Synthesis and cytotoxic activity of certain benzothiazole derivatives against human MCF-7 cancer cell line.

A new series of benzothiazole has been synthesized as cytotoxic agents. The new derivatives were tested for their cytotoxic activity toward the human breast cancer MCF-7 cell line against cisplatin as the reference drug. Many derivatives revealed good cytotoxic effect, whereas four of them, 4, 5c, 5d, and 6b, were more potent than cisplatin, with IC values being 8.64, 7.39, 7.56, and 5.15 μm compared to 13.33 μm of cisplatin. The four derivatives' cytotoxic activity was accompanied by regulating free radicals production, by increasing the activity of superoxide dismutase and depletion of intracellular reduced glutathione, catalase, and glutathione peroxidase activities, accordingly, the high production of hydrogen peroxide, nitric oxide, and other free radicals causing tumor cell death as monitored by reduction in the synthesis of protein and nucleic acids. Most of the tested compounds showed potent to moderate growth inhibitory activity; in particular, compound 6b exhibited the highest activity suggesting it is a lead compound in cytotoxic activity.