Protective effect of simvastatin in the cyclophosphamide-induced hemohrragic cystitis in rats / Efeito protetor da sinvastatina na cistite hemorrágica induzida pela ciclofosfamida em ratos

PURPOSE: Cyclophosphamide (CYP) is an antineoplastic agent used for the treatment of many neoplastic and inflammatory diseases. Hemorrhagic cystitis is a frequent side effect of CYP. Several studies show that simvastatin has important pleiotropic (anti-inflammatory and immunomodulatory) effects. The purpose of the study was to investigate the effect of simvastatin on bladder, ureter and kidney injury caused by CYP. METHODS: Adult male Wistar rats were randomly divided into three groups. The CYP/SIM group received simvastatin microemulsion by gavage during 7 days (10 mg/kg body wt) before the administration of CYP and the CYP/SAL group rats received saline 0.9 percent. The control rats were not treated. After that, all rats were treated with a single dose of CYP 200 mg/kg body wt intraperitoneally. The rats were killed 24 h after CYP administration. Plasma cytokines (TNF-α, IL-1β, IL-6) were measured by ELISA. Macro and light microscopic study was performed in the bladder, kidney and ureter. RESULTS: In the bladders of CYP/SIMV treated rats edema of lamina propria with epithelial and sub-epithelial hemorrhage were lower than in CYP/SAL treated rats. The scores for macroscopic and microscopic evaluation of bladder and ureter were significantly lower in CYP/SIMV rats than in CYP/SAL rats. The kidney was not affected. The expression of TNF-α, IL-1β and IL-6 was significatly lower in CF/SINV rats (164.8±22, 44.8±8 and 52.4±13) than in CF/SAL rats (378.5±66, 122.9±26 e 123.6±18), respectively. CONCLUSION: The results of the current study suggest that simvastatin pretreatment attenuated CYP-induced urotelium inflammation and decreased the activities of cytokines.

OBJETIVO: Ciclofosfamida (CF) é um agente antineoplásico frequente implicado na etiologia da cistite hemorrágica. Vários estudos mostram que a sinvastatina tem importantes efeitos pleiotrópicos (anti-inflamatórios e imunomoduladores). O objetivo do trabalho foi estudar os efeitos da sinvastatina na prevenção de cistite hemorrágica e lesões uroteliais induzidas por CF em modelo experimental. MÉTODOS: Doze ratos Wistar foram distribuídos de forma randomizada em três grupos: nos ratos do grupo experimental (CF/SINV), foi administrada microemulsão de sinvastatina 10mg/Kg, por via oral (gavagem), durante 7 dias antes da administração de CF e os ratos do grupo controle (CF/SAL), foram tratados com solução salina 0,9 por cento nas mesmas doses e prazos. O grupo controle não foi tratado. Todos os ratos foram tratados com CF 200mg/Kg intraperitonial (dose única) e 24 horas após foram sacrificados. Exame macro e microscópico foi feito na bexiga e os rins e ureteres foram avaliados microscopia. Foram realizadas dosagens plasmáticas de TNF-α, IL-1β, IL-6 (ELISA). RESULTADOS: O escore para avaliação macroscópica do dano à bexiga e o escore para avaliação do dano histológico na bexiga e nos ureteres mostraram-se significativamente menores no grupo CF/SINV em comparação ao grupo CF/SAL (p<0,05). Os rins não foram afetados. A expressão de TNF-α, IL-1β, IL-6 também foi significativamente menor (p<0,05) no grupo CF/SINV (164,8±22, 44,8±8 e 52,4±13) em comparação ao grupo CF/SAL (378,5±66, 122,9±26 e 123,6±18), respectivamente. CONCLUSÃO: O estudo demonstrou eficácia da sinvastatina na atenuação da cistite hemorrágica e lesão ureteral induzidas por CF em ratos Wistar, através da interferência nas citocinas plasmáticas e nas lesões uroteliais.

Hind limb ischemic preconditioning induces an anti-inflammatory response by remote organs in rats

Ischemic preconditioning (IPC), a strategy used to attenuate ischemia-reperfusion injury, consists of brief ischemic periods, each followed by reperfusion, prior to a sustained ischemic insult. The purpose of the present study was to evaluate the local and systemic anti-inflammatory effects of hind limb IPC in male Wistar rat (200-250 g) models of acute inflammation. IPC was induced with right hind limb ischemia for 10 min by placing an elastic rubber band tourniquet on the proximal part of the limb followed by 30 min of reperfusion. Groups (N = 6-8) were submitted to right or left paw edema (PE) with carrageenan (100 µg) or Dextran (200 µg), hemorrhagic cystitis with ifosfamide (200 mg/kg, ip) or gastric injury (GI) with indomethacin (20 mg/kg, vo). Controls received similar treatments, without IPC (Sham-IPC). PE is reported as variation of paw volume (mL), vesical edema (VE) as vesical wet weight (mg), vascular permeability (VP) with Evans blue extravasation (µg), GI with the gastric lesion index (GLI; total length of all erosions, mm), and neutrophil migration (NM) from myeloperoxidase activity. The statistical significance (P < 0.05) was determined by ANOVA, followed by the Tukey test. Carrageenan or Dextran-induced PE and VP in either paw were reduced by IPC (42-58.7 percent). IPC inhibited VE (38.8 percent) and VP (54 percent) in ifosfamide-induced hemorrhagic cystitis. GI and NM induced by indomethacin were inhibited by IPC (GLI: 90.3 percent; NM: 64 percent). This study shows for the first time that IPC produces local and systemic anti-inflammatory effects in models of acute inflammation other than ischemia-reperfusion injury.