Antinociceptive and wound healing activities of Croton adamantinus Müll. Arg. essential oil

Leaves of Croton adamantinus have been used to treat inflammation and skin wounds in the semi-arid area of the Northeast of Brazil. In order to evaluate if the essential oil (EO) was responsible for the claimed activities; antinociceptive, wound healing and antimicrobial tests were carried out. Twenty constituents were identified in C. adamantinus EO by GC–MS, ¹H-NMR and ¹³C-NMR, the major compounds being methyl-eugenol (14.81 %) and 1,8-cineol (13.74 %). Antinociceptive activity was evaluated by the formalin test and the abdominal contortion assay in mice. The EO (50 and 100 mg/kg) decreased the licking time of both phases of the formalin test when compared to the vehicle, but not to morphine (7.5 mg/kg). In the abdominal contortion assay, the EO (50 and 100 mg/kg) reduced the number of contortions compared to the vehicle and to indometacin (10 mg/kg). The wound healing activity was verified also using two experimental models: excisional wound and dead space. Topical treatment with the EO (1 %) increased the wound contraction from the third day of treatment (compared with nitrofurazone 0.2 %), while systemic treatment (50 mg/kg/day) increased granulation tissue formation and reduced the water content. C. adamantinus EO also showed antimicrobial activity against Staphylococcus aureus in disk diffusion method. These results corroborate the ethnobotanical use of this specie by Brazilian population.