Anti-inflammatory and antialgic actions of a nanoemulsion of Rosmarinus officinalis L. essential oil and a molecular docking study of its major chemical constituents

We evaluate the anti-inflammatory and antialgic potency of a nanoemulsion (NEORO) containing the essential oil of Rosmarinus officinalis L. (EORO), which is composed primarily of limonene, camphor and 1,8-cineole. The EORO and NEORO were administered orally 30 min prior to starting the experiments. In a test of rat paw oedema induced by carrageenan, NEORO was effective in doses of 498 µg/kg, and it inhibited 46% of the maximum peak of the oedema; in a dose of 300 mg/kg, EORO inhibited 50% of the maximum peak of the oedema. In an acetic acid-induced writhing test, NEORO yielded a dose-dependent effect, and a dose of 830 µg/kg inhibited 84% of the algesic process; a dose of 100 mg/kg of EORO inhibited 55%. In an assay for H₂S production in rat stomachs, a dose of 498 µg/kg of NEORO inhibited H₂S production in all of the measurement phases, and a dose of 100 mg/kg EORO inhibited 60% and influenced the effect of the ethanol significantly, reducing the production of H₂S. We suggest that NEORO potentiated the effect of EORO, demonstrating effectiveness in doses 600 times lower than those applied with EORO. Among the major compounds of EORO, the camphor molecule exhibited the largest number of interactions with the therapeutic targets related to the inflammatory process, suggesting that it is responsible for EORO’s anti-inflammatory and antialgic effects. This work paves the way for future investigations related to the therapeutic role of NEORO in the inflammation process.