Study on the analgesic effect and mechanism of Zhitong capsule in adjuvant arthritis rats.
OBJECTIVE
To observe the analgesic effect of Zhitong Capsule (ZTC) and study its mechanism in adjuvant arthritis (AA) rats.


METHODS
Forty-eight male Sprague-Dawley rats were randomly divided into six groups with 8 rats in each group. On the first day, except to those in the normal group that were treated with normal saline, the same amount of Freund's complete adjuvant (FCA) was given through intradermal injection into the right hind paw to all the rats in the other groups. From the 17th day of the modeling on, the rats in groups of ZTC were administered daily through gastrogavage with a dose of 1000, 500, 250 mg/kg respectively, while equal volume of normal saline was given to those in the normal group and model group, and an equal volume of aspirin (ASA) solution was given to rats in the ASA group through gastrogavage for 10 days, once per day, and on the 27th day, the analgesic effect of ZTC was measured with heat withdraw method. The activities and contents of superoxide dismutase (SOD) and lipid peroxides (LPO) in serum were observed by spectrophotometry, and the level of beta-endorphin (beta-EP) in hypothalamus were determined by the assay of immunohistochemistry.


RESULTS
ZTC showed significant effects on enhancing the pain threshold and at the same time it increased the activities of SOD and reduced the contents of LPO in serum. ZTC could also increase the level of beta-EP in hypothalamus.


CONCLUSIONS
ZTC has analgesic effect and its mechanism is probably related with its effect in inhibiting the level of oxygen free radicals in serum and increasing the level of beta-EP of hypothalamus in rats.
The Medical College of Yangzhou University, Jiangsu Province, China.
Yan-qing
YQ
Liu
Gao-yang
GY
Chen
Shi-yu
SY
Guo
Guang-zheng
GZ
Jiu
D000698:Analgesia / Q000379:methods*; D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D007031:Hypothalamus / Q000378:metabolism; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D008516:Medicine, Chinese Traditional; D010146:Pain / Q000503:physiopathology; D017288:Pain Threshold / Q000187:drug effects; D008517:Phytotherapy; D028321:Plant Preparations / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000097:blood; D014018:Tissue Distribution; D001615:beta-Endorphin / Q000378:metabolism
D008054:Lipid Peroxides; D028321:Plant Preparations; D001615:beta-Endorphin; D013482:Superoxide Dismutase