Local effect of simvastatin combined with different osteoconductive biomaterials and collagen sponge on new bone formation in critical defects in rat calvaria

Purpose To evaluate the local effect of simvastatin (SVT) combined with deproteinized bovine bone (DBB) with hydroxyapatite/β-tricalcium phosphate biphasic ceramics (HA/TCP) and with collagen sponge (CS) on bone repair in critical size defects (CSDs) in rat calvaria. Methods Forty-two 5-mm diameter CSDs were made bilaterally in the calvaria of 18 rats. The animals were allocated according to the type of biomaterial and associations used to fill the CSD. After 8 weeks, the animals were euthanized, and their calvaria were evaluated for repaired tissue composition using histologic and histometric analyses. Results In the histometric analysis, the use of SVT showed to increase bone formation in the CSDs when combined with all the bone substitutes tested in this study (p<0.05). Greater bone formation was observed in the groups with SVT compared to the groups without SVT. Conclusions The use of SVT without the need for a vehicle and combined with a commercially available biomaterial may be a cheaper way to potentiate the formation of bone tissue without the need to produce new biomaterials. Therefore, SVT combined with DBB induced significantly greater new bone formation than did the other treatments.(AU)

The influence of simvastatin in induced peritoneal fibrosis in rats by peritoneal dialysis solution with glucosis 4.25% / Influência da sinvastatina na fibrose peritoneal induzida em ratos pelo uso de solução de diálise peritoneal com glicose a 4, 25%

PURPOSE: To investigate the influence of using simvastatin on the peritoneal fibrosis induced in rats using peritoneal dialysis solution with glucoses 4.25%. METHODS: Prospective controlled study in 20 non-uremic Wistar rats. The animals received a peritoneal infusion of 10 ml/100 g of peritoneal dialysis solution glucose 4.25% on a daily basis. The animals were divided in two groups: experimental and control. The experimental group received simvastatin 4 mg/kg/d, by a gastric tube. The control group did not receive any drug. The follow-up was 21 and 49 days. At the end, one surgical procedure was performed to get histological samples of visceral and parietal peritoneum. The samples were analyzed using Hematoxylin Eosin and Sirius Red, to evaluate the severity of the fibrosis. RESULTS: The analysis showed that the intensity of the fibrosis, the peritoneal thickness and the cell number in experimental and control groups were not statistically significant different in experimental and control groups. CONCLUSION: The simvastatin do not decrease the intensity of fibrosis on the peritoneal membrane that happens on rats on peritoneal dialysis.(AU)

OBJETIVO: Investigar a influência do uso da sinvastatina na fibrose peritoneal induzida em ratos pelo uso de solução de diálise peritoneal rica em glicose. MÉTODOS: Estudo prospectivo controlado, em ratos Wistar não urêmicos. Foram estudados 20 animais. Os animais foram submetidos diariamente à punção abdominal, sendo infundida solução de diálise peritoneal com glicose a 4,25% na dose de 10 ml/100 g de peso. Os animais foram divididos em dois grupos: experimental e controle. O grupo experimental recebeu sinvastatina na dose de 4 mg/kg/dia por gavagem. O grupo controle não recebeu nenhuma droga. Foram acompanhados por 21 e 49 dias. Ao final do período foram submetidos à procedimento cirúrgico para retirada de peritônio parietal e visceral. As amostras obtidas foram analisadas histologicamente, usando-se coloração Hematoxilina - Eosina e Sirius Red, para avaliação do grau de fibrose. RESULTADOS: A análise mostrou que a intensidade da fibrose, a espessura do peritônio e o número de células não atingiram diferença estatisticamente significante entre os grupos experimental e controle. CONCLUSÃO: A sinvastatina não foi capaz de alterar a intensidade da fibrose peritoneal induzida pelo uso de solução de diálise em ratos.(AU)

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.(AU)

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.(AU)

Effects of simvastatin in abdominal sepsis in rats / Efeitos da sinvastatina na sepse abdominal em ratos

