Depressive effect of a traditional Chinese medicine (sho-saiko-to) on endotoxin-induced nitric oxide formation in activated murine macrophage J774A.1 cells.

The present study investigated whether or not Sho-saiko-to (crude powder extract, TJ-9) can suppress nitric oxide (NO) generation by endotoxin-activated J774A.1 cells in order to study the preventive mechanism of Sho-saiko-to against endotoxemia. In this experiment, we estimated the NO2- in the murine macrophage cell line J774A.1 using the Griess method. Our results clearly demonstrated that J774A.1 cells stimulated with endotoxin (0.01-10 micrograms/ml) can effectively produce NO, and the production was dependent on the dose of endotoxin. On the other hand, we investigated the suppressive effect of TJ-9 (10-100 micrograms/ml) on NO generation by endotoxin (0.1 microgram/ml)-activated J774A.1 cells. The NO level when the cells were incubated with endotoxin and TJ-9 (10-20 micrograms/ml) was slightly lower than that in cells treated with endotoxin alone. In contrast, treatment with TJ-9 (50-100 micrograms/ml) significantly inhibited endotoxin-activated NO generation in J774A.1 cells, whereas the treatment with TJ-9 (10-100 micrograms/ml) alone was ineffective in inducing NO formation and in inhibiting cell viability in the J774A.1 cells. These findings suggest that a Kampo presciption of Sho-saiko-to shows a suppressive effect on NO generation in macrophages stimulated with endotoxin, and that it may be useful in improving endotoxin-shock symptoms.