Evaluation of Analgesic and Anti-inflammatory Potential of 80% Methanol Leaf Extract of Otostegia integrifolia Benth (Lamiaceae)

Introduction: Pain and inflammatory disorders are the most prevalent syndromes. Different herbs were used for treatment of pain and inflammation including members of the genus Otostegia. As a result, this research investigated the in vivo analgesic and anti-inflammatory effects of 80% methanol leaf extract of Otostegia integrifolia in mice. Methods: The analgesic and anti-inflammatory effects of the plant was evaluated using hot plate method, acetic-acid induced writhing test, and carrageenan and formalin induced paw edema. Three experimental groups (100, 200, and 400 mg/kg) received the extract while morphine 10 mg/kg and aspirin 150 mg/kg were used as a positive control for analgesic and anti-inflammatory tests accordingly. Distilled water (10 mL/kg) was used as negative control. Results: From the experimental groups, OI400 displayed significant analgesic and anti-inflammatory activities (P<0.001). In acetic acid induced writhing tests, the number of writhes decreased significantly (P<0.001) in all experimental groups. Similarly, OI400 reduced the mean paw edema significantly in carrageenan and formalin induced paw edema (P<0.05 and P<0.001, respectively). Conclusion: In general, the results obtained in this study demonstrated that the extract exhibited significant analgesic and anti-inflammatory potential in mice.