Protection of Taurine Against Arsenic-Induced DNA Damage of Mice Kidneys

The Protective Effects of Taurine, a Non-essential Amino Acid, Against Metals Toxicities: A Review Article

Taurine is a non-proteinogenic amino acid derived from cysteine. It is involved in several phenomena such as the regulation of growth and differentiation, osmoregulation, neurohormonal modulation, and lipid metabolism. Taurine is important because of its high levels in several tissues such as the central nervous system (CNS), heart, skeletal muscles, retinal membranes, and platelets. In this report, we present the functional properties of taurine indicating that it has potential effects on various metal toxicities. Therefore, a comprehensive literature review was performed using the Scopus, PubMed, and Web of Science databases. According to the search keywords, 61 articles were included in the study. The results indicate that taurine protects tissues against metal toxicity through enhancement of enzymatic and non-enzymatic antioxidant capacity, modulation of oxidative stress, anti-inflammatory and anti-apoptotic effects, involvement in different molecular pathways, and interference with the activity of various enzymes. Taken together, taurine is a natural supplement that presents antitoxic effects against many types of compounds, especially metals, suggesting public consumption of this amino acid as a prophylactic agent against the incidence of metal toxicity.

Taurine Alleviates Cadmium-Induced Hepatotoxicity by Regulating Autophagy Flux

Our previous studies have confirmed that cadmium (Cd) exposure causes hepatotoxicity; it also induces autophagy and blocks the autophagy flux. Therefore, we hypothesized that Cd hepatotoxicity could be alleviated through nutritional intervention. Taurine (Tau) has various biological functions such as acting as an antioxidant, acting as an anti-inflammatory, and stabilizing cell membranes. In order to explore the protective effect and internal mechanism of Tau on Cd-induced hepatotoxicity, normal rat liver cell line BRL3A cells were treated with Cd alone or in combination with Tau to detect cell injury and autophagy-related indexes in this study. We found that Tau can alleviate Cd-induced cell-proliferation decline and morphological changes in the cell. In addition, Tau activates autophagy and alleviates the blockage of Cd-induced autophagy flux. In this process, lysosome acidification and degradation were enhanced, and autophagosomes were further fused with lysosomes. Then, we found that Tau alleviated autophagic flux block by promoting the transfer of membrane fusion proteins STX17 and SNAP29 to autophagosomes and the translocation of VAMP8 to lysosomes, which in turn attenuated the hepatocyte injury induced by Cd exposure. This will further reveal the hepatotoxicity mechanism of Cd and provide the theoretical basis for the prevention and treatment of Cd poisoning.

A review of mechanisms underlying the protective effects of natural compounds against arsenic-induced neurotoxicity

Arsenic (As) is a toxic metalloid that is widely distributed in the earth's crust. People are continuously exposed to this toxicant in their food and drinking water. Inorganic arsenic occurs in two oxidation states, arsenite 3⁺ (iAs³⁺) and arsenate 5⁺ (iAs⁵⁺). The most toxic form is its trivalent form which interferes with the electron transfer cycle and induces overproduction of reactive oxygen species, leading to depletion of the antioxidant defense system, as well as altering fatty acid levels and mitochondrial action. Since arsenic crosses the blood-brain barrier, it can damage cells in different regions of the brain, causing neurological disorders through the induction of oxidative stress, inflammation, DNA damage, and cell death. Hydroxytyrosol, taurine, alpha-lipoic acid, ellagic acid, and thymoquinone have been shown to effectively alleviate arsenic-induced neurotoxicity. The protective effects are the result of the anti-oxidative and anti-inflammatory properties of the phytochemicals and in particular their anti-apoptotic function via the Nrf2 and PI3/Akt/SIRT1 signaling pathways.

