Phosphatidylethanolamine (PE) has an antioxidant effect by itself or in the presence of tocopherol. Due to this antioxidant action, it plays a role as an intracellular storage of docosahexaenoic acid （DHA） which is preferentially taken up by PE. Plasmalogen-type PE（P-PE）present in the brain protects from DHA radical damage more strongly by the vinyl ether bond in its structure. Brain PE produces N-acyl ethanolamine from N-acyl PE by phospholipase D. It acts as a ligand for various receptors represented by anandamide (a blissful substance) and exerts various physiological functions. Decreased DHA-binding P-PE (DHA-P-PE) in the brain and lipoproteins loaded from the liver with DHA-P-PE were associated with the pathology of dementia, 7 years before mild onset. DHA-P-PE found in the skin is recognized by a specific phospholipase A2G2F as a substrate and metabolized to lyso-DHA-P-PE, which is a psoriasis responsible metabolite. Lyso-DHA-P-PE was recognized as a novel lipid mediator that regulates skin homeostasis and diseases. PE affects the utilization of PE methyl transferase-mediated phosphatidylcholine production in the placenta and fetus in the choline metabolism pathway during pregnancy. PE unevenly distributed in the inner leaflet of the cell membrane has its unsaturated fatty acid and is protected from radical damage from the outside. Furthermore, PE interacts with tocopherols present in the membrane, and protects fatty acids with ethanolamine and vinyl ether bond.
Objective: Phosphatidylinositol 50（ PI 50） intake has been shown to stimulate neuronal activation and nerve cell proliferation, which may enhance learning and memory ability in rats. In the present study, we aimed to clarify whether these effects of PI 50 are due to phosphatidylinositol（ PI） by using treatments of PI-degraded preparations compared with PI 50 in a rat model. Methods: Male Wistar rats were divided into（1） distilled water,（2） PI 50, and（3） PI degraded preparation administration groups. The effects of oral administration of PI 50 or a PI-degraded preparation on memory and learning ability in rats were investigated using behavioral and molecular biological techniques. Results: We found that the group administered with PI 50 showed improvements in spatial memory, and learning ability, as well as increased c-Fos- and BrdU-positive cells in the hippocampus, and showed a significant increase in BDNF, PKC- α , and MAPK protein expression compared to the group administered with distilled water. However, these effects were not confirmed in the PI-degraded preparation administration group. Conclusion: The results suggested that learning ability and memory in rats were enhanced by PI 50 administration, which may be due to the action of the PI within PI 50. In the future, it will be necessary to study the preventive and ameliorating effects of PI 50 in cognitive diseases.
The vegetable intake of Japanese has been insufficient against the target (350 g/day) for decades. We believe that one of the reasons for this is the lack of opportunity to know one's own vegetable intake correctly, therefore we developed a device to estimate vegetable intake by measuring skin carotenoid levels easily and non-invasively. For measuring skin carotenoid levels, a sensor which could detect a specific range of wavelength of light reflected from the skin was used. Multiple studies, including ours, have suggested that skin carotenoid levels measured by the sensor show a statistically significant positive correlation with blood carotenoid concentrations and vegetable intake calculated by dietary surveys although the correlation between skin carotenoid levels and vegetable intake was relatively low. The measured value has been suggested to associate with the results of several items of health checkup, especially those related to metabolic syndrome such as body mass index, visceral fat area, blood pressure, fasting blood sugar, and serum lipid, etc. It has also been found that regular measurement of skin carotenoid levels contributes to habituation of vegetable intake behavior. In the near future, we expect that this kind of measurements will become widespread in the field of dietary guidance.
Preterm birth occurs in 5% of all pregnancies in Japan, giving a life-long adverse impact on the baby. The regulation of inflammation balance in the uteroplacental system is a key to successful pregnancy. Deterioration of inflammatory regulation in the pregnant uterus is a major factor related to preterm birth. Inflammatory eicosanoids such as prostaglandin （PG）F2α and PGE2, are produced by the omega-6 fatty acid metabolic pathway and play an essential role in the progress of parturition controlling cervical ripening and uterine contraction. In contrast, accumulating evidence have suggested that the metabolic pathway of omega-3 fatty acids is closely involved in pregnancy maintenance with its anti-inflammatory functions physiologically against omega-6-derived substances. Past studies have implied that enhanced intake of omega-3 fatty acid in pregnant women reduces the incidence of preterm birth. Supporting those clinical findings, we previously found that fat-1 transgenic mice which have an omega-3 fatty acid-dominant internal environment were resistant to inflammation induced preterm birth. In the background mechanism, we confirmed that omega-3 fatty acid metabolites such as resolvin and 18-HEPE suppressed uterine inflammation. In this review article, the importance of omega-3 fatty acids in the control of uterine inflammation is discussed from a wide range of perspectives from basic researches to clinical intervention in pregnant women.
