Anticancer and immune effect of the extracted brown Raoultella planticola pigment on murine mammary adenocarcinoma (AMN3).

BACKGROUND

Raoultella planticola is a developing pathogen that can infect both humans and animals. Raoultella spp. commonly colonize the gastrointestinal and upper respiratory systems. It usually causes pneumonia, bile tract infections, and bacteremia.

AIM: In this study, the anticancer activity of an isolated brown pigment of a R. planticola isolate was tested in vitro.

METHODS

The laboratory examination included culturing in brain-heart infusion broth, conducting biochemical tests, using the automatic VITEK2 Compact for bacterial isolate identification, performing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to evaluate the cytotoxic effect on both the mammary cancer cell line (AMN3) and normal rat fibroblast (REF), and utilizing an enzyme-linked immunosorbent assay to measure cytokine levels.

RESULTS

Raoultella planticola was found in cow nasal swabs with respiratory problems. The extracted pigment had a significant cytotoxic effect (decreased cell viability) at doses of 2,067.5 μg/ml (p <0.0001 and 0.0001, respectively) and 1,033.5 μg/ml (p < 0.0001 and 0.003, respectively). However, the lowest dose (516.875 μg/ml, p > 0.43 and p > 0.18) could not inhibit the growth of malignant or healthy cells. The first and second highest pigment concentrations reduce Interleukin-1 beta and Tumor Necrosis Factor-alpha and increase Fas in the AMN3 cell supernatant (p < 0.05). In the AMN3 cell supernatant, the lowest concentration significantly increased IL-1β levels (p < 0.0472) and Fas levels (p < 0.0146), but did not affect TNF-α levels (p < 0.1274). Pigment concentrations at the first and second highest levels significantly reduced IL-1β and TNF-α levels in the REF cell supernatant (p < 0.05), whereas the lowest concentration did not. All pigment doses did not affect the Fas levels in the REF cell supernatant (p > 0.05).

CONCLUSION

In a concentration-dependent manner, the extracted pigment may exert cytotoxic effects and impact cytokine secretion levels in cancerous and normal cell types.