 2 articles), recovery (n = 1 article). Taurine also caused a change in metabolites: decrease in lactate, creatine kinase, phosphorus, inflammatory markers, and improved glycolytic/fat oxidation markers (n = 5 articles). Taurine dosing appears to be effective at ~ 1-3 g/day acutely across a span of 6-15 days (1-3 h before an activity) which may improve aerobic performance (TTE), anaerobic performance (strength, power), recovery (DOMS), and a decrease in metabolic markers (creatine kinase, lactate, inorganic phosphate). CONCLUSIONS: Limited and varied findings prohibit definitive conclusions regarding the efficacy of taurine on aerobic and anaerobic performance and metabolic outcomes. There are mixed findings for the effect of taurine consumption on improving recovery from training bouts and/or mitigating muscle damage. The timing of taurine ingestion as well as the type of exercise protocol performed may contribute to the effectiveness of taurine as an ergogenic aid. More investigations are needed to better understand the potential effects of taurine supplementation on aerobic and anaerobic performance, muscle damage, metabolic stress, and recovery.

Caffeinated energy drinks in the Canadian context: health risk assessment with a focus on cardiovascular effects.

In Canada, caffeinated energy drinks (CEDs) currently sold under Temporary Marketing Authorizations must meet strict eligibility criteria. These criteria, which include compositional and labelling requirements, were developed based on the outcome of a health risk assessment conducted by Health Canada (HC) in 2013. HC updated its assessment by reviewing new information with the focus on potential cardiovascular effects associated with the consumption of CEDs available for sale in Canada. Due to limited data on CED consumption among Canadians to derive accurate exposure information, the composition of a typical CED was characterized to assess the potential effects of single ingredients and synergistic interactions between ingredients on the cardiovascular system. Surveillance data on potential adverse effects related to CED consumption was also analyzed. After extensive review, HC's updated assessment confirms the current risk management approach for CEDs is health protective for Canadian consumers, including the potential for cardiovascular effects. The available evidence supports that moderate consumption (up to 500 mL per day) of a typical CED authorized for sale in Canada is safe for the general population of healthy adults and adolescents. It also re-confirms that vulnerable sub-populations (i.e., children, pregnant and/or breastfeeding women, and caffeine-sensitive individuals) should not consume CEDs. Novelty: Consumption up to 500 mL per day of a typical CED is not associated with an increased risk of cardiovascular effects. Children, pregnant and/or breastfeeding women, and caffeine-sensitive individuals should not consume CEDs.

Taurine attenuates valproic acid-induced hepatotoxicity via modulation of RIPK1/RIPK3/MLKL-mediated necroptosis signaling in mice.

Valproic acid (VPA) is known as a common drug in seizure and bipolar disorders treatment. Hepatotoxicity is the most important complication of VPA. Taurine (Tau), an amino acid, has antioxidant effects. The present research was conducted to evaluate the protective mechanisms of Tau on VPA-induced liver injury, especially focusing on the necroptosis signaling pathway. The sixty-four male NMRI mice were divided into eight groups with eight animals per each. The experiment groups pretreated with Tau (250, 500, 1000 mg/kg) and necrostatine-1 (Nec-1, 1.8 mg/kg) and then VPA (500 mg/kg) was administered for 14 consecutive days. The extent of VPA-induced hepatotoxicity was confirmed by elevated ALP (alkaline phosphatase), AST (aspartate aminotransferase), ALT (alanine aminotransferase) levels, and histological changes as steatosis, accumulation of erythrocytes, and inflammation. Additionally, VPA significantly induced oxidative stress in the hepatic tissue by increasing ROS (reactive oxygen species) production and lipid peroxidation level along with decreasing GSH (glutathione). Hepatic TNF-α (tumor necrosis factor) level, mRNA and protein expression of RIPK1 (receptor-interacting protein kinase 1), RIPK3, and MLKL (mixed lineage kinase domain-like pseudokinase) were upregulated. Also, the phosphorylation of MLKL and RIPK3 increased in the VPA group. Tau could effectively reverse these events. Our data suggest which necroptosis has a key role in the toxicity of VPA through TNF-α-mediated RIPK1/RIPK3/MLKL signaling and oxidative stress. Our findings suggest that Tau protects the liver tissue against VPA toxicity via inhibiting necroptosis signaling pathway mediated by RIPK1/RIPK3/MLKL and suppressing oxidative stress, and apoptosis.

