Inhalation of Cedrus atlantica essential oil alleviates pain behavior through activation of descending pain modulation pathways in a mouse model of postoperative pain

Ethnopharmacological relevance Cedrus atlantica essential oil ( Ca EO) presents analgesic and anti-inflammatory sedative properties. However, it remains unknown whether Ca EO alleviates acute postoperative pain. Materials and methods Here, we investigated the effect of Ca EO on postoperative pain and its mechanisms related to the descending pain control in Swiss males mice induced by a plantar incision surgery (PIS) in the hindpaw. Results Inhalation of Ca EO (5′, 30′ or 60′) markedly reduced mechanical hypersensitivity. This effect was prevented by pre-treatment with naloxone or p-chlorophenylalanine methyl ester (PCPA, 100 mg/kg, i.p.)-induced depletion of serotonin. In addition, p -alpha-methyl-para-tyrosin (AMPT, 100 mg/kg, i.p.)-induced depletion of norepinephrine, intraperitoneal injection of the α 2 -adrenergic receptor antagonist yohimbine (0.15 mg/kg, i.p.) or haloperidol (1 mg/kg, i.p.) an antagonist of dopaminergic (D1 and D2) receptors prevented the effect of Ca EO on hypersensitivity. Conclusions These findings suggest that Ca EO alleviates postoperative pain by activating the descending pain modulation pathways on the opioidergic, serotonergic, noradrenergic (α 2 -adrenergic) and dopaminergic (dopamine D1 and D2 receptors) systems.