Cytotoxic Effect of Prodigiosin, Natural Red Pigment, Isolated from Serratia marcescens UFPEDA 398

Prodigiosin is a secondary metabolite, with red pigmentation, produced by Serratia marcescens. Red pigment is a natural alkaloid whose chemical structure has three pyrrole rings. Prodigiosin has been described for several biological activities, including antitumor, inducing apotosis in T and B lymphocytes. This work aimed to evaluate the cytotoxic activity of prodigiosin in NCHI-292, HEp-2, MCF-7 and HL-60 tumor cell lines. The red pigment was isolated from Serratia marcescens UFPEDA 398 biomass whose fractions were previously separated by column chromatography, purified, identified and further characterized by GC-MS and compared with the computerized library of m/z values. The pigment corresponded to prodigiosin with maximum absorption at 534 nm, molecular weight 323 and structural formula C₂₀H₂₅N₃O. During the prodigiosin purification process a purple absorbance fraction at 272.65 nm was also observed. Significant cytotoxic effects of prodigiosin were evidenced for NCHI-292, Hep-2, MCF-7 and HL-60 tumor cell lines. The isolated purple fraction had no cytotoxic effect (IC₅₀ 11.3 µg/mL) when compared to prodigiosin (IC₅₀ 3.4 µg/mL) for the tumor cell lines studied. The MCF-7 strain was slightly more pigment resistant (IC₅₀ 5.1 µg/mL). Therefore, further studies will be needed to elucidate the antitumor mechanisms of prodigiosin action against tumor strains from flow cytometry tests. However, although these data are preliminary, it was evidenced that prodigiosin showed cytotoxic activity in tumor cell lines suggesting promising antitumor properties. In this sense, future studies on the cytotoxic and genotoxic effects of prodigiosin produced by S. marcecsens UFPEDA 398 are suggested.