Contributory roles of innate properties of cetyl alcohol/gelucire nanoparticles to antioxidant and anti-inflammation activities of quercetin.

The protective effects of synthetic lung surfactant Exosurf® (containing cetyl alcohol) against endotoxin-induced inflammation have been demonstrated in the literature. Thus, it is envisioned that nanoparticles loaded with quercetin (Q-NPs) prepared with binary mixtures of cetyl alcohol (CA) and Gelucire 44/14® (gelucire) as matrix materials will be capable of overcoming some of the protracted challenges confronting clinical application of quercetin and possess innate protective activity against inflammatory responses, which could be synergistic with quercetin. The NPs were stable in simulated biological media while retaining their particle size and spherical morphology. Further analysis by gel permeation chromatography, spectroscopic analysis (ultraviolet-visible, fluorescence, and Fourier transform infrared spectroscopy) indicated entrapment of quercetin in NPs. Q-NPs effectively enhanced xanthine oxidase inhibitory and free radical scavenging effect of quercetin. Furthermore, Q-NPs showed marked reduction (compared to quercetin alone) in production of nitric oxide and cytokine (interleukin-6 and tumor necrosis factor alpha) from lipopolysaccharide-activated macrophages. Superiority of Q-NPs over quercetin alone was confirmed from in vivo anti-inflammatory efficacy studies in BALB/c mice. Data from additional studies with blank NPs (without quercetin) showed that the NPs reported herein most likely possessed intrinsic protective properties against LPS-induced inflammation. Although further mechanistic studies are warranted, the overall work depicted a novel approach of possible exploiting innate protective properties of NPs in quercetin delivery for treating oxidative stress and inflammation.