Impact of plant extracts tested in attention-deficit/hyperactivity disorder treatment on cell survival and energy metabolism in human neuroblastoma SH-SY5Y cells.

Plant extracts such as Hypericum perforatum and Pycnogenol (R) have been tested as alternatives to the classical ADHD drugs. It has been possible to describe neuroprotective effects of such plant extracts. A reduction of ADHD symptoms could be shown in clinical studies after the application of Pycnogenol (R), which is a pine bark extract. The impacts of the standardized herbal extracts Hypericum perforatum, Pycnogenol (R) and Enzogenol (R) up to a concentration of 5000 ng/mL on cell survival and energy metabolism in human SH-SY5Y neuroblastoma cells has been investigated in the present examination. Hypericum perforatum significantly decreased the survival of cells after treatment with a concentration of 5000 ng/mL, whereas lower concentrations exerted no significant effects. Pycnogenol (R) induced a significant increase of cell survival after incubation with a concentration of 32.25 ng/mL and a concentration of 250 ng/mL. Other applied concentrations of Pycnogenol (R) failed to exert significant effects. Treatment with Enzogenol (R) did not lead to significant changes in cell survival. Concerning energy metabolism, the treatment of cells with a concentration of 5000 ng/mL Hypericum perforatum led to a significant increase of ATP levels, whereas treatment with a concentration of 500 ng/mL had no significant effect. Incubation of cells with Pycnogenol (R) and Enzogenol (R) exerted no significant effects. None of the tested substances caused any cytotoxic effect when used in therapeutically relevant concentrations. Copyright (c) 2010 John Wiley & Sons, Ltd.