Alpha-pinene reduces in vitro and in vivo leukocyte migration during acute inflammation

Alpha-pinene (PIN) is a monoterpene derived from essential oils of plants. Some biological activities are associated with PIN, such as antibacterial, antihypernociceptive, anti-inflammatory and antioxidant. This study was performed to evaluate the anti-inflammatory activity of PIN on the leukocyte behavior through in vivo and in vitro leukocyte migration. In the cell viability assay, PIN (3, 10, 30, 90 𝜇g/mL) showed low cytotoxicity and in the acute toxicity in mice, no deaths or other signs of toxicity were observed at doses up to 3 g/kg (orally). In vitro chemotaxis revealed that PIN (1, 3, 10, 30 𝜇g/mL) promoted a significant reduction of neutrophil migration in response to fMLP and LTB 4 stimulation. In the carrageenan-induced peritonitis assay, PIN, at doses of 200 and 400 mg/kg, decreased the infiltration of peritoneal exudate leukocytes and of polymorphonuclear leukocytes. Additionally, PIN pretreatment resulted in a significant decrease in the number of rolling (200, 400 mg/kg) and adherent leukocytes (200, 400 mg/kg) to the perivascular tissue. In conclusion, PIN has a significant inhibitory effect on leukocyte migration, an important step in inflammatory response. PIN may be considered as a potential agent for treatment inflammatory process with excessive leukocyte migration, however, further studies are necessary to confirm this possibility.