Sleep hormone can prolong ageing in cells
Scientists from the Russian Academy of Sciences’ Institute of Theoretical and Experimental Biophysics claim it’s possible to slow down the ageing process of the human body by using the hormone melatonin, which regulates sleep and wakefulness. By administering the hormone for a prolonged period of time on rats, they found that cells isolated from the rodents’ liver that produce heat and electricity (i.e. mitochondria) remained intact and did not die.
Under normal conditions and over time, pores appear in mitochondria through which these "powerhouse" cells lose the enzymes necessary for normal operation. Experiments revealed that constant administration of melatonin helped keep mitochondria in a good shape in both young and very old rats. The next step could be testing on humans.
Electrical impulse for a cell
"Our research has shown that administration of melatonin makes it possible to considerably reduce the loss of the protein cytochrome, which is responsible for cell ‘respiration’," said Olga Krestinina, a senior researcher at the institute who took part in the experiment. "This inhibiting effect of melatonin makes it possible to retain other important chemical compounds inside the mitochondria. For example, phosphodiesterase cyclic nucleotides, which do not allow cells to ‘dry up’. When a body grows old, their level decreases, whereas we have been able to keep it at the right level."
Cyclic nucleotides keep mitochondria in a state that ensures a sufficient amount of heat and electrical impulses are produced in a body. That is why mitochondria are often referred to as "powerhouses” that feed all the cells of the body that have their own DNA.
As a result of the experiments, the scientists have established that cells do not age because of mutations, as previously thought. The cause lies in the membranes or "cell shells": Over time, they become decrepit, simply "leaking" the essential chemical compounds through pores that form in them. It turned out that the hormone melatonin effectively "nourishes" the cell membrane, maintaining it in its normal state.
"With ageing, the content of melatonin in a body decreases rapidly, as does the concentration of calcium ions," Krestinina explained. "This leads to the disruption of normal operation of cells and their subsequent death. In addition to ageing, these processes also occur in patients suffering from ischemic heart disease, septic shock, Parkinson and Alzheimer diseases. Disruption in mitochondrial activity causes active forms of oxygen to be produced in large quantities, leading to oxidative stress."
How to slow down the oxidation of cells
Russian biologists decided to find out whether it’s possible to slow down the oxidation of cells by directly introducing a mitochondria substance that would "extinguish" oxygen molecules that destroy the cell. They chose melatonin for a simple reason – young people have this hormone in abundance, while ageing bodies have a shortage of it. The scientists decided to check whether the behavior of young and old cells change if the concentration of melatonin they contain is increased.
The Russian scientists’ discovery is part of a major project aimed at creating drugs that strengthen mitochondria. In the future, these drugs could be used not only to tackle the ageing process, but also to treat serious liver and heart conditions as well as cancerous tumors.