Potential of Natural Products in Hangeshashinto Water Extract on the Direct Suppression of Stomatitis Induced by Intra-/Extracellular Advanced Glycation End-Products

Oral mucositis (stomatitis) is a painful condition that affects the mouth lining. Kampo medicines (e.g., Hangeshashinto [Chinese name, Ban-Xia-Xie-Xin-Tang], Orento, and Orengedokuto) have been widely used to treat stomatitis, such as gargling with Hangeshashinto. However, the mechanisms by which Kampo medicines work are not widely understood due to their oral administration and the subsequent digestion, absorption, and metabolization of their components. Stomatitis is associated with advanced glycation end-products (AGEs) in patients with lifestyle diseases, and can be induced by both intra- and extracellular AGEs (blood and dietary AGEs). Various natural products inhibit intracellular AGE generation and suppress cytotoxicity, such as inflammation caused by extracellular AGEs. This review summarizes 19 natural products identified in the Hangeshashinto water extract and 16 natural products identified in the crude drug extract. The data show that several natural products, such as glycyrrhizin, baicalin, 6-shogaol, quercetin, epigallocatechin-3-galate, and genistein, inhibit intracellular AGEs and suppress extracellular AGE inflammation. Furthermore, several natural products in the Hangeshashito water extract can suppress cytotoxicity in stomatitis.