The Concomitant Effect of Shikonin and Glutathione Peroxidase-1 on Enhanced Survival of Dopaminergic Neurons against Parkinsonian Toxicity

the aim of this study was to examine the effect of glutathione peroxidase-1 (GPX-1) and shikonin on enhanced survival of dopaminergic neurons PC12 against parkinsonian toxicity. in order to overexpress GPX-1 in PC12 neurons, recombinant lentiviruses carrying both GPX-1 and reporter GFP genes were generated and used to infect target cells. The survival rate of the transduced neurons in the presence or absence of shikonin was then quantified. following GFP gene expression observed under the fluorescent microscope, the overexpression of GPX-1 was determined using the RT-PCR analysis. Changes in cell survival against parkinsonian toxicity were examined in the presence of two factors: GPX-1 overexpression and shikonin treatment. The results indicated that both GPX-1 overexpression and shikonin treatment of the PC12 cells increased significantly cell survival against parkinsonian toxicity. Survival increased by 14% after GPX-1 overexpression and by 11% following shikonin treatment. More importantly, when the two factors were applied simultaneously (by shikonin treatment of GPX-1-overexpressing cells) they saved 83% of the neuronal cells that was up by 29%. This increase of survival rate was significant compared to the increase achieved by each factor alone. our data showed that GPX-1 gene overexpression and shikonin treatment not only individually increase PC12 cell survival against oxidative stress caused by the parkinonian toxin 6-OHDA, but also will function additively and/ or synergistically if they are applied together.