Science Daily

by Fujita Health University

    Consuming too much salt can affect more than blood pressure. Growing evidence suggests that excessive salt intake may also interfere with memory, thinking, and emotional well-being. High salt (HS) consumption is already a major public health concern because of its connection to hypertension, but its potential effects on the brain make finding ways to reduce the damage even more important.

    Researchers in Japan have identified a promising possibility in LPC70, a compound derived from soy. Previous research found that this ingredient could reduce high blood pressure and cognitive problems associated with a high-salt diet (HSD) in mice. The latest study takes a closer look at how it works, revealing that the compound influences important chemical signals in the brain and kidneys.

How a Soy Compound May Counter the Effects of Excess Salt

    The research centers on prostaglandins (PGs), signaling molecules made from a fatty acid called arachidonic acid (AA). These substances act much like local hormones, helping regulate essential functions throughout the body.

    In the cardiovascular system, prostaglandins help control blood pressure by balancing the widening and narrowing of blood vessels. Their effects in the brain are more complicated. Depending on which receptors they activate, they can trigger signals that either protect nerve cells or contribute to harmful processes, potentially affecting memory, thinking, and emotional responses.

    LPC70 is a form of soy lysolecithin in which lysophosphatidylcholine (LPC) accounts for more than 70% of the phospholipids. Although earlier experiments showed that LPC70 could ease salt-related hypertension and cognitive difficulties, scientists had not fully understood the mechanisms responsible, particularly its influence on prostaglandin signaling.

    To investigate, a research team led by Professor Akihiro Mouri and Dr. Hisayoshi Kubota, working with Dr. Kazuhiro Kagotani, examined how LPC70 affected these signaling pathways in mice consuming a high-salt diet.

    Dr. Kubota, the study's first author, played a central role in the experiments. He assessed blood pressure, monitored behavioral changes, and analyzed molecular activity associated with prostaglandins. His work helped clarify how LPC70 produces different effects in the organs involved in salt-related cardiovascular and cognitive problems.

    Prof. Mouri and Dr. Kubota are affiliated with the Department of Regulatory Science for Evaluation and Development of Pharmaceuticals & Devices at Fujita Health University Graduate School of Medical Science, as well as the International Center for Brain Science (ICBS) at Fujita Health University in Japan. Dr. Kagotani is affiliated with Tsuji Oil Mills Co., Ltd, in Japan and the Tsuji Health and Beauty Science Laboratory at Mie University, Japan.

    The findings were released online on May 14, 2026, and published in Volume 197 of Neurochemistry International on July 1, 2026.

    "We wanted to understand the role of LPC70 in coordinating changes in PG signaling across organ systems," mentioned Prof. Mouri. "Our study originated from a collaborative research project with Tsuji Oil Mills Co., Ltd, a company that develops naturally derived food ingredients," he added.

Soy Compound Improves Blood Pressure and Memory in Mice

    As expected, mice that consumed a high-salt diet developed elevated blood pressure. However, the consequences extended beyond their cardiovascular health.

    The animals also became less socially interactive and had difficulty recognizing objects they had encountered before, indicating problems with memory. Interestingly, their general movement and anxiety-like behavior showed no substantial changes. This pattern suggests that excessive salt selectively disrupted more complex cognitive and social functions rather than causing widespread behavioral impairment.

    When researchers supplemented the animals' diets with LPC70, several of these effects were reduced. Blood pressure improved, and the mice performed better on tests of social interaction and object recognition memory.

    These improvements prompted the researchers to examine what was happening inside the animals' kidneys and brains.

Different Protective Effects in the Kidneys and Brain

    In the kidneys, a high-salt diet increased the expression of two components involved in prostaglandin signaling: cyclooxygenase-2 (COX-2) and the PGE2 receptor EP3. Both may contribute to the development of high blood pressure associated with excessive salt consumption.

    LPC70 reduced these salt-related increases, suggesting that the compound helps correct changes in kidney signaling that can interfere with normal blood pressure regulation.

    The researchers found a different response in the prefrontal cortex, a brain region essential for thinking, memory, and social behavior.

    Excess salt reduced the expression of the PGD2 receptor DP1, which plays a role in protective and anti-inflammatory signaling in the brain. LPC70 restored expression of this receptor without changing DP2, another receptor associated with potentially harmful effects on nerve cells.

    This distinction is important because it suggests that LPC70 does not simply increase or suppress all prostaglandin activity. Instead, it may selectively favor signaling pathways that help protect the brain, potentially explaining the improvements in memory and social behavior observed in the mice.

A Surprising Change in Chemical Signaling

    The team also discovered an unexpected change involving arachidonic acid, the fatty acid the body uses to produce prostaglandins.

    Mice consuming excess salt had lower levels of circulating arachidonic acid. Yet when they received LPC70, levels of prostaglandins derived from this fatty acid, including PGE2 and PGD2, increased.

    This seemingly contradictory result suggests that LPC70 may help the body use available arachidonic acid more efficiently to produce prostaglandins under high-salt conditions.

    Taken together, the findings reveal a coordinated but highly selective response. In the kidneys, LPC70 appears to suppress signaling changes associated with hypertension. In the brain, it restores signaling linked to protection against inflammation and damage.

    The compound's effects therefore depend on both the organ involved and the specific prostaglandin receptors being regulated.

Could Soy-Based Ingredients Help Protect Against Excess Salt

    The results suggest that LPC70 could eventually become a useful functional food ingredient for reducing some of the health consequences of excessive salt intake.

    Its ability to improve blood pressure and cognitive performance in mice raises the possibility that it could support cardiovascular and brain health, particularly among people whose diets contain high amounts of salt.

    However, the findings come from animal experiments, and further clinical studies are needed to determine whether the same benefits occur in humans.

    "Our study elucidates LPC70's role in PG signaling, laying the groundwork for future clinical research and dietary interventions aimed at reducing hypertension-related cognitive decline and promoting healthy aging globally," concluded Prof. Mouri.

    The research provides a clearer picture of how a soy-derived compound can influence the body's response to excessive salt, opening new possibilities for nutritional approaches to protecting long-term health.

Research Funding and Support

    The study received support through Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS: 20K07931, 22K07606, 22K11891, and 23H02843).

    Additional support came from the Fujita Mind-Brain Research & Innovation Center for Drug Generation (Fujita Mind-BRIDGe) through Japan's Peak Research Universities (J-PEAKS) Program (JPJS00420240019), along with the Japan Science and Technology Agency FOREST Program (JPMJFR215H).

    Tsuji Oil Mills Co., Ltd. provided funding for the research. Grants and other support were also supplied by the Education and Research Facility of Animal Models for Human Diseases at Fujita Health University, the Smoking Research Foundation, and the Takeda Science Foundation.