2.6. Prostate Cancer Proliferation Assay

The experiments were carried out under aseptic conditions, i.e. through the use of a class 2 biosafety cabinet (Thermoscientific™, USA) that had been sterilized with ultraviolet light and 70% ethanol prior to and after usage. Each PCa cell line was harvested when 90% confluent, and seeded at a density of 2500 cells/well in 96-well plates. The cells were subsequently incubated overnight as described previously (Section 2.3). All sixteen extracts were then added to the wells at gradient concentrations (0.94–20 mg dry tomato equivalent/mL) through a series of serial dilutions. Following incubation for 96 h, cell proliferation was measured using the SRB assay [28]. A dose-response curve, for each extract and cell line, was then generated using IBM® SPSS® Statistics version 22 (IBM, USA). The dose-response curves were then used for calculating the half-maximal inhibitory concentration (IC50) of the extracts. This experiment was performed for two biological repeats and four technical repeats.