The effect of intracerebroventricular amyloid beta 1-42 application on cognitive functions in aged rats supplemented with taurine and the change of peroxisomal proteins in this process.

OBJECTIVE: The aim of our study is to investigate the change of peroxisomal proteins in the neurodegenerative and oxidative process caused by the neurotoxicity of Aß 1-42 in aged rats supplemented with taurine and to show the possible positive effects of taurine in this process. METHODS: 30 Wistar albino rats were randomly divided into 5 groups as control, sham, Aß 1-42, taurine, and Aß 1-42+taurine. Taurine administration continued for 6 weeks (1000 mg/kg/day with drinking water). Stereotaxic surgery was applied to all groups (intracerebroventricular per lateral ventricle needle only or 5 µl, PBS, or Aß 1-42). Spatial learning and memory performances of the animals were evaluated with Morris water maze and elevated plus maze. The levels of MDA and GSH were measured as oxidative stress parameters in the cerebral cortex and hippocampus. Expressions of CAT, PEX14, PMP70 of peroxisomal membrane proteins were indicated by Western blot analysis. RESULTS: Our results showed that injection of Aß 1-42 decreased the spatial learning and memory performance, cortex CAT and hippocampus PEX14, PMP70 and GSH levels, and increased cortex and hippocampus MDA levels (p < 0.05). Although the administration of taurine partially ameliorated the adverse effects of Aß 1-42 injection, a significant difference was found only at the hippocampus GSH levels (p < 0.05). Also, taurine caused anxiety at this dose (p < 0.05). DISCUSSION: In conclusion, decreased peroxisomal proteins and antioxidant capacity in neurodegenerative and oxidative processes induced by intracerebroventricular Aß 1-42 injection showed that peroxisomes may play a role in this process and taurine supplementation may have positive effects especially in increasing antioxidant capacity.

Age-related decline in the taurine content of the skin in rodents.

Taurine, a sulfur-containing amino acid, occurs at high concentrations in the skin, and plays a role in maintaining the homeostasis of the skin. We investigated the effects of aging on the content and localization of taurine in the skin of mice and rats. Taurine was extracted from the skin samples of hairless mice and Sprague Dawley rats, and the taurine content of the skin was determined by high-performance liquid chromatography (HPLC). The results of the investigation revealed that the taurine content in both the dermis and epidermis of hairless mice declined significantly with age. Similar age-related decline in the skin taurine content was also observed in rats. In contrast, the taurine content in the sole remained unchanged with age. An immunohistochemical analysis also revealed a decreased skin taurine content in aged animals compared with younger animals, although no significant differences in the localization of taurine were observed between the two age groups. Supplementation of the drinking water of aged mice with 3% (w/v) taurine for 4 weeks increased the taurine content of the epidermis, but not the dermis. The present study showed for the first time that the taurine content of the skin decreased with age in mice and rats, which may be related to the impairment of the skin homeostasis observed with aging. The decreased taurine content of the epidermis in aged animals was able to be rescued by taurine supplementation.

Cost-effectiveness of taurolidine locks to prevent recurrent catheter-related blood stream infections in adult patients receiving home parenteral nutrition: a 2-year mirror-image study.

