RESUMO
The apolar fraction F1 of Thalassia testudinum was chemically characterized by gas chromatography-mass spectrometry, which led to the identification of 43 metabolites, all of them reported for the first time in the genus Thalassia. More than 80% of the F1 composition was constituted by aromatic metabolites including the major components 1,1-bis(p-tolyl)ethane (6.0%), 4,4'-diisopropylbiphenyl (4.8%) and a 1,1-bis(p-tolyl)ethane isomer (4.7%). This lipophilic fraction was assayed for its antioxidant effects and skin protective action. In vitro assays showed that F1 strongly scavenged DPPH* (IC(50) 312.0 ± 8.0 µg mL(-1)), hydroxyl (IC(50) 23.8 ± 0.5 µg mL(-1)) and peroxyl radical (IC(50) 6.6 ± 0.3 µg mL(-1) ), as well as superoxide anion (IC(50) 50.0 ± 0.7 µg mL(-1)). Also, F1 markedly inhibited the spontaneous lipid peroxidation (LPO) in brain homogenates (IC(50) 93.0 ± 6.0 µg mL(-1)) and the LPS-stimulated nitrite generation on RAW624.7 macrophages (58.6 ± 3.2%, 400 µg mL(-1)). In agreement with these findings, its topical application at 250 and 500 µg cm(-2) strikingly reduced skin damage on mice exposed to acute UVB radiation by 45% and 70%, respectively and significantly attenuated the LPO developed following the first 48 h after acute exposure to UVB irradiation, as manifested by the decreased malondialdehide level and by the increased of reduced gluthatione content. Our results suggest that F1 may contribute to skin repair by attenuating oxidative stress due to its antioxidant activity.
Assuntos
Sequestradores de Radicais Livres/farmacologia , Radicais Livres/antagonistas & inibidores , Hydrocharitaceae/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Pele/efeitos dos fármacos , Protetores Solares/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/metabolismo , Radicais Livres/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Glutationa/análise , Glutationa/biossíntese , Interações Hidrofóbicas e Hidrofílicas , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Lipopolissacarídeos/efeitos adversos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Malondialdeído/análise , Camundongos , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Pele/metabolismo , Pele/efeitos da radiação , Protetores Solares/química , Protetores Solares/metabolismo , Extratos de Tecidos/metabolismo , Raios Ultravioleta/efeitos adversosRESUMO
Se realizaron estudios de una nueva formulación (gel del Vimang), para evaluar en este caso parámetros histopatológicos, de un modelo in vivo; partiendo del antecedente que por resultados in vitro se sabe que el Vimang posee propiedades antioxidantes