Genotoxic and antigenotoxic effects of catechin and tannins from the bark of Hamamelis virginiana L. in metabolically competent, human hepatoma cells (HepG2) using single cell electrophoresis - Dauer,A.; Hensel,A.; Lhoste,F.; Knasmueller,S.; Mersch-Sundermann,V. (Phytochemistry, 2003)