Effects Of Glucosides Of Chaenomeles Speciosa On Pain

Chaenomeles speciosa (sweet) Nakai has traditionally been used in Chinese medicine to relieve pain and to treat inflammatory diseases such as rheumatoid arthritis. In the present study, glucosides of Chaenomeles speciosa(GCS), for the first time, were abstracted from Xuanzhou's Chaenomeles speciosa by modern isolation technique. Several animal pain models were built to study the analgesic effects of GCS, including its potential analgesic site and its possible mechanisms. AIM: To observe the analgesic effects of GCS on several pain models. To explore its potential analgesic site and its mechanism. To compare analgesic potency of GCS with those of glucosides of Tripterygium Wilfordii (GTW) and sinomenine (SIN). METHOD: The effects of GCS on normal and inflammatory animals were observed by mice hotplate test, mice writhing test and arthritic flexion test of adjuvant arthritis(AA) rats; the analgesic ED50 of GCS , GTW and SIN were assayed by mice writhing test; the analgesic site of GCS was analysed by mice formalin test and mice hotplate test after intracerebroventricular (icv) administration; the concentration of prostaglandin E2 (PGE2) and tumor necrosis factor-a (TNF-a) in the synovial cells of AA rats were measured by radioirnmunoassay ; the effect of GCS on mice's capillary permeability was observed by dimethylbenzene-induced capillary hyperpermeability test.RESULTS: After four-day intragastric(ig) administration of GCS (60, 120, 240 mg-kg-1), mice's hotplate latency were prolonged. The analgesic effects of GCS started on the 3rd day and became stable on the 4th day. After ig administration of GCS (60 , 120 , 240 mg-kg-1) for 4 days, mice's writhing responses were decreased dose-dependently. In AA rats, after ig administration of GCS(30, 60, 120mg-kg-1)either from 7d to 14d after inflammation induction (prophylactic scheme)or from 17d to 24d after inflammation induction (therapeutic scheme), the scores of arthritic flexion test were decreased compared with that of AA model groups. The analgesic ED50 of GCS, GTW and SIN by mice writhing test were respectively equal to 152.52 mg-kg"1 (95% confidence interval is 84.25-276.11 mg-kg-1), 43.93 mg-kg"1 (95% confidence interval is 39.85-48.37 mg-kg"1) and 57.72 mg-kg"1 (95% confidence interval is 31.48-105.33 mg-kg'1) . After four-day ig administration of GCS(60, 120, 240 mg-kg"1), the second-phase reponses of mice formalin test were reduced compared with vehicle group, but the first-phase reponses had not been reduced. After one-time icv administration of GCS (1.5, 3, 6 mg-kg-1) , mice's hotplate latency had not been changed. In AA rats, on 24d after inflammation induction, the concentration of PGEi and TNF-a of synovial cells were both decreased. Besides, dimethylbenzene-induced capillary hyperpermeability were inhibited by ig administration of GCS(120, 240 mg-kg-1) for 4 days.CONCLUSION: GCS had anagesic effects, which related to its inhibitory effects on peripheral inflammation.