Anticancer effects of selenium compounds on human colonic carcinoma cells

Studies performed so far on different human carcinoma cell lines, as well as numerous case-control and epidemiological studies have given proof to the protective effects of selenium against cancer. However, the anticancer properties of selenium are site-specific. The aim of this work was to evaluate the cytotoxic effect of selenium against CaCo2 human colon carcinoma cells, and SW620 lymph node metastasis of colon carcinoma cell line. Three selenium compounds, seleno-DL-cystine (SeC), seleno-L-methionine (SeM) and sodium selenite were used. Initial number of cells was 210 4 and the cells were incubated for 72 h with the aforementioned Se compounds at 10, 100 and 1000 µmol Se concentrations. Cytotoxicity was measured by the MTT cell survival assay. In the present study, decreased viabilities of both CaCo2 and SW620 cells were established following the treatment with selenite, SeC, and SeM. At 10 µmol Se levels all three chemical forms exerted a more or less anticipated cytotoxic effect with viability decreases ranging from 22 to 37%. However, the other two levels of 100 and 1000 µmol Se did not exhibit an expected proportional rise in cytotoxic effect compared to 10 µmol, which warrants further research on the reasons for increased resistance of these cells. Cell morphology also indicates that investigated Se forms induced apoptotic cell death in both cell lines. The results confirm the applicability of Se in the prevention and treatment of the investigated cancer sites

Effects of dealcoholized red and white wines on human tumour and normal cells proliferation

Recent studies performed on some tumour cell lines have given proof to the antiproliferative activity of compounds isolated from red wines against tumours. The purpose of this study was to evaluate potential cytotoxic activity of different concentrations of selected Croatian red and white wines on the growth of human normal and tumour cells in vitro. Effects on growth of cervical carcinoma (HeLa), colon carcinoma (Caco-2, HT-29), poorly differentiated cells from lymph node metastasis of colon carcinoma (SW-620), larynx carcinoma cells (HEp-2) and normal fibroblasts (WI38) were tested by MTT-assay. Radioactive substrate incorporation tests were used for assessing effects on DNA, RNAs and proteins syntheses. Concentration of polyphenols in wines was assessed according to the method of Singleton and Rossi. Ethanol in the wine concentrates was determined by MS-GC method. Results of the cytotoxicity test showed that colon carcinoma cells (Caco-2, HT-29), as well as colon carcinoma metastasis (SW620) were the most affected by dealcoholized red wines in concentrations 25% and 12.5% v/v. Amount of total phenols in the red wines was significantly higher (5-10 times) compared to the white wines. The red wine with the greatest polyphenol content was shown to be the most effective. Red wine samples in concentration 25% v/v statistically significantly inhibited the growth of all tested cell lines, including fibroblasts. Tested white wines showed no or negligible growth inhibitory effect against tumour and normal cells. Tumour cells, HeLa and Hep-2, treated by red wine V3 (12.5% v/v) and Hep-2 cells treated by red wine V4 (12.5% v/v) exhibited slightly growth-stimulatory effects. Biosynthesis assay of DNA, RNA and proteins indicated a standstill in the growth of treated cells. Our results indicate that polyphenol-rich domestic wine might have potential pro-therapeutic effect on transformed colonic cells