May cannabinoids prevent the development of chemotherapy-induced diarrhea and intestinal mucositis? Experimental study in the rat.

BACKGROUND: The antineoplastic drug 5-fluoruracil (5-FU) is a pirimidine analog, which frequently induces potentially fatal diarrhea and mucositis. Cannabinoids reduce gastrointestinal motility and secretion and might prevent 5-FU-induced gut adverse effects. Here, we asked whether cannabinoids may prevent diarrhea and mucositis induced by 5-FU in the rat.
METHODS: Male Wistar rats received vehicle or the non-selective cannabinoid agonist WIN 55,212-2 (WIN; 0.5 mg kg-1 injection-1 , 1 injection day-1 , 4 consecutive days) by intraperitoneal (ip) route; on the first 2 days, animals received also saline or 5-FU (150 mg kg-1 injection-1 , cumulative dose of 300 mg kg-1 ). Gastrointestinal motor function was radiographically studied after barium contrast intragastric administration on experimental days 1 and 4. Structural alterations of the stomach, small intestine and colon were histologically studied on day 4. PAS staining and immunohistochemistry for Ki67, chromogranin A and CD163 were used to detect secretory, proliferating, and endocrine cells, and activated macrophages respectively. KEY
RESULTS: As shown radiographically, 5-FU induced significant gastric emptying delay (on days 1 and 4) and diarrhea (on day 4). WIN did not significantly alter the motility curves obtained for either control or 5-FU-treated animals but tended to reduce the severity of 5-FU-induced diarrhea and increased permanence of barium from day 1 to the beginning of day 4 in 5-FU-treated animals. 5-FU-induced mucositis was severe and not counteracted by WIN. CONCLUSIONS AND INFERENCES: 5-FU-induced diarrhea, but not mucositis, was partly prevented by WIN at a low dose. Cannabinoids might be useful to prevent chemotherapy-induced diarrhea.