Background: Over the past few years, fabrication of nanoparticles (NPs) has been deployed widely in technologies and many concerns have emerged about the hazardous effect on human health after NPs exposure.

Objective: Green synthesis of gold NPs (AuNPs) and assessment of their activity in 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast cancer mouse model.

Methods: Chloroauric acid (HAuCl₄) was used in formation of AuNPs with the help of Curcuma longa as aqueous reducing extract and stabilizing agent at room temperature. Formed NPs were characterized with UV-Vis spectrometry, Fourier-transform infrared spectroscopy (FTIR), Zetasizer measurement, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Virgin female albino mice with DMBA-induced breast cancer were treated with formed AuNPs for 5 consecutive days and were dissected after 28 days of the beginning of treatment.

Results: UV-Vis spectrometry showed absorbance maximum peak at 530 nm for formed AuNPs, FTIR confirmed formation of plant extract layer around formed NPs; zetasizer measurement revealed 278.2 nm as an average size of produced NPs; SEM and TEM approved formation of monodisperse spherical AuNPs. Biochemical analysis of untreated breast cancer group revealed marked changes in liver and kidney functions manifested by raised activity levels of alanine transaminase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine. Whereas, the treated group with AuNPs post-breast cancer induction displayed reduction in the activities (of ALT, AST and creatinine), while the BUN activity level was raised. Histopathological examination showed heavy incidence of tumor foci in the breast and lymph nodes belonged to the untreated breast cancer group confirmed with intense response to Ki-67 antibodies. While the treated group with AuNPs post-breast cancer induction showed degenerated tumor foci in the breast and lymph nodes with weak response to Ki-67 antibodies.

Conclusion: AuNPs were successfully synthesized using HAuCl₄ and C. longa extract confirmed their ability to control DMBA-induced breast cancer in virgin female Swiss albino mice.