Cytokinins are phytohormones that regulate plant growth, development and senescence. Experiments both in vitro and in vivo demonstrate that they can also have diverse effects on animal cells and tissues. Particularly interesting is their ability to protect cells against various forms of stress and prevent some detrimental effects of cell aging. For example, human skin fibroblasts cultured in the presence of kinetin or trans-zeatin retain some characteristics of cells of lower passage. Kinetin is even able to increase the lifespan of invertebrates. In this chapter, we review protective effects of cytokinins in animals at molecular, cellular, tissue and organismal levels. We also discuss potential application of cytokinins for the treatment of age-related diseases, including neurodegenerations, inflammatory diseases and disorders caused by aberrant cell proliferation.
