Triptolide Alleviates Neuropathic Pain by Inhibiting the Activation of Microglial Toll-Like Receptor 3.

BACKGROUND: Current data indicates the incidence of neuropathic pain after surgical nerve injury is as high as 50%, thus representing a major problem for patients and for the medical system. Triptolide, a traditional Chinese herb, has anti-inflammatory effects on various neurodegenerative and neuroinflammatory diseases. This agent also reduces peripheral nerve injury-induced neuropathic pain, although the mechanism underlying this effect is still unknown. MATERIALS AND METHODS: The effects of triptolide on spinal nerve ligation (SNL) injury-induced neuropathic pain was studied in an animal model using behavioral, morphological and molecular biological methods. RESULTS: Repeated administration of intrathecal triptolide was found to alleviate SNL- or Poly(I:C) (toll-like receptor 3 agonist) injection-induced mechanical allodynia without any motor impairment. The mechanism by which triptolide reduces SNL- and Poly(I:C) injection-induced microglial activation appears to be via the inhibition of OX42 expression, which is a microglial-specific marker. Intrathecal triptolide also suppressed SNL- and Poly(I:C) injection-induced expression of spinal TRIF. TRIF transmits signals from activated TLR3 and is the downstream adaptor of TLR3 in microglia. In addition, intrathecal triptolide inhibited the expression of spinal pro-inflammatory IL-1 ß following SNL or Poly(I:C) injection. CONCLUSIONS: Intrathecal triptolide can suppress the TLR3/TRIF/IL-1 ß pathway in spinal microglia following SNL. This could be the underlying mechanism by which triptolide alleviate neuropathic pain induced by peripheral nerve injury.

[Effect of curcumin on the expression of high mobility group box 1 and apoptotic neurons in hippocampus after global cerebral ischemia reperfusion in rats].

OBJECTIVE: To explore the effects of curcumin on the expression of high mobility group box 1 (HMGB1) and apoptotic neurons in hippocampus after global cerebral ischemia/reperfusion in SD rats. METHODS: A total of 192 male SD rats were randomly divided into 4 groups: sham group (SH), ischemia-reperfusion group (IR), curcumin group (Cur) and solvent control group (SC). Bilateral vertebrate arteries were electrocauterized and bilateral common carotid arteries liberated in 3 ischemic groups. Isasteric curcumin solutions (200 mg/kg) or menstruum were injected intraperitoneally at 1 hour pre-ischemia in Cur and SC groups. The rats in each group were ligated for 15 minutes and then decapitated at 1, 3, 5 and 7 d post-reperfusion respectively. Cell morphology was observed on hematoxylin & eosin-stained slides. Apoptotic neurons were detected in CA1 region by TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Western blot was used to make a semi-determination of HMGB1 expression. RESULTS: At each time point, the number of apoptotic neurons was much more in IR and SC groups than that in SH group (P < 0.05). And the number of apoptotic neurons at 1, 3, 5, 7 d post-reperfusion was only 41%, 57%, 65% and 70% in Cur group respectively (P < 0.05). The expressional level of HMGB1 in IR and SC groups was significantly lower at 1d post-reperfusion (0.685 ± 0.050; 0.695 ± 0.053 vs 0.977 ± 0.063, P < 0.05). And it was significantly higher at 3, 5, 7 d post-reperfusion in IR and SC groups than that in SH groups (1.360 ± 0.045/1.353 ± 0.045; 1.342 ± 0.046/1.338 ± 0.047; 1.319 ± 0.052/1.322 ± 0.035 vs 0.992 ± 0.031; 0.978 ± 0.090; 0.992 ± 0.075, P < 0.05). The level at 1 d post-reperfusion (0.842 ± 0.063) in Cur group was significantly higher than that in IR and SC groups but lower than that in SH group. And it was lower at 3, 5, 7 d post-reperfusion (1.125 ± 0.023, 1.098 ± 0.073, 1.087 ± 0.089) than those in IR and SC groups (P < 0.05). There was no significant difference of HMGB1expression level between IR and SC groups. CONCLUSION: The expression level of HMGB1 in hippocampus is significantly reduced at 1 d post-reperfusion. Then it significantly increases and a high level is maintained until 7 d after global cerebral ischemia/reperfusion. Curcumin can reduce hippocampal neuronal apoptosis and injury. Such an effect may be due to an inhibition of the synthesis and release of HMGB1.

Sufentanil reduces emergence agitation in children receiving sevoflurane anesthesia for adenotonsillectomy compared with fentanyl.

BACKGROUND: Emergence agitation is a common problem in pediatric anesthesia, especially after sevoflurane induction and maintenance anesthesia. The purpose of this study was to investigate the effect of sufentanil to reduce emergence agitation after sevoflurane anesthesia in children undergoing adenotonsillectomy compared with fentanyl. METHODS: One hundred and five children, aged 3 - 11 years, were randomly allocated to receive normal saline (control group), sufentanil 0.2 µg/kg (S2) or fentanyl 2 µg/kg (F2) 1 minute after loss of the eyelash reflex. Anesthesia was induced and maintained with sevoflurane. Time to tracheal extubation, recovery time, Paediatric Anesthesia Emergence Delirium (PAED) scale, and emergence behavior were assessed. RESULTS: The incidence of severe agitation was significantly lower in S2 and F2 groups vs. the control group, 4/32 and 15/34 vs. 24/34 respectively, (P = 0.002, 0.009, respectively). PAED scales were significantly different among three groups (P = 0.007), and lower in the S2 and F2 groups than in the control group (P = 0.007 and P = 0.025, respectively). And the incidence of severe agitation and the PAED scale score was significantly different between the S2 and F2 groups (P = 0.007, P = 0.019, respectively). Time to tracheal extubation and recovery time were similar in all three groups. CONCLUSIONS: Administration of sufentanil at 0.2 µg/kg after induction of anesthesia reduced emergence agitation in children receiving sevoflurane anesthesia for adenotonsillectomy compared with fentanyl. This was without delaying the recovery time or causing significant hypotension.