Chamomile is a widely used medicinal plant and, as observed in our previous studies, also accumulates some metals in its above-ground biomass. We therefore tested selected metabolic responses after treatments with 60 and 120 mu M Al for 7 days. Shoot Al content was not elevated in comparison with control (12.3-14.1 mu g g(-1) DW) while total root Al increased strongly, reaching 2680 and 4400 mu g g(-1) DW in 60 and 120 mu M treatments, respectively. "Intra-root" Al represented 83.6(60 mu M treatment) and 75.8% (120 mu M treatment) of total root Al. Soluble proteins were not significantly affected. Free amino acids were almost unaffected in shoots while in roots the highest content was found in 60 mu M Al. Ascorbate- and guaiacol-peroxidase activities were the highest in 60 mu M Al-exposed roots. On the other hand, phenylalanine ammonia-lyase activity, total soluble phenols, flavonoids, a sum of 13 phenolic acids and partially two flavonols (quercetin and kaempferol) increased in the shoots. Present study has shown lower Al toxicity and unaltered shoot Al content seems to be the most positive outcome in comparison with previously tested metals (Cd, Ni and Cu). Our results indicate that phenols in shoots and free amino acids in roots are influenced by Al excess in chamomile plants. Possible mechanisms in the context of available literature are suggested and discussed. (C) 2010 Elsevier B.V. All rights reserved.