Tilia cordata Mill. Extracts and scopoletin (isolated compound): differential cell growth effects on lymphocytes.

Aqueous extracts or infusions obtained from the flowers of Tilia species are widely used for the treatment of anxiety in folk medicine. In this work, the antiproliferative action of aqueous, dichloromethane and ethanol extracts obtained from Tilia cordata Mill. flowers on tumoral (BW 5147 lymphoma) and normal lymphocytes is described. Both extracts showed a selective action on tumoral cells, inducing apoptosis. In the case of normal T cells these extracts suppressed mitogen-induced proliferation without affecting viability, suggesting a suppressive but not cytotoxic effect. These effects were clearly concentration dependent. A coumarin (scopoletin), the main component in the dichloromethane extract presented antiproliferative action on BW 5147 cells, suggesting that it may be at least partly responsible for the activity displayed by this extract.