This study explored whether sulforaphane changed basal [Ca(superscript 2+)](subscript i) levels in suspended Madin-Darby canine kidney (MDCK) cells by using fura-2 as a Ca(superscript 2+)-sensitive fluorescent dye. Sulforaphane at concentrations between 2.5-10μM increased [Ca(superscript 2+)](subscript i) in a concentration-dependent manner. This Ca(superscript 2+) influx was inhibited by phospholipase A2 inhibitor aristolochic acid but not by Ca(superscript 2+) channel blockers such as nifedipine, nimodipine, nicardipine, diltiazem, verapamil, econazole and SK&F96365. The Ca(superscript 2+) signal was abolished by removing extracellular Ca(superscript 2+). In Ca(superscript 2+)-free medium, pretreatment with sulforaphane did not alter the endoplasmic reticulum Ca(superscript 2+) pump inhibitor thapsigargin-induced Ca(superscript 2+) release suggesting sulforaphane did not induce slow Ca(superscript 2+) release from endoplasmic reticulum. At concentrations between 1 and 20μM, sulforaphane induced concentration-dependent decrease in cell viability which was not affected by pre-chelation of cytosolic Ca(superscript 2+) with BAPTA/AM. Flow cytometry data suggest that 20 (but not 5 and 10)μM sulforaphane induced significant increase in sub G1 phase indicating involvement of apoptosis. Collectively, in MDCK cells, sulforaphane induced [Ca(superscript 2+)](subscript i) rises by causing Ca(superscript 2+) entry through phospholipase A2-sensitive pathways without inducing Ca(superscript 2+) release from the endoplasmic reticulum. Sulforaphane also induced Ca(superscript 2+)-independent cell death that might involve apoptosis.