Prolonging life: steroid hormone instead of starvation

In experiments on roundworms Caenorhabditis elegans, researchers at Claude Bernard University, Leon, working under the direction of Hugo Aguilani, identified a steroid hormone that increases life expectancy and reduces fertility, that is, reproducing the effects of a low-calorie diet.

Reducing the caloric content of the diet increases the life expectancy of a number of species, ranging from yeast to mammals. There is also evidence that following a low-calorie diet reduces the likelihood of developing age-related diseases, such as cancer, neurodegenerative diseases and muscle tissue atrophy. These patterns have been demonstrated in mice and monkeys, which makes experts think about the possible positive effect of reducing the amount of calories consumed on human health.

However, compliance with such extreme diets is a very difficult task, since the result of this can be exhaustion of the body and the development of undesirable side effects, not only physiological (decreased fertility), but also psychological (irritability, decreased libido). Therefore, such diets are not recommended from the point of view of maintaining health.

The authors identified a hormone in nematodes Caenorhabditis elegans, the secretion of which is triggered in response to calorie restriction of food. It turned out that the synthesis of this hormone, which is a derivative of cholesterol and is known as dafachronic acid, is necessary to increase life expectancy. At the same time, it is also involved in a decrease in fertility associated with a low-calorie diet. The data obtained by the researchers indicate the existence of a direct relationship between the effects of a low-calorie diet.

Increased life expectancy of animals with a low-calorie diet (orange curve)
compared to the life span of animals not restricted in food (white curve).
Daphachronic acid (indicated in orange between the two curves)
it is synthesized in response to a low - calorie diet and is necessary
to increase life expectancy.

In addition, a receptor was identified in nematodes, through which daphachronic acid exerts its influence at the level of the cell nucleus. It turned out that this hormone can activate a large number of genes, among which there are both involved in fertility mechanisms and slowing down the aging process.

The researchers plan to study in detail the mechanisms of action of dafachronic acid and to search for methods of selective triggering of its effects, providing protection against age-related diseases. They hope that in the future the data they have obtained will find clinical application, since there is a close analogue of daphachronic acid and its receptor in the mammalian body, including humans.

Article by M. Thondamal et al. Steroid hormone signaling links reproduction to lifespan in dietary-restricted Caenorhabditis elegans is published in the journal Nature Communications.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on CNRS materials: Steroid hormone to fight age-related diseases. 

15.09.2014