title: Enantio-selective inhibition of (1R,9S)- and (1S,9R)-beta-hydrastines on dopamine biosynthesis in PC12 cells.
abstract: The inhibitory effects of (1R,9S)- and (1S,9R)-enantiomers of beta-hydrastine (BHS) on dopamine biosynthesis in PC12 cells were investigated. (1R,9S)-BHS decreased the intracellular dopamine content with the IC50 value of 14.3 microM at 24 h, but (1S,9R)-BHS did not. (1R,9S)-BHS was not cytotoxic at concentrations up to 250 microM towards PC12 cells. In these conditions, (1R,9S)-BHS inhibited tyrosine hydroxylase (TH) activity mainly in a concentration-dependent manner (33% inhibition at 20 microM) and decreased TH mRNA level in PC12 cells. The inhibitory patterns of dopamine content and TH activity by (1R,9S)-BHS showed similar behavioral curves. (1R,9S)-BHS at 10-50 microM also reduced the intracellular cyclic AMP level and Ca2+ concentration. In addition, treatment of L-DOPA at 20-50 microM for 24 h increased the intracellular dopamine content to 198-251% compared with the control in PC12 cells. However, the increase in dopamine levels induced by L-DOPA (20-50 microM) was reduced when L-DOPA was combined with (1R,9S)-BHS (10-50 microM). These results indicate that (1R,9S)-BHS, but not (1S,9R)-BHS, reduced dopamine content and L-DOPA-induced increase in dopamine content, in part, through the inhibition of TH activity and TH gene expression in PC12 cells: thus, (1R,9S)-BHS proved to have a function to regulate dopamine biosynthesis.
authors.affiliation: College of Pharmacy, and Research Center for Bioresource and Health, Chungbuk National University, San 48, Gaeshin-Dong, Heungduk-Gu, Cheongju 361-763, South Korea.
authors.forename: Shou Yu
authors.initials: SY
authors.lastname: Yin
authors.forename: Yu Mi
authors.initials: YM
authors.lastname: Kim
authors.forename: Jae Joon
authors.initials: JJ
authors.lastname: Lee
authors.forename: Chun Mei
authors.initials: CM
authors.lastname: Jin
authors.forename: Yoo Jung
authors.initials: YJ
authors.lastname: Yang
authors.forename: Jing Jie
authors.initials: JJ
authors.lastname: Ma
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Kang
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kai
authors.forename: Myung Koo
authors.initials: MK
authors.lastname: Lee
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000378:metabolism; D044182:Benzylisoquinolines; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis* / Q000378:metabolism; D015259:Dopamine Agents / Q000494:pharmacology; D007980:Levodopa / Q000494:pharmacology; D016716:PC12 Cells; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D013237:Stereoisomerism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D000470:Alkaloids; D044182:Benzylisoquinolines; D015259:Dopamine Agents; D012333:RNA, Messenger; D007980:Levodopa; C013024:hydrastine; D000242:Cyclic AMP; D014446:Tyrosine 3-Monooxygenase; D001142:Aromatic-L-Amino-Acid Decarboxylases; D002118:Calcium; D004298:Dopamine