Effect of total isoflavones from pueraria lobata on the expressions of preproenkephalin, prodynorphin and D2 dopamine receptor mRNA in PC12 cells induced by MPP +

Objective The aim of the study was to observe the effect of total isoflavones from pueraria lobata (TIP) on D2 dopamine receptor mRNA, preproenkephalin mRNA and prodynorphin mRNA expressions in Parkinson’s disease (PD) model cells induced by 1-methyl-4-phenylpyridinium ion (MPP + ). Methods TIP was dissolved in 0.1 M NaOH and added to the culture medium at a final concentrations of 50 mg/L, 100 mg/L and 200 mg/L. Some cells (control) were exposed to 0.001 M NaOH. TIP was added to PC12 cells 30 min prior to the administration of MPP + . TIP and MPP + remained in the culture medium for 96 h. D2 dopamine receptor mRNA, preproenkephalin mRNA and prodynorphin mRNA expressions were assayed by real-time quantitative reverse transcription-PCR. Results The D2 dopamine receptor mRNA and preproenkephalin mRNA expressions were up-regulated in MPP + group compared with the control group, and prodynorphin mRNA expression was down-regulated in that. The D2 dopamine receptor mRNA expression being down-regulated and prodynorphin mRNA expression being up-regulated in TIP group compared with the MPP + group. And there was no effect of TIP on preproenkephalin gene expression in PC12 cells induced by MPP + . Conclusion The results suggest that TIP down-regulates the D2 dopamine receptor mRNA expression, up-regulates prodynorphin mRNA expression and not affects preproenkephalin gene expression in PC12 cells induced by MPP + .