Omega-3 polyunsaturated fatty acids modulate sphingolipid metabolism in the hippocampus of aged rats

Neural cell membranes are rich in sphingolipids, which are powerful regulators of brain homeostasis. Ceramide is a potent signaling molecule involved in critical events in neurodegenerative brain diseases. The ω-3 polyunsaturated fatty acids (ω-3 PUFAs) are a group of essential fatty acids that serve as key components of cell membranes and energy sources, playing a vital role in maintaining normal brain function. This study aims to determine the impact of supplementing old rats with ω-3 PUFAs on hippocampal sphingolipid metabolism. To investigate the effect of ω-3 PUFAs on sphingolipid metabolism in aged rats, a comparison was made between 3-month-old and 24-month-old rats. The 24-month-old rats were divided into two groups: the experimental group received a diet supplemented with ω-3 PUFAs, and the control group received a diet supplemented with beef fat. Next, lipids were extracted from hippocampus homogenates and separated into classes (sphingomyelin, ceramide, glucosylceramide, and sphingosine) using thin-layer chromatography, followed by quantitative analysis. It has been determined that ceramide, glucosylceramide, and sphingosine synthesis increase in the hippocampus of 24-month-old rats with a non-significant decrease in the synthesis of sphingomyelin as compared to the 3-month-old animals. The nutritional factor ω-3 PUFA used in this work reduces the mass and de novo synthesis of the proapoptotic lipid ceramide in the hippocampus, which increases with age. Concurrently, ω-3 PUFAs also increase the levels of newly synthesized sphingomyelin in this region. These findings provide evidence that PUFAs act as physiological regulators of sphingolipid metabolism, reducing ceramide accumulation in the hippocampus during aging. Moreover, these results suggest that ω-3 PUFAs may help mitigate the risk of neurological diseases and alleviate age-related brain dysfunction in old age.