title: Modification of rat model of sciatica induced by lumber disc herniation and the anti-inflammatory effect of osthole given by epidural catheterization.
abstract: One of the most treatable causes of lower back pain and associated sciatica is lumbar disc herniation (LDH), which is characterized by rupture of the hard outer wall (annulus fibrosis) in a lumbar intervertebral disc. In the current study, we aimed to: (1) develop and characterize a rat model of sciatica induced by LDH, while introducing a novel method of epidural catheterization; (2) use this model to evaluate the effect of osthole on pain due to LDH, and (3) gain insight into the mechanisms through which osthole affects sciatica induced by LDH. The results indicate that our newly developed rat model maintained mechanical allodynia for 28 days without reduction. Moreover, cyclooxygenase-2 (COX-2) and nitric oxide synthase (NOS) were overexpressed in the associated inflammatory response, which is consistent with clinical manifestations of the disease. We then used this model to study the effect and mechanisms through which osthole affected pain due to LDH. Our study suggests that osthole is capable of reversing hyperalgesia due to LDH, potentially through modulation of activity of COX-2 and NOS, two important proteins for the exacerbation of pain due to LDH. Finally, a molecular modeling simulation showed that osthole has unique binding capabilities to both NOS and COX-2. As the model-induced mechanical hyperalgesia response was consistent, and the position of the catheter tip and the extension/spreading of the drug in the epidural space were reliable, this study developed an improved model to study remedies for sciatic pain. Moreover, our studies demonstrate that osthole may be a feasible treatment for the reduction of pain due to hyperalgesia.
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Wei
authors.forename: Sui-Lin
authors.initials: SL
authors.lastname: Mo
authors.forename: Neel R
authors.initials: NR
authors.lastname: Nabar
authors.forename: Yuling
authors.initials: Y
authors.lastname: Chen
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Qiu-Lan
authors.initials: QL
authors.lastname: He
authors.forename: Xue-Nong
authors.initials: XN
authors.lastname: Zou
authors.forename: Xian-Guo
authors.initials: XG
authors.lastname: Liu
authors.forename: Lai-Bao
authors.initials: LB
authors.lastname: Sun
authors.forename: Shu-Feng
authors.initials: SF
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002404:Catheterization; D003374:Coumarins / Q000494:pharmacology / Q000627:therapeutic use*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004195:Disease Models, Animal; D007268:Injections, Epidural; D007405:Intervertebral Disc Displacement / Q000150:complications* / Q000188:drug therapy / Q000201:enzymology; D008159:Lumbar Vertebrae; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010146:Pain / Q000188:drug therapy / Q000201:enzymology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012585:Sciatica / Q000188:drug therapy / Q000201:enzymology / Q000209:etiology*
chemical_list: D000893:Anti-Inflammatory Agents; D003374:Coumarins; D019001:Nitric Oxide Synthase; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; C046627:osthol