Objectives: Oral mucositis is a significant toxicity related to the mammalian target of rapamycin inhibitor everolimus. Oxidative stress and pro-inflammatory cytokines, which contribute to treatment-related mucositis, can be targeted with Hippophae rhamnoides extract (HRE). Herein, we assessed the effects of HRE on everolimus-induced mucositis in rats. Methods: Eighteen rats were equally divided into healthy, everolimus, and everolimus plus HRE groups. Malondialdehyde (MDA) and total glutathione (tGSH) levels along with interleukin-1 beta (IL-1?) and tumor necrosis factor-alpha (TNF-?) gene expression levels were measured in the tongue and buccal mucosa tissues of all groups, histopathological changes were also evaluated. We tested the significance of variations with one-way variance analysis. We also analyzed the differences between groups with Kruskal–Wallis test and Mann–Whitney U-test. Results: HRE significantly decreased MDA and increased tGSH levels and reduced IL-1? and TNF-? gene expression in both tissues administered everolimus (p<0.001 for each). Histological examination revealed that HRE improved epithelial formation and keratinization, disrupted by everolimus, and alleviated everolimus-related mononuclear cell infiltration (p<0.05 for each). Conclusion: In light of these results, HRE may be a promising agent to manage oral mucositis caused by everolimus, given the lack of effective therapeutic options for this type of adverse event. Keywords: Everolimus, hippophae rhamnoides, oral mucositis
Corresponding Author: Muhammet Ozer