Cancer exerts a significant impact on animal health and remains a substantial challenge in veterinary medicine, particularly in cases involving aggressive tumors. This study investigates the potential of a newly identified probiotic strain, Lactobacillus casei FG12 (L. casei FG12), as a natural therapeutic agent for breast and liver cancers induced in rats. To establish the cancer models, 7,12-dimethylbenz[a]anthracene (DMBA) and trichloroethylene (TCE) were employed to induce breast and liver tumors, respectively. The probiotic strain was confirmed via MALDI-TOF MS. FG12 demonstrated robust antioxidant capacity, scavenging 89% of DPPH radicals, alongside broad-spectrum antibacterial activity. In vitro analyses revealed that the strain decreased the viability of HepG2 and MCF-7 cancer cells by 81% and 85%, respectively. A total of ninety rats were allocated into nine treatment groups, including healthy controls, L. casei FG12-treated, Fluorouracil-treated, and cancer-induced groups. This research demonstrated in vivo that L. casei FG12 diminished early cancer indicators such as cellular degeneration, necrosis, and atypia in hepatic tissue, as well as hyperplastic alveolar nodules in mammary glands. The probiotic suppressed the expression of pro-apoptotic genes BCL-2 and HIF-1α, elevated the expression of Caspase-3, and restored oxidative balance. Histological examinations indicated that tissue structures resembled normal tissue, suggesting that L. casei FG12 provided significant protection against carcinogen-induced tissue damage. The findings concluded that L. casei FG12 exhibits strong multi-target potential as a probiotic for cancer prevention and support in veterinary therapeutic practices.

To Cite This Article: Alharbi MG and Alanazi H, 2025. Anticancer and antioxidant properties of a novel probiotic Lactobacillus casei FG12 against 7,12-Dimethylbenz [a]anthracene and Trichloroethylene-induced breast and liver cancer in rats. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.313