Researchers from the Universities of Edinburgh and Aberdeen report that giving melatonin prior to chemotherapy treatment prevents nerve damage and development of chemotherapy-induced pain in rats.
A recent study published in the Journal of Pineal Research revealed that melatonin – a drug commonly used to ease the side effects of jet, can help in preventing chemotherapy induced neuropathic pain (CINP) – a debilitating pain condition experienced by cancer patients because of chemotherapy treatment. A study conducted reports that the prevalence for CINP is 68.1% within a month after chemotherapy, and around 30% of the patients continue to suffer from it 6 months later. Moreover, severe CINP can necessitate dose reductions or termination of the chemotherapy treatment.
Current medications for this condition aim to relieve symptoms rather than target the pathological cause. Thus, researchers at the Universities of Edinburgh and Aberdeen targeted the underlying biological disruptions in CINP by investigating the role of mitochondria. Mitochondria are organelles which act as the cell’s powerhouse by converting oxygen and nutrients into energy. Disturbances in this process can lead to oxidative damage: an imbalance in the antioxidants and reactive oxygen that are crucial for mitochondrial functioning. Dr. Carole Torsney, who co-led the study, credited the pioneering work of Flatters and Bennett at McGill University for demonstrating that “mitochondrial dysfunction is a feature of chemotherapy induced neuropathy.”
Melatonin assisting treatment through mitochondria
When asked about the choice of drug, Dr. Torsney explained that melatonin “preferentially accumulates inside mitochondria and is a potent antioxidant. In other words, melatonin facilitates delivery of treatment to exactly where it is required.” In this study, researchers found that melatonin prevented damage to mitochondria in nerve cells. In addition, giving melatonin prior to chemotherapy treatment prevented nerve damage and reduced pain responses in rats. The drug had no effect when given after CINP had developed in the animal, suggesting melatonin acts as a protective agent rather than a cure. Importantly, melatonin did not interrupt the beneficial of chemotherapy.
Translational benefits
When asked about the effect of melatonin on humans, Dr.Torsney tells us that In fact, melatonin is now being tested in humans as a potential prevention of CINP in chemotherapy patients. Professor Lesley Colvin, a pain specialist at the University of Edinburgh, stated to ScienceDaily:
“We are actively exploring an early-phase clinical study to see if these exciting laboratory findings might translate to direct benefit for patients undergoing chemotherapy. This is an area of real unmet need, where new therapies are urgently required.”
Taken together, these promising findings suggest melatonin use could be rapidly incorporated in the clinic. Importantly, as Dr.Torsney points out “mitochondrial dysfunction is also a feature of other conditions such as pain resulting from diabetic neuropathy.” Thus, exploring the effects of melatonin in pre-clinical models of these conditions could reveal further potential of melatonin in alleviating patients’ pain.