Aloin attenuates chronic constriction injury-induced neuropathic pain in rats by inhibiting inflammatory cytokines and oxidative stress

摘要

Objective:To investigate the effect of aloin against chronic constriction injury(CCI)-induced neuropathic pain in rats.Methods:Rats were randomly divided into 7 groups:GroupⅠ(normal control),GroupⅡ(sham-operated),GroupⅢ(CCI control)and GroupⅣ,Ⅴ,Ⅵ,andⅦ,which underwent CCI surgery and then were administered with aloin(5 mg/kg,p.o.;25 mg/kg,p.o.;125 mg/kg,p.o.)and gabapentin(50 mg/kg,p.o.),respectively for 14 days.Peripheral neuropathy was induced by silk ligatures(4-0)loosely placed around the sciatic nerve.Nociceptive thresholds against mechanical stimuli(Von-Frey filaments)and thermal stimuli(12°Cand 40°C)were measured at midplantar paw region ipsilateral to the compressed nerve on day-3,7,11,and 14.The concentration of cytokines including tumor necrosis factor-α(TNF-α),interleukin-6,and interleukin-1βwas estimated at day-7.At day 14,motor nerve conduction velocity was determined under urethane anesthesia(1.25 g/kg).Oxidative stress parameters(malondiadehyde,glutathione,catalase,and superoxide dismutase)were estimated in sciatic nerve homogenates at day 14.Representative nerve samples were processed for histological investigations.Results:Aloin significantly reduced CCI-induced mechanical and thermal allodynia.It also improved motor nerve conduction velocity and decreased oxidative stress in nerve tissues.In addition,it decreased pro-inflammatory cytokine levels and restored the histoarchitecture of compressed sciatic nerve.Conclusions:Aloin mitigates CCI-induced neuropathic pain in rats by inhibiting oxidative stress and pro-inflammatory cytokines in the afflicted sciatic nerve.