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 and Aim: Many learning and memory abilities decline in several diseases such as Alzheimer's and dementia. The present study investigated the effects of alcoholic extract of Morus alba leaves on scopolamine-induced spatial memory impairment in rats
Material and Methods: In this experimental study, forty male Wistar rats were divided into 5 groups [n=8]: control group, scopolamine control group, and groups receiving scopolamine plus alcoholic extract of Morus Alba leaves at doses of 100, 200 and 400 mg/kg/day. After 28 days, learning and spatial memory was evaluated by the Morris water maze. Statistical analysis was performed by repeated measures ANOVA and Bonferroni test
Results: In scopolamine control group, the injection of scopolamine caused learning [P<0.0001] and spatial memory [P<0.05] impairment compared to the control group. Administration of alcoholic extract of Morus alba leaves at the doses of 100 [P<0.05], 200 [P<0.0001], and 400 mg/kg [P<0.0001] improved learning ability in rats. Also, these extracts at doses of 200 and 400 mg/kg prevented impairment of spatial memory in rats [P<0.05]
Conclusion: According to the results of this study an alcoholic extract of Morus alba leaves can enhance learning and memory function in rats receiving scopolamine