Beneficial effects of taurine on serum lipids in overweight or obese non-diabetic subjects.
Amino Acids. 2004 Jun;26(3):267-71. Epub 2003 Dec 15.
Zhang M, Bi LF, Fang JH, Su XL, Da GL, Kuwamori T, Kagamimori S.
Taurine has beneficial effects on lipid metabolism in experimental animals fed with high-cholesterol or high fat diets. Whether taurine benefits lipid metabolism in humans has rarely been investigated. The aim of this study was to evaluate the effects of taurine on serum lipids in overweight or obese young adults. Thirty college students (age: 20.3+/-1.7 years) with a body mass index (BMI) >/=25.0 kg/m(2), and with no evidence of diabetes mellitus were selected and assigned to either the taurine group (n=15) or the placebo group (n=15) by double-blind randomization. Taurine 3 g/day or placebo was taken orally for 7 weeks. Triacylglycerol (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and plasma glucose were measured before and after supplementation. The atherogenic index (AI) was calculated as (TC-HDL-C)/HDL-C. There were no differences in any baseline parameter between the two groups. Taurine supplementation decreased TG and AI significantly. Body weight also reduced significantly in the taurine group. These results suggest that taurine produces a beneficial effect on lipid metabolism and may have an important role in cardiovascular disease prevention in overweight or obese subjects.
The role of taurine in the central nervous system and the modulation of intracellular calcium homeostasis.
Foos TM, Wu JY.
Department of Molecular Biosciences, University of Kansas, Lawrence 66045, USA.
The effects of taurine in the mammalian nervous system are numerous and varied. There has been great difficulty in determining the specific targets of taurine action. The authors present a review of accepted taurine action and highlight recent discoveries regarding taurine and calcium homeostasis in neurons. In general there is a consensus that taurine is a powerful agent in regulating and reducing the intracellular calcium levels in neurons. After prolonged L-glutamate stimulation, neurons lose the ability to effectively regulate intracellular calcium. This condition can lead to acute swelling and lysis of the cell, or culminate in apoptosis. Under these conditions, significant amounts of taurine (mM range) are released from the excited neuron. This extracellular taurine acts to slow the influx of calcium into the cytosol through both transmembrane ion transporters and intracellular storage pools. Two specific targets of taurine action are discussed: Na(+)-Ca2+ exchangers, and metabotropic receptors mediating phospholipase-C.
Taurine induces anti-anxiety by activating strychnine-sensitive glycine receptor in vivo.
Zhang CG, Kim SJ.
Department of Pharmacology and Metabolic Diseases Research Laboratory, School of Dentistry, Kyung Hee University, Seoul, Korea.
Taurine has a variety of actions in the body such as cardiotonic, host-defensive, radioprotective and glucose-regulatory effects. However, its action in the central nervous system remains to be characterized. In the present study, we tested to see whether taurine exerts anti-anxiety effects and to explore its mechanism of anti-anxiety activity in vivo. The staircase test and elevated plus maze test were performed to test the anti-anxiety action of taurine. Convulsions induced by strychnine, picrotoxin, yohimbine and isoniazid were tested to explore the mechanism of anti-anxiety activity of taurine. The Rotarod test was performed to test muscle relaxant activity and the passive avoidance test was carried out to test memory activity in response to taurine. Taurine (200 mg/kg, p.o.) significantly reduced rearing numbers in the staircase test while it increased the time spent in the open arms as well as the number of entries to the open arms in the elevated plus maze test, suggesting that it has a significant anti-anxiety activity. Taurine's action could be due to its binding to and activating of strychnine-sensitive glycine receptor in vivo as it inhibited convulsion caused by strychnine; however, it has little effect on picrotoxin-induced convulsion, suggesting its anti-anxiety activity may not be linked to GABA receptor. It did not alter memory function and muscle activity. Taken together, these results suggest that taurine could be beneficial for the control of anxiety in the clinical situations.
Antioxidant role and subcellular location of hypotaurine and taurine in human neutrophils.
Green TR, Fellman JH, Eicher AL, Pratt KL.
Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland 97207.
The subcellular location of taurine, and its precursor, hypotaurine, within human neutrophils has been examined by nitrogen cavitation, Percoll-gradient centrifugation and HPLC analysis. Hypotaurine and taurine were found to reside within the cytosolic compartment of the cell. The ratio of taurine to hypotaurine is approx 50:1. The cytosolic concentration of taurine is approx. 50 mM. The concentration of hypotaurine decreased by 80% when resting neutrophils were converted into actively respiring cells by exposure to opsonized zymosan. These results prompted in vitro studies on the antioxidant properties of hypotaurine. We demonstrate by EPR spectroscopy that hypotaurine competes with 5,5'-dimethyl-1-pyrroline N-oxide) (DMPO) for hydroxyl radicals, and that it is the sulfinyl group which confers hydroxyl radical scavenging activity to it. Following its exposure to hydroxyl radicals, two oxidation products were isolated by HPLC, one of which has been identified as taurine. The biological roles of hypotaurine and taurine in the neutrophil are discussed with respect to their antioxidant properties and subcellular location within the cell.
Therapeutic applications of taurine.
Thorne Research, Inc., Dover, ID 83825, USA.
Taurine is a conditionally-essential amino acid which is not utilized in protein synthesis, but rather is found free or in simple peptides. Taurine has been shown to be essential in certain aspects of mammalian development, and in vitro studies in various species have demonstrated that low levels of taurine are associated with various pathological lesions, including cardiomyopathy, retinal degeneration, and growth retardation, especially if deficiency occurs during development. Metabolic actions of taurine include: bile acid conjugation, detoxification, membrane stabilization, osmoregulation, and modulation of cellular calcium levels. Clinically, taurine has been used with varying degrees of success in the treatment of a wide variety of conditions, including: cardiovascular diseases, hypercholesterolemia, epilepsy and other seizure disorders, macular degeneration, Alzheimer's disease, hepatic disorders, alcoholism, and cystic fibrosis.