BACKGROUND & AIMS: The use of long-term taurolidine locks (LTTL) seems to be effective in preventing catheter-related blood stream infections (CRBSI), especially in patients on home parenteral nutrition (HPN). This work targets the cost-effectiveness of LTTL in a cohort of adult HPN patients. METHODS: A monocentric mirror-image design study was conducted in our referral centre among long-term HPN patients experiencing recurrent CRBSI. From 7th January 2011, LTTL were started after the third CRBSI episode within 12 months. CRBSI data was prospectively collected until 7th January 2013, in the same way as it had retrospectively been done before initiating LTTL. A cost-effective analysis was conducted to estimate the incremental costs and effects on CRBSI with LTTL. The efficacy of LTTL on CRBSI rate was assessed over 1000 days of catheter use. RESULTS: A total of 31,100 catheter days were analysed in 37 patients (median [interquartile range (IQR)]) aged 58 [42-68] years. The mean ± SD proven CRBSI rate was 3.18 ± 3.51 per 1000 catheter days before the introduction of LTTL and 0.39 ± 1.50 per 1000 catheter days after its introduction (p < 0.0001). Considering both proven and probable CRBSI requiring hospital management, LTTL reduced by (mean [bootstrap CI 95%]) -2.63 [-3.26 to -2.06] infections per patient (from 2.89 [2.31 to 3.49] before to 0.26 [0.13 to 0.41] after) as well as incremental costs by -7 258 [-10 450 to -4 016] € (from 11 176 [8 004 to 14 968] € before to 3 918 [2 390 to 5 445] € after). CONCLUSION: Implementing LTTL to prevent recurrent CRBSI is cost-effective by dramatically decreasing their incidence.

Taurine supplementation reduces myeloperoxidase and matrix-metalloproteinase-9 levels and improves the effects of exercise in cognition and physical fitness in older women.

Immunosenescence contributes to cognitive impairment and neurodegeneration, and those conditions could be attenuated by non-pharmacological anti-inflammatory strategies, such as exercise and supplementation with the amino acid taurine. Since taurine body content decreases with aging, we investigated the effects of supplementation (alone and combined with exercise) on oxidative stress, extracellular matrix degradation, white blood cells, neurotrophins, cognition and physical fitness of elderly women. Forty-eight women (83.58 ± 6.98 years) were enrolled into exercise training only (EO: n = 13), taurine supplementation (TS: n = 12), exercise training + taurine supplementation (ETTS: n = 11), and control group (CG: n = 12). All interventions lasted 14 weeks. Exercise was applied twice a week, and taurine was given once a day (1.5 g). Data collection occurred before and after interventions with the determination of myeloperoxidase (MPO), matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) levels, and white blood cell counts (WBC). Montreal cognitive assessment (MoCA) and physical fitness tests were also evaluated. Concentration of MPO and MMP-9 decreased after intervention in TS (p < 0.05). No effect of time or time × group was observed for WBC parameters; however, univariate analysis showed a significant decrease in lymphocytes for TS, while an increase in monocytes occurred in the CG (p < 0.05). MoCA scores decreased over time in the CG (p < 0.05). Improvements in physical fitness occurred in ETTS (better agility and aerobic capacity), mostly likely due to exercise and boosted by taurine supplementation. No changes in BDNF levels were observed (p > 0.05), while NGF concentration were undetectable in almost subjects. Exercise together with taurine supplementation appears to be a valuable strategy to enhance health-related outcomes in older persons.

Taurine represses age-associated gut hyperplasia in Drosophila via counteracting endoplasmic reticulum stress.

As they age, adult stem cells become more prone to functional decline, which is responsible for aging-associated tissue degeneration and diseases. One goal of aging research is to identify drugs that can repair age-associated tissue degeneration. Multiple organ development-related signaling pathways have recently been demonstrated to have functions in tissue homeostasis and aging process. Therefore, in this study, we tested several chemicals that are essential for organ development to assess their ability to delay intestinal stem cell (ISC) aging and promote gut function in adult Drosophila. We found that taurine, a free amino acid that supports neurological development and tissue metabolism in humans, represses ISC hyperproliferation and restrains the intestinal functional decline seen in aged animals. We found that taurine represses age-associated ISC hyperproliferation through a mechanism that eliminated endoplasmic reticulum (ER) stress by upregulation of the target genes of unfolded protein response in the ER (UPRER ) and inhibiting the c-Jun N-terminal kinase (JNK) signaling. Our findings show that taurine plays a critical role in delaying the aging process in stem cells and suggest that it may be used as a natural compound for the treatment of age-associated, or damage-induced intestinal dysfunction in humans.

