[The effects of anthocyanin on chronic inflammatory pain induced by complete Freund's adjuvant and its mechanism].

OBJECTIVE: To investigate the effects and mechanisms of anthocyanin from Ligustrum vicaryi on chronic inflammatory pain induced by complete Freund's adjuvant. METHODS: Thirty male SD rats were randomly divided into three groups (n=10):normal saline control group (NS), chronic inflammatory pain model group(Mod, injected with complete Freund's adjuvant(CFA) 100 µl to the left hind leg), anthocyanin treatment group(Ant, dosed with anthocyanins (90 m), mechanical pain threshold (MPT), and left toe volume in each group were measured before modeling and 1,3,5,7,9,11,13 days after operation. Antioxidant indexes in serum were mensurated by spectrophotometer, and the total capsaicin receptor (TRPV1) and phosphorylated capsaicin receptor (p-TRPV1) in hippocampus were detected by Western blot. RESULTS: In comparison with controls, HPT and MPT were improved (P<0.05),toe swelling was reduced(P<0.05), the serum level of SOD was increased (P<0.01), while the levels of MDA and NO were decreased (P<0.05), the ratio of P-TRPV1/TRPV1 protein was depressed in Mod rat hippocampal region treated with anthocyanin. CONCLUSIONS: The results show that anthocyanins has an analgesic effect on chronic inflammatory pain induced by CFA, and its mechanism may be related to the improvement of antioxidant capacity and the reduction of TRPV1 phosphorylation.

Expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis.

AIM: To determine the expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis and its clinical significance. METHODS: A cervical spondylosis model was established in rats by destroying the stability of cervical posterior column, and the cord segments C(4-6) and gastric antrum were collected 3, 4 and 5 mo after the operation. Rats with sham operation were used as controls. c-fos neuronal counter-staining was performed with an immunohistochemistry method. Every third sections from C(4-6) segments were drawn. The 10 most labeled c-fos-immunoreactive (Fos-IR) neurons were counted, and the average number was used for statistical analysis. The mean of Fos-IR neurons in myenteric plexus was calculated after counting Fos-IR neurons in 25 ganglia from each antral preparation, and expressed as a mean count per myenteric ganglion. RESULTS: There were a few c-fos-positive neurons in the cervical cord and antrum in the control group. There was an increased c-fos expression in model group 3, 4 and 5 mo after operation, whereas there was no significant increase in c-fos expression in the control group at 3, 4 and 5 mo. More importantly, there was a significant difference in c-fos expression between rats followed up for 3 mo and those for 5 mo in the model group (11.20+/-2.26 vs 27.68+/-4.36, P<0.05, for the cervical cord; and 11.3+/-2.3 vs 29.3+/-4.6, P<0.05, for the gastric antrum). There was no significant difference between rats followed up for 3 mo and those for 4 mo and between rats followed up for 4 mo and those for 5 mo in the model group. CONCLUSION: c-fos expression in gastric myenteric plexus was dramatically associated with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis. If this hypothesis is confirmed by further studies, functional gastrointestinal diseases such as functional dyspepsia and irritable bowel syndrome could be explained by neurogastroenterology.