The protective effects of silymarin nanoemulsion on 5-fluorouracil-induced gastrointestinal toxicity in rats

5-Fluorouracil (5FUra) is the third most popular chemotherapeutic component employed to treat solid tumors. In the present study, we aimed to appraise the silymarin (SM) and silymarin nanoemulsion (SMN) effect on 5FUra-induced gastrointestinal toxicity in adult male rats. A total of 30 male Wistar rats were divided into 6 groups including the control (Crl) group, and groups treated with SMN (5 mg.kg^-1), SM (5 mg.kg^-1), 5FUra + SMN (5 mg.kg^-1), and 5FUra + SM (5 mg.kg^-1) by IP injection for 14 days. And gastrointestinal toxicity was induced by a single intraperitoneal (IP) injection of 5FUra (100 mg.kg^-1) for the last group in the study. Treating rats with SM and SMN diminished elevating malondialdehyde (MDA) levels, and improved total antioxidant capacity (TAC) levels. Also, the intensity of mRNA expression of interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-α) caused by 5FUra in the gastrointestinal tissue tract, and macroscopic oral ulcerations decreased, ass well as weight loss was prevented, particularly in the SMN group. Moreover, in the microscopic scope, there were significant improvements in the levels of hyperemia, hyaline, and inflammatory cell infiltration in the tongue, esophagus, and intestinal tissues in the FUra + SMN and FUra + SM groups compared to 5FUra. Hence, treatment with SM and SMN reduced oxidative stress, histopathological degeneration, and gene expression of inflammatory markers in the gastrointestinal tract. According to the results, treatment with SM and SMN markedly decreases the gastrointestinal toxicity caused by 5FUra.