RESUMEN
Cancer prevention is one of the most urgent problems in the field of public health worldwide. The methanol extract of watercress ( Nasturtium officinale) inhibits 12-O-tetradecaonoylphorbol-13-acetate (TPA)-induced ear edema in mice. The extract also exhibits marked antitumor activity in in vivo two-stage carcinogenesis test in mice using 7,12-dimethylbenz[α]anthracene as an initiator and TPA as a promoter. From the active fraction of the methanol extract, sitosterol 3-O-glucopyranoside (1) was isolated and identified. This compound was evaluated for its inhibitory effects on TPA-induced inflammation (1 µg/ear) in mice, and had a 50% inhibitory dose of 299 nmol/ear. These results indicate that watercress extracts are useful in cancer prevention.
RESUMEN
Cancer prevention is an important issue in the field of public health. In Oriental countries, Eucommia bark (the bark of <i>Eucommia ulmoides</i>) is used in tonics and anti-hypertensive medicines. Eucommia bark has inhibitory activity against 12-<i>O</i>-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. We demonstrated that at a dose of 1 mg/mouse, a methanol extract of Eucommia bark markedly inhibited the tumour-promoting activity of TPA in mice with skin tumour formation following initiation with 7,12-dimethylbenz[<i>a</i>]anthracene (DMBA). These results suggest the potential use of Eucommia bark in cancer prevention.<br>
RESUMEN
Chaga (the sclerotia of <i>Inonotus obliquus</i>) has been widely used as a folk medicine in the treatment of cancer, cardiovascular disease and diabetes in Russia, Poland, and several Baltic countries. More recently, this herb has been assessed for its cancer-preventing activity. Using a mouse model of skin cancer, oral administration of Chaga was found to inhibit tumor promotion by 12-<i>O</i>-tetradecanoylphorbol-13-acetate following initiation with 7,12-dimethylbenz[<i>a</i>]anthracene in mouse skin.<br>
RESUMEN
The incidence of tumor and the time of expression, cellular localization and the molecular weight of tumor associated proteins of rat skin tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA) with or without 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were studied. The time of the development of skin tumors in 0.1% DMBA-TPA treated rats was significantly shorter than that in rats which were treated with DMBA alone. In the complete carcinogenesis case, papillomas developed more slowly and were less common and also squamous cell carcinomas appeared much later. From the analysis of the proteins of each experimental group by SDS-PAGE and two dimensional gel electrophoresis, at least three tumor associated proteins were identified (54kd, pl = 5.66; 27kd, pl = 5.85; 11kd, pl = 4.90). Also these proteins were found in rat dorsal skin from 14 days gestation to 21 days postpartum, and disappeared after 28 days. In conclusions, two stage skin carcinogenesis could be successfully demonstrated in Sprague-Dawley rats and abnormal proteins were produced in DMBA or DMBA-TPA induced skin tumor. The tumor associated proteins of skin tumor induced by DMBA or DMBA-TPA were appeared at the late initiation stage or early promotion stage, and they were localized in plasma membrane and were glycoproteins that are thought to be related to the epidermal differentiation process.
Asunto(s)
Ratas , 9,10-Dimetil-1,2-benzantraceno , Animales , Antígenos de Superficie/análisis , Carcinoma de Células Escamosas/análisis , Membrana Celular/metabolismo , Estudio Comparativo , Glicoproteínas/análisis , Proteínas de la Membrana/análisis , Papiloma/análisis , Ratas Endogámicas , Neoplasias Cutáneas/análisis , Acetato de TetradecanoilforbolRESUMEN
The incidence of tumor and the time of expression, cellular localization and the molecular weight of tumor associated proteins of rat skin tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA) with or without 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were studied. The time of the development of skin tumors in 0.1% DMBA-TPA treated rats was significantly shorter than that in rats which were treated with DMBA alone. In the complete carcinogenesis case, papillomas developed more slowly and were less common and also squamous cell carcinomas appeared much later. From the analysis of the proteins of each experimental group by SDS-PAGE and two dimensional gel electrophoresis, at least three tumor associated proteins were identified (54kd, pl = 5.66; 27kd, pl = 5.85; 11kd, pl = 4.90). Also these proteins were found in rat dorsal skin from 14 days gestation to 21 days postpartum, and disappeared after 28 days. In conclusions, two stage skin carcinogenesis could be successfully demonstrated in Sprague-Dawley rats and abnormal proteins were produced in DMBA or DMBA-TPA induced skin tumor. The tumor associated proteins of skin tumor induced by DMBA or DMBA-TPA were appeared at the late initiation stage or early promotion stage, and they were localized in plasma membrane and were glycoproteins that are thought to be related to the epidermal differentiation process.