Chemoprevention of induced colonic aberrant crypt foci in rats by the combination of meloxicam and grapefruit juice

To explore the chemopreventive effects of meloxicam, grapefruit juice or the combination against the induction of colonic aberrant crypt foci in the rat model. Male albino rats were divided into 5 groups. In group A [positive control], rats received oral dimethylhydrazine, which in Group B, rats received oral meloxicam and dimethlhydrazine. Regarding group C, rats were allowed to drink grapefruit juice, ad.libitum, then received dimethlhydrazine, and in group D, rats received the combination [meloxicam and grapefruit juice]. Group E [negative control], received oral saline only. Blood samples were collected every week from group B and D for meloxicam analysis. All animals were sacrificed under ether anesthesia on the last day of the 15th weeks. Colon tissues were removed, cut open longitudinally, rinsed with saline and stained with 0.25% methylene blue and then examined microscopically for the presence of aberrant crypt follicle. Samples containing aberrant crypt foci were sectioned at 4 micro m thickness and stained with hematoxyline and eosin. Aberrant Crypt Foci [ACF] are considered as an early neoplastic cell lesions that are characterized by unstable colonic epithelia which encompasses many dysplastic crypts. The data obtained in this study revealed that rats which received meloxicam or the combination [meloxicam and grapefruit juice] resulted in a significant reduction in the incidence of aberrant crypt foci counts compared to the control group. While, rats allowed to only drink grapefruit juice, showed insignificant reduciotn of aberrant crypt foci count. Furthermore, a significant increase in plasma level of meloxicam was detected in rats that received the combination. It is concluded that the addition of grapefruit juice to meloxicam in the treatment resulted in a greater chemopreventive activity than meloxicam or grapefruit juice. Furthermore, grapefruit juice resulted in a significant rise of plasma level of meloxicam. This is the first time to report the interaction between meloxicam and grapefruit

Comportamiento del cáncer colorrectal humano en el ratón atímico / Behavior of human colorectal cancer in the athymic mouse

La obtención y caracterización de tumores colorrectales humanos, xenotrasplantdos en ratones atímicos constituye una práctica importante de la investigación oncológica contemporánea, cuyo empleo permitió obtener en nuestras condiciones el crecimiento de 9 (33 %) de los 27 tumores implantados, 5 de los cuales (55,5 %) constituyen ya tumores establecidos en tres o más pases seriados, sin que por ello se observen variaciones en sus características histológicas, grado de diferenciación o expresión del antígeno carcinoembrionario (CEA). Ninguna correlación entre el crecimiento tumoral en el ratón atímico y diversos factores epidemiológicos (raza, sexo y edad), clínicos (sintomatología, tiempo de evolución y estadiamiento) y morfofuncionales (tipo histológico, diferenciación y expresión CEA). puede ser establecida como criterio predictivo del comportamiento tumoral después del trasplante. La localización anatómica de la lesión primaria, sin embargo, mostró evidencias de un mejor comportamiento al xenotrasplante cuando los tumores procedían del colon proximal (ciego)