Fig. 6. Effects of RAW 264.7 macrophage-conditioned media: non-treated (CM-NT) or PBP-treated (CM-PBP) on the M1/M2 macrophage subtype following co-culture with 4T1 cells. Cells were co-cultured in 50% CM for 72 h. Cell cultures of the following control groups were also performed: RAW 264.7 macrophages alone (RAW), 4T1 cells alone (4T1), cells co-cultured in fresh 1% FBS/DMEM medium (vehicle), cells stimulated with only PBP (PBP) and original RAW 264.7 macrophage-conditioned media (CM-NT only and CM-PBP only for cytokine measurements). M1 macrophage polarization was assessed using the following markers: determination of IL-6 and TNF-α levels and activity of inducible nitric oxide synthase (iNOS). The concentrations of IL-10 and TGF-β, and arginase 1 activity were indicative of M2 macrophage polarization. Data are shown as the mean ± SEM of six independent experiments. Asterisks indicate significant differences between the vehicle and the all other tested groups (***P<0.001; **P<0.01, *P<0.05). Hash marks show significant differences between CM-NT and CM-PBP or CM-NT only and CM-PBP only, respectively ^{(# # #}P<0,001; ^{# #}P<0.01, ^#P<0.05).