Vitamin D (VD3) antioxidative and anti-inflammatory activities: Peripheral and central effects

Abstract

Vitamin D (VD3, cholecalciferol), besides its role on bone calcium homeostasis, has also been shown to present anti-inflammatory actions. The objectives of the present work were to further extend these findings, focusing onVD3action mechanisms at the molecular level and onits central and peripheral effects. For that, VD3 antinociceptive and mainly anti-inflammatory activities were evaluated by acute models of nociception (formalin test) and inflammation (carrageenan-induced paw edema), in mice pretreated orally for 7 days with VD3 (0.5 and 1.0 mg/kg). Afterwards, the edematous paws were evaluated by immunohistochemical assays for TNF-alpha. In addition, brains from mice pretreated with VD3, at the same conditions, were harvested for iNOS andCOX-2 immunohistochemical (IHC) assays. The anti-inflammatory effect of VD3 on human neutrophil degranulation was evaluated by the release of myeloperoxidase (MPO) activity, as well as by the reactive oxygen species production. VD3 significantly reduced the licking time in the formalin test, at the second phase (inflammatory pain). VD3 also reduced the edema volume and the number of polymorphonuclear (PMN) cells, as well as the TNF-alpha expression in the edematous paws, compared with the control group. Furthermore, VD3 significantly decreased iNOS and COX-2 expressions in brain areas, such as hippocampus and prefrontal cortex, and inhibited the degranulation of activated neutrophils by the reduction of ROS production and MPO release. Based in these results, VD3 presents anti-inflammatory and antioxidative effects, manifested at peripheral and central sites as showed in the present work for the first time.

Keywords: Anti-inflammatory effect; Antioxidant effect; COX-2; TNF-Alpha; Vitamin D3 (cholecalciferol); iNOS.