Abstract
Cancer, a disease threatening human life, is caused by the disturbance of the normal cell cycle, which results in the spontaneous growth of normal and malignant cells, the lack of differentiation between the two, and consequently malignant growths. Nowadays, various synthetic agents are applied for cancer therapy; nevertheless, reports have confirmed that these chemical agents are associated with various adverse complications. This experimental study was designed to assess the anti-tumor activities of zinc nanoparticles (ZnNPs) green synthesized by the Astragalus maximus (A. maximus) extract against Ehrlich solid tumors (EST) in mice. To induce the EST model, 0.2 ml of cell suspension was intramuscularly injected into the right thigh of the mice. Five days post-injection, the mice were assigned to five groups (eight mice each): EST mice treated with normal saline, EST mice orally treated with ZnNPs 10 mg/kg/day, EST mice orally treated with ZnNPs 25 mg/kg/day, and EST mice orally treated with ZnNPs 50 mg/kg/day for 14 days. Afterward, the volume of the tumor, tumor growth inhibition, body weight, tumor markers, oxidant/antioxidant markers, and tumor necrosis factor-alpha level were assessed in the tested mice. The results showed that after the treatment of EST mice with cyclophosphamide and ZnNPs at 10, 25, and 50 mg/kg, the volume of the tumor, and the serum amount of tumor markers (alpha-fetoprotein and carcinoembryonic antigen) were significantly reduced (P<0.001). It was found that ZnNPs at 10, 25, and 50 mg/kg markedly declined oxidative markers and increased the level of antioxidant enzymes (superoxide dismutase and glutathione peroxidase), compared to the control group, which received normal saline (P<0.001). To conclude, this study reported the unveiling of the anti-tumor activity of ZnNPs green synthesized by the A. maximus extract, mainly at a dose of 50 mg/kg against EST in mice. However, further supplementary studies are required to clarify all the anti-tumor aspects of these nanoparticles.