Melatonin protects against muscle damage and restores the proportion of fibers altered by obesity and diabetes, according to a study by the ibs.GRANADA and the UGR

Researchers They show that this hormone improves muscle energy efficiency and could become an innovative therapy to combat "diabesity"

An international study led by researchers from the Granada Biosanitary Research Institute (ibs.GRANADA) and the University of Granada (UGR) has revealed that melatonin, known for its ability to regulate the sleep/wake cycle, can restore the composition of muscle fibers and protect skeletal muscle from damage caused by obesity and its type 2 diabetes, known as "diabesity."

The results, published in the journals Free Radical Biology and Medicine y Antioxidants, show that this hormone improves mitochondrial function, reduces cellular stress and prevents programmed cell death, offering a new therapeutic strategy to combat this metabolic disease.

Improvement and protection of the muscles

The study, led by the professor of Pharmacology at the UGR and member of the MP09-Neuropharmacology of Pain group
Ahmad Agil, from the ibs.GRANADA, demonstrated that the administration of melatonin in obese and diabetic rodents for 12 weeks was able to promote the conversion of glycolytic (fast) muscle fibers to oxidative (slow) fibers, improving the energy efficiency of the muscle. This change not only optimizes energy production, but also protects the muscle from deterioration caused by "diabesity", a condition that combines obesity and type 2 diabetes.

The work, in which scientists from the Department of Pharmacology at the University of Granada, the Federico Olóriz Institute of Neurosciences and the Granada Biosanitary Research Institute (ibs.GRANADA) participated, as well as other collaborating institutions such as the Department of Nutrition and Bromatology and the Department of Histology at the UGR, the Centre for Endocrinology, Diabetes and Nutrition in Madrid, the University of Qatar and Yarmuk University in Jordan, focused on skeletal muscle, a key organ that accounts for more than 50% of body weight. Muscle fibres are divided into three types: slow-twitch fibres (type I) or red fibres due to the large number of mitochondria they possess, fast-twitch fibres (type IIb) or white fibres and intermediate fibres (type IIa). In addition, each muscle in our body has a specific, variable and changing proportion of each of these types of fibres, depending on the type of movement performed. During short-duration, intense muscular activities, white fibers with glycolytic metabolism predominate, and during prolonged, low-intensity muscular activities, red fibers with oxidative metabolism predominate.

Melatonin was able to restore the healthy proportion of these fibers, increasing oxidative fibers and reducing glycolytic fibers, reversing the effects of “diabesity,” which improves the muscle’s ability to burn fat (reducing fat accumulation, and therefore obesity) and produce energy. In addition, melatonin showed effects similar to those of prolonged aerobic activity, especially improving mitochondrial function and regulating calcium levels in cellular compartments, which reduces cell stress and prevents programmed cell death. “We discovered that melatonin restores calcium levels in mitochondria and the endoplasmic reticulum, which contributes to reducing cell damage,” says Dr. Agil.

These results are in line with those published over the last 15 years by this research group. Their findings could open up new perspectives for the development of therapeutic strategies based on the pharmacological administration of melatonin, aimed at improving muscle health in patients with diabetes. "Our main challenge is the application of melatonin in the field of medicine," the authors of the paper point out.

Confirm the results in humans

Obesity and type 2 diabetes are two of the most prevalent metabolic diseases in the world, affecting nearly 900 million and 800 million people, respectively. Both conditions are closely related and often coexist in what is known as “diabesity.” This disorder not only reduces the quality of life of patients, but also represents a challenge for health systems.

The findings of this study open up new perspectives for the therapeutic use of melatonin, a substance with a well-established safety profile. For the person responsible for this research, "our results reinforce the idea that melatonin could have therapeutic applications in metabolic diseases, improving the muscular health of patients." Therefore, he reminds us that maintaining a healthy, active and balanced lifestyle during the day accompanied by a proper night's rest is key to preserving muscular health and preventing the negative effects of obesity.

The study, funded by the Spanish Ministry of Science, Innovation and Universities and the European Regional Development Fund (ERDF), suggests that melatonin could become an accessible and effective therapy to combat “diabesity” and its complications. However, the researchers stress the need to conduct clinical studies in humans to confirm these results and determine the optimal dose in each case. “If we manage to demonstrate its efficacy in humans, we could be looking at an innovative treatment that would improve the lives of millions of people,” concludes Dr. Agil.