PURPOSE: Statins are widely recognized as hypolipemic drugs, but some studies have observed anti-inflammatory and immunomodulatory effects, known as pleiotropic. The aims of this work was to study possible anti-inflammatory effects of simvastatin in abdominal sepsis. Serum pro-inflammatory cytokines and leukocytes count were determined in an experimental model of abdominal sepsis, using cecal ligation and puncture (CLP) in rats. METHODS: Twenty eigth Wistar rats weighing 285±12g were randomly divided in: CLP/Sinvastatin rats (n=7), treated with 10 mg/Kg of oral simvastatin 18 and 2 hs berofe CLP; CLP/Saline group rats (n=7), treated with oral saline; group Sham/Simvastatin (n=7), treated with simvastatin, and group Sham/Saline (n=7), treated with saline. Serum TNF-alpha, IL-1beta and IL-6 by ELISA and total leukocytes, neutrophils, lymphocytes, and eosinophils were determined 24 hs after CLP. ANOVA and Tukey test were used considering significant p<0.05. RESULTS: It was demonstrated that serum TNF-alpha, IL-1beta and IL-6 were respectively 364,8±42pg/mL; 46,3±18pg/mL and 28,4±13pg/mL in CLP/Sinvastatin rats, significantly lower (p<0.05) than in group CLP/Saline (778,5±86pg/ml; 176,9±46pg/ml; 133,6±21 pg/ml, respectively). The same results were observed in total leukocytes and neutrophils counts. CONCLUSION: These results clearly demonstrate that simvastatin is an effective agent that reduces cytokines levels and leukocyte count in sepsis, independently of its well-known lipid-lowering effects. Thus, HMG-CoA reductase inhibitors like simvastatin have important anti-inflammatory effects in abdominal sepsis in rats.(AU)

OBJETIVO: As estatinas são agentes reconhecidamente hipolipemiantes. Vários estudos têm revelado que eles têm ações pleiotrópicas, como antiinflamatória e imunomoduladora. Tentando-se entender o papel antiinflamatório da sinvastatina na sepse, foram analisados os níveis de citocinas pró-inflamatórias e contagem de leucócitos em modelo de sepse abdominal por ligadura e punção do ceco (LPC) em ratos. MÉTODOS: Foram utilizados 28 ratos Wistar pesando 285±12g, assim divididos: grupo sepse (n=14), submetidos a LPC e grupo sham (n=14), submetidos a laparotomia e manipulação suave do ceco. No grupo LPC/sinvastatina (n=7) os ratos receberam 10mg/kg de sinvastatina via oral 18 e 2 horas antes da LPC e no grupo LPC/salina (n=7) os ratos receberam injeção oral de solução salina 0,9 por cento. Os animais dos grupos sham/sinvastatina (n=7) e sham/salina (n=7) receberam o mesmo tratamento. Dosagem de TNF-alfa, IL-1beta e IL-6 por ELISA e contagem de leucócitos totais, neutrófilos, linfócitos e eosinófilos foram realizadas em todos os animais. Análise estatística foi feita pelo ANOVA e teste de Tukey, com significância p<0,05. RESULTADOS: Ficou demonstrado que as dosagens de TNF-alfa, IL-1beta e IL-6 atingiram valores de 364,8±42pg/ml; 46,3±18pg/ml e 28,4±13pg/ml no grupo submetido à sepse e tratados com sinvastatina, significantemente mais baixos do que no grupo sepse não tratados (778,5±86pg/ml; 176,9±46pg/ml; 133,6±21 pg/ml, respectivamente). O mesmo ocorreu na contagem de leucócitos totais e neutrófilos. CONCLUSÃO: A sinvastatina mostrou ação anti-inflamatória em ratos Wistar, diminuiu níveis de citocinas e leucócitos, sugerindo uso potencial na prevenção ou atenuação dos efeitos da sepse abdominal.(AU)