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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.

Effects of transient inhibition of the core part of the nucl. accumbens (NAcC) by lidocaine on nicotine-induced conditioned place preference in male Wistar rats were examined. Lidocaine (2%) was injected into the NAcC of nicotine-conditioned animals before each nicotine i.p. injection. On the test day, behavior of the animals in a two-compartment apparatus was recorded during 10 min. Results revealed that i.p. injections of nicotine (1.0 or 1.5 mg/kg) induced place preference. Transient lidocaine-induced inhibition of one or both sides of the NAcC did not change place preference but changed the numbers of compartment crossings, rearings, and sniffings. Inhibition of the left part and both parts of the structure reduced sniffing and increased place preference; inhibition of the right part of the nucleus increased the intensity of this phenomena. Keywords: nicotine, conditioned place preference, lidocaine, core part of the nucl. accumbens, shell part of the nucl. accumbens, rat.