Armillariella Oral Solution Ameliorates Small Intestinal Damage in a Mouse Model of Chemotherapy-Induced Mucositis

Background: Armillariella oral solution (AOS) shows therapeutic effect on gastrointestinal disorders. We aimed to investigate the potential efficacy of AOS on chemotherapy-induced intestinal mucositis in mice. Methods: Intestinal mucositis was induced in C57BL/6 mice by daily intraperitoneal injection of 5-FU (50 mg/kg) for 7 days. Effects of AOS (at 1, 5, and 10 mL/kg), or combined Bifidobacterium and Lactobacillus (CBL, 450 mg/kg) on the accompanying morphometry and histology, expression of Ki-67, caspase-3, Lgr5 and apoptosis of intestinal crypt cells were assessed. Results: Continuous administration of 5-FU to mice caused severe intestinal mucositis, which was histologically characterized by the destruction of intestinal crypts and shortening of villi, accompanied by diarrhea and body weight loss. Daily AOS administration dose-dependently reduced the severity of intestinal mucositis, diarrhea and body weight loss. Similar beneficial effects were observed with CBL. The expression of Ki-67 and Lgr5 decreased and the expression of caspase-3, and the number of apoptotic cells increased 24 h after the first 5-FU administration (P < 0.05), and these responses were significantly reduced by AOS treatment (P < 0.05, at 5 or 10 mL/kg). Conclusions: AOS can alleviate 5-FU-induced mucositis in mice via increasing Lgr5 expression and suppressing apoptotic responses in the intestinal crypt cells.