RESUMO
BACKGROUND: Resveratrol (RSV) has attracted interest as an alternative drug for the treatment of acute lung injury (ALI) and other pulmonary diseases, but its poor oral bioavailability is a limitation. In this study, we employed drug delivery nanotechnology to improve the stability, lung localization and efficacy of orally administered resveratrol to control lung damage leading to ALI. METHODS AND MATERIALS: RSV-loaded lipid-core nanocapsules (RSV-LNCs), prepared by interfacial deposition of biodegradable polymers, were given orally to A/J mice prior to lipopolysaccharide (LPS) intranasal instillation. Inflammatory changes, oxidative stress and lung tissue elastance were assessed 24 h after LPS challenge. RESULTS: RSV-LNCs (5 mg/kg), given 1, 4, 6 or 12 h but not 24 h before provocation, inhibited LPS-induced leukocyte accumulation in the bronchoalveolar fluid (BALF), whereas unloaded nanocapsules (ULNCs) or free RSV (5 mg/kg) were ineffective. RSV-LNCs (2.5-10 mg/kg) but not ULNCs or RSV improved lung function and prevented total leukocyte and neutrophil accumulation equally in both BALF and lung tissue when given 4 h before LPS challenge. Similar findings were seen concerning the generation of a range of pro-inflammatory cytokines such as IL-6, KC, MIP-1α, MIP-2, MCP-1 and RANTES in lung tissue. In addition, only RSV-LNCs inhibited MDA levels and SOD activity in parallel with blockade of the ERK and PI3K/Akt pathways following LPS provocation. CONCLUSION: Nanoformulation of RSV in biodegradable oil-core polymers is an effective strategy to improve the anti-ALI activity of RSV, suggesting that the modified-release formulation of this plant polyphenol may be of great value in clinical conditions associated with ALI and respiratory failure.