Compared with the CTRL group, the GSH level was downregulated in the SN of PD rats, whereas EGCG increased the GSH level; moreover, EGCG did not decrease the GSH level in the SN of PD rats when CID755673 was used to inhibit the PKD1 expression and Ad-PARP-1 was used to activate the Parthanatos (Figure 4a). Here, PARP1 is linked to Parkinson disease.