Salvianolic Acid-A Induces Apoptosis, Mitochondrial Membrane Potential Loss and DNA Damage in Small Cell Lung Cancer Cell Lines

Purpose: To examine the anticancer effect of salvianolic acid-A against human small cell lung cancer (SCLC) cells (H-69).
Methods: In vitro antiproliferative effect of salvianolic acid against SCLC cell lines was evaluated by 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis induction by salvianolic acid-A in these cells was measured by videomicroscopy along with fluorescence microscopy using Hoechst 33258 staining. The effect of the compound on mitochondrial membrane potential loss was detected by flow cytometry using rhodamine-123 as fluorescent probe. Gel electrophoresis was used to analyze DNA fragmentation after salvianolic acid treatment.
Results: The results revealed that salvianolic acid-A induces dose-dependent as well as timedependent growth inhibitory effects against SCLC cancer cells. Videomicroscopy analysis revealed that SCLC cells became rounded (dead) and refringent after drug treatment which increased with increase in salvianolic acid-A dose. Fluorescence microscopy demonstrated that salvianolic acid-A induced dosedependent chromatin condensation in SCLC cells which is characteristic of apoptosis. DNA fragmentation was induced by various doses of the compound again hinting at apoptosis. Flow cytometry analysis using rhodamine-123 showed that salvianolic acid-A also caused substantial loss of mitochondrial membrane potential.
Conclusion: The results suggest that salvianolic acid-A is a potential anticancer and apoptotic agent against drug-resistant small cell lung cancer.

Keywords
Lung cancer; Apoptosis; Salvianolic acid-A; Flow cytometry; Anticancer activity; Videomicroscopy; Fluorescence microscopy; Mitochondrial membrane potential; Rhodamine-123