R. T. Al-Muswie¹, M. N. Abdulsayed², D. A. Alghezi³*^,
B. A. Ghyadh⁴, A. J. Alfahdawi⁵

¹Basic Science Department, College of Dentistry, University of Thi-Qar, Thi-Qar, Iraq;
²Otolaryngology-Head and Neck Department, College of Medicine,
University of Thi-Qar, Thi-Qar, Iraq;
³Microbiology Department, College of Medicine, University of Thi-Qar, Thi-Qar, Iraq;
⁴Biology Department, College of Science, University of Thi-Qar, Thi-Qar, Iraq;
⁵Department of Pathological Analysis, College of Applied Sciences,
University of Fallujah, Al-Anbar, Iraq;
*e-mail: Dhafer.a.f.alghezi@bath.edu

Received: 25 October 2025; Revised: 12 December 2025;
Accepted: 03 April 2026; Available on-line: April 2026

Cancer remains a predominant cause of mortality globally, and the suboptimal effectiveness of existing­ therapeutic modalities has catalyzed the exploration of novel treatment approaches. Nanomaterials, specifically selenium nanoparticles (SeNPs), have exhibited encouraging anticancer activity. This investigation aimed to evaluate the human oral squamous cell carcinoma (OSCC) cells viability and expression of prolifera­tion and apoptosis molecular markers under treatment with SeNPs. Selenium nanoparticles were synthesized with the use of Lactobacillus plantarum cultured in a medium containing selenium dioxide. The methods of energy-dispersive X-ray, scanning electron and atomic force microscopy were used to determine the SeNPs composition and three-dimensional images. MTT viability assay and qRT-PCR analysis of cyclin D1 and Bax gene expression were applied. OSCC cells were treated with SeNPs in a range of 25–200 µg/ml for 24 h. It was demonstrated that SeNPs induced a dose-dependent inhibition of cell viability with IC₅₀ value of 97 μg/ml. At lower concentrations (25–50 µg/ml) SeNPs transiently suppressed Bax and elevated Cyclin D1 expression­, indicating the adaptive proliferative response. At higher concentrations (100–200 µg/ml), SeNPs induced apoptotic pathways and G1-phase cell cycle arrest, significantly upregulating Bax and downregulating­ Cyclin D1 expression. These findings underscore the Selenium nanoparticles potential as nanotherapeutic agents for OSCC treatment.