Hangeshashinto (TJ-14) prevents radiation-induced mucositis by suppressing cyclooxygenase-2 expression and chemotaxis of inflammatory cells

Purpose Radiation-induced oral mucositis is the most common side effect of radiotherapy in head and neck cancer; however, effective modalities for its prevention have not been established. In this study, we evaluated the effectiveness of Hangeshashinto (TJ-14), a Japanese herbal medicine, for preventing radiation-induced mucositis and elucidated its effect on inflammatory responses, including inflammatory cell chemotaxis and cyclooxygenase-2 (COX2) expression, in an animal model. Methods Syrian hamsters, 8-9 weeks old, were enrolled in this study. Animals were irradiated with a single 40 Gy dose to the buccal mucosa. Hamsters freely received a treatment diet mixed with 2% TJ-14 or a normal diet daily. The therapeutic effect was determined based on the visual mucositis score, body weight, and histological examination of infiltrated neutrophils and COX2 expression. Results TJ-14 significantly reduced the severity of mucositis. The percentage with severe mucositis (score >= 3) was 100% in the untreated group and 16.7% in the TJ-14 group (P < 0.05). There was no difference in body weight change between the groups; however, weight gain in the untreated group tended to be suppressed compared to that in the TJ-14 group during the peak period of mucositis. In addition, TJ-14 inhibited the infiltration of neutrophils and COX2 expression in irradiated mucosa (P < 0.05). Conclusions TJ-14 reduced the severity of mucositis in an animal model by suppressing the inflammatory response. Because TJ-14 is inexpensive and its safety is established, it is a promising candidate for the standard treatment of radiation-induced mucositis in cancer patients.