title: [Effects and mechanisms of osthole on sciatica induced by lumber disc herniation].
abstract: OBJECTIVE
  To study the effects of osthole on sciatica induced by lumber disc herniation and its mechanisms.
  
  
  METHODS
  54 male SD rats were randomly divided into 6 groups. Model (M) group (n = 12): Autologous nucleus pulposus was harvested from the tail and applied to the L5 dorsal root ganglion (DRG) and epidural space. Epidural catheterization was performed. Control(C) group (n = 12): On the basis of nucleus pulposus group, 50 microL tween-80 was administered epidurally on the day 6th after surgery. T2 (n = 6), T6 (n = 12), T13 (n = 6) and T20 (n = 6) group: 50 microL 2% osthole was administered epidurally on the 2th, 6th, 13th day and 20th after surgery respectively. General behaviors were observed and 50% paw withdrawal threshold (50% PWT) was measured 1 day before surgery, on the 1st, 3th, 7th,14th, 21th, 28th day after surgery, immediately before and 1 hour after osthole or tween-80 administration in each group. On the 7th day after surgery, the left L5 DRGs were obtained for detecting the expression of NOS and COX-2 in M, C and T6 group with 6 rats.
  
  
  RESULTS
  No lameness or autophagy was oberserved. 50% PWT decreased after surgery (P < 0.05). In T2 and T6 group, 50% PWT after osthole administration were significantly higher than those of M group and C group (P < 0.05), which recovered to the same level as 1 day before surgery (P > 0.05). In T13 and T20 group, 50% PWT 1 hour after osthole administration were significantly higher than those of M group and C group (P < 0.05), which recovered to the same level as 1 day before surgery (P > 0.05), but on days after 1 hour after administration, there was no significant difference when 50% PWT compared with M group or nucleus C group (P > 0.05). NOS positive cells and COX-2 positive cells were no significant difference when M group compared with C group (P > 0.05). But these positive cells in T6 group were significantly lower than those of M group and C group (P < 0.05).
  
  
  CONCLUSIONS
  50 microL 2% osthole could completely inhibit the mechanical allodynia in the rat model of sciatica induced by lumbar disc herniation when it was administered epidurally on 2 or 6 day after surgery. But when administered on 13 or 20 day after surgery, its analgesic effect was transient. The effect of 50 microL 2% osthole epidural administration on day 6 after surgery on the rat model of sciatica induced by lumbar disc herniation may relate to inhibition of the expression of COX-2 and NOS in DRG.
authors.affiliation: Department of Anesthesiology, First-affiliated Hospital, Guangzhou 510080, China. wwwmmming@126.com
authors.forename: Ming
authors.initials: M
authors.lastname: Wei
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Qiu-Lan
authors.initials: QL
authors.lastname: He
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Zheng-Hua
authors.initials: ZH
authors.lastname: Ren
authors.forename: Lai-Bao
authors.initials: LB
authors.lastname: Sun
authors.forename: Xian-Guo
authors.initials: XG
authors.lastname: Liu
mesh_terms: D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal; D003374:Coumarins / Q000008:administration & dosage / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004195:Disease Models, Animal; D005727:Ganglia, Spinal / Q000378:metabolism* / Q000601:surgery; D007268:Injections, Epidural; D007405:Intervertebral Disc Displacement / Q000150:complications*; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012585:Sciatica / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D013126:Spinal Nerve Roots / Q000293:injuries
chemical_list: D000700:Analgesics; D003374:Coumarins; D019001:Nitric Oxide Synthase; D051546:Cyclooxygenase 2; C046627:osthol