RESUMO
The ameliorating effect of the root extract of Platycodon grandiflorum (Campanulaceae) on ethanol-induced cognitive dysfunction in mice was investigated. The mice with repeated administration of the root extract of P. grandiflorum, crude saponin fraction and platycoside E, a main ingredient of crude saponin fraction, showed a markedly prolonged step-through latency period (STL) on the passive avoidance task performed after acute ethanol intoxication, respectively. The present results suggest that the memory enhancing effect of the extract was ascribed mainly to the saponin fraction and that saponin of P. grandiflorum, particularly platycoside E could exert a beneficial effect on memory impairment in mice.
Assuntos
Campanulaceae/química , Transtornos da Memória/prevenção & controle , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Saponinas/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Depressores do Sistema Nervoso Central/antagonistas & inibidores , Depressores do Sistema Nervoso Central/toxicidade , Cognição/efeitos dos fármacos , Cognição/fisiologia , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/prevenção & controle , Transtornos Cognitivos/psicologia , Modelos Animais de Doenças , Etanol/antagonistas & inibidores , Etanol/toxicidade , Masculino , Memória/efeitos dos fármacos , Memória/fisiologia , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/psicologia , Camundongos , Camundongos Endogâmicos ICRRESUMO
BACKGROUND: The purpose of the present study was to investigate the effects of vitamin E on oxidative stress and cell membrane fluidity in the liver of streptozotocin (STZ)-induced diabetic rats. METHODS: Sprague-Dawley male rats weighing 100 +/- 10 g were fed a vitamin E-free diet (the DM-0E group), a 40 mg vitamin E/kg diet (the DM-40E group), or a 400 mg vitamin E/kg diet (the DM-400E group). RESULT: Dietary vitamin E reduced the increased concentration of lipid peroxides in the liver tissues of diabetic rats through decreasing their increased phospholipase A(2) (PLA(2)) activity and phosphatidylethanolamine hydrolysis. However, vitamin E reduced the accumulation of superoxide radical and decreased the generation of oxidative damage substances, such as the carbonyl value, increased membrane fluidity and lowered oxidative damage. CONCLUSIONS: Vitamin E was found to be excellent for regulating the activity of PLA(2), reducing the generation of reactive oxygen species and damaging oxidative substances, and maintaining cell membrane fluidity in the liver of diabetic rats.
Assuntos
Diabetes Mellitus Experimental/enzimologia , Fígado/enzimologia , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosfolipases A/metabolismo , Vitamina E/administração & dosagem , Animais , Diabetes Mellitus Experimental/metabolismo , Relação Dose-Resposta a Droga , Hidrólise , Peroxidação de Lipídeos/fisiologia , Fígado/efeitos dos fármacos , Masculino , Fluidez de Membrana/efeitos dos fármacos , Fluidez de Membrana/fisiologia , Microssomos Hepáticos , Estresse Oxidativo/fisiologia , Fosfatidiletanolaminas/metabolismo , Fosfolipases A2 , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
A novel triterpenoid saponin, deapioplatycoside E (1) was isolated from the root extract of Platycodon grandiflorum, together with the seven known saponins 2 - 8, i. e., platycoside E (2), deapioplatycodin D3 (3), platycodin D3 (4), polygalacin D2 (5), platycodin D2 (6), deapioplatycodin D (7) and platycodin D (8). The structure of the new saponin 1 was determined on the basis of spectral analysis and chemical evidence. The crude saponin fraction (ED50: ca. 10 - 15 microg/mL) and compounds 6 - 8 (ED50: ca. 4 - 18 microg/mL) exhibited significant inhibition on the proliferation of five kinds of cultured human tumor cell lines, i. e., A549 (non-small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCT-15 (colon), in vitro.