Figure 4.

Astragaloside IV (AS-IV) decreases the hydrogen peroxide (H₂O₂) -induced increase in the Bax/Bcl-2 ratio, decreases the expression of α-synuclein (α-syn) and increases the expression of tyrosine hydroxylase (TH) in SH-SY5Y cells. The expression of Bax and Bcl-2 was determined by western blot analysis. (A) Bax/Bcl-2 ratio following exposure to H₂O₂ and pre-treatment with 50–200 µmol/l of AS-IV. (B) Western blot nalysis and (C) a double immunofluorescence assay showing the expression of α-syn and TH in SH-SY5Y cells exposed to H₂O₂. The data are the means ± SEM (n=3). ^**P<0.01 vs. control (untreated cells); ^##P<0.05 vs. H₂O₂ (300 µmol/l).