Production of IL-8 primarily promotes angiogenic responses in cancer cells, which lead to favorable disease progression. Suppressing this production may, therefore, be a significant therapeutic intervention in targeting tumor angiogenesis. This study aimed to evaluate the reduction effects of xanthones in cancer cell lines. Nine known prenylated xanthones (1–9), isolated from the pericarp of Garcinia mangostana Linn (GML), were tested for their ability to suppress IL-8 (interleukin-8) of the SP-C1 (Supri's Clone 1) tongue cancer cell line. Of these compounds, 8-hydroxycudraxanthone-G (4) suppressed IL-8 within 48 hours. This is the first report of 8-hydroxycudraxanthone G suppressing the production of IL-8 (45% at 15.7 μg/mL in 48 hours). These results suggest that the prolonged suppression of IL-8 production by cancer cell lines is concerned in the anti-cancer activity of 8-hydroxycudraxanthone.
