First, taurine is a proven anti-inflammatory agent that neutralizes the neutrophil oxidant, hypochlorous acid. One of the primary mechanisms of taurine cytoprotection appears to involve its antioxidant activity, which is mediated by three distinct events. Recent studies have uncovered novel mechanisms responsible for taurine-mediated cytoprotection ( Table 1). The present review discusses the mechanisms underlying the cytoprotective activity of taurine, the influence of taurine on a wide range of diseases and the nutritional value of taurine supplementation. Thus, the cytoprotective actions of taurine contribute to an improvement in the clinical and nutritional health of humans. Taurine supplementation is also linked to diminished body mass index ( Yamori et al., 2010) and reduced levels of inflammation markers in obese women ( Rosa et al., 2014). Particularly noteworthy is a World Health Association study involving 50 population groups in 25 different countries throughout the world, which reports that elevated dietary taurine consumption is associated with decreased risk of hypertension and hypercholesterolemia ( Yamori et al., 2004 Sagara et al., 2015). Nonetheless, human studies have revealed the nutritional value of taurine.

Thus, unlike cats, humans do not readily develop overt signs of taurine deficiency although parenteral feeding can be associated with taurine deficiency ( Arrieta et al., 2014). Although humans are incapable of synthesizing large amounts of taurine, the retention of taurine by human tissues is greater than that of cats or fox. By contrast, taurine is classified as a conditionally essential nutrient or a functional nutrient in man ( Gaull, 1986, 1989 Bouckenooghe et al., 2006). Not only does taurine deficiency cause pathology in those animals but it also shortens their lifespan ( Ito et al., 2014a Park et al., 2014). In some species, such as the cat and fox, taurine is an essential nutrient ( Schmidt et al., 1976 Novotny et al., 1991 Ito et al., 2008 Ripps and Shen, 2012). Equally promising are studies showing the nutritional value of taurine ( McCarty, 2013). Results of many clinical studies have been encouraging, suggesting a promising future for taurine therapy ( Ginguay et al., 2016). Although most of those studies have focused on taurine-mediated reversal of pathology in animals, there have been attempts to translate the basic science findings into clinical applications. It also has stimulated research into its potential therapeutic uses. These findings have provided impetus for the use of taurine in infant formula, nutritional supplements and energy drinks.

Because taurine regulates fundamental events in the cell, while altering the balance between life and death, interest in taurine’s physiological functions has grown. Although taurine possesses many functions in mammals, its cytoprotective actions have attracted the most attention, as they dramatically alter the health and nutritional status of various species. Taurine is a β-amino acid found in very high concentration in most cells, with levels particularly high in excitable tissues. 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. 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 present review summarizes studies supporting a role of taurine in the treatment of diseases of muscle, the central nervous system, and the cardiovascular system. 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 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. These findings have spurred interest in the potential use of taurine as a therapeutic agent. 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. Taurine is an abundant, β-amino acid with diverse cytoprotective activity.

Taurine benefits