Isoleucine-Proline-Proline (IPP) and Leucine-Lysine-Proline (LKP) are food-derived tripeptides whose antihypertensive functions have been demonstrated in hypertensive rat models. However, peptides display low oral bioavailability due to poor intestinal epithelial permeability and instability. IPP and LKP were formulated into nanoparticles using chitosan via ionotropic gelation and then coated with zein. Following addition of zein, a high encapsulation efficiency of 80% was obtained for the nanoparticle. In simulated gastric fluid, 20% cumulative release of the peptides was achieved after 2 h, whereas in simulated intestinal fluid, ~90% cumulative release was observed after 6 h. Higher colloidal stability (39-41 mV) was observed for the coated NP compared to uncoated ones (30-35 mV). In vitro cytotoxicity studies showed no reduction in cellular viability of human intestinal epithelial Caco-2 and HepG2 liver cells upon exposure to nanoparticle and nanoparticle components. Administration of nanoparticle encapsulating IPP and LKP by oral gavage to spontaneously hypertensive rats attenuated systolic blood pressure for 8 h. This suggests that the nanoparticle provide appropriate release to achieve prolonged hypotensive effects in vivo. In conclusion, chitosan-zein nanoparticles have potential as oral delivery system for the encapsulation of IPP and LKP.
What will audience learn from your presentation?
- Convert low value industrial co-streams into high value food supplements.
- Food derived peptides with a health promoting effect on lifestyle diseases such as hypertension.
- In this research we have used pharmaceutical drug assessment methods (in vitro, ex-vivo and in vivo) and adapted them for nutraceutical/food bioactive assessment.