MECHANICAL AND THERMAL ANALGESIA OF Ocimum kilimandscharicum

Resumo

Introduction: Ocimum kilimandscharicum is a botanical genus of the Lamiaceae family, known for its various biological activities1. It is popularly used as digestive and anti-diarrheal as well as presenting gastroprotective effect, but its analgesic potential has not yet been explored2. Objectives: In the experiment, it was evaluated the mechanical and thermal analgesic potential of the extract ethanolic of the O. kilimandscharicum (EEOK) plant in different concentrations and to compared it with the control group. Material and Methods: Male mice were divided into 4 experimental groups (n=6/group). Extract was tested at 100 and 300 mg/kg. The negative control group received oral saline solution 0,9%. The positive control group received dexamethasone (1mg/kg, s.c.). After 1 hour, paw edema was induced by intraplantar injection of 300 ?g carrageenan administered in the right paw and 0,1 mL of sterile saline was injected into the left paw (control). Mechanical hyperalgesia was measured after 3 and 4 hours of carrageenan administration by determination of paw withdrawal thresholds with the aid of Von Frey apparatus and the determination of cold allodynia was measured with the use of acetone. Results: Carrageenan increased mechanical hyperalgesia and cold sensitivity in the control group. The EEOK at 100 and 300 mg/kg decreased mechanical hyperalgesia by carrageenan after 3 hours, and there was a slight increase of this effect after 4 hours. Cold allodynia, in the group with EEOK at 100 mg/kg, was reduced about 70 and 50%, respectively, after 3 and 4 hours, while dexamethasone reduced by 40%.. Discussion and Conclusion: The extract of O. kilimandscharicum presented analgesic properties on the experimental test in mice. However, further studies must be performed out in other models to show the inflammation parameters that can be inhibited by this extract, the compounds responsible for the effect as well as the likely mechanisms of action.