Breast cancer is the most fatal malignancy in females. Among various cancer therapies, targeted therapy focuses on specific factors in cancer cells to slow tumor growth without damaging healthy cells. Se NPs are promising anticancer agents and can be enhanced by conjugating targeting molecules like FA and Pterostilbene loaded on Arabic Gum. Se@Pt-AG-FA nanoformulation was radio-prepared and characterized by TEM. The experimental design involved:60 female rats divided into three groups: negative control (n=10), positive control (n=20), and treated group (n=20) with an intraperitoneal injection of Se@Pt-AG-FA (4ml/kg/twice weekly for 2 months), the last two groups bearing breast cancer induced by MNU. The tumor volume and survival rate were recorded weekly. In breast tissues, the gene expressions of BCL2 and BAX were evaluated by RT-PCR, and a pathological examination was done. Also, CBC parameters were evaluated. The current results recorded that Se@Pt-AG-FA reduced the tumor volume to 9.98 mm3 and increased the survival rate to 75% in the treated group. Se@Pt-AG-FA upregulates BAX gene expression (17.2) and downregulates BCL2 gene expression (0.196), and the BAX/BCL2 ratio recorded 87.9 which is an excellent indicator for apoptosis. The pathological examination confirmed that the nanoformulation has a potency effect on breast cancer suppression. In conclusion, Se@Pt-AG-FA has a potent effect as an anticancer targeting therapy for breast cancer models, so it is recommended to increase the validation studies on human cases as a targeting therapy for breast cancer.