ABSTRACT
Forty-seven plant extracts of 10 species of the genus Euphorbia (Euphorbiaceae) used by Colombian traditional healers for the treatment of ulcers, cancers, tumors, warts, and other diseases, were tested in vitro for their potential antitumour (antiproliferative and cytotoxic) and antiherpetic activity. To evaluate the capacity of the extracts to inhibit the lytic activity of herpes simplex virus type 2 (HSV-2) and the reduction of viability of infected or uninfected cell cultures, the end-point titration technique (EPTT) and the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colorimetric assay were used, respectively. The therapeutic index of the positive extracts for the antiviral activity was determined by calculating the ratio CC50 (50 percent cytotoxic concentration) over IC50 (50 percent inhibitory concentration of the viral effect). Five of the 47 extracts (11 percent) representing 3 out of 10 Euphorbia species (30 percent) exhibited antiherpetic action; the highest activity was found in the leaf/stem water-methanol extracts from E. cotinifolia and E. tirucalli. The therapeutic indexes of these two plant species were > 7.1; these extracts exhibited no cytotoxicity. Six extracts (13 percent) representing 4 plant species (40 percent) showed cytotoxic activity. The highest cytotoxicity was found in the dichloromethane extract obtained from E. cotinifolia leaves and the CC50 values for the most susceptible cell lines, HEp-2 and CHO, were 35.1 and 18.1 æg/ml, respectively
Subject(s)
Humans , Animals , Female , Cricetinae , Antiviral Agents , Euphorbia/chemistry , Herpesvirus 2, Human , Plant Extracts , Antiviral Agents , Cells, Cultured , Colombia , Colorimetry , Endpoint Determination , Plant ExtractsABSTRACT
El tejido epitelial gastrointestinal normal presenta estructuras glicoesfingolipídicas que son propias de los antígenos ABH, las cuales confieren propiedades biológicas esenciales, dirigen el recambio y el tráfico transcelular y tienen gran importancia para la interacción entre células durante el desarrollo, crecimiento y diferenciación. Está descripto que la glicosilación aberrante es un atributo común del crecimiento neoplásico y uno de los principales determinantes del fenómeno relacionado con el cáncer, como es el crecimiento invasivo de la metástasis. El objetivo de este trabajo fue estudiar la expresión de los antígenos ABH en células epiteliales de neoplasias gastrointestinales. Se trabajó con catorce muestras de tumores gastrointestinales en tacos de parafina aplicando la técnica SRCA (Specific Red Cell Adherence). Se demostró que en 13 de las 14 muestras hubo pérdida total o parcial, o cambio de la expresión antigénica