Gut toxicity can limit the use of radiotherapy in cancer patients.

Oral melatonin can protect the small intestine in rats subjected to radiotherapy of the tongue, according to a study published in the open-access journal PLOS ONE by Germaine Escames from Universidad de Granada, Spain, and colleagues.

Gut toxicity - a debilitating condition involving deep ulcerations - can limit the doses of radiotherapy given to cancer patients. However, this side effect currently has no effective treatment. Following up on their previous work suggesting that melatonin might protect the gut from radiotherapy, Escames and colleagues irradiated the tongues of rats daily for five days, treated the rats with oral melatonin-gel for 21 days after radiation, and then assessed their small intestines for changes.

The researchers found that melatonin helped protect the small intestine of rats from radiotherapy, likely by protecting mitochondria and so reducing inflammation. Inflammatory mediators increase intestinal cell death, and the researchers found that melatonin reduced intestinal cell death in rats, thus facilitating intestinal recovery. This work suggests that oral treatment with melatonin might help prevent radiotherapy-induced gut toxicity in cancer patients.

Article: Melatonin protects rats from radiotherapy-induced small intestine toxicity, Fernández-Gil B, Moneim AEA, Ortiz F, Shen Y-Q, Soto-Mercado V, Mendivil-Perez M, et al., PLoS ONE, doi:10.1371/journal.pone.0174474, published 12 April 2017.