RESUMO
Excessive UV-B radiation by sunlight produces inflammatory and oxidative damage of skin, which can lead to sunburn, photoaging, and cancer. This study evaluated whether nanoencapsulation improves the protective effects of rice bran oil against UVB radiation-induced skin damage in mice. Lipid-core nanocapsules containing rice bran oil were prepared, and had mean size around 200 nm, negative zeta potential (â¼-9 mV), and low polydispersity index (<0.20). In order to allow application on the skin, a hydrogel containing the nanoencapsulated rice bran oil was prepared. This formulation was able to prevent ear edema induced by UVB irradiation by 60 ± 9%, when compared with a hydrogel containing LNC prepared with a mixture of medium chain triglycerides instead of rice bran oil. Protein carbonylation levels (biomarker of oxidative stress) and NF-κB nuclear translocation (biomarker of pro-inflammatory and carcinogenesis response) were reduced (81% and 87%, respectively) in animals treated with the hydrogel containing the nanoencapsulated rice bran oil. These in vivo results demonstrate the beneficial effects of nanoencapsulation to improve the protective properties of rice bran oil on skin damage caused by UVB exposure.
Assuntos
Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Portadores de Fármacos , Edema/prevenção & controle , Nanopartículas , Óleos de Plantas/administração & dosagem , Pele/efeitos dos fármacos , Queimadura Solar/prevenção & controle , Raios Ultravioleta , Animais , Anti-Inflamatórios/química , Antioxidantes/química , Química Farmacêutica , Citoproteção , Modelos Animais de Doenças , Edema/metabolismo , Edema/patologia , Hidrogéis , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , NF-kappa B/metabolismo , Nanomedicina , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Óleos de Plantas/química , Carbonilação Proteica/efeitos dos fármacos , Óleo de Farelo de Arroz , Pele/metabolismo , Pele/patologia , Queimadura Solar/metabolismo , Queimadura Solar/patologia , Tecnologia Farmacêutica/métodosRESUMO
In this study we assessed the involvement of monoamine oxidase B (MAO-B), a key enzyme implicated in monoamine metabolism, on postoperative (plantar incision) and neuropathic (partial sciatic nerve ligation) pain models in mice. Paw incision submitted mice showed a significant decrease in mechanical threshold compared with the sham-operated mice, characterizing the development of mechanical allodynia. The selective and irreversible MAO-B inhibitor selegiline, at a dose sufficient to selectively inhibit MAO-B activity (10 mg/kg), showed an anti-allodynic effect from 0.5 to 6 h after incision. Likewise, partial sciatic nerve ligation submitted mice also developed mechanical allodynia, which was reversed by selegiline (10 mg/kg) from 2 to 6 h after treatment. In addition, a significant increase on striatal MAO-B activity was observed in neuropathic mice compared with the sham-operated animals, which was reversed by selegiline treatment. Taken together, our results showed that MAO-B seems to exert a critical role in the development of postoperative and neuropathic pain.