5-Sulfosalicylic acid, a sulfonated salicylic acid derivative, is effective against breast cancer cell lines with less toxicity [1] and possesses antioxidant activities [2].

5-Sulfosalicylic acid, at concentrations ranging from 0.5 to 4 mM over 24 hours, reduces the viability of MCF-7 cells according to a cell cytotoxicity assay. Using MCF-7 and HUVEC cell lines, the treatment at 1 mM led to viabilities of 63.3% and 70.4% in MCF-7 and HUVEC control cells, respectively.