Palmitic acid

Palmitic acid (PA) binds TLR4 via the adaptor protein MD2 and that the TLR4 signal induced by this compound stimulates dendritic cells activation and maturation accompanied by a robust IL-1β response. It is a TLR4/MD-2 ligand. This chemical exerts pro-inflammatory activity through TLR4[1].

The INS-1 cells are seeded onto 96-well plates at 4,000 cells/well with 10% BSA and incubated with T0901317 (10 μmol/L), palmitic acid (250 μmol/L), a combination of T0901317 and this compound or PBS (mock control) for 24 or 48 h. After the treatment incubation, 20 μl of MTT solution (5 mg/mL MTT in PBS, pH 7.4) are added to each well, followed by incubation at 37°C for 4 h. The supernatants are removed from the wells and DMSO (15 μl/well) is added to dissolve the crystals. The optical density at a wavelength of 490 nm is measured using a microplate reader.

In a dose-dependent fashion, palmitic acid rapidly reduces mouse locomotor activity by a mechanism that did not rely on TLR4, MyD88, IL-1, IL-6 or TNFα but is dependent on fatty acid chain length. This compound induces anxiety-like behavior in mice while increasing amygdala-based serotonin metabolism[2].