Cytotoxic effects of the synthetic oestrogens and androgens on Balb/c 3T3 and HepG2 cells

The aim of the study was to test and compare the cytotoxic potential of two synthetic oestrogens: diethylstilboestrol (DES) and ethinyloestradiol (EE₂) and two androgens: testosterone propionate (TP) and trenbolone (TREN) on two cell lines. The fibroblast cell line Balb/c 3T3 and the hepatoma cell line HepG2 were selected. To get more insight into the mode of toxic action, four methods were used, which evaluated different biochemical endpoints: mitochondrial activity (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide reduction assay), lysosomal activity (neutral red uptake assay), total protein content, and lactate dehydrogenase release. Cytotoxicity was assessed after 24, 48, and 72 h exposure to eight concentrations ranging from 0.78 to 100 μg/mL. Concentration- and time- dependent effects were observed. Depending on the line and assay used, half maximal effective concentration after 72 h (EC_50-72h) values ranged as follows: DES 1-13.7 μg/mL (Balb/c 3T3) and 3.7-5.2 μg/mL (HepG2); EE₂ 2.1-14.3 μg/mL (Balb/c 3T3) and 1.8-7.8 μg/mL (HepG2); TP-14.9-17.5 μg/mL (Balb/c 3T3), and 63.9- 100 μg/mL (HepG2); and TREN 11.3-31.4 μg/mL (Balb/c 3T3) and 12.5-59.4 μg/mL (HepG2). The results revealed that oestrogens were more toxic than androgens and the most affected endpoint was mitochondrial activity. In contrast to oestrogens, for which EC_50-72h values were similar in both lines and by all assays used, Balb/c 3T3 cells were more sensitive than HepG2 cells to TP.