517 Background: The cause of chemotherapy-induced oral mucositis (COM) is thought to be direct injury and indirect stomatotoxic effects that result from the release of inflammatory mediators, loss of protective salivary constituents, and therapy-induced neutropenia. We previously found that gargling with hangeshashinto (HST), a traditional Japanese medicine, was effective for treatment of COM. Focusing on the pain and inflammation of COM, we reported at ASCO-GI 2013 and DDW 2013 that HST exhibited ameliorating effects in a hamster model of COM and multi-targeted effects on prostaglandin E2 (PGE2) production, followed by identification of active ingredients by PGE2 culture systems and LC-MS/MS. Our aim in this study was to address whether HST affects protective oral constituents. Methods: Human oral keratinocytes (HOK) and human salivary gland (HSG) cells were used for cell culture assays. Expression levels of mRNAs for antimicrobial peptides, extracellular matrixes, keratinocyte growth factor, amylase, COX-1/COX-2, and cNOS/iNOS in cells with or without HST (10–300 μg/mL) treatment were measured by RT-PCR. Results: HST increased gene expressions of some antimicrobial peptides (defensin β1, adrenomedullin, cathelicidin antimicrobial peptide), and amylase 1A in HSG cells. Further, HST dramatically inhibited COX-2 and iNOS mRNAs in IL-1β treated HOK cells, while it exerted no or little effect on expressions of any protective oral constituents in non-treated HOK cells. A random test to identify the ingredients that increase defensin β1 revealed that isoquinoline alkaloids like berberine were active. Conclusions: HST is expected to maintain oral homeostasis through two paths: increased production of antimicrobial peptides and decreased oral damage induced by excessive prostanoids and nitric oxide. HST thus functions as a multitarget agent, indicating that it may be beneficial in COM treatment.