Taurine as a Natural Antioxidant: From Direct Antioxidant Effects to Protective Action in Various Toxicological Models

Natural antioxidants have received tremendous attention over the last 3 decades. At the same time, the attitude to free radicals is slowly changing, and their signalling role in adaptation to stress has recently received a lot of attention. Among many different antioxidants in the body, taurine (Tau), a sulphur-containing non-proteinogenic β-amino acid, is shown to have a special place as an important natural modulator of the antioxidant defence networks. Indeed, Tau is synthesised in most mammals and birds, and the Tau requirement is met by both synthesis and food/feed supply. From the analysis of recent data, it could be concluded that the direct antioxidant effect of Tau due to scavenging free radicals is limited and could be expected only in a few mammalian/avian tissues (e.g., heart and eye) with comparatively high (>15-20 mM) Tau concentrations. The stabilising effects of Tau on mitochondria, a prime site of free radical formation, are characterised and deserve more attention. Tau deficiency has been shown to compromise the electron transport chain in mitochondria and significantly increase free radical production. It seems likely that by maintaining the optimal Tau status of mitochondria, it is possible to control free radical production. Tau's antioxidant protective action is of great importance in various stress conditions in human life, and is related to commercial animal and poultry production. In various in vitro and in vivo toxicological models, Tau showed AO protective effects. The membrane-stabilizing effects, inhibiting effects on ROS-producing enzymes, as well as the indirect AO effects of Tau via redox balance maintenance associated with the modulation of various transcription factors (e.g., Nrf2 and NF-κB) and vitagenes could also contribute to its protective action in stress conditions, and thus deserve more attention.

Effects of maternal taurine supplementation on maternal dietary intake, plasma metabolites and fetal growth and development in cafeteria diet fed rats

BACKGROUND

Maternal obesity may disrupt the developmental process of the fetus during gestation in rats. Recent evidence suggests that taurine can exert protective role against detrimental influence of obesogenic diets. This study aimed to examine the effect of maternal cafeteria diet and/or taurine supplementation on maternal dietary intake, plasma metabolites, fetal growth and development.

METHODS

Female Wistar rats were fed a control diet (CON), CON supplemented with 1.5% taurine in drinking water (CONT), cafeteria diet (CAF) or CAF supplemented with taurine (CAFT) from weaning. After 8 weeks all animals were mated and maintained on the same diets during pregnancy and lactation.

RESULTS

Dietary intakes were significantly different between the groups. Both CAF and CAFT fed dams consumed less water in comparison to CON and CONT dams. Taurine supplementation only increased plasma taurine concentrations in CONT group. Maternal plasma adiponectin concentrations increased in CAF and CAFT fed dams compared to CON and CONT fed dams and there was no effect of taurine. Hyperleptinemia was observed in CAF fed dams but not in CAFT fed dams. Malondialdehyde was significantly increased only in CAF fed dams. Litter size, sex ratio and birth weight were similar between the groups. There was an increase in neonatal mortality in CONT group.

DISCUSSION

This study showed that maternal taurine supplementation exerted modest protective effects on cafeteria diet induced maternal obesity. The increased neonatal mortality in CONT neonates indicates possible detrimental effects of taurine supplementation in the setting of normal pregnancy. Therefore, future studies should investigate the optimal dose of taurine supplementation and long term potential effects on the offspring.

Ameliorative effect of taurine against diabetes and renal-associated disorders (Review)

To develop novel therapeutic methods for both diabetic and renal disorders, scientists had initially focused on elucidating the molecular mechanisms of taurine in established cell lines and mouse models. Although a large amount of data have been revealed, taurine has been confirmed to be the next step of novel promising therapeutic interventions against diabetic disorders. Taurine appears to ameliorate diabetes 1-related complications in various organs through its antioxidant, anti-inflammatory and anti-hormonal actions. In type 2 diabetes, taurine has been positively implicated in glucose homeostasis, exerting potent hypoglycemic, anti-obesity, hypotensive and hypolipidemic effects. Of particular interest is that taurine provides protection against renal dysfunction, including hypertension and proteinuria, specific glomerular and tubular disorders, acute and chronic renal conditions, and diabetic nephropathy. The ameliorative effects of taurine against renal disorders are based on its osmoregulatory properties, its association with signaling pathways and its association with the renin-angiotensin-aldosterone system (RAAS). Further clinical studies are required to ensure the importance of research findings.