Planta medica

Effects of hydrastine derivatives on dopamine biosynthesis in PC12 cells.

PMID 11582536


The effects of hydrastine derivatives on dopamine biosynthesis in PC12 cells were investigated. Treatments of PC12 cells with (1R,9S)-beta-hydrastine hydrochloride [(+)-beta-hydrastine HCl] and (1R,9S)-beta-hydrastine [(-)-beta-hydrastine] showed 50.6 % and 33.1 % inhibition of dopamine content at a concentration of 10 microM for 48 h. However, (1S,9R)-beta-hydrastine [(+)-beta-hydrastine] and hydrastinine hydrochloride did not reduce dopamine content. The IC(50) values of (1R,9S)-beta-hydrastine hydrochloride and (1R,9S)-beta-hydrastine were 9.3 microM and 20.7 microM , respectively. Next, the intracellular mechanisms of (1R,9S)-beta-hydrastine hydrochloride in PC12 cells were investigated. Dopamine content decreased at 6 h and reached a minimal level at 24 h after the exposure of PC12 cells to 20 microM (1R,9S)-beta-hydrastine hydrochloride. Tyrosine hydroxylase (TH) activity was inhibited at 6 h following the treatment with (1R,9S)-beta-hydrastine hydrochloride, and was maintained at a reduced level for up to 36 h in PC12 cells (17 - 27 % inhibition at 20 microM), whereas TH mRNA level was not found to alter for 24 h. However, the level of intracellular Ca++ concentration decreased by treatment with (1R,9S)-beta-hydrastine hydrochloride at 20 microM by 18.4 % inhibition relative to the control level in PC12 cells. These results suggest that (1R,9S)-beta-hydrastine hydrochloride contributes partially to the decrease in dopamine content by the inhibition of TH activity in PC12 cells.

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