Anti‐tumor effect of Japanese herbal medicine Ninjinto in mouse melanoma: Efficacy of preventive treatment

Abstract

Aim:We evaluated the anti-tumor effect of the Japanese herbal medicine Ninjinto in a mouse melanoma. Methods: In in vitro experiments, B16F1 melanoma cells were cultured alone or in the presence of Ninjinto. Cell count, viability, concentration of interleukin (IL)-4 and 6, interferon (IFN)-γ in the medium, IL-6 messenger RNA level in cells, and morphological changes were assessed. In vivo, approximately 5 × 10 5 B16F1 cells in 50 μL phosphate-buffered saline were injected s.c. into the flank of C57BL/6 mice that had received plain drinking water or water containing 4 mg/mL of Ninjinto for 1 month. Tumor volume was measured using digital calipers. The presence of immune cells and expression of CD4, Foxp3, and IFN-γ at the site of the tumor were investigated on immunohistochemistry.