Nanodelivery system based on zein-alginate complexes enhances in vitrochemopreventive activity and bioavailability of pomelo [Citrus maxima(Burm.) Merr.] seed limonoids

Limonin and nomilin, the major limonoid components of pomelo [Citrus maxima(Burm.) Merr.] seeds, have been reported to be potential cancer chemopreventive agents, but their low aqueous solubility and limited bioavailability impede their applications as nutraceuticals. In this study, a zein-alginate encapsulation system was utilized to produce highly dispersible limonin and nomilin nanoparticles (172.7 ± 7.4 and 273.3 ± 2.3 nm dia., respectively) with high encapsulation efficiencies and high stabilities at both ambient and refrigerated storage conditions. In vitrorelease studies showed that the nanodelivery system can delay and minimize the release of the limonoids in simulated gastric fluid (SGF) and preferentially release these compounds in simulated intestinal fluid (SIF). Furthermore, zein-alginate encapsulated limonin and nomilin exhibited significantly improved glutathione S-transferase (GST)-inducing activity, free radical-scavenging activity, and anti-angiogenic activity. These results demonstrate that the zein-alginate complexes can serve as effective oral delivery system for limonin and nomilin.