Effect of MPP
and EGCG on PGC-1α and SIRT1 protein expression in PC12 cells. (A) vehicle-only control, (B) MPP+ alone, MPP+ 500 μmol/L, (C) EGCG alone, 10 μmol/L EGCG, (D) 10 μmol/L EGCG + 500 μmol/L MPP+ (treatment with EGCG for 30 min, followed by MPP+ treatment). Results show that EGCG pretreatment could enhance PGC-1α and SIRT1 protein expression, and this up-regulation was higher than respective treatments with MPP+ and EGCG alone. β-actin was used as an internal reference. *P < 0.05 vs. vehicle-only control.