The Study On β-Aescin Treating Neuropathic Pain

ObjectiveTo observe the resisting neuropathic pain’s effect through intrathecal injection of the β-Aescin 20μg and 40μg respectively, analysis of cytokine expression profile changes of spinal dorsal horn, clear the relationship between intrathecal beta seven leaf saponin sodium treatment effects on neuropathic pain and cytokines TNF-α, IL-1 beta and IL-6 expression in spinal dorsal horn.Methods1.To establish an experimental animal model:male SD rats weighing 180-200g, intraperitoneal injection of midazolam (2mg/kg) and ketamine (40mg/kg) anesthesia, PE-10 catheter from rat foramen magnum into the subarachnoid space into the 7-7.5cm to the lumbosacral spinal cord segment to the tail side, the other end is fixed in the experimental drugs for injection the external carotid.7 days later, no motor dysfunction in rats, in the same anesthesia, ligation in SD rats side waist 5-6 nerve, to build models of neuropathic pain,7 days later, for the next step of the experiment.2. Experimental drugs:physiological saline,β-Aescin 20 μg and 40μg respectively from the PE-10 catheter into the subarachnoid.3. Nociceptive stimulation experiments:(1) Determination of mechanical threshold. The rats were placed in a metal screen net organic glass box in adaptation after 15min, with central ligation of the vonFrey fiber wire vertical stimulated rat lateral hindpaw, continuous time less than 6 seconds, rats foot or licking behavior as positive reaction. Determination of first from the 2G stimulus onset, when the intensity of the stimulus does not cause positive reactions are given adjacent high level efforts to stimulate, positive are given adjacent small level efforts to stimulate. So continuously, until the emergence of the first positive response and negative reaction of the saddle, and then the continuous determination of 4 times the maximum force is 15g, greater than this value is denoted as 15g, each time interval of stimulus for 30s. (2) Determination of thermal pain threshold. SD rats were put into a glass plate perspex box placed in a 3mm thick, stimulator irradiated rats ligated side close to the glass plate with heat radiation plantar part. Recording radiation began to rats appeared foot lift time, by the time of 30s, each rat was measured 5 times,3 times the average value after. Each determination interval determination as 5min.4 The use of real-time fluorescent quantitative RT-PCR for analysis of cytokine expression changes of spinal dorsal horn.ResultsIncreasing with the enhancement of the experimental drug dose, The percentage of the maximum effect (MPE) of β-Aescin group using 20 μg and 40 μg were significantly higher than those in the saline group (P<0.05); β-Aescin could slow the decline of the rats’ PWL (Paw Withdrawal Latency, PWL); and reduce the cytokines’level about TNF-a, IL-1 beta and IL-6 expression in spinal dorsal horn.ConclusionThe intrathecal injection of β-Aescin in rat produced a dose-dependent anti nerve pathological pain effect.its mechanism may be its inhibition of TNF-a, IL-1 beta, IL-6 expression.