State Key Laboratory of Natural Medicines, Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing 210009, China.
Acta Pharmacol Sin. 2013 Mar;34(3):403-13. doi: 10.1038/aps.2012.187. Epub 2013 Feb 11.
To explore the effects of norisoboldine (NOR), a major isoquinoline alkaloid in Radix Linderae, on joint destruction in rats with adjuvant-induced arthritis (AIA) and its underlying mechanisms.
AIA was induced in adult male SD rats by intradermal injection of Mycobacterium butyricum in Freund's complete adjuvant at the base of the right hind paw and tail. From d 14 after immunization, the rats were orally given NOR (7.5, 15, or 30 mg/kg) or dexamethasone (0.5 mg/kg) daily for 10 consecutive days. Joint destruction was evaluated with radiological scanning and H&E staining. Fibroblast-like synoviocytes (FLS) were prepared from fresh synovial tissues in the AIA rats. The expression of related proteins and mRNAs were detected by ELISA, Western blotting and RT-PCR.
In AIA rats, NOR (15 and 30 mg/kg) significantly decreased the swelling of paws and arthritis index scores, and elevated the mean body weight. NOR (30 mg/kg) prevented both the infiltration of inflammatory cells and destruction of bone and cartilage in joints. However, NOR (15 mg/kg) only suppressed the destruction of bone and cartilage, but did not obviously ameliorate synovial inflammation. NOR (15 and 30 mg/kg) significantly decreased the serum levels of receptor activator of nuclear factor κB ligand (RANKL), IL-6, PGE2, and MMP-13, but not the osteoprotegerin and MMP-1 levels. The mRNA levels of RANKL, IL-6, COX-2, and MMP-13 in synovium were also suppressed. Dexamethasone produced similar effects in AIA rats as NOR did, but without elevating the mean body weight. In the cultured FLS, treatment with NOR (10 and 30 mmol/L) significantly decreased the secretion of RANKL, IL-6, PGE2, and MMP-13 proteins. Furthermore, the treatment selectively prevented the activation of MAPKs, AKT and transcription factor AP-1 component c-Jun, but not the recruitment of TRAF6 or the activation of JAK2/STAT3. Treatment of the cultured FLS with the specific inhibitors of p38, ERK, AKT, and AP-1 significantly decreased the secretion of RANKL, IL-6, PGE2, and MMP-13 proteins.
NOR can alleviate joint destruction in AIA rats by reducing RANKL, IL-6, PGE2, and MMP-13 expression via the p38/ERK/AKT/AP-1 pathway.
探讨乌药堿（NOR）对佐剂诱导关节炎（AIA）大鼠关节破坏的作用及其机制。
在大鼠右后足底部和尾部皮内注射分枝杆菌丁酸弗氏完全佐剂诱导 AIA。免疫后 14 天，大鼠每天口服 NOR（7.5、15 或 30 mg/kg）或地塞米松（0.5 mg/kg），连续 10 天。通过放射扫描和 H&E 染色评估关节破坏。从 AIA 大鼠的新鲜滑膜组织中制备成纤维样滑膜细胞（FLS）。通过 ELISA、Western blot 和 RT-PCR 检测相关蛋白和 mRNA 的表达。
在 AIA 大鼠中，NOR（15 和 30 mg/kg）显著降低了爪子肿胀和关节炎指数评分，并提高了平均体重。NOR（30 mg/kg）预防了炎症细胞浸润和关节中骨和软骨的破坏。然而，NOR（15 mg/kg）仅抑制了骨和软骨的破坏，但对滑膜炎症没有明显改善。NOR（15 和 30 mg/kg）显著降低了血清核因子κB 受体激活剂配体（RANKL）、IL-6、PGE2 和 MMP-13 的水平，但对骨保护素和 MMP-1 的水平没有影响。滑膜中 RANKL、IL-6、COX-2 和 MMP-13 的 mRNA 水平也受到抑制。地塞米松在 AIA 大鼠中产生与 NOR 相似的作用，但不提高平均体重。在培养的 FLS 中，NOR（10 和 30 mmol/L）处理显著降低了 RANKL、IL-6、PGE2 和 MMP-13 蛋白的分泌。此外，该处理选择性地阻止了 MAPKs、AKT 和转录因子 AP-1 组成部分 c-Jun 的激活，但不阻止 TRAF6 的募集或 JAK2/STAT3 的激活。培养的 FLS 用 p38、ERK、AKT 和 AP-1 的特异性抑制剂处理后，RANKL、IL-6、PGE2 和 MMP-13 蛋白的分泌明显减少。
NOR 可通过 p38/ERK/AKT/AP-1 通路减少 RANKL、IL-6、PGE2 和 MMP-13 的表达，从而减轻 AIA 大鼠的关节破坏。
