Fabrication of Luteolin Loaded Zein-Caseinate Nanoparticles and its Bioavailability Enhancement in Rats.

Luteolin loaded zein nanoparticles (Lut-ZNP) were prepared by using sodium caseinate as an electrostatic stabilizer. The formulation of the nanoparticles was optimized. Lut-ZNP were spray-dried, and the physicochemical properties were characterized by SEM, XRD, FT-IR and DSC. Then, the bioavailability of luteolin in rats was determined. Under the formulation of luteolin, zein and sodium caseinate with mass ratio of 1:5:15, the particle size, ζ-potential, encapsulation efficiency and loading efficiency of Lut-ZNP were 171.8 nm, -49.05 mV, 85.85% and 3.15%, respectively. Luteolin existed in the nanoparticles with amorphous form. Lut-ZNP exhibited good redispersibility in water after drying. Compared with free luteolin, the solubility, stability and release of luteolin in Lut-ZNP were greatly improved. Besides, the fecal excretion of luteolin in rats was significantly reduced after oral administration of Lut-ZNP. In addition to native luteolin, its metabolites including sulfate, glucuronidate and methylated glucuronidate were found in rat plasma. Lut-ZNP significantly increased the plasma concentrations of luteolin and its metabolites, and the bioavailability of luteolin was enhanced by 2.92 times.

[Screening for lifespan-extension mutants with paraquat in Arabidopsis].

Genetic analyses of lifespan in model animals have revealed that extended lifespans are closely associated to increased resistance to oxidative stress. In the model plant Arabidopsis, late-flowering mutants are also found to be more tolerant to oxidative stress. However, Arabidopsis mutants with extended lifespans are poorly studied so far. In this study, a screening system for mutants with extended lifespans in Arabidopsis was established using paraquat, a potent herbicide that exacerbates O2-. radical production. The relationship between lifespan and resistance to oxidative stress was examined with one of the mutants, SFNA-9-4. Compared to that of wild type, the lifespan of SFNA-9-4 is significantly extended, and its resistance to oxidative stress is also significantly elevated. These results suggest that, as in Drosophila, paraquat can also be used to screen for mutants with extended lifespans in Arabidopsis.