Suppressing effects of dietary supplementation of the organoselenium 1,4-phenylenebis(methylene)selenocyanate and the Citrus antioxidant auraptene onlung metastasis of melanoma cells in mice

The modifying effects of the organoselenium 1,4-phenylenebis(methylene)sele nocyanate (p-XSC) and the Citrus antioxidant auraptene as dietary supplemen ts on experimental pulmonary metastasis of B16BL6 murine melanoma cells wer e investigated in an i.v. injection model in mice. Seven groups of male C57 BL/6 mice were fed a basal diet (control group) or the basal diet supplemen ted with p-XSC (4, 8, or 15 mg/kg) or auraptene (250, 500, or 1000 mg/kg). All mice were fed their respective diet for 2 weeks before and after i.v. i njection of 1 x 10(5) viable melanoma cells. At termination of the study, t he incidence of lung metastatic tumors was determined. Cross-sectional area s and tumor volumes were analyzed morphometrically, In addition, apoptotic indices of lung metastatic tumors of all groups were counted. The incidence s of lung metastasis In mice Fed the diet mixed with 8 or 15 mg p-XSC/kg we re significantly smaller than that in mice fed the basal diet. The mean num bers of metastatic lung tumors were significantly lower in mice fed p-XSC ( 4, 8, and 15 mg/kg) and auraptene (500 and 1000 mg/kg) than in controls. Cr oss-sectional areas and volumes of the tumors were also significantly decre ased in mice given p-XSC (8 or 15 mdg/kg) and auraptene (500 mg/kg, Apoptot ic indices in mice fed the diets mixed with p-XSC (4, 8, or 15 mg/kg) and a uraptene (500 and 1000 mg/kg) were significantly greater than those in the control group, These results indicate that in mice, diet supplementation wi th p-XSC and auraptene reduces pulmonary metastasis of B16BL6 melanoma cell s and inhibits the growth of these metastatic tumors in lung, in part, by i nducing apoptosis, We suggest that these agents, especially p-XSC, mag be v aluable in preventing metastatic diseases in future studies in the clinic.