Fabrication of nanoparticles using partially purified pomegranate ellagitannins and gelatin and their apoptotic effects.

METHODS

Nanoparticles possess unique chemical and biological properties compared to bulk materials. Bioactive food components encapsulated in nanoparticles may have increased bioavailability and bioactivities.

RESULTS

Self-assembled nanoparticles made of partially purified pomegranate ellagitannins (PPE) and gelatin were fabricated using three PPE-to-gelatin mass ratios (1:5, 5:5, and 7:5). The PPE contained 16.6% (w/w) of punicalagin A, 32.5% (w/w) of punicalagin B, and a small amount of ellagic acid-hexoside and ellagic acid (1%, w/w). Nanoparticles fabricated using the ratio 5:5 had a particle size of 149.3±1.8 nm, positive zeta-potential of 17.8±0.9 mV, production efficiency 53.0±4.2%, and spherical morphology under scanning electron microscopy. Loading efficiency of punicalagin A and punicalagin B in these particles were 94.2±0.4% and 83.8±0.5 %, respectively. Loading capacity was 14.8±1.5% and 25.7±2.2%, respectively. Only punicalagin anomers were able to bind with gelatin to form nanoparticles, whereas ellagic acid-hexoside or ellagic acid could not. Fourier transform infrared spectroscopy suggested that the interactions between ellagitannins and gelatin were hydrogen bonding and hydrophobic interactions. PPE-gelatin nanoparticle suspension was less effective than PPE in inducing the early stage of apoptosis on human promyelocytic leukemia cells HL-60. But they had similar effects in inducing late stage of apoptosis and necrosis.

CONCLUSIONS

Pomegranate ellagitannins bind with gelatin to form self-assembled nanoparticles. Ellagitannins encapsulated in nanoparticles had decreased apoptotic effects on leukemia cells HL-60.