Inhibitory effect of the rhizomes of Alpinia officinarum on TPA-induced inflammation and tumor promotion in two-stage carcinogenesis in mouse skin.

The methanol extract of galangal (the rhizomes of Alpinia officinarum L.) exhibited remarkable antitumor-promoting activity on an in vivo two-stage carcinogenesis test of mice using 7,12-dimethylbenz[a]anthracene as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter. Seven diarylheptanoids (1-7) were isolated and identified from the active fraction of the methanol extracts of the galangal. These compounds, 1-7, were evaluated for their inhibitory effects on TPA-induced inflammation (1 microg/ear) in mice. These compounds (1-7) tested showed marked anti-inflammatory effects, with a 50% inhibitory dose of 0.8-2.7 micromol/ear.