132374.fig.002a
(a)
132374.fig.002b
(b)
132374.fig.002c
(c)
132374.fig.002d
(d)
Figure 2: Log concentration-inhibition curves of S-petasin and its reference drugs on phosphodiesterase 3 (PDE3) and PDE4 activities. S-Petasin (a, b), milrinone, a selective PDE3 inhibitor (c), and Ro 20-1724, a selective PDE4 inhibitor (d) concentration-dependently inhibited PDE3 (a, c) and PDE4 (b, d) activities. Each value represents the mean ± SEM (n = 4–8).