In vitro and in vivo Effects of Riboflavin Sodium Phosphate on the Phagocytic Activity of Peritoneal Macrophages in Mice

Abstract

The in vitro and in vivo effects of riboflavin sodium phosphate (vitamin B2 sodium phosphate : VB2Na) on host defense mechanisms, especially macrophage function, were investigated in mice. VB2Na (100mg/kg) was injected intraperitoneally or intravenously at 1 day before the phagocytosis assay. After intraperitoneal administration, the phagocytic index of peritoneal macrophages in the control and VB2Na-treated groups was 8.3±1.6% and 34.6±6.8%, respectively, with the index being about 4-fold higher in the treated mice (p<0.01). After intravenous administration, the phagocytic index of peritoneal macrophages was 6.6±2.1% and 15.4±3.7% in control and VB2Na-treated mice, respectively, and the treated mice again showed a significantly higher index (p<0.01). Intravenous administration of VB2Na showed as effective as intraperitoneal administration. In a separate investigation of the direct effect of VB2Na on macrophage activity, we determined the in vitro phagocytic index of mouse peritoneal macrophages for latex particles in the presence of various concentrations of VB2Na. Addition of VB2Na at a concentration of more than 25μg/ml increased the phagocytic index. Thus, our results suggest that VB2Na enhances macrophage function both in vitro and in vivo.