Antidepressant‐like effect of rosmarinic acid during LPS‐induced neuroinflammatory model: The potential role of cannabinoid receptors/PPAR‐γ signaling pathway

Rosmarinic acid (RA), an ester of caffeic acid and 3, 4‐dihydroxyphenyllactic acid, has anti‐inflammatory and neuroprotective activities. Herein, this study investigated in silico the drug‐likeness and the potential molecular targets to RA. Moreover, it tested the antidepressant‐like potential of RA in the lipopolysaccharide (LPS)‐induced depression model. RA (MW = 360.31 g/mol) meets the criteria of both Lipinski's rule of five and the Ghose filter. It also attends to relevant pharmacokinetic parameters. Target prediction analysis identified RA's potential targets and biological activities, including the peroxisome proliferator‐activated receptor (PPAR) and the cannabinoid receptors CB1 and CB2. In vivo, RA's acute, repetitive, and therapeutic administration showed antidepressant‐like effect since it significantly reduced the immobility time in the tail suspension test and increased grooming time in the splash test. Further, the pretreatment with antagonists of CB1, CB2, and PPAR‐γ receptors significantly blocked the antidepressant‐like effect of RA. Altogether, our findings suggest that cannabinoid receptors/PPAR‐γ signaling pathways are involved with the antidepressant‐like effect of RA. Moreover, this molecule meets important physicochemical and pharmacokinetic parameters that favor its bioavailability. RA constitutes a promising, innovative, and safe molecule for the pharmacotherapy of major depressive disorder.