ABSTRACT
Background and Aim: despite identification of the antinociceptive effects of rosemary and peppermint essential oils, use of these essential oils has been limited due to its low solubility in water and low bioavailability. Use of nanoparticles is one of the ways to overcome these limitations. The aim of this study was to evaluate the antinociceptive effect of nano-emulsions containing rosemary and peppermint essential oils in an animal model of osteoarthritis [OA]
Materials and Methods: in this experimental study nano-emulsions containing rosemary and peppermint essential oils were prepared by spontaneous emulsification. In order to investigate the analgesic effect, 30 male rats were randomly assigned to 5 groups: sham [receiving saline injection into the knee], osteoarthritis[receiving intra-articular injection of 2 mg monosodiumiodoacetate], OA [receiving gels containing nano-emulsion, or rosemary and peppermint essential oil or diclofenac sodium]. Treatments were administered topically at a dose of 1 ml daily. Mechanical and thermal allodynia and thermal hyperalgesia tests were performed on the 1 st, 4th, 7th and 14th days after injection. Data were analyzed by repeated measures ANOVA
Results: OA group showed a significant increased behavioral response to the mechanical and thermal stimuli on all days of the experiment compared to the control group [P<0.001]. Use of nano-emulsion or diclofenac gel led to significant increase in the response threshold to vonFrey fillamets [P<0.001], decreased response to acetone [P<0.05], and increased paw withdrawal latency [P<0.05]. Histopathology of knee tissues confirmed the results of behavioral tests
Conclusion: nano-emulsion containing essential oils of rosemary and peppermint reduced pain of osteoarthritis in rats. The nano-emulsification process seems to enhance the antinociceptive effect of rosemary and peppermint essential oils
ABSTRACT
Background: through its membrane and intracellular receptors, vitamin D regulates many vital functions in the body including its well-known actions on musculoskeletal system. Growing body of evidences demonstrate that vitamin D undergoes some of behavioral aspects of neurocognition. The present study was designed to evaluate the effect of food regimens without vitamin D or with a supplement of 1,25[OH]2D3 on spatial performance of adult rats
Methods: the animals were trained in the Morris water maze to find a hidden platform. The time spent and the distance traveled to find the platform, speed of navigation and the percentage of unsuccessful trials were considered for assessment of the task learning
Results: our findings indicated that the vitamin D-deprived rats had a significant lower performance compared to both the controls and the animals receiving 1,25[OH]2D3 supplementation. Concerning the unsuccessful trials, lack of vitamin D resulted in the highest failures in the maze navigation. The regimen with additional 1, 25[OH] 2D3 did not considerably influence learning of the maze task
Conclusion: we concluded that while vitamin D deficiency deteriorates the spatial task learning, the 1,25 [OH] 2D3 supplementation did not effectively underlie the maze performance. Iran. Biomed. J. 17 [1]: 42-48, 2013