Enhanced expression of inducible nitric oxide synthase by Juzen-taiho-to in LPS-activated RAW264.7 cells, a murine macrophage cell line.

We have investigated the effect of Juzen-taiho-to (TJ-48) on inducible NO synthase (iNOS) expression and nitric oxide (NO) production in RAW264.7 cells, a murine macrophage cell line. TJ-48-lipopolysaccharide (LPS) combination induced iNOS mRNA expression earlier, stronger and remained longer that paralleled but with a higher NO production compared to LPS stimulation. TJ-48 itself showed no inducible effect either on NO production or iNOS mRNA expression. This phenomenon could be considered to contribute, at least in part, to the beneficial effects of TJ-48 through the iNOS-mediated activation of biodefense mechanism.