IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB) ISSN: 2455-264X, Volume 7, Issue 5 (Sep. – Oct. 2021), PP 45-54 www.iosrjournals.org DOI: 10.9790/264X-0705014554 www.iosrjournals.org 45 | Page Selenium nanoparticles provoke the expression of proliferating cell nuclear antigen (PCNA) gene in testicular tissues of rats treated with deltamethrin insecticide Mona Ragheb *1 , Afaf A. Shalaby 1 , Hala M. Ragab 2 Areej A. Yaseen 3 and Aliaa M. Issa 4 1- Rodents Research Dept., Research Institute of Medical Entomology (RIME), General Organization of Teaching Hospitals and Institutes (GOTHI) P.O. Box 12311, Cairo, Egypt. 2- Biochemistry Department, Genetic Engineering & Biotechnology Research Division (GEBRD), National Research center (NRC), , P.O. Box 12311, Dokki, Cairo, Egypt. 3- National Hepatology and Tropical Medicine Research Institute, General Organization of Teaching Hospitals and Institutes (GOTHI), Kasr Eleiny, Cairo, Egypt. 4- Zoology Dept., Faculty of Science, Cairo University, Cairo, Egypt. Abstract: Background: Deltamethrin insecticide showed severe toxicity to testicular tissues regarding damages in their architecture, deterioration in fertility hormones secretion and severe anomalies in their structure. However, selenium nanoparticles exhibit protective role that can recover such damages, anomalies and strengthen the reproductive potency as well. The aim of this study was to investigate the effect of selenium nanoparticles on the expression of the proliferating cell nuclear antigen (PCNA) gene in testes of rats treated with 13.5 mg/ kg bwt and 27 mg/Kg bwt deltamethrin corresponding to its 1/10 and 1/5 LD 50 using corn oil as a solvent for 28 days. Materials and Methods: In this prospective five groups each of ten adult albino male rats were considered. One group was the control with rat fed on corn oil while in the second group rats were treated with 0.5mg/Kg bwt nanoselenium, rats in third and fourth groups were treated with 13.5 mg/ kg bwt and 27 mg/Kg bwt deltamethrin respectively. While, in the last group rats were treated with 0.5mg/Kgbwt nanoselenium and 27mg/Kg bwt deltamethrin. Results: Results implied significant increase in the relative testes weight index among rats treated with nanoselenium. Levels of testosterone, luteinizing and follicle stimulating hormones were estimated showing a significant increase among groups treated with nano selenium compared to those that were untreated (P< 0.05). Histological studies were also carried out on treated testes along with estimating the enzymes of antioxidant status that also implied significant increase on the levels of catalase, superoxide dismutase enzymes and non significant increase in the glutathione reductase levels among nanoselenium treated groups. Conclusion: General results implied a positive and protective effect of selenium nanoparticles towards the adverse effects of deltamethrin on the male reproductive potency regarding the expression of the proliferating cell nuclear antigen (PCNA) gene in treated testes. Key Word: Deltamethrin, Proliferating cell nuclear antigen (PCNA), Selenium nanoparticles, Testicular immunocytochemistry, Testicular histology. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 06-09-2021 Date of Acceptance: 20-08-2021 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Deltamethrin is a synthetic pyrethroid insecticide used in many fields including agriculture, household pest control and disease vector control. Although it was thought to be the least toxic pesticide, many reports revealed its toxic effects in mammalian and non-mammalian animal species 1. Many studies had pointed out that it is severely toxic, showing its particular harmfulness to the male reproductive health 2. Selenium (Se), is an essential trace element that can play a crucial role in the maintenance of diverse physiological functions, body metabolism and cellular homeostasis. Definitely, selenium nanoparticles (SeNPs), which are of growing importance not only because of their nutrients digestibility, medicinal therapy, targeted drug delivery system and production of vaccines, but also due to their high bioavailability and digestive efficiency 3. Recently, SeNPs have been introduced as alternatives for seleno compounds and many researchers have focused on the