Combination Index (CI) values of the interaction between Nos with Dox against human MDA-MB-231 and MDA-MB-468 TNBC cells.

The human lung cancer cell lines MDA-MB-231 and MDA-MB-468 breast cancer cells were obtained from American Type Culture Collection (Rockville, MD). Different concentrations of Nos were employed to study the effect on IC50 of Dox. Variable ratios of drug concentrations and mutually non-exclusive equations were used to determine the CI. The CI values represent mean of four experiments. CI>1.3: antagonism; CI 1.1–1.3: moderate antagonism; CI 0.9–1.1: additive effect; CI 0.8–0.9: slight synergism; CI 0.6–0.8: moderate synergism; CI 0.4–0.6: synergism; CI 0.2–0.4: strong synergism.