Figure 3
Enhancement of PEA effects on B16 cell viability by hydrolysis inhibitors. (A) The FAAH inhibitors (URB597, CAY10402) and dual FAAH/MAGL inhibitors (MAFP, CAY10499) potentiate PEA cytotoxicity. B16 cells were seeded 5 h before treatment (2000 cells/well in microwells) and incubated with PEA (10 μM) with or without URB597, CAY10402, MAFP, CAY10499 or CCP (at 10 μM). After 72 h of treatment, cytotoxicity was assessed by a MTT test. Data are the mean of three experiments (performed in quintuplicate) and are expressed as percentage of the vehicle control. Significantly different (**P < 0.01) from PEA incubation. (B) URB597, MAFP and CAY10499 slightly decrease B16 cell viability. Cells were seeded 5 h before treatment (2000 cells/well in microwells) and incubated with inhibitors at a concentration of 10 μM. After 72 h of treatment, cytotoxicity was assessed by a MTT test. Data are the mean of three experiments performed in quintuplicate and are expressed as percentage of the vehicle control. Significantly different (**P < 0.01) from vehicle incubation. (C) URB597 increases intracellular levels of PEA as measured by HPLC-MS. B16 cells were incubated for 8 h with URB597 (1 μM). We found in control cells 25.4 ± 3.8 pmol of PEA/107 cells. Data are the mean of three experiments performed in quadruplicate and are expressed as percentage of the vehicle control. Significantly different (***P < 0.001) from vehicle incubation.