Inflammation is the principal response invoked by the body to address injuries. Despite inflammation constituting a crucial component of tissue repair, it is well known that unchecked or chronic inflammation becomes deleterious, leading to progressive tissue damage. Studies over the past years focused on foods rich in polyphenols with anti-inflammatory and immunomodulatory properties, since inflammation was recognized to play a central role in several diseases. In this review, we discuss the beneficial effects of resveratrol, the most widely investigated polyphenol, on cancer and neurodegenerative, respiratory, metabolic, and cardiovascular diseases. We highlight how resveratrol, despite its unfavorable pharmacokinetics, can modulate the inflammatory pathways underlying those diseases, and we identify future opportunities for the evaluation of its clinical feasibility.
1 November 2013 in Neurobiology of Learning and Memory
Several studies have reported that orally ingested trans-resveratrol is extensively metabolized in the enterocyte before it enters the blood and target organs. Additionally, trans-resveratrol is photosensitive, easily oxidized and presents unfavorable pharmacokinetics. Therefore, it is of great interest to stabilize trans-resveratrol in order to preserve its biological activities and to improve its bioavailability in the brain. Here, trans-resveratrol was loaded into lipid-core nanocapsules and analyzed for particle size, polydispersity and zeta potential. The nanocapsule distribution in brain tissue was evaluated by intraperitoneal (i. p.) and gavage routes in healthy rats. The lipid-core nanocapsules had a mean diameter of 241 nm, a polydispersity index of 0.2, and a zeta potential of –15 mV. No physical changes were observed after 1, 2 and 3 months of storage at 25 °C. Lipid-core nanocapsules showed high entrapment of trans-resveratrol and displayed a higher trans-resveratrol concentration in the brain, the liver and the kidney after daily i. p. or gavage administration than that observed for the free trans-resveratrol. Because trans-resveratrol is a potent cyclooxygenase-1 inhibitor, gastrointestinal damage was evaluated. The animals that were administered with trans-resveratrol-loaded lipid-core nanocapsules showed significantly less damage when compared to those administered with free trans-resveratrol. In summary, lipid-core nanocapsules exhibited great trans-resveratrol encapsulation efficiency. trans-Resveratrol-loaded lipid-core nanocapsules increased the concentration of trans-resveratrol in the brain tissue. Gastrointestinal safety was improved when compared with free trans-resveratrol. Thus, trans-resveratrol-loaded lipid-core nanocapsules may be used as an alternative potential therapeutic for several diseases including Alzheimer's disease.
Based on the structure of polymeric nanocapsules containing a lipid-dispersed core composed of caprylic/capric trygliceride (CCT) and sorbitan monostearate (SM), we hypothesized that varying the core component concentrations the drug release kinetic could be modulated. Our objective was also to determine the parameters which were responsible for controlling the drug release kinetics. The nanocapsules were prepared by interfacial deposition of poly(epsilon-caprolactone). Interfacial hydrolysis of indomethacin ester (IndOEt) was used to simulate a sink condition of release. Mathematical modeling showed that the IndOEt half-lives increased (198 to 378 and 263 to 508 min) with the increase in the core lipid concentrations, and that the release mechanism was the anomalous transport. By increasing the SM concentration, the diameters were constant (around 250 nm) and the surface areas increased (from 1.06 × 104 to 1.51 × 104 cm2 ⋅ ml–1), while by increasing the CCT concentration, the diameters increased (215 to 391 nm) and the surface areas reduced (1.46 × 104 to 1.06 × 104 cm2 ⋅ ml–1). The presence of SM increased the viscosity of CCT and the IndOEt apparent permeability decreased from 4.26 × 10–7 to 2.54 × 10–7 cm ⋅ s–1, while for CCT series, the apparent permeability was constant around 3.0 × 10–7 cm ⋅ s–1. A mathematical correlation was established and the IndOEt apparent permeability can be estimated by the SM concentration. In conclusion, varying the CCT and SM concentrations the IndOEt release was controlled by the nanocapsule surface area and by the viscosity of the core, respectively.