At equimolar concentrations, D-lactic acid dimer is more cytotoxic than L-lactic acid when directly applied to human HeLa cells in culture. The cytotoxicity of D-lactic acid dimer is an independent effect exclusive of the lower pH when applied to cancer cells in culture. At equimolar concentrations, D-lactic acid dimer is less cytotoxic than L-lactic acid when applied to normal human fibroblasts in culture. D-lactic acid dimer is cytotoxic when applied to human retinoblastoma cells in culture in a dose-dependent fashion. The experimental data supports the cytotoxic mechanism of D-lactic acid dimer via the Warburg effect.
