Nanodispersions of monoglycerides of punicic acid: a potential nutrient precursor with higher oxidative stability and cytotoxicity
Punicic acid belongs to one of conjugated linolenic acids isomers (CLnAs) and contains many outstanding functions related to human health such as anti-carcinogenic, anti-diabetes, anti-hyperlipidemia, anti-obesity and anti-atherosclerotic properties; moreover, interest in the punicic acid is growing. Note that since punicic acid is extremely susceptible to oxidation, antioxidants were often added to increase its stability. However, sometimes such method resulted in the great decrease of its antitumor activity. In addition, punicic acid is quite insoluble in water and only a minor fraction of it can be absorbed. Therefore, the present study aims to identify a method, which can maintain the cytotoxicity when there is an increase in the oxidative stability and solubility of punicic acid. In brief, free punicic acid was modified with glycerol and the amphiphilic monoglycerides of punicic acid were obtained, which were further dispersed to nanodispersions. Oxidative stability, cytotoxicity to NIH3T3 cells and digestion in intestinal juice of such nanodispersions under different conditions were studied. It was found that such nanodispersions showed higher oxidative stability, higher solubility in water. Most importantly, its cytotoxicity to NIH3T3 cells was also as strong as that of free punicic acid. Furthermore, since it can be hydrolyzed by pancreatin in intestinal juice, the nanodispersions formed by monoglycerides of punicic acid can be used as nutrient precursor of free punicic acid.