Cytotoxic potential of a pigment from Serratia marcescens against HepG2 and Jurkat cell lines and optimization of culture conditions for enhanced pigment production

Abstract

Background: Pigment from micro-organism is one of the emerging areas of research and many pigments have been
extensively studied for their therapeutic potential. Methodology: Our aim was to analyze the anticancer property of a
red pigment extracted from Serratia marcescens JGI 27against HepG2 and Jurkat cell lines. The cell viability was
evaluated by MTT assay. As the red pigment extracted from S. marcescens exhibited high cytotoxicity to the tested
cancer cell lines, the pigment production was optimized under various culture conditions like, temperature shock,
incubation time, carbon sources, nitrogen sources and metal ions. Pigment yield was analyzed spectrophotometrically
at 487 nm. Results: The IC50 value of the red pigment was calculated around < 20μg/mL concentration. The
percentage viability of lymphocytes and CHO was found to be negligible at all the selected concentration even after
72 hrs of incubation. When the bacterial culture was kept at 37°C for 48 hrs and then 50°C for 48 hrs, the yield of the
pigment was found to be highest. Supplimentation of sucrose (1%), beef extract (1%) and Fecl30. 01% resulted in
enhanced pigment production from S. marcescens JGI 27. Supplementation with the metal ions with at concentration
resulted in highest pigment production. Conclusion: It is concluded that red pigment from S. marcescens JGI 27 was
found to have a promising cyotoxic effect against HepG2 and Jurkat cell lines and it is non-toxic to normal peripheral
human lymphocytes and CHO cell lines. At optimum physical and cultural parameters the pigment production was
found to be highest.