study of chronic administration of matricaria recutita extract on c-fos expression during morphine withdrawal in male adult mice

introduction: there are some evidences that the matricaria recutita extract has sedative effects and relieves symptoms of morphine withdrawal syndrome. symptoms of this syndrome are due to increased expression of fos transcription factor in brain. in this study the effect of chronic hydro alcoholic extract (30 mg/kg) of matricaria recutita on jumping behavior and expression of fos transcription factor during morphine withdrawal were investigated in male mice. material and methods: mice were divided into 5 groups (morphine + saline, morphine + naloxone, morphine + chronic extract of matricaria recutita +naloxone, morphine + saline + naloxone, saline + naloxone). to develop morphine dependence, mice were injected subcutaneously with increasing doses of morphine for 4 days. mice received a final morphine injection (40 mg/kg) 3h prior to naloxone (5 mg/kg) on the fourth day of testing. for chronic application, matricaria recutita extract (30 mg/kg, intra peritoneal) was administered concurrently with morphine for 4 days. to study the behavior of mice, jumping sign of morphine withdrawal was assessed 30min after naloxone injection. in cellular study, 90min after the naloxone injection, mice were decapitated and their brains were separated, then mrna was extracted from brain tissues. using dig-labeled dna probe of c-fos and beta-actin and dot blot technique, expression of c-fos was analyzed by zero d scan software. results: the rate of jumping sign due to abstinence from morphine was increased compared to control groups and chronic application of matricaria recutita extract at 30 mg/kg led to significant decreases in jumping sign and amount of expression of c-fos after naloxone-precipitated abstinence. conclusion: it seems that the sedative effect of matricaria recutita extract is via modulation of c-fos expression; therefore it has a permanent inhibitory effect regarding morphine dependence.