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 Introduction: Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis distinguished by infiltration of leukocytes into the central nervous system. Changes in composition and levels of unsaturated fatty acids, affect the integrity of blood-brain barrier. In this study, we evaluated the effect of Sesame oil on the leukocyte infiltration into the brain of MOG35-55 induced EAE male C57BL/6 mice. Materials and Methods: In this experimental study, male C57BL/6 mice were placed in two therapeutic groups (n=10 per group) with age and weight-matched as follow: 1.Sesame oil-treated EAE mice received 4ml/kg/day of Sesame oil given i.p. from day -3 until day +19 after disease induction, 2.Non-treated EAE mice (EAE control) received Phosphate buffer alone with same schedule. EAE was induced by immunization of mice with MOG35-55 peptide and complete Freund's adjuvant. Leukocytes infiltration into the brain was investigated 20 days after immunization. Data was analyzed using Mann-Whitney U test. Results: The results show that Sesame oil-treated mice had significantly less clinical score of EAE (2.6±0.4) than non-treated EAE induced mice (4.2±0.6), (p<0.001). Also, there was a significant difference at number of the infiltrating cells in brain between Sesame oiltreated (80±20) and non treated EAE-induced mice (150±30), (p<0.01). Conclusion: These results indicate that Sesame oil reduces infiltration of leukocytes into the brain of EAE mice, therefore lessening the histological changes and clinical signs and thus ameliorating the disease.

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  Background: Although the roles of steroid hormones in the activation and maintenance of reproductive function are proved well, emerging evidence indicated that these steroids influence on performance of learning and memory. These effects are complex and vary with task, gender, and age, as well as the regimens of steroid exposure. This study was carried out in order to assess the role of progesterone administration in newborns rats on Morris water maze learning ability after adolescence.

  Methods and Materials : This experimental study was carried out on 36 newborns Wistar rats. Rats were divided randomly into 6 groups female progesterone, male progesterone, female sesamoide, male sesamoid rats and male and female control rats. Progesterone groups were treated with a single injection of progesterone (100 mg/kg) and sesamoid groups were received the same volume of sesamoid oil as the progesterone vehicle in day 1 or 2 after brith, 60 days later, spatial memory ability was determined in Morris water maze.

  Results : The results of this study show that water maze learning can enhance by administration of sesamoid oil in newborn female pups in compared to progesterone and control groups (p<0.05). In addition, adding progesterone to sesame oil reduce water maze learning to control level.

  Conclusion: The hypothesis that progesterone impaired spatial reference memory in female rats was supported by this experiment.