Betaine suppresses proinflammatory signaling during aging:: The involvement of nuclear factor-κB via nuclear factor-inducing kinase/IκB kinase and mitogen-activated protein kinases

Betaine is an important human nutrient obtained from various foods. In the present study, we assessed the anti-inflammatory effect of betaine on nuclear factor-kappa B (NF-kappa B) during aging. Sprague-Dawley (SD) rats, ages 7 and 21 months, were used in this study. The older rats were fed betaine. To elucidate the effect of betaine on oxidative stress-induced NF-kappa B and its signaling pathway at molecular levels, YPEN-1 cells were used. Results showed that betaine suppressed NF-kappa B and its related gene expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), vascular cell adhesion molecule-1 (VCAM-1), and intracellular cell adhesion molecule-1 (ICAM-1) in aged kidney. Furthermore, betaine attenuated oxidative stress-induced NF-kappa B via nuclear factor-inducing kinase/I kappa B kinase (NIK/IKK) and mitogen-activated protein kinases (MAPKs) in the YPEN-1 cells. On the basis of these results, we concluded that betaine suppressed the age-related NF-kappa B activities associated with upregulated NIK/IKK and MAPKs that were induced by oxidative stress. Thus, betaine might be useful as a preventive agent against the activation of NF-kappa B induced during inflammation and aging.