Plasmalogen Inhibits Body Weight Gain by Activating Brown Adipose Tissue and Improving White Adipose Tissue Metabolism

Plasmalogen, a phospholipid, exhibits preventive and therapeutic effects on dementia. Phospholipids improve fat metabolism, but it is unknown whether plasmalogen has an effect on fat metabolism. In this study, the effects of plasmalogen were determined by administering plasmalogen to KK-Ay mice. As a result, weight gain was significantly suppressed in the plasmalogen-treated group compared with the control group from 7 wk after the start of administration. In addition, plasmalogen administration increased uncoupling protein 1 (UCP1) expression in brown adipose tissue. The effect is thought to result from liver kinase B1 (LKB1)/AMP-activated protein kinase (AMPK)/PR domain containing 16 (PRDM16)/peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) pathway activation via adrenergic beta 3 receptors. Furthermore, the expression of the carnitine palmitoyltransferase-1 (CPT-1) gene associated with thermogenic factors and beta-oxidation was increased. We investigated the browning of white adipose tissue, but no increase in UCP1 gene expression was observed in perirenal adipose tissue, epididymis adipose tissue, mesenteric adipose tissue and inguinal region white adipose tissue. In contrast, plasmalogen increased the activity of AMPK, which is a central enzyme in lipid metabolism, in perirenal adipose tissue. Furthermore, the activity of the protein kinase A (PKA)/LKB1/AMPK/acetyl-coenzyme A carboxylase (ACC), stearoyl-CoA desaturase-1 (SCD-1), and hormone -sensitive lipase (HSL) pathways was confirmed. Plasmalogen may inhibit weight gain by activating brown fat to increase heat production, inhibiting lipid synthesis, and promoting lipolysis in white fat.