Anti-proliferative action of silibinin on human colon adenomatous cancer HT-29 cells / Acción anti-proliferativa de silibinina sobre el cáncer adenomatoso de colon humano las células HT-29

Background: Silibinin a flavonoid from milk thistle(Silybum marianum) exhibit a variety of pharmacological actions, including anti-proliferative and apoptotic activities against various types of cancers in intact animals and cancer cell lines. In the present study, the effect of silibininon human colon cancer HT-29 cells was studied. Method: Incubations of cells with different silibinin concentrations (0.783-1,600 ug/ml) for 24, 48 or 72 h showed a progressive decline in cell viability. Results: Loss of cell viability was time dependent and optimum inhibition of cell growth (78%) was observed at72 h. Under inverted microscope, the dead cells were seenas cell aggregates. IC50 (silibinin concentration killing50% cells) values were 180, 110 and 40ug/ml at 24, 48 and72 h respectively. Conclusion: These findings re-enforce the anticancer potential of silibinin, as reported earlier for various other cancer cell lines (Ramasamy and Agarwal (2008), Cancer Letters, 269: 352-62) (AU)

Antecedentes: Silibinina un flavonoide a partir de laleche de cardo mariano (Silybum marianum) exhiben una variedad de acciones farmacológicas, incluyendo actividad esantiproliferativos y apoptóticos contra varios tipos de cánceres en animales intactos y líneas celulares de cáncer. En el presente estudio, se estudió el efecto de silibinina en células humanas de cáncer de colon HT-29.Método: Las incubaciones de las células con diferentes concentraciones silibinin (0,783-1.600 ug/ml) para 24, 48o 72 horas mostró un descenso progresivo de la viabilidad celular. Resultados: La pérdida de la viabilidad celular fue de tiempo de inhibición dependiente y óptima de crecimiento de las células (78%) se observó a las 72 horas. Bajo microscopio invertido, las células muertas fueron vistos como los agregados de células. IC50 (concentración de silibinina matar a las células 50%) los valores fueron 180,110 y 40 ug/ml a las 24, 48 y 72 horas, respectivamente. Conclusión: Estos resultados volver a hacer cumplir la potenciales contra el cáncer de silibinina, como se informó anteriormente para varias otras líneas celulares de cáncer (Ramasamy y Agarwal (2008), Cancer Letters,269: 352-62) (AU)

Effect of antioxidant supplementation on digestive enzymes in radiation induced intestinal damage in rats.

PURPOSE: Intestinal mucosa, a rapidly proliferating tissue, is highly sensitive to radiation and undergoes apoptosis as a consequence of over generation of oxidative free radicals and the lack of the antioxidants. Thus the present study was designed to investigate the intestinal damage induced by radiation and to study if supplementation of the diet with antioxidant vitamins could ameliorate the intestinal damage and its digestive activity, as determined by the expression of various border enzymes. MATERIALS AND METHODS: Swiss Albino rats (150-200 g body weight) were divided into six groups. Group I: Control untreated; Group II: Irradiated; Group III: Irradiated + vitamin A; Group IV: Irradiated + vitamin C; Group V: Irradiated + vitamin E; and Group VI: Irradiated + lycopene. Animals were exposed to whole body γ-radiation from (60)Co at the rate of 8 Gy for 15 min/rat. Intestinal morphology and changes in various digestive enzymes together with, DNA damage was studied in six groups and each group consisted of 18 animals. RESULTS: The gastrointestinal toxicity resulted in malabsorption, diarrhoea, weight loss, loss of appetite, abdominal haemorrhage and hair loss. The activities of sucrase and alkaline phosphatase were elevated and those of lactase, leucine aminopeptidase (LAP) and gamma-glutamyl transpeptidase or tranferase (γ-GTP) were markedly reduced. Antioxidant vitamin A, C or E supplementations prevented changes in brush border enzyme activities as compared to lycopene administration in rat intestine by radiation exposure. Intestinal histology showed that the vitamin supplementation to irradiated rats minimized the intestinal damage in rats. CONCLUSION: These findings suggest that the epithelial lining of the intestine is highly sensitive to radiation exposure and supplementation of antioxidant vitamins is helpful in minimizing the intestinal damage and supplementation by vitamin E was most potent in ameliorating the intestinal aberrations.