Hassan, Elsayed S. EShafaa, Medhat WFaraag, Ahmed H. IEssawy, Ehab Bakkar, Ashraf AAL‑Megrin, Wafa AEl‑Khadragy, Manal FAbdelfattah, Mohamed SAbdel Moneim, Ahmed E2022-07-072022-07-072022-06-30https://doi.org/10.1007/s11356-022-21678-whttps://bit.ly/3yNxsBCProdigiosins have been shown to have anticancer activities. 5-Fluorouracil (5-FU) is broadly used chemotherapeutic drug that treats diferent solid tumors including breast cancer but has low response rates and a variety of side efects. In this study, we evaluated the anticancer properties of prodigiosins in a murine model “Ehrlich tumor” and tested whether it can be added to 5-FU to potentiate its efects. Markers of oxidative stress; MDA, NO, and GSH levels were evaluated as well as antioxidant enzyme activities of CAT SOD, GR, and GPx. The levels of Bax, Bcl-2, PCNA, and NF-κB proteins were measured using ELISA kits. The mRNAs of p53 and Cdc2 and Casp3 were quantitatively measured by real-time PCR and ELISA respectively. Cell cycle analysis was performed using fow cytometery. Prodigiosins did not infuence tumor volume. Prodigiosins have not induced oxidative stress while 5-FU did increase MDA, NO but decreased GSH levels. The combination prodigiosins and 5-FU did reduce oxidative stress markers; MDA, NO and increased GSH levels. Prodigiosins signifcantly increased CAT only while 5-FU did decreased SOD, CAT, GPx, and GR. The combination prodigiosins and 5-FU increased the lev- els of these enzymes again. Prodigiosins increased the Bax/Bcl-2 ratio while the combination deceased it. In conclusion, prodigiosins have pronounced anticancer properties but their combination with 5-FU decreased oxidative stress exerted by 5-FU but weakened the apoptotic efects of 5-FU. Prodigiosins could afect a key mechanism through which 5-FU exerts its tumor inhibitory efects.en-USProdigiosins Ehrlich solid carcinoma Oxidative stress ApoptosisArticlehttps://doi.org/10.1007/s11356-022-21678-w