We investigated the effect of epigallocatechin-gallate (EGCG), the main constituent of green tea polyphenols, on human glioblastoma cell lines U-373 MG and U-87 MG, rat glioma cell line C6, and rat nonfunctioning pituitary adenoma cell line MtT/E.Cell viability was determined by assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and the extent of apoptosis was studied by ow cytometric analysis.Apoptosis was also characterized by morphology using uorescent microscopy.The role of insulin-like growth factor-I (IGF-I) was studied by assay with MTT, immunohistochemistry, and immunoradiometric assay.After 72-h exposure, a statistically signi cant loss of viability (P = < 0.0001) was observed at concentrations of 12.5, 25, 50, and 100 µg/ml in U-373 MG cells and U-87 MG cells.EGCG at concentrations of 50 µg/ml and higher signi cantly reduced the viability of C6 cells.EGCG inhibited viability of MtT/E cells only at a concentration of 100 µg/ml.Quantitative study by ow cytometry demonstrated that lower doses of EGCG (12.5, 25, 50 µg/ml) induced apoptosis in U-373 MG, U-87 MG, and C6 cells; however, only the highest dose (100 µg/ml) induced apoptosis in MtT/E cells.Compared with other cell lines, MtT/E cells showed stronger IGF-I immunoreactivity.Neutralization of IGF-I with an antihuman IGF-I antibody reduced viability of the cell lines.It can be concluded that EGCG has an inhibitory effect on malignant brain tumors, and IGF-I may be involved in the effects of EGCG.
In this paper, we present an algorithm to compute a basis of the space of algebraic modular forms on the maximal order of the definite quaternion algebra of discriminant $2$, and provide a database of such bases. One of our motivations is to study congruence relations of algebraic modular forms.
