Effects of curcumin on type 2 diabetic neuropathic pain and expression of inositol-requiring enzyme 1α in spinal dorsal horn and dorsal root ganglia in rats / 中华麻醉学杂志

ABSTRACT

ObjectiveTo investigate the effects of curcumin on type 2 diabetic neuropathic pain (DNP)and expression of inositol-requiring enzyme 1α (IRE1α) in spinal dorsal horn and dorsal root ganglia (DRG) in rats.MethodsType 2 diabetes mellitus was induced by high-fat and high-sucrose diet and intraperitoneal streptozotocin (STZ) 35 mg/kg,and confirmed by fasting blood glucose level ＞ 16.7 mmol/L in male SD rats.Type 2 DNP was confirmed by the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWI.) measured on day 14 after STZ administration ＜ 80％ of the baseline value.The rats were then randomly divided into 3 groups ( n =27 each)DNP group,curcumin group (group Cur) and solvent control group (group SC).Curcumin and corn oil 100 mg/kg (25 mg/ml) were given intraperitoneally once a day for 14 consecutive days starting from 14 days after administration of streptozocin in Cur and SC groups respectively.Another 27 rats were chosen and served as control group (group C) and fed with common fodders.MWT and TWL were measured at 3,7 and 14 day after curcumin administration.The expression of IRE1α in spinal dorsal horn and DRG was detected by Western blot.ResultsCompared with group C,MWT was significantly decreased and TWL was significantly shortened,and the expression of IRE1α was up-regulated in DNP,Cur,and SC groups (P ＜ 0,05),Compared with group DNP,MWT were significantly increased,TWL was significantly prolonged,and the expression of IRE1α in spinal dorsal horn and DRG was down-regulated in group Cur (P ＜ 0.05).There was no significantdifference in the parameters mentioned above between DNP and SC groups (P ＞ 0.05).ConclusionCurcumin can attenuate type 2 1)NP and inhibition of the expression of IRE1α in spinal dorsal horn and DRG is involved in the mechanism.