Balancing Risks versus Benefits: Vitamin C Therapy versus Copper Oxide Nanoparticles Toxicity in Albino Rats' Submandibular Salivary Gland.

Objectives:  This study aimed to examine the suppressive effect of the natural antioxidant vitamin C (VC) against submandibular gland toxicity induced by copper oxide nanoparticles (CuO-NPs).

Materials and methods:  Three groups of 30 mature male albino rats (4 weeks old) weighing between 150 and 200 g were selected. The rats were randomly assigned for 6 weeks to receive: intraperitoneal injection (IP) of vehicle (control group); IP of 2.5 mg/kg body weight (bw) of CuO-NPs (CuO-NPs group); and IP of 2.5 mg/kg bw of CuO-NPs, combined with a daily oral dose of 100 mg/kg bw of VC in drinking water via gavage (CuO-NPs/VC group). The rats were euthanized, and their submandibular glands were dissected for histological evaluation, including hematoxylin and eosin staining and immunohistochemistry for K_i-67 and caspase-3.

Statistical analysis:  The area expression for K_i-67 and caspase-3 was statistically analyzed using GraphPad Prism. Following analysis of variance analysis, Tukey's post hoc was used for multiple comparisons. The significance level was set at p < 0.05.

Results:  CuO-NPs caused significant cytotoxic effects on submandibular salivary gland cells in albino rats. This led to an increase in K_i-67 and caspase-3 levels compared with the control group. VC administration improved tissue histology and reduced K_i-67 and caspase-3 levels in the VC/CuO-NPs group compared with rats treated with CuO-NPs alone.

Conclusion:  The study revealed significant cytotoxic effects of CuO-NPs on the submandibular salivary gland of albino rats. VC effectively mitigated these toxic effects, suggesting its potential as a readily available antioxidant.