The Effect of Oral Administration of L-Tyrosine, Folic acid and Pyridoxine on Perphenazine Induced Catatonia in Rat

L-tyrosine, B6 and folic acid are involved in biosynthesis of DOPA and consequently dopamine. The aim of this study was to investigate the antiparkinsonian effect of these agents in perphenazine-induced catatonia in rats. Murprogo method or scored muscular rigidity, which is induced by a phenothiazine, was used to evaluate the antiparkinsonian effect of these agents. A significant decrease in muscular rigidity was observed in groups that received L-tyrosine. However, groups which had received vitamin(s) only showed no significant decrease in muscular rigidity as compared with the control group. On the other hand, the group receiving folic acid plus L-tyrosine showed a lower degree of muscular rigidity in comparison with the other groups. In conclusion, L-tyrosine has been found to be effective in improving perphenazine-induced muscular rigidity. Furthermore, when used in combination with folic acid, L-tyrosine could be found advantageous in the early stages of Parkinson’s disease.