The anti-inflammatory and anti-nociceptive properties of Rosmarinus officinalis L. (ROL) extract and its major constituent, carnosol in male NMRI mice (W:25-30 g) have been evaluated in the present study. Formalin (2%, 20 microL) was injected into the plantar portion of the hind paw and resulting pain and inflammation was studied for 60 min. The plant extract, carnosol and other drugs were administered intraperitoneally or subcutaneously 30 min before formalin injection. In a separate experiment, the effects of the extract and carnosol on plasma corticosterone levels and activity of the enzymes cyclooxygenase type 1 and 2 (COX1 and COX2) were investigated. Injection of different doses of ROL and carnosol reduced pain in the phase 2 of the formalin test, which was not inhibited by naloxone and/or memantine. In addition, pretreatment of the animals with ROL and/or carnosol reduces the formalin-induced inflammation. Furthermore, the extract and carnosol did not affect plasma corticosterone levels compared with the control group. Interestingly, both the extract and carnosol inhibited COX1 and COX2 activity. It could be concluded that ROL extract and carnosol suppressed pain and inflammation induced by formalin injection, which may be due to inhibition of COX1 and COX2 enzymes activity.

Background: Few studies have been done considering the effectiveness of aqueous extract of cinnamon in neurological diseases. In previous studies, reducing the pain of hydro-alcoholic cinnamon extract in the second phase (chronic) of the formalin test and reduction of inflammation in animal models as well as in humans following cinnamon administration have been emphasized. There are also studies on the anti-Alzheimer's effects of this extract. However, the effects of CWE of this plant on the incidence of diseases associated with the nervous system, especially depression, have not been investigated.Objective: In the present study, the effects of CWE on depression induced by forced swimming test (FST) in mice were investigated. Methods: Cinnamon aqueous extract was obtained by boiling method of cinnamon powder. Male NMRI mice (25-30 g) were used (n=8/group). Different doses of CWE (25, 50, 100, and 200 mg/kg) were administered intraperitoneally to the animals 30 min before the (FST). In addition, fluoxetine (20 mg/kg) was administered to distinct animals as positive control.Results: Intraperitoneal (50, 100, and 200 mg/kg) injections of CWE significantly reduced the animals' immobilization in a dose-dependent manner which in doses of 100 and 200 mg/kg was similar to fluoxetine effect. Conclusion: It could be concluded that the CWE can inhibit depression induced by FST in mice.Since the exact composition of the extract is not identified, the exact mechanism(s) by which the extract reduces the FST is not clear.