Growth inhibitory effect of paradicsompaprika in cancer cell lines.

We investigated whether components of paradicsompaprika have direct antitumor effects or inhibitory effects on cancer growth, using its water extract. We applied collagen gel droplet embedded culture drug sensitivity test (CD-DST) as a screening method, which was developed based on the characteristics of cell culture on collagen matrix. Colon adenocarcinoma cells, epithelial cells of lung cancer, and cervical cancer cells were used. Paradicsompaprika is classified as Capsiucum annume L. var. grossum of Solanaceae. It is the first of the Hungarian species that was planted in Japan. It is available as TOMA-P in Japan. TOMA-P contains abundant carotenoids including capsanthin and beta-carotene. Water extract of paradicsompaprika was added to each cell at each concentration, and the mixture was cultured for 24 h and 7 days. The inhibitory effects against lung cancer and cervical cancer were observed concentration- and time-dependently. The effect was more prominent against lung cancer. The growth of bowel cancer cells was observed after the 7-day exposure of paradicsompaprika at the concentrations below the highest concentration compared to the control. At the highest concentration, the growth inhibition was not different between the 24-h exposure and the 7-day exposure, which suggests that tumor dormancy was induced. Results of the present study suggest that the water extract of paradicsompaprika can be a candidate of a new anticancer agent. Fat soluble component of paradicsompaprika, capsanthin is regarded as an anti-promoter of cancer. Thus, paradicsompaprika possesses chemopreventive and inhibitory effects on cancer cells.

Prediction of cell kill kinetics of anticancer agents using the collagen gel droplet embedded-culture drug sensitivity test.

A vital component of chemotherapy is selecting effective anticancer agents for the patient and determining an appropriate dose and administration regimen. Prediction of the drug sensitivity of each patient and cell kill kinetics of the drug may improve the outcome of treatment and avoid unnecessary dosing of the drug. For this reason, the development and clinical application of anticancer drug sensitivity tests and cell kill kinetics tests which successfully reflect clinical outcomes are required. In the present study, we tried to establish a cell kill kinetics test through the use of new anticancer agents: paclitaxel, docetaxel, SN-38, vinorelbine, and gemcitabine. These agents were studied at concentrations close to their clinical doses using a collagen gel droplet embedded-culture drug sensitivity test (CD-DST). It is thought that the mechanism, by which the anticancer agents used in this study exert their effects is dependent on the cell cycle; however, the cell kill kinetics of these agents at clinical concentrations has not yet been clarified in vitro. We investigated the drug sensitivity and cell kill kinetics of these new anticancer agents against a human colon cancer strain. Results of this study suggest that the test method established by us can predict drug sensitivity and cell kill kinetics of the agents, and can be a useful tool in deciding appropriate treatment regimen for individual patients.