Ginkgolic
acids may induce malignant cell death via the
B-cell lymphoma 2 (Bcl-2)-associated X
protein (Bax)/Bcl-2 apoptosis pathway. Concurrently, apoptosis, autophagy and
mitochondrial dysfunction may also be involved in bringing about this endpoint. The anticancer effect of Ginkgolic
acids (GAs) was investigated using the HepG2 cell line. The median lethal dose of the GAs of the HepG2 was measured via an MTT assay, the dose-response curves were evaluated and changes in cell morphology were monitored by microscopy. Autophagy in HepG2 cells was down regulated using
3-methyladenine (3-MA) or Beclin-1-specific
small interfering RNA (
siRNA) and the expression of apoptosis associated
proteins caspase-3, Bax/Bcl-2, and the autophagy-associated
protein 5 and
microtubule-associated protein 1A/1B-light chain 3 in the GA-treated HepG2 cells were all measured by western blot analysis. The level of apoptosis in the GA-treated cells was also assessed using
terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling (TUNEL) assay, and the mitochondrial membrane potential (Δψm) was detected by immunofluorescence. The results of the MTT and TUNEL assays indicated that the proliferation of HepG2 cells treated with GAs was significantly reduced compared with the control group, and the rate of the inhibition was dose-dependent. Western blot analysis indicated that treatment with the Gas induced apoptosis and autophagy in the HepG2 cells. The Δψm of the GA-treated HepG2 cells was decreased compared with the control, as monitored by immunofluorescence. However, upon the administration of 3-MA or Beclin-1-specific siRNAs (inhibitors of the autophagy), the expression levels of the apoptosis- and autophagy-associated
proteins were decreased. In conclusion, the results of the present study indicated that GAs are potent
anticancer agents that function through a combination of the apoptosis, autophagy and mitochondrial pathways.