The effects of peripheral and central administration of hypericum perforatum L and the role of alpha-adernergic system
© Biranvand and Khaksarian; licensee BioMed Central Ltd. 2008
Published: 17 April 2008
In this study, the effect of peripheral and central administration of aqueous extract Hypericum Perforatum L (HP) on acute and chronic pain models using formalin and tail flick tests were evaluated.
Materials and methods
At first stage, for assessment of the antinociceptive effect intraperitoneal (i.p) of different dose of HP were used, in later stage, for central effects Hp was filtered and administrated intrathecal (i.t) and intracerebroventricular(i.c.v) and the last, Yohimbine and Prazocin were administrated before i.p injection of it.
HP (i.p) with the above mentioned doses significantly produced analgesia in both tests. HP induced analgesia in the first phase of formalin and tail flick tests, while at higher dose produced analgesia in both phases of formalin and tail flick tests. The i.c.v administration of HP produced analgesia in both phases of formalin test, while it had no effect on tail flick latency. Yohimbine significantly reversed antinociceptive effect HP in the first phase of formalin test. Prazocin had no significant effect on formalin and tail flick tests.
According to our results peripheral and central administration of HP can produced analgesia. HP has an antinociceptive effect at spinal and central levels, and spinal effect seems to be more potent. Further investigation of the role of other neurotransmitter system such as opioidergic and serotonergic system is recommended.
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