The anticancer effects of α-
santalol, a major component of
sandalwood oil, have been reported against the development of certain
cancers such as
skin cancer both in vitro and in vivo. The primary objectives of the current study were to investigate the
cancer preventive properties of α-
santalol on human
prostate cancer cells PC-3 (
androgen independent and P-53 null) and LNCaP (
androgen dependent and P-53 wild-type), and determine the possible mechanisms of its action. The effect of α-
santalol on cell viability was determined by
trypan blue dye exclusion assay. Apoptosis induction was confirmed by analysis of cytoplasmic
histone-associated DNA fragmentation using both an apoptotic ELISA kit and a
DAPI fluorescence assay.
Caspase-3 activity was determined using
caspase-3 (active) ELISA kit. PARP cleavage was analyzed using immunoblotting. α-
Santalol at 25-75 μM decreased cell viability in both cell lines in a concentration and time dependent manner. Treatment of
prostate cancer cells with α-
santalol resulted in induction of apoptosis as evidenced by DNA fragmentation and nuclear staining of apoptotic cells by
DAPI. α-
Santalol treatment also resulted in activation of
caspase-3 activity and PARP cleavage. The α-
santalol-induced apoptotic cell death and activation of
caspase-3 was significantly attenuated in the presence of pharmacological inhibitors of
caspase-8 and
caspase-9. In conclusion, the present study reveals the apoptotic effects of α-
santalol in inhibiting the growth of human
prostate cancer cells.