Effects of the food additive monosodium glutamate on cisplatin-induced gastrointestinal dysmotility and peripheral neuropathy in the rat.

Abstract

Cisplatin is an antineoplastic drug known to produce intense vomiting, gastric dysmotility, and peripheral neuropathy. Monosodium glutamate (MSG) is a flavor enhancer with prokinetic properties potentially useful for cancer patients under chemotherapy. Our aim was to test whether MSG may improve gastrointestinal motor dysfunction and other adverse effects induced by repeated cisplatin in rats. Male Wistar rats were exposed or not to MSG (4gL-1 ) in drinking water from week 0 to 1week after treatment. On the first day of weeks 1-5, rats were treated with saline or cisplatin (2mgkg-1 week-1 , ip). Gastrointestinal motility was measured by radiological methods after first and fifth administrations, as well as 1week after treatment finalization. One week after treatment, the threshold for mechanical somatic sensitivity was recorded. Finally, samples of stomach, terminal ileum and kidneys were evaluated in sections using conventional histology. The myenteric plexus was immunohistochemically evaluated on distal colon whole-mount preparations. Monosodium glutamate prevented the development of cisplatin-induced neuropathy and partially improved intestinal transit after the fifth cisplatin administration with little impact on gastric dysmotility. MSG did not improve the histological damage of gut wall, but prevented the changes induced by cisplatin in the colonic myenteric plexus. Our results suggest that MSG can improve some dysfunctions caused by anticancer chemotherapy in the gut and other systems, associated, at least partially, with neuroprotectant effects. The potentially useful adjuvant role of this food additive to reduce chemotherapy-induced sequelae warrants further evaluation.