Use of alternative protein sources for fishmeal replacement in the diet of largemouth bass (Micropterus salmoides). Part II: effects of supplementation with methionine or taurine on growth, feed utilization, and health.

Fishmeal has long been a staple protein feedstuff for fish, but its global shortage and high price have prompted its replacement with alternative sustainable sources. In this experiment involving largemouth bass (a carnivorous fish), a new mixture of feedstuffs (45% poultry byproduct meal, 30% soybean meal, 15% blood meal, and 10% krill shrimp meal) was added to low (14.5%) fishmeal diets along with 0.0%, 0.5% taurine, 0.5% methionine, or 0.5% taurine plus 0.5% methionine (dry matter basis). The positive control diet [65.3% fishmeal (46% crude protein on dry matter basis)] and all low-fishmeal diets contained 40% true protein and 10% lipids. There were 3 tanks per treatment group (20 fish/tank). Fish with the mean initial body weight of 16.6 g were fed to satiety twice daily. Compared with the unsupplemented low-fishmeal group, supplementing either 0.5% methionine or 0.5% methionine plus 0.5% taurine to the low-fishmeal diet improved (P < 0.05) the growth, feed utilization, retention of dietary protein and lipids, and health of largemouth bass, reduced (P < 0.05) the occurrence of black skin syndrome from ~ 40 to ~ 10%. Histological sections of tissues from the fish with black skin syndrome showed retina degeneration, liver damage, and enteritis in the intestine. Compared with methionine supplementation, supplementing 0.5% taurine alone to the low-fishmeal diet did not affect the growth or feed efficiency of fish and had less beneficial effects (P < 0.05) on ameliorating the black skin syndrome. These results indicated that: (a) the basal low-fishmeal diet was inadequate in methionine or taurine; and (b) dietary supplementation with methionine was an effective method to improve the growth performance, feed efficiency, and health of largemouth bass. Further studies are warranted to understand the pathogenesis of the black skin syndrome in largemouth bass.

Effects of long-term taurine supplementation on age-related changes in skeletal muscle function of Sprague-Dawley rats.

Taurine (2-aminoethanesulfonic acid) is a free amino acid found abundantly in mammalian tissues. Increasing evidence suggests that taurine plays a role in the maintenance of skeletal muscle function and increase of exercise capacity. Most energy drinks contain this amino acid; however, there is insufficient research on the effects of long-term, low-dose supplementation of taurine. In this study, we investigated the effects of long-term administration of taurine at low doses on aging in rodents. In Experiment 1, we examined age-related changes in aging Sprague-Dawley (SD) rats (32-92 weeks old) that O2 consumption and spontaneous activity decreased significantly with aging. In Experiment 2, we examined the effects of long-term (21-week) administration of taurine on healthy aging SD rats. SD rats were stabilized for 32-34 weeks and divided into three groups, administrated water (control), 0.5% taurine (25 mg/kg  body weight (BW)/day), or 1% taurine (50 mg/kg  BW/day) from age 34 to 56 weeks (5 days/week, 5 mL/kg BW). Our findings suggest that long-term administration of taurine at relatively low dose could attenuate the age-related decline in O2 consumption and spontaneous locomotor activity. Upon intestinal absorption, taurine might modulate age-related changes in respiratory metabolism and skeletal muscle function via peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), succinate dehydrogenase (SDH), cytochrome c (Cycs), myocyte enhancer factor 2A (MEF2A), glucose transporter 4 (GLUT4), and myoglobin, which are regulated by the activation of AMP-activated protein kinase (AMPK). This article examines the mechanism underlying the effects of taurine on age-related changes, which may have potential clinical implications.

