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

To investigate the effects and mechanisms of anthocyanin from Ligustrum vicaryi on chronic inflammatory pain induced by complete Freund's adjuvant.

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.

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.

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.