Cancer is the most common cause of death worldwide. Annually, more than ten million new cancer cases are diagnosed, and more than six million deaths occur due to cancer. Nonetheless, over 80% of human cancer may be preventable through proper nutrition. Numerous nutritional compounds are effective in preventing cancer. Selenium and zinc are essential micronutrients that have important roles in reducing oxidative stress and protecting DNA from the attack of reactive oxygen species. Selenium is an essential trace element that possesses several functions in many cellular processes for cancer prevention. Meanwhile, zinc may have protective effects on tumor initiation and progression, and it is an essential cofactor of several mammalian proteins. Results show that both selenium and zinc provide an effective progression of DNA repair system; thus, cancer development that originated from DNA damage is decreased. Results mostly focus on the separate effects of these two elements on different cell types, tissues, and organs, and their combined effects are largely unknown. This review aimed to emphasize the joint role of selenium and zinc specifically on DNA repair for cancer prevention.
Cause of Death ; DNA Damage ; DNA Repair ; DNA ; Humans ; Joints ; Micronutrients ; Oxidative Stress ; Reactive Oxygen Species ; Selenium ; Trace Elements ; Zinc

OBJECTIVE: Chemotherapeutic drugs, such as cisplatin (CP), which are associated with oxidative stress and apoptosis, may adversely affect the reproductive system. This study tests whether administration of propolis and nano-propolis (NP) can alleviate oxidative stress and apoptosis in rats with testicular damage induced by CP. METHODS: In this study, polymeric nanoparticles including propolis were synthesized with a green sonication method and characterized using Fourier transform-infrared spectroscopy, Brunauer-Emmett-Teller, and wet scanning transmission electron microscopy techniques. In total, 56 rats were divided into the following seven groups: control, CP, propolis, NP-10, CP + propolis, CP + NP-10, and CP + NP-30. Propolis (100 mg/kg), NP-10 (10 mg/kg), and NP-30 (30 mg/kg) treatments were administered by gavage daily for 21 d, and CP (3 mg/kg) was administered intraperitoneally in a single dose. After the experiment, oxidative stress parameters, namely, malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT), and apoptotic pathways including B cell leukemia/lymphoma-2 protein (Bcl-2) and Bcl-2-associated X protein (Bax) were measured in testicular tissues. Furthermore, sperm quality and weights of the testis, epididymis, right cauda epididymis, seminal vesicles and prostate were evaluated. RESULTS: Propolis and NP (especially NP-30) were able to preserve oxidative balance (decreased MDA levels and increased GSH, CAT, and GPx activities) and activate apoptotic pathways (decreased Bax and increased Bcl-2) in the testes of CP-treated rats. Sperm motility in the control, CP, and CP + NP-30 groups were 60%, 48.75%, and 78%, respectively (P < 0.001). Especially, NP-30 application completely corrected the deterioration in sperm features induced by CP. CONCLUSION The results show that propolis and NP treatments mitigated the side effects of CP on spermatogenic activity, antioxidant situation, and apoptosis in rats.
Animals ; Antioxidants/metabolism* ; Cisplatin/toxicity* ; Male ; Oxidative Stress ; Propolis ; Rats ; Rats, Sprague-Dawley ; Sperm Motility ; Testis