Effects of Analgesic and Anti-inflammatory of Sophocarpine and Related COX- 2/PGE2 Signaling Pathway / 中国药房

ABSTRACT

OBJECTIVE： To study analgesic and anti-inflammatory effects of sophocarpine （SC） on inflammatory pain model mice and related COX-2/PGE2 signaling pathway. METHODS： （1）Analgesic experiment. Totally 50 mice were randomly divided into blank control group （normal saline）， positive control group （aspirin， 100 mg/kg） and SC high-dose， medium-dose and low-dose groups （40， 20， 10 mg/kg）， with 10 mice in each group. They were given relevant medicine once a day intragastrically for consecutive 5 d. 2 h after last medication， mice in each group was given glacial acetic acid solution intraperitoneal injection； writhing times of mice within 15 minutes were recorded. Other 50 mice were collected； they were grouped and given medicine as above. The response pain threshold （Tr） of mice was determined by intelligent hot plate instrument 15， 30， 60， 120 min after last administration. （2）Anti-inflammatory and mechanism experiment. Other 60 mice were randomly divided into blank control group （normal saline）， model control group （normal saline）， positive control group （aspirin， 100 mg/kg）， SC high-dose， medium-dose and low-dose groups （40， 20， 10 mg/kg）， with 10 mice in each group； they were given relevant medicine intragastrically， once a day， for consecutive 5 d. 60 min after last medication， except for blank control group， other groups were given 1％ carrageenan to induce inflammation. 1， 3， 5 h after inducing inflammation， the degree of paw swelling were determined in each group. Other 30 mice were randomly divided into blank control group （normal saline）， model control group （normal saline）， SC group （40 mg/kg）， with 10 mice in each group； they were given relevant medicine intragastrically once a day， for consecutive 5 d. 60 min after last medication， except for blank control group， other groups were given 1％ carrageenan to induce inflammation in other groups. 5 h later， the levels of SOD， MDA， GSH-Px and T-AOC in paw swelling tissue of mice were determined by biochemical method. The level of PGE2 in paw swelling tissue was determined by ELISA. The mRNA and protein expressions of COX-1 and COX-2 in paw swelling tissue of mice were detected by RT-PCR and Western blot method. RESULTS： In analgesic experiment， compared with blank control group， writhing times of mice were decreased significantly in administration groups （P＜0.05 or P＜0.01）， Tr were increased significantly 30， 60， 120 min after last medication （P＜0.05 or P＜0.01）. In anti-inflammatory and mechanism experiment， compared with blank control group， the degree of paw swelling were increased significantly in model control group 1， 3， 5 h after inducing inflammation （P＜0.01）； the levels of SOD， GSH-Px and T-AOC in paw swelling tissue were decreased significantly （P＜0.01）； the levels of MDA and PGE2 were increased significantly （P＜0.01）， and mRNA and protein expressions of COX-2 were increased significantly （P＜0.01）. Compared with model control group， the degree of paw swelling were decreased significantly in positive control group， SC high-dose and low-dose groups 3 and 5 h after inducing inflammation （P＜0.05 or P＜0.01）. The levels of SOD， GSH-Px and T-AOC in paw swelling tissue were increased significantly in SC group （P＜0.05 or P＜0.01）， while the levels of MDA and PGE2 were decreased significantly （P＜0.01） as well as mRNA and protein expressions of COX-2 were decreased significantly （P＜0.05）. There was no statistical significance in other indexes （P＞0.05）. CONCLUSIONS： SC possesses good anti-inflammatory and analgesic effects， and its mechanism may be related to anti-oxidative stress and inhibition of COX-2/PGE2 signaling pathway.