Dietary taurine modulates hepatic oxidative status, ER stress and inflammation in juvenile turbot (Scophthalmus maximus L.) fed high carbohydrate diets.

This study was conducted to explore the beneficial role of taurine against chronic high carbohydrate diet-induced oxidative stress, endoplasmic reticulum (ER) stress and inflammation, and to understand the underlying molecular mechanisms in turbot. Two 10-week feeding trials were simultaneously conducted. For the one, six experimental diets with graded levels of taurine supplementation (0, 0.4%, 0.8%, 1.2%, 1.6% and, 2.0%, respectively) and 15% of carbohydrate were used. For the other one, three graded levels of dietary taurine supplementation (0.4%, 1.2% and 2.0%, respectively) with 21% of carbohydrate were used. The results showed that higher expression level of inflammation cytokines and ER stress related genes were detected in higher dietary carbohydrate group. In both feeding trials, 1.2% of dietary taurine supplementation improved anti-oxidative status by decreasing the content of malondialdehyde, increasing the catalase activity and total anti-oxidative capacities. In feeding trial 1, appropriate taurine supplementation lowered contents of tumour necrosis factor-a, interleukin-6, aspartate aminotransferase and alkaline phosphatase in plasma, and decreased the expressions of pro-inflammatory cytokines, such as interleukin-8 (il-8) and interferon-γ (ifn-γ). Furthermore, dietary taurine reduced ER stress by decreasing the mRNA levels of activating transcription factor 6, protein kinase R-like endoplasmic reticulum kinase and G protein-coupled receptor 78. The optimal dietary taurine content was estimated as 1.40% based on the analysis of specific growth rate. In feeding trial 2, dietary taurine supplementation attenuated liver inflammation partly referring to significantly down-regulated mRNA levels of nuclear transcription factor-κB p65, ifn-γ, interleukin1ß and up-regulate the transcript of ribosomal protein S6 kinase 1. Dietary taurine supplementation in feeding trial 2 significantly increased the Nrf2-related factor 2 protein level and decreased the NFκB p65 protein level only at 21% of dietary carbohydrate level. Taurine can alleviate the oxidative damage and inflammation caused by 21% of dietary carbohydrate to a certain degree. Overall, the present study confirmed that dietary taurine supplementation improved growth performance and anti-oxidative response, and reduced liver inflammatory and ER stress processes induced by high dietary carbohydrate in turbot.

Taurine supplementation associated with exercise increases mitochondrial activity and fatty acid oxidation gene expression in the subcutaneous white adipose tissue of obese women.

PURPOSE: To evaluate the effects of taurine supplementation associated or not with chronic exercise on body composition, mitochondrial function, and expression of genes related to mitochondrial activity and lipid oxidation in the subcutaneous white adipose tissue (scWAT) of obese women. METHODS: A randomized and double-blind trial was developed with 24 obese women (BMI 33.1 ± 2.9 kg/m2, 32.9 ± 6.3 y) randomized into three groups: Taurine supplementation group (Tau, n = 8); Exercise group (Ex, n = 8); Taurine supplementation + exercise group (TauEx, n = 8). The intervention was composed of 3 g of taurine or placebo supplementation and exercise training for eight weeks. Anthropometry, body fat composition, indirect calorimetry, scWAT biopsy for mitochondrial respiration, and gene expression related to mitochondrial activity and lipid oxidation were assessed before and after the intervention. RESULTS: No changes were observed for the anthropometric characteristics. The Ex group presented an increased resting energy expenditure rate, and the TauEx and Ex groups presented increased lipid oxidation and a decreased respiratory quotient. Both trained groups (TauEx and Ex) demonstrated improved scWAT mitochondrial respiratory capacity. Regarding mitochondrial markers, no changes were observed for the Tau group. The TauEx group had higher expression of CIDEA, PGC1a, PRDM16, UCP1, and UCP2. The genes related to fat oxidation (ACO2 and ACOX1) were increased in the Tau and Ex groups, while only the TauEx group presented increased expression of CPT1, PPARa, PPARγ, LPL, ACO1, ACO2, HSL, ACOX1, and CD36 genes. CONCLUSION: Taurine supplementation associated with exercise improved lipid metabolism through the modulation of genes related to mitochondrial activity and fatty acid oxidation, suggesting a browning effect in the scWAT of obese women.

