ABSTRACT
Aim To observe the analgesic effect of oxymatrine(OMT)and its mechanism.Methods A peripheral mononeuropathy was produced in adult mice by placing loosely constrictive ligatures around the common sciatic nerve.The antinociceptive effects of the OMT were assessed in mechanical allodynia and cold allodynia tests.The CAMKII inhibitor KN-93 and AIP were adopted to investigate the influence of OMT on the analgesic effect and analyze its analgesic mecha-nisms.Western blot was used to evaluate the expres-sions of tCaMKII and pCaMKII protein.Results The intraperitoneal administration of OMT (1 60,80 mg· kg -1 )increased the paw withdrawal threshold in the mechanical allodynia test (P <0.05 ),OMT (1 60, 80,40 mg·kg -1 ,ip)remarkably decreased the paw lifts in the cold allodynia test (P <0.05).Ith KN-93 (1 .25 μg/site),AIP (0.02 μg/site)significantly en-hanced the analgesic effect of OMT (35 mg·kg -1 ) (P <0.01 ).Protein expression of pCaMKII was de-creased by OMT(1 60 mg·kg -1 ).Conclusion OMT has significant protective effects on chronic constriction injury(CCI)in mice,and the effective mechanism of OMT inhibits the expression of CaMKII receptor.
ABSTRACT
Chemotherapy drugs treatment causes neuropathic pain, hyperalgesia and allodynia are common components of neuropathic pain, so effectively therapeutic strategy is required. In this study, we evaluated the antinociceptive effects of matrine on vincristine-induced neuropathic pain in mice. Vincristine (100 µg/kg i.p.) was administered once per day for 7 days (day 0-6) in mice. Matrine (15, 30, 60 mg/kg, i.p.) was repeated administration in early phase (day 0-6) or late phase (day 7-13). Hyperalgesia and allodynia were evaluated by withdrawal response using von Frey filaments, plantar and cold-plate on 7, 14 and 21 day. Injection of vincristine produced mechanical hyperalgesia and cold allodynia. Matrine was found to produce a protective role in both von Frey filaments and cold-plate test. The analysis of the effect supports the hypothesis that matrine is useful in therapy of vincristine-induced neuropathic pain. In conclusion, this study demonstrates that administration of matrine is associated with antinociceptive effect on mechanical and cold stimuli in a mice model of vincristine-induced neuropathy pain.
Subject(s)
Alkaloids/therapeutic use , Analgesics/therapeutic use , Antineoplastic Agents, Phytogenic/toxicity , Neuralgia/drug therapy , Quinolizines/therapeutic use , Vincristine/toxicity , Animals , Disease Models, Animal , Hyperalgesia/drug therapy , Mice , Mice, Inbred ICR , Neuralgia/chemically induced , Pain Threshold/drug effects , MatrinesABSTRACT
CONTEXT: Sophora alopecuroides L. (Leguminosae) is a commonly used Chinese herbal drug that possesses antipyretic, anti-inflammatory and analgesic effects. Among various alkaloids isolated from S. alopecuroides, matrine has been identified as the major bioactive component contributing to a variety of pharmacological effects, and studies have also shown that matrine has an analgesic effect. OBJECTIVE: To investigate the antinociceptive effects of matrine on neuropathic pain induced by chronic constriction injury (CCI) in mice. MATERIALS AND METHODS: The von Frey, plantar, cold-plate, locomotor activity and rota-rod test were performed to assess the degree of mechanical, radiant, thermal, spontaneous locomotor activity and motor coordination changes respectively, at different time intervals, i.e., one day before surgery and 7, 8, 10, 12 and 14 days post surgery. Matrine was administered from the 8th day after the surgery for seven days. RESULTS: Our present study shows that matrine at the dose of 30 mg/kg i.p. increased the paw withdrawal threshold (0.88 ± 0.16), paw withdrawal latency (7.01 ± 0.11) and the counts of paw withdrawal (19.7 ± 1.15) from the day 8 for the nerve injured paw compared to the CCI group (0.18 ± 0.04, 4.62 ± 0.18, 44.3 ± 2.99, respectively). Matrine, in a dose-dependent effect, was also found to produce a protective role in both plantar and cold-plate tests. The analysis of the effect supports the hypothesis that matrine is useful in neuropathic pain therapy. DISCUSSION AND CONCLUSION: The results of this study suggest that matrine could be useful in the treatment of different kinds of neuropathic pains as an adjuvant to conventional medicines.
