The oral delivery of avenanthramide-C encapsulated by barley self-assembly peptides reduces high-fat diet-induced brain oxidative stress and inflammation

Avenanthramide-C (AVN-C) is a phenolic compound derived from oats with numerous biological activities, such as anti-oxidant, anti-inflammation, neuroprotection, etc. However, the bioavailability of AVN-C is low due to poor water solubility and stability in the gastrointestinal tract, which restricts its application. In this study, the barley self-assembly peptides were employed to load AVN-C to improve its stability and bioavailability as the form of nanoparticles. The results showed that the bioaccessibility of AVN-C in nanoparticles reached nearly 50%, while that of the free AVN-C was less than 10% during gastrointestinal digestion, and the pharmacokinetic studies indicated that the C_max and area under curve (AUC) of AVN-C-loaded nanoparticles were about 3 times as free AVN-C, indicating a significantly increased bioavailability. Notably, the T_max changed from 30 min to 45 min, indicating a sustained release of the AVN-C-loaded nanoparticles. Moreover, the brain delivery effects of AVN-C-loaded nanoparticles were determined by using high-fat diet (HFD)-induced mice. The results showed that the AVN-C-loaded nanoparticles could suppress oxidative stress and inhibit the expression of inflammatory factors, TNF-α and IL-1β, in the HFD mice brain. Transcriptomic analysis indicated an alteration of gene expression profiles after the delivery of nanoparticles. In a word, the nanoparticles formed by barley self-assembling peptides improved the in vivo stability and bioavailability of AVN-C and facilitated the exertion of its biological activity.