Role of Hypotaurine in Protection against UVA-Induced Damage in Keratinocytes.

Photoageing and skin cancer are major causes of morbidity and are a high cost to society. Interest in the development of photoprotective agents for inclusion in topical cosmetic and sunscreen products is profound. Recently, amino acids with a sulfinic group, notably hypotaurine, have been included as ingredients in cosmetic preparations. However, the mechanism of action of hypotaurine as a possible anti-aging agent is unknown, despite its use as a free radical scavenger. To address this issue, we investigated hypotaurine uptake in a human keratinocyte model and examined its effect on UVR-induced cytotoxicity. Hypotaurine was taken up by keratinocytes in a time- and concentration-dependent manner, with levels remaining significantly above baseline 48 h after washout. A cytoprotective effect of pre-incubation with 2.5-5 mMhypotaurine was shown as indicated by increased cell viability when keratinocytes were irradiated with UVA at 5 or 10 Jcm-2 , with the level of hypotaurine also significantly reduced. These findings indicate a potential cytoprotective effect of hypotaurine against the deleterious effects of UVA irradiation. This provides support for further studies to evaluate the potential photoprotective benefits of hypotaurine supplementation of topical cosmetic and sunscreen products.

Impact of locking solutions on conditioning biofilm formation in tunnelled haemodialysis catheters and inflammatory response activation.

INTRODUCTION: The surface of tunnelled cuffed catheters provides an optimal environment for the development of biofilms, which have recently been described as conditioning films because of the presence of adherent biological materials. These biofilms are associated with infection and thrombosis and potentially increase patients' inflammatory response. These complications could be reduced by the use of locking solutions. OBJECTIVE: To analyse biofilm formation, using confocal and electron microscopy, in tunnelled cuffed catheters locked with three different solutions and to determine the relationship between these solutions and inflammatory response. STUDY DESIGN: This prospective study included 35 haemodialysis patients with tunnelled cuffed catheter removal for non-infection-related reasons. The participants were divided into three groups according to the lock solution used: (1) heparin 1: 5000 IU; (2) citrate 4%; and (3) taurolidine 1.35%, citrate 4% and heparin 500 IU (taurolock); in the latter group, 25,000 IU taurolidine-urokinase was used in the last weekly session. All tunnelled cuffed catheters were cultured, and the inner surface was evaluated with confocal and electron microscopy. The inflammatory profile of included patients was determined at tunnelled cuffed catheter removal. RESULTS: There were no differences in clinical or demographic variables between the three subgroups. Biofilm thickness was lower in the taurolidine group than in the citrate 4% and heparin groups (28.85 ± 6.86 vs 49.99 ± 16.56 vs 56.2 ± 15.67 µm, respectively; p < 0.001), as was biofilm volume (1.01 ±1.18 vs 3.7 ± 2.15 vs 5.55 ±2.44, µm3, respectively; p < 0.001). The mean interleukin-6 value was 39%, which was 50% lower than in the citrate and heparin groups, but without significance differences. CONCLUSION: Our results show that biofilms were found in all tunnelled cuffed catheters, but the thickness and volume were significantly lower in tunnelled cuffed catheters locked with taurolidine solution. Therefore, the type of locking solution used in tunnelled cuffed catheters should maintain tunnelled cuffed catheter sterility and prevent catheter-related bloodstream infections. No significant difference was observed in the inflammatory profile according to the type of locking solution.