Breast cancer is one of the most cancers in women of developed and developing countries. The optimum
management of which requires a multidisciplinary approach including the use of certain biochemical
and histopathological markers. The effect of polysaccharide spirulina along zinc oxide nanoparticles on
MNU induced mammary carcinogenesis was investigated in female Sprague rats. Injection of N-methyl
N-Nitrosourea induced a significant increase in ALT, AST, Mammary MDA and serum NO levels. On
other hand marked depletion in mammary GSH, CAT, SOD and GPx. These changes were confirmed
by histopathological changes that observed after MNU intoxication. Administration of polysaccharide
spirulina and ZnO nanoparticles was able to mitigate mammary carcinogenic damage induced by MNU
as evidence to pronounced curative effect against lipid peroxidation, serum NO level and deviated
enzymatic variables as well as maintained glutathione status, antioxidant enzymes in addition
histopathological changes directed toward control. The results of the present study suggest that
polysaccharide spirulina and ZnO nanoparticles have potential to exert curative effects against
mammary carcinogenesis.