Characterization of Urinary N-Acetyltaurine as a Biomarker of Hyperacetatemia in Mice

Acetate is an important metabolite in metabolic fluxes. Its presence in biological entities originates from both exogenous inputs and endogenous metabolism. Because the change in blood acetate level has been associated with both beneficial and adverse health outcomes, blood acetate analysis has been used to monitor the systemic status of acetate turnover. The present study examined the use of urinary N-acetyltaurine (NAT) as a marker to reflect the hyperacetatemic status of mice from exogenous inputs and endogenous metabolism, including triacetin dosing, ethanol dosing, and streptozotocin-induced diabetes. The results showed that triacetin dosing increased serum acetate and urinary NAT but not other N-acetylated amino acids in urine. The co-occurrences of increased serum acetate and elevated urinary NAT were also observed in both ethanol dosing and streptozotocin-induced diabetes. Furthermore, the renal cortex was determined as an active site for NAT synthesis. Overall, urinary NAT behaved as an effective marker of hyperacetatemia in three experimental mouse models, warranting further investigation into its application in humans.

Taurine reduces the risk for metabolic syndrome: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Metabolic syndrome (MetS) is a cluster of interconnected risk factors that significantly increase the likelihood of cardiovascular disease and type 2 diabetes. Taurine has emerged as a potential therapeutic agent for MetS. This meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the effects of taurine supplementation on MetS-related parameters.

METHODS

We conducted electronic searches through databases like Embase, PubMed, Web of Science, Cochrane CENTRAL, and ClinicalTrials.gov, encompassing publications up to December 1, 2023. Our analysis focused on established MetS diagnostic criteria, including systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C). Meta-regression explored potential dose-dependent relationships based on the total taurine dose administered during the treatment period. We also assessed secondary outcomes like body composition, lipid profile, and glycemic control.

RESULTS

Our analysis included 1024 participants from 25 RCTs. The daily dosage of taurine in the studies ranged from 0.5 g/day to 6 g/day, with follow-up periods varying between 5 and 365 days. Compared to control groups, taurine supplementation demonstrated statistically significant reductions in SBP (weighted mean difference [WMD] = -3.999 mmHg, 95% confidence interval [CI] = -7.293 to -0.706, p = 0.017), DBP (WMD = -1.509 mmHg, 95% CI = -2.479 to -0.539, p = 0.002), FBG (WMD: -5.882 mg/dL, 95% CI: -10.747 to -1.018, p = 0.018), TG (WMD: -18.315 mg/dL, 95% CI: -25.628 to -11.002, p < 0.001), but not in HDL-C (WMD: 0.644 mg/dl, 95% CI: -0.244 to 1.532, p = 0.155). Meta-regression analysis revealed a dose-dependent reduction in DBP (coefficient = -0.0108 mmHg per g, p = 0.0297) and FBG (coefficient = -0.0445 mg/dL per g, p = 0.0273). No significant adverse effects were observed compared to the control group.

CONCLUSION

Taurine supplementation exhibits positive effects on multiple MetS-related factors, making it a potential dietary addition for individuals at risk of or already experiencing MetS. Future research may explore dose-optimization strategies and potential long-term benefits of taurine for MetS management.

Taurine mitigates the development of pulmonary inflammation, oxidative stress, and histopathological alterations in a rat model of bile duct ligation

Lung injury is a significant complication associated with cholestasis/cirrhosis. This problem significantly increases the risk of cirrhosis-related morbidity and mortality. Hence, finding effective therapeutic options in this field has significant clinical value. Severe inflammation and oxidative stress are involved in the mechanism of cirrhosis-induced lung injury. Taurine (TAU) is an abundant amino acid with substantial anti-inflammatory and antioxidative properties. The current study was designed to evaluate the role of TAU in cholestasis-related lung injury. For this purpose, bile duct ligated (BDL) rats were treated with TAU (0.5 and 1% w: v in drinking water). Significant increases in the broncho-alveolar lavage fluid (BALF) level of inflammatory cells (lymphocytes, neutrophils, basophils, monocytes, and eosinophils), increased IgG, and TNF-α were detected in the BDL animals (14 and 28 days after the BDL surgery). Alveolar congestion, hemorrhage, and fibrosis were the dominant pulmonary histopathological changes in the BDL group. Significant increases in the pulmonary tissue biomarkers of oxidative stress, including reactive oxygen species formation, lipid peroxidation, increased oxidized glutathione levels, and decreased reduced glutathione, were also detected in the BDL rats. Moreover, significant myeloperoxidase activity and nitric oxide levels were seen in the lung of BDL rats. It was found that TAU significantly blunted inflammation, alleviated oxidative stress, and mitigated lung histopathological changes in BDL animals. These data suggest TAU as a potential protective agent against cholestasis/cirrhosis-related lung injury.

