Anticancer role of mango (Mangifera indica L.) peel and seed kernel extracts against 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis in female rats

Breast cancer is the second leading cause of cancer death among women. The present study is an effort to reveal the antiproliferative and antioxidant actions of mango seed kernel extract (KE), peel extract (PE), and their combination (KEPE) on mammary tumors induced by 7,12 dimethylbenz[a]anthracene (DMBA). Seven groups of adult female Sprague-Dawley rats were prepared, including C: (control), DMBA: (rats were administered with DMBA), (DMBA-KE), (DMBA-PE), and (DMBA-KEPE): rats were administered with DMBA and then treated with KE, PE, and (both KE and PE), respectively, (KE) and (PE): rats were administered with KE and PE, separately. The study focused on the assessment of markers of endocrine derangement [serum 17-beta estradiol (E2)], apoptosis [caspase-3 and deoxyribonucleic acid fragmentation (DNAF)], and oxidative stress [lipid peroxidation and antioxidants (glutathione, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and superoxide dismutase)]. Histopathological examination and immunohistochemical expression of caspase-3 and estrogen receptor-alpha (ER-alpha) in mammary gland tissues (MGTs) were determined, as well as the characterization of mango extracts. The results showed that DMBA administration induced mammary tumors by increasing cell proliferation and evading apoptosis. In addition, DMBA administration caused oxidative stress by the production of reactive oxygen species, which increased lipid peroxidation and decreased cellular antioxidants, allowing cancer to progress. In contrast, treatment with DMBA-KE, DMBA-PE, or DMBA-KEPE diminished mammary tumors induced by DMBA, where they reduced oxidative stress via increased antioxidant parameters including reduced glutathione, superoxide dismutase, total glutathione peroxidase, glutathione reductase, and glutathione S-transferase. Also, different treatments decreased proliferation through the reduction of E2, and ER-alpha expression levels. However, these treatments increased the apoptosis of unwanted cells as they increased caspase-3 activity and DNAF. All these changes led to the prevention of breast injuries and the reduction of mammary tumors. This demonstrates that the contents of mango extracts, especially phenolics and flavonoids, have an important role in mammary tumor treatment through their potential antioxidant, antiproliferative, proapoptotic, and anti-estrogenic effects. KE and PE administration for 4 weeks had no adverse effects. Conclusion: Each of KE, PE, and KEPE has a therapeutic effect against DMBA-induced mammary tumors via induction of apoptosis and reduction of each of the OS, proliferation, and estrogenic effects. So, they can play an important role in the pharmacological tole.