Experimental osteoarthritis model by means of medial meniscectomy in rats and effects of diacerein administration and hyaluronic acid injection / Modelo experimental de osteoartrite através da meniscectomia medial em ratos e efeitos da administração de diacereína e da injeção de ácido hialurônico

CONTEXT AND OBJECTIVE: The development of a slow and progressive mechanical model for osteoarthritis is important for correlation with clinical practice, and for evaluating the effects of disease-modifying medications. A mechanical osteoarthritis model was developed to evaluate the effects of intra-articular hyaluronic acid (HA) injection and oral diacerein administration. DESIGN AND SETTING: Experimental study at the Department of Orthopedics and Traumatology, Universidade de São Paulo. METHOD: Total medial meniscectomy was performed on seven groups of ten Wistar rats each, comprising four control groups (C) and three study groups (S). C.I: operated, non-medicated; C.II: operated, injections of HA vehicle; C.III: non-operated, non-medicated; C.IV: operated, non-medicated, sacrificed three months post-meniscectomy; S.I: operated, receiving intra-articular HA injections; S.II: operated, oral diacerein from the third to the seventh postoperative month; S.III: operated, received both medications. All the animals (except C.IV) were sacrificed seven months post-meniscectomy. All femurs and tibias were assessed histologically. RESULTS: The most severe degenerative histological changes were in the tibias of the operated knees. On the contralateral side, all groups had mild changes on the tibial surface. The femoral surface had ...

CONTEXTO E OBJETIVO: Desenvolver um modelo osteoartrítico mecânico lento e progressivo é importante para correlação com a prática clínica e para avaliar os efeitos de medicamentos modificadores da doença. Um modelo mecânico de osteartrite foi desenvolvido para avaliar os efeitos de injeção intra-articular de hialuronato de sódio (AH) e de administração de diacereína oral. DESENHO E LOCAL: Estudo experimental no Departamento de Ortopedia e Traumatologia, Universidade de São Paulo. MÉTODO: Meniscectomia medial total foi feita em sete grupos de dez ratos Wistar, sendo quatro grupos controle (C) e três grupos estudo (E). C.I: operado, não medicado; C.II: operado, recebendo injeções do veículo do AH; C.III: não operado, não medicado; C.IV: operado, não medicado, sacrificado três meses pósmeniscectomia; EI: operado, recebendo injeções de AH intra-articular; E.II: operado, recebendo diacereína oral do terceiro ao sétimo mês pós-operatório; E.III: operado, recebeu ambas medicações. Todos os animais (exceto C.IV) foram sacrificados sete meses pós-meniscectomia. Todos os fêmures e tíbias foram analisados histologicamente. RESULTADOS: As alterações histológicas degenerativas ...

Inhibition of formaldehyde-induced arthritis by a purified fraction prepared from Wilbrandia (cf) verticillata which contains novel norcucurbitacin glucosides

The anti-inflammatory activity of a purified fraction of the rhizome of Wilbrandia (cf) verticillata, which contains two novel norcucurbitacin glucosides, is reported. The increase of vascular permeability induced by acetic acid in mice (N = 5) was inhibited 69% and 90% by 50 and 100 mg/kg of the purified fraction, po (P<0.01). Acetylsalicylic acid (200 mg/kg), po, inhibited the response by 62% under the same conditions (P<0.05). The purified fraction (100 mg/kg, po) also significantly inhibited paw swelling in the rat formaldehyde-induced arthritis model on 8 of 10 days and reduced the swelling by 63% on day 10. Dexamethasone (1 mg/kg, ip) was more effective than the extract under the same conditions. These data partially characterize the anti-inflammatory activity of the purified fraction from this plant which is used in Brazilian folk medicine for the treatment of arthritis and related disorders