Profiling inflammatory and oxidative stress biomarkers following taurine supplementation: a systematic review and dose-response meta-analysis of controlled trials

Taurine (Tau) has modulatory effects on inflammatory and oxidative stress biomarkers; however, the results of clinical studies are not comprehensive enough to determine the effect of different durations and doses of Tau supplementation on inflammatory and oxidative stress biomarkers. The current study was conducted based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. For this purpose, PubMed/Medline, Scopus, and Embase databases were systematically searched to obtain the relevant studies published before 30th March 2021. Meta-analysis was performed on controlled clinical trials by using the random-effects method. Non-linear relationship between variables and effect size was performed using dose-response and time-response analyses. The Cochrane Collaboration's tool was used to evaluate the quality of included studies. Tau supplementation can reduce the levels of malondialdehyde (MDA) (SMD = -1.17 µmol/l; 95% CI: -2.08, - 0.26; P = 0.012) and C-reactive protein (CRP) (SMD = -1.95 mg/l; 95% CI: -3.20, - 0.71; P = 0.002). There have been no significant effects of Tau supplementation on the levels of tumor necrosis factors-alpha (TNF-α) (SMD = -0.18 pg/ml; 95% CI: -0.56, 0.21; P = 0.368), and interleukin-6 (IL-6) (SMD = -0.49 pg/ml; 95% CI: -1.13, 0.16; P = 0.141). Besides, Tau has more alleviating effect on oxidative stress and inflammation on 56 days after supplementation (P < 0.05). Tau can decrease the levels of CRP and MDA. Based on the currently available evidence, Tau has no significant effect on the level of TNF-α and IL-6. Eight-week of Tau supplementation has more beneficial effects on inflammatory and oxidative stress biomarkers.

Oyster broth concentrate and its major component taurine alleviate acute alcohol‐induced liver damage

Our previous study showed that oyster hydrolysate (OH) protected against the liver damage caused by a single instance of ethanol (EtOH) binge drinking. Oyster broth concentrate (OBC) was discovered in the process of searching for a different substance derived from oysters (Crassostrea gigas) with economic value. OBC is a by‐product of boiling oysters at 95°C for 3 min. In this study, we investigated the effects of OBC and its major component taurine on blood and liver tissues obtained from a single‐EtOH‐binge‐drinking mouse model. The preadministration of OBC enhanced EtOH metabolism by increasing the activities of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and catalase. In addition, the preadministration of OBC reduced cytochrome P450 2E1 (CYP2E1) activity, reactive oxygen species (ROS) generation, Ca²⁺ concentrations, apoptotic signals, and inflammatory mediators in liver tissues. The reduction of apoptotic and inflammatory signals by OBC resulted from the downregulation of endoplasmic reticulum (ER) stress molecules and NF‐κB activity. Taurine administration showed similar effects to OBC. These results show that OBC protected against acute EtOH‐induced liver damage through the action of taurine. Our findings suggest that OBC could be an economically valuable substance and a functional food with hepatoprotective effects.

Taurine Inhibits Kupffer Cells Activation Induced by Lipopolysaccharide in Alcoholic Liver Damaged Rats

Taurine, a β free amino-acid, takes various biological functions including maintain the normal hepatic structure and function. In this study, the regulation mechanism of taurine on lipopolysaccharide (LPS) induced activation of Kupffer cells (KC) in the liver of rats with alcoholic liver disease (ALD) were explored. Male wistar rats were intragastrically administered with alcohol and pyrazole, and ate high-fat diet in order to establish ALD model. Taurine were administered in drinking water simultaneous with and after ALD model establishment. The preventive trial was lasted for 12 weeks, while the curative trial was lasted for 4 weeks. Finally, blood and liver were collected in order to detect the concentrations of plasma LPS and hepatic tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Hepatic total RNA were extracted, gene expressions of LPS binding protein (LBP), leukocyte differentiation antigen 14 (CD14), toll-like receptors (TLR4), nuclear transcription factor (NF-κB) and TNF-α were detected by semi-quantitative RT-PCR. The results showed significant elevated levels of plasma LPS, hepatic TNF-α, IL-1β and IL-6 in ALD rats (P < 0.05), and heightened gene expressions of LBP, CD14, TLR4, NF-κB and TNF-α (P < 0.05); Taurine no matter administered preventively or curatively can reduce the levels of plasma LPS, hepatic TNF-α, IL-1β, IL-6, and down-regulate the gene expressions of LBP, CD14, TLR4, NF-κB and TNF-α. The results demonstrated that taurine can prevent and cure ALD by reducing the production and transformation of LPS as well as inhibiting the opening and the transmission of LPS induced KC activation and the downstream signaling pathway.

Ameliorative effects of pepsin-digested chicken liver hydrolysates on development of alcoholic fatty livers in mice

With developments in economics and increasing work loads, alcohol abuse becomes more and more severe, leading to occurrences of alcoholic liver disease (ALD).

Protective effects of Cholestin on ethanol induced oxidative stress in rats

BACKGROUND

Male Wistar rats were divided into seven groups as follows: group A, basal diet; group B, basal diet with Cholestin at 0.1667 g kg⁻¹ body weight (BW); groups C-F, oral feeding of ethanol at 7.9 g kg⁻¹ BW; groups D-F, Cholestin in diet at 0.1667, 0.3333 and 0.5 g kg⁻¹ BW respectively; group G, silymarin in diet at 200 mg kg⁻¹ BW.

RESULTS

The results showed that treatment with Cholestin for 8 weeks reduced the impact of ethanol toxicity on serum markers of liver damage: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). The antioxidant system was significantly enhanced: plasma and hepatic thiobarbituric acid-reactive substance (TBARS) levels were lowered while hepatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), ethanol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities and non-enzymatic antioxidants (vitamin E, vitamin C and GSH) were elevated.

CONCLUSION

Cholestin shows a protective effect against hepatotoxicity indices in ethanol-fed rats comparable to that of silymarin, as supported by the evaluation of liver histopathology. The data suggest that Cholestin exerts its hepatoprotective effect by decreasing lipid peroxidation and improving antioxidants status, thus proving itself as an effective antioxidant in ethanol-induced oxidative damage in rats.