Lycopene alleviates chemotherapy-induced mucositis via enhancing intestinal barrier function and attenuating TLR4/MyD88/NF-κB signaling cascade

5-Fluorouracil (5-FU) is one of the most common chemotherapeutic agents used in treating solid tumors. Lycopene is a natural exogenous carotenoid with antioxidant, anti-inflammatory, immunomodulatory, and anticancer activity. Intestinal mucositis is a commonly encountered complication for chemotherapy. However, effective or preventive treatment for this common complication is still need to be elucidated. The current study aimed to appraise the effect of lycopene on 5-FU-induced intestinal mucositis (FUIIM). Twenty-eight male rats were divided randomly and equally into four groups: control, lycopene, FUIIM, and 5-FU + lycopene groups. Parameters for mucosal barrier integrity, redox and inflammatory status, and apoptosis were immunoassayed in addition to histological assessment. Decreased body weight, significantly impaired redox status, increased caspase 3 level, toll-like receptor (TLR) 4 level, myd88 and NF-κB expression. However, decreased Bcl-2, and Ki-67 expression were detected in 5-FUIIM group. Furthermore, impairment in intestinal barrier integrity, represented by decreased Occludin and claudin1 levels with impaired histological features and ultrastructural features, were also detected. Meanwhile, lycopene co-administration protected against weight loss, heightened oxidative stress, apoptosis, inflammation, disturbed intestinal barrier integrity, and impaired histological and ultrastructure features. In conclusion, lycopene significantly improved intestinal mucositis, barrier integrity and gut toxicity induced by 5-FU in rats.