Resveratrol-loaded nanoemulsion gel system to ameliorate UV-induced oxidative skin damage: from in vitro to in vivo investigation of antioxidant activity enhancement.

Abstract

In the present study resveratrol nanoemulsion gel was developed and optimized with the aim of enhancing the permeability and antioxidant activity against ultraviolet (UV)-induced oxidative skin damage. Droplet size, polydispersity index, drug permeation flux, permeability coefficient and drug deposition in skin of resveratrol-loaded nanoemulsion were found to be 65.00 ± 5.00nm, 0.171 ± 0.082, 144.50μg/cm2/h, 2.90 × 10-2cm/h and 45.65 ± 4.76%, respectively, whereas drug permeation flux, permeability coefficient and drug deposition in skin from nanoemulsion gel were found to be 107.70μg/cm2/h, 2.06 × 10-2cm/h and 62.65 ± 4.98%, respectively. Confocal studies depicted deeper penetration of resveratrol from nanoemulsion gel. Differential scanning calorimetry and Fourier-transform infrared spectrophotometer studies confirmed that nanoemulsion gel enhanced fluidization of stratum corneum lipids and conformational disruption of lipid bilayer, thereby enhancing skin permeation of resveratrol. Histopathology study of skin revealed that resveratrol-loaded nanoemulsion gel inhibited UV-induced spongosis, edema and epidermal hyperplasia response. Levels of glutathione, superoxide dismutase, catalase and protein carbonyl in the skin of UV-irradiated rats were significantly (p < 0.01) improved in the skin of animals treated with nanoemulsion gel. Experimental results suggested that nanoemulsion gel could be explored as a promising carrier for topical delivery of resveratrol for prevention of UV-induced oxidative skin damage owing to its enhanced permeability and retention effect.