Preparation Of High Purity Punicic Acid And Its Regulation Of Lipid Metabolism In Mice

Evidences have demonstrated punicic acid(PUA)has a positive regulatory effect on lipid metabolism.However,the mechanism by which PUA exerts the regulation effect remains unclear.This study aimed to elucidate the effect of PUA on obesity and liver steatosis in mice induced by high?fat diet(HFD),and to explore the possible mechanism.(1)The optimum parameters for purification of PUA from pomegranate seed oil by using low temperature crystallization process were investigated.The optimum process conditions were determined as follows: the solvent was acetone+acetonitrile(2:1),the crystallization temperature was-20℃,the solid-liquid ratio was 1:6(g/ml),and the crystallization time was 26 h.The rate of recovery was 90.3% and the purity of punicic acid was increased from 72.9% to 93.7% under optimal condition.The purity of punicic acid was increased to 97.2% after secondary crystallization under optimal condition.(2)The effects of PUA on obesity and hepatic steatosis induced by high fat diet in ICR male mice were investigated by supplemtation with PUA for 8 weeks.Mice were divided into normal control group(CD),high-fat diet group(HFD)and high-fat diet+PUA treatment group(HFDPUA)(n=8).HFDPUA group was gavaged daily with 0.1 ml pomegranate seed oil,while CD and HFD groups were gavaged daily with 0.1 ml corn oil.The results showed that PUA supplementation for 8 weeks significantly reduced the weight gain and total weight gain induced by HFD,reduced the weight of perirenal and epididymal fat,and significantly reduced the fat cell hypertrophy induced by HFD in mice.PUA supplementation for 8 weeks significantly reduced the content of triglyceride(TG)in liver,significantly reduced the accumulation of fat in liver cells and improved steatosis.These results indicated that PUA supplementation can significantly improve liver steatosis and obesity induced by HFD in mice.(3)16S rDNA high-throughput sequencing was performed to investigate the effect of PUA treatment on the richness and diversity of gut microbiota.The result showed that PUA supplementation increased the diversity of intestinal flora and regulated the composition of intestinal flora at various taxonomic levels.At the phylum level,HFD increased the proportion of Firmicutes/Bacteroidetes,while PUA significantly increased the abundance of Bacteroidetes and decreased the ratio of Firmicutes/Bacteroidetes.At the family level,PUA increased the relative abundance of Muribaculaceae、Bacteroidaceae,while reduces the abundance of Desulfovibrionaceae and Helicobacteraceae.At the genus level,PUA reversed the increase of relative abundance of Anaerotruncus,Faecalibaculim and Mucispirillum,and the decrease of relative abundance of Lactobacillus,Roseburia and Oscillibacter.An altered Desulfovibrionaceae was positively correlated with the weight of epididymis and perirenal adipose tissue and the contents of TG and TC in liver.An altered family Deferribacteraceae and Helicobacteraceae were positively correlated with the weight of epididymis and perirenal adipose tissue,while an altered family Muribaculaceae was negatively correlated with the weight of epididymis and perirenal adipose tissue and the contents of TG and TC in liver.These results demonstrated that PUA can at least in part ameliorate obesity and liver steatosis in mice induced by HFD by regulating gut microbiota composition.