Aims: Bacterial pigments are promising compounds in the prevention and treatment of various cancers. In the current study, the antioxidant, cytotoxic, and antimicrobial effects of a red pigment obtained from a marine bacterial strain were investigated. Methods and results: Optimization of the pigment production by the marine strain was conducted using the one-factor-at-a-time approach. Chemical identification of the pigment was achieved by UV-visible, FTIR and HPLC analyses. The biological activities of the pigment were evaluated by DPPH, MTT, and microbroth dilution assays. The strain was identified as Arthrobacter, and its pigment was related to carotenoids. The EC50 antioxidant activity of the pigment was evaluated as 4.5 mg/ml. It showed moderate anti-cancer effects on an esophageal cancer cell line, KYSE30, while no inhibition was observed on normal HDF cells. The pigment had no anti-bacterial effects on the four tested strains. Conclusion: The anti-tumor activity of a carotenoid related pigment from Arthrobacter sp. was reported for the first time. Significance and impact of the study: Marine environments are interesting sources for the identification of novel bioproducts. The identification of carotenoid pigments from marine bacteria with remarkable antioxidant and anti-cancer activities would result in better insights into the potential pharmaceutical applications of carotenoids and marine environments.

Keywords