RESUMEN
Nobiletin and 3,5,6,7,8,3',4'-heptamethoxyflavone (HPT), isolated from the peel of Citrus plants, were examined for the anti-tumor-initiating activity on two-stage carcinogenesis of mouse skin tumors induced by a nitric oxide donor, (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexenamide, as an initiator and 12-O-tetradecanoylphorbol-13-acetate as a promoter. HPT exhibited the remarkable anti-tumor-initiating effect on mouse skin and it suggested the possibility of HPT being a chemopreventive agent against nitric oxide (NO) carcinogenesis.
Asunto(s)
Citrus/química , Flavonas , Flavonoides/farmacología , Neoplasias Cutáneas/prevención & control , 9,10-Dimetil-1,2-benzantraceno/administración & dosificación , Animales , Anticarcinógenos/farmacología , Carcinógenos/administración & dosificación , Femenino , Ratones , Nitrocompuestos/administración & dosificación , Papiloma/inducido químicamente , Papiloma/prevención & control , Extractos Vegetales/química , Extractos Vegetales/farmacología , Neoplasias Cutáneas/inducido químicamente , Organismos Libres de Patógenos Específicos , Acetato de Tetradecanoilforbol/efectos adversos , Factores de TiempoRESUMEN
To search for possible anti-tumor promoters, thirteen flavones (1-13) obtained from the peel of Citrus plants were examined for their inhibitory effects on the Epstein-Barr virus early antigen (EBV-EA) activation by a short-term in vitro assay. Of these flavones, 3,5,6,7,8,3',4'-heptamethoxyflavone (HPT) (13) exhibited significant inhibitory effects on the EBV-EA activation induced by the tumor promoter, 12-O-tetradecanoylphorbol 13-acetate (TPA). Further, compound 13 exhibited remarkable inhibitory effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.
Asunto(s)
Antígenos Virales/metabolismo , Flavonoides/farmacología , Papiloma/metabolismo , Extractos Vegetales/farmacología , Neoplasias Cutáneas/metabolismo , Activación Viral/efectos de los fármacos , Animales , Femenino , Flavonoides/química , Flavonoides/aislamiento & purificación , Ratones , Ratones Endogámicos ICR , Papiloma/inducido químicamente , Papiloma/tratamiento farmacológico , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Neoplasias Cutáneas/inducido químicamente , Neoplasias Cutáneas/tratamiento farmacológico , Acetato de Tetradecanoilforbol , Factores de TiempoRESUMEN
Four new furanone-coumarins, clauslactones-N (4), -O (5), -P (6) and -Q (7) were isolated from the leaves and twigs of Clausena excavata BURM. f. (Rutaceae) collected in Indonesia and their structures were elucidated by spectroscopic analysis.
Asunto(s)
4-Butirolactona/análogos & derivados , Cumarinas/química , Extractos Vegetales/química , 4-Butirolactona/química , Espectroscopía de Resonancia Magnética , Modelos QuímicosRESUMEN
To search useful compounds in Citrus fruit for cancer chemoprevention, we carried out a primary screening of extracts of fruit peels and seeds from 78 species of the genus Citrus and those from two Fortunella and one Poncirus species, which were closely related to the genus Citrus. These Citrus extracts inhibited the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) as a useful screening method for anti-tumor promoters. Our results indicated that Citrus containing substances may be inhibit susceptibility factors involved in the events leading to the development of cancer.
Asunto(s)
Anticarcinógenos/farmacología , Citrus/química , Herpesvirus Humano 4/crecimiento & desarrollo , Activación Viral/efectos de los fármacos , Animales , Antígenos Virales/fisiología , Antivirales/farmacología , Linfoma de Burkitt/tratamiento farmacológico , Carcinógenos , Embrión de Pollo , Ensayos de Selección de Medicamentos Antitumorales , Herpesvirus Humano 4/efectos de los fármacos , Humanos , Extractos Vegetales/farmacología , Semillas/química , Acetato de Tetradecanoilforbol , Células Tumorales CultivadasRESUMEN
Twenty-five acridone alkaloids from Citrus plants were examined for their inhibitory effects on Epstein-Barr virus activation by a short-term in vitro assay. 5-Hydroxynoracronycine (20) and acrimarine-F (25) showed remarkable inhibitory effects.