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

Punicic acid (PA) is a chief component of pomegranate seed oil with several health benefits. In this study, the in vitro 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 in vivo 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.