<i>In vitro</i> and <i>in vivo</i> immune-enhancing effects of punicic acid and the action mechanisms as revealed <i>via</i> microbiome and lipid profiling

Punicic acid (PA) is a chief component of pomegranate seed oil with several health benefits. In this study, the <i>in vitro</i> immunomodulatory activity of PA was assessed using RAW264.7 cells, revealing that PA activated the macrophages, facilitated the concentration of immune-related cytokines and enzymes, and regulated the immune-related NF-κB and MAPK signaling pathways. Further, the <i>in vivo</i> immune-enhancing effect of PA was evaluated with the cyclophosphamide (CTX)-induced immune-compromised mouse model with 16S rDNA amplicon sequencing and relative quantification of lipidome. Results indicated that high doses of PA (200 mg kg^-1) remarkably restored CTX-induced immune injury by enhancing the innate and adaptive immunity to stimulate the secretion of immune-related factors. In addition, PA improved gut microbiota dysbiosis and ameliorated lipid metabolism disorders. Our research provides a theoretical basis for the exploitation of PA as a functional component with immune-enhancing effects and adds to the potential health uses of pomegranate seed oil.