Synthesis and anti-cancer activity of benzothiazole containing phthalimide on human carcinoma cell lines.

Phthalic anhydride is a highly toxic substance, facing, however, the problem of hydrolysis. In fact, it is rapidly hydrolyzed in aqueous medium, generating phthalic acid as the final product, which is almost harmless to viable cells. Here we describe the 'one pot' condensation reaction for the synthesis of phthalic imide derivative (benzothiazole containing phthalimide), exhibiting in vitro cytotoxic potential on human cancer cell lines. We further demonstrated that both caspase-dependent and -independent pathways are involved in our novel benzothiazole containing phthalimide induced apoptosis on cancer cells.

Paradoxical proliferative potential of iron (II) sulphate on cancer cells after the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay.

There are several scientific approaches for the determination of cellular growth influences of known or novel substances under in vitro conditions, among which colourimetric absorption measurement is considered to be one of the convenient methods. [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) assay is one of the commonly used colourimetric absorption assays based on the ability of dehydrogenase from viable cells to produce the brown soluble formazan detectable at 490 nm. Here we have tested the possible growth influence of iron (II) sulphate on two human cancer cell lines, the K562 chronic myelogenous leukaemia and T47D breast carcinoma cells, based on the MTS assay. We found that iron (II) sulphate possessed an inhibitory effect when added at 16- to 125-microM concentrations, but iron (II) sulphate became growth stimulatory when its concentration was further increased to 1000 microM. In addition, a dose-dependent increase in absorbance at the same wavelength was observed when we repeated the experiments without the addition of MTS and phenazine methosulfate. When we further repeated the cell growth determinations using adenosine triphosphate content assay for K562 and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for T47D, iron (II) sulphate showed a consistent dose-dependent growth inhibitory effect. Morphological investigation after methylene blue staining clearly demonstrated that iron (II) sulphate, at a concentration of 1000 microM, is cytotoxic to T47D cells. Interestingly, a consistent increment for the absorbance at 490 nm was further observed with increased iron (II) sulphate concentration either in the presence or absence of MTS even in a cell-free environment. Thus we conclude that iron (II) sulphate is actually growth inhibitory and even cytotoxic at high concentrations towards the K562 and T47D cancer cells and the paradoxical proliferative activity of iron (II) sulphate on these two cancer cell lines using the MTS assay was solely due to the oxidation of initial pale green iron (II) to brownish iron (III) during incubation in the aqueous condition.

Synthesis and structure evaluation of a novel cantharimide and its cytotoxicity on SK-Hep-1 hepatoma cells.

A remarkable control of the potency of cantharimide is described based on the electronic properties of functional group and it exhibits a relatively less toxic effect to the non-malignant hematological disorder bone marrow cells.