Cell & Stem Cell Research

Lithium (Li) salts have been widely used in psychiatry as mood stabilizing agents for 60 years. Li found in variable amounts in foods, especially grains, vegetables, and in some areas, the drinking water provides a significant source of the element. Therefore, dietary intake in humans depends on location, type of foods consumed, and fluid intake. Traces of Li have been detected in humanorgans and tissues, leading to speculation that the element was responsible for specific functions in the human body. It was not until the 20th century that studies performed in the 1970’s and 1990’s, primarily in rats and goats, maintained on Li-deficient diets demonstrated higher mortality, altered reproductive and behavioural abnormalities. Such deficiencies have not been detected in humans; however, studies performed on populations living in areas with low Li levels in water supplies have been associated with higher rates of suicides, homicides, and the arrests rate for drug abuse and other crimes. Li appears to play a significant role in early fetal development as evidenced by high Li levels during the early gestational period. Biochemically, the mechanism of Li action involves multi-factor and interconnected pathways with enzymes, hormones, vitamins, and growth and transforming factors. Thisody of evidence now appears sufficient to label Li as an essential element with the recommended RDA for a 70 kg adult of 1000 mg/day. Of extreme importance for the future is the growing body of evidence indicating Li can be used effectively for the treatmentof acute brain injuries, e.g., ischemia and chronic neurodegenerative dis- eases such as Alzheimer’s disease, Parkinson’s disease, Tauopathies, and Huntington’s disease. This conclusion is based upon evidence showing Li as important in neurogenesis as well as protecting neurons from neurotoxicity. Li influences stem cells, both neuronal and marrow derived, thus, the additional therapeutic implications for this element in clinical medicine to treat disorders associated with the faulty production of blood and nerve cells or as a tool to enhance blood stem cell mobilization for transplantation are needed.