Figure 3.

Effect of compounds 1–6 on colony formation of human colorectal carcinoma HT-29, melanoma RPMI-7951, and breast cancer MDA-MB-231 cell lines. HT-29, RPMI-7951, and MDA-MB-231 cells (2.4 × 10⁴ /mL) treated with/without investigated 1–6 (0.1, 0.5, and 1 µM) and subjected into a soft agar. The culture was maintained at 37 °C in a 5% CO₂ atmosphere for 2 weeks. The colonies were counted under a microscope with the aid of the ImageJ software program (n = 6 for control and each compound, n—quantity of photos). The asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001) indicate a significant decrease in colony formation in cells treated with compounds compared with the nontreated cells (control).