We investigated the effect of lignin F, isolated from the alkaline extract of the cone of Pinus parviflora Sieb. et Zucc, on the cytotoxic activity and radical intensity (measured by ESR spectroscopy) of various natural products. Lignin F slightly inhibited the proliferation of human oral tumor cell
Hydrolyzable tannins showed higher cytotoxic activity against human oral squamous cell carcinoma and salivary gland tumor cell lines than against normal human gingival fibroblasts, whereas gallic acid, a component unit of tannins, showed much weaker selective cytotoxicity. The cytotoxic activity of