Scientists talked about protecting memory from the effects of excess salt
Soy lysolecithin LPC70 reduced blood pressure and memory impairment in mice fed a high-salt diet. Japanese researchers have linked these changes to the way signaling molecules work in the kidneys and brain. The results so far relate only to animal experiments and require verification in clinical trials. How scientists studied the effects of excess salt, why the soy component acted differently in different organs, and what remains to be found out - in the Izvestia material.
Why do scientists study more than just pressure?
Excessive salt intake is known primarily as a risk factor for high blood pressure. However, researchers are also interested in its possible connection with memory and behavior disorders.
A team from Fujita University of Public Health in Japan studied these processes in mice. The authors sought to find out whether a food component could mitigate the effects of a high-salt diet and what molecular changes accompany such an effect.
The focus was on LPC70— soy lysolecithin, in which lysophosphatidylcholine accounts for more than 70% of the total amount of phospholipids. Therefore, LPC70 is more accurately described as a composition with a high proportion of a specific component, rather than as a separate new substance first discovered in soybeans.
Previous experiments have already indicated its potential effect with a high-salt diet. The new work aimed to clarify the mechanisms, especially those related to prostaglandins— molecules involved in signaling between cells.
"We wanted to understand the role of LPC70 in coordinated changes in prostaglandin signaling pathways in different organ systems," explained Akihiro Mouri, professor at Fujita University of Public Health.
How did the experiment go?
The mice received a high-salt feed containing 8% sodium chloride for ten weeks. The researchers compared the performance of animals treated with LPC70 on the background of such a diet with the performance of mice without this supplement. The duration and composition of the experimental diet are indicated in the abstract of the scientific article.
The scientists measured blood pressure, assessed behavior and the ability to recognize previously encountered objects. Additionally, they analyzed the activity of genes associated with prostaglandin pathways and changes in lipid molecules.
Animals on a high-salt diet had increased systolic blood pressure. In addition, they interacted less with other mice and performed worse on the task of recognizing objects. At the same time, the researchers did not find significant changes in general motor activity and anxiety-like behavior. According to their interpretation, the violations affected individual cognitive and social functions.
The addition of LPC70 reduced the increase in blood pressure and improved the results of behavioral tests compared with a high-salt diet without it. These observations became the basis for a more detailed study of changes in the kidneys and brain.
What connects salt, kidneys and brain
The authors focused on prostaglandins, lipid signaling compounds that are formed from arachidonic acid. They are involved in the regulation of various processes, including vascular reactions. Their effect depends on which receptor they interact with. Therefore, an increase in the amount of a certain prostaglandin cannot be automatically considered beneficial or harmful to the entire body.
It is this selectivity that is important for interpreting the results. LPC70 did not just equally enhance or suppress one process in all tissues: the researchers found different changes in the kidneys and prefrontal cortex.
What changes were found in the kidneys
High-salt diet increased the expression of cyclooxygenase-2, or COX-2, and EP3 receptor genes in the kidneys. Both components are associated with prostaglandin signaling pathways and may be involved in the development of hypertension with excess salt.
These changes were less pronounced in mice treated with LPC70. The authors consider this result as a possible link related to the observed improvement in blood pressure.
At the same time, the molecular parameters help to formulate an explanation, but do not allow us to consider the entire mechanism definitively established. In the abstract itself, the protective effect of LPC70 is cautiously described as potentially related to a change in prostaglandin signals.
How the brain reacted
The picture in the prefrontal cortex was different. This area is involved in cognitive processes and social behavior. On a high-salt diet, the expression of the DP1 receptor, through which prostaglandin D2 acts, decreased. According to the university, this pathway is associated with neuroprotective and anti-inflammatory processes.
LPC70 restored DP1 expression without changing the index of another receptor, DP2. According to the researchers, such a response may shift the transmission of signals towards the protection of nervous tissue.
This is a possible explanation for improvements in memory and social behavior in mice. However, the results of a behavioral test are not equivalent to evidence of dementia prevention or memory restoration in humans.
Why does the growth of prostaglandins not contradict the protective effect
An additional result concerned arachidonic acid, the starting substance for the formation of prostaglandins. In mice on a high-salt diet, its level in the bloodstream decreased. At the same time, the content of prostaglandins formed from LPC70 increased in animals treated with LPC70, including PGE2 and PGD2.
The authors suggest that LPC70 may contribute to more efficient use of available arachidonic acid. But this explanation still needs to be clarified: the measured changes in concentrations alone do not describe all the stages of formation and decomposition of these molecules.
The resulting picture shows why it is important to take into account simultaneously the number of signaling substances, their receptors and the organ in which the changes occur. One general indicator cannot replace such an analysis.
What the results mean for a person
Researchers consider LPC70 as a potential functional food ingredient. However, the applicability of the results to humans has not yet been established: it is necessary to check the effectiveness, safety and suitable conditions of use.
The experiment also does not allow us to conclude that ordinary soy or any soy lecithin give the same effect. A certain composition was used in the work, and a high-salt diet was part of the laboratory model.
"Our study reveals the role of LPC70 in prostaglandin signaling, laying the foundation for future clinical research," said Mowry.
So far, scientists have shown that, against the background of a single experimental diet, changes in blood pressure, memory, and behavior in mice were accompanied by selective molecular shifts in different organs. The next step is to determine whether this pattern can be used to help people. The study does not yet provide any reason to consider LPC70 as a way to compensate for excessive salt intake.
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