Figure 2. Minimal effect of tryptophan metabolites 3-hydroxyanthranilic acid (3-HAA), 3-hydroxy-DL-kynurenine (3-HK), kynurenine, quinolinate and kynurenic acid on viability of human RCC cell lines.

Equal numbers of cells were plated in 96-well plates, treated (n = 6 wells/treatment) for three days with different doses of each metabolite then cell viability measured using an MTT assay. Data are an average of two independent experiments and representative of at least three experiments. *P ≤ 0.05.