Immune cells actively participate to the central nervous system (CNS) injury either damaging or protecting neural tissue with release of various mediators. Residential microglia and monocyte-derived macrophages play a fundamental role within the injured CNS and, here, special emphasis will be placed on M1 and M2 macrophages for their different functional activities. On the other hand, peripheral T regulatory (Treg) cells exert antiinflammatory activities in the diseased host. In this respect, activation of Treg cells by nutraceuticals may represent a novel approach to treat neuroinflammation. Omega-3 fatty acids and polyphenols will be described as substances endowed with antioxidant and anti-inflammatory activities. However, taking into account that Treg cells act in the later phase of CNS injury, favoring immune suppression, manipulation of host immune system with both substances requires caution to avoid undesired side effects.