Enhanced bioactivity and efficient delivery of quercetin through nanoliposomal encapsulation using rice bran phospholipids

BACKGROUND Quercetin is a phenolic compound occurring in many food plants and agricultural crops. It is reported to possess various health-promoting properties. However, the poor bioavailability of quercetin, due to its low aqueous solubility and its degradation during digestion, limits its nutraceutical applications. This study aimed to encapsulate quercetin in nanoliposomes using rice-bran phospholipids for its efficient delivery and controlled release, the protection of its structural stability, and enhancement of its bioactivity. RESULTS Nanoliposomal encapsulation of quercetin by thin film-sonication method yielded spherical nanoparticles (157.33 +/- 23.78 nm) with high encapsulation efficiency (84.92 +/- 0.78%). Storage stability studies showed that nanoliposomal quercetin was stable at 4 degrees C and 27 degrees C for 6 and 5 months, respectively, as indicated by unchanged antioxidant activity and quercetin retention. Nanoliposomal quercetin showed a slow, limited release pattern in simulated gastric fluid (SGF), and an initial burst release followed by a slow constant releasing pattern in simulated intestinal fluid (SIF). A 1004-fold increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity was observed in quercetin nanoliposomes (SC50 = 4.04 +/- 0.01 ppm) compared to non-encapsulated quercetin (SC50 = 4053.03 +/- 5.61 ppm). Similarly, the anti-angiogenic activity of quercetin, as evaluated by duck embryo chorioallantoic membrane (CAM) assay, was enhanced twofold to fivefold by nanoliposomal encapsulation. CONCLUSION This study showed that nanoliposomal encapsulation in rice-bran phospholipids enhanced the radical-scavenging and anti-angiogenic activities of quercetin. Furthermore, this study demonstrated that nanoliposomes can serve as efficient oral delivery system for quercetin. (c) 2018 Society of Chemical Industry