CASP9 and Parkinson disease: The PD flies exposed to 10, 20, 30 and 40 μM of kaempferol showed a dose dependent significant decrease of 1.18 1.33, 1.60 and 1.77 folds, respectively, in the activity of caspase-9 compared to the PD flies (Fig. 3a; p < 0.05).