Effect of Purified Violacein from Chromobacterium Violaceum Strains on Cancer Cells

Rehab Ahmed Alsofayan, Tennessee State University


According to the American Cancer Society, cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells. If the spread is not controlled, it can result in death. Due to this fact, the demand for a therapy increased. Chromobacterium violaceum (CV) is a bacterium that produces a purple color pigment called violacein. According to some studies in the past, this purple pigment violacein is capable of killing or inhibiting the growth of cancer cells. Also, it has been shown to have antibacterial, anti-protozoal, and anti-parasite activity. Further, violacein has not been considered cytotoxic on normal cells. Based on these studies, it was hypothesized that violacein would be beneficial to combat cancer cells. The goal of this research is to determine if Violacein produced by strains of CV (14N23 and 14N1) isolated from the Tennessee Copper Basin and 12472 obtained from ATCC have anticancer activity. Plus, the goal was to compare the results of this study, which used purified violacein with the results of crude extract violacein on growth of cancer cell. Three different violacein extract corresponding to 14N23, 14N1, and 12472 strains of Chromobacterium violaceum were purified to be used and re-suspended in DMSO at different molarities. Three different cancer cell lines, BT20, SW620, and HeLa treated with the pure violacein extracts to study its effects on these cells. The AlamarBlue® Cell Viability Assay Protocol and fluorescent analysis were used to evaluate the growth analysis of the extracts. The study revealed significant differences in the activity of these violacein extracts on SW620 cancer cell line (colon cancer), BT20 cancer cell line (breast cancer), and HeLa cancer cell line (cervical cancer). Violacein 14N1 was found to significantly reduce colon cancer growth at highest three concentrations treatment, 14N23 reduced the same at the highest two concentrations, while the effects of 12472 on this cancer cell line was insignificant. 14N1 showed significant effect on breast cancer cell on the highest four concentrations, 14N23 at the highest three concentrations, while 12472 did not show any significant effect. However, 14N1 and 14N23 reduced viability of colon cancer more than it did breast cancer at the highest concentration treatments; 14N1 and 14N23 reduced the colon cancer viability by over 80%, but the breast cancer by 55% and 70%. The anticancer effect of these extracts of violacein was even more pronounced on cervical cancer than the other two cancer cell lines. This study also compared the effects of these pure extracts violacein with their crude extracts reported in Mehta’s study. The results showed that the pure violacein extracts were more effective on cancer than crude extracts. In conclusion, further studies will seek to understand how violacein from these strains exert their anticancer activity. In addition, future studies should seek to assess the anticancer activity of violacein on other cancer cell lines, such as the throat cancer, cancer of the liver, prostate cancer and others.

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Recommended Citation

Rehab Ahmed Alsofayan, "Effect of Purified Violacein from Chromobacterium Violaceum Strains on Cancer Cells" (2017). ETD Collection for Tennessee State University. Paper AAI10243069.