Epigallocatechin gallate stimulated histamine production and downregulated histamine H1 receptor in oral cancer cell lines expressing histidine decarboxylase.

Objectives: Increased histamine production and the overexpression of receptors (H1R∼H4R) has been reported in several tumors. The effects of TGFβ1 and epigallocatechin gallate (EGCG) on histamine synthesizing enzymes (HDCs), and the histamine transporter systems and receptors were investigated in this study.

Methods: Four oral cancer cell lines (HSC2, HSC3, HSC4, and SAS) were treated with or without TGFβ1 or EGCG for 24 h.