Amália Cínthia Meneses Rêgo

Effects of simvastatin in abdominal sepsis in rats

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 eight Wistar rats weighing 285+/-12 g were randomly divided in: CLP/Sinvastatin rats (n=7), treated with 10 mg/Kg of oral simvastatin 18 and 2 hs before 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+/-42 pg/mL; 46.3+/-18 pg/mL and 28.4+/-13 pg/mL in CLP/Sinvastatin rats, significantly lower (p<0.05) than in group CLP/Saline (778.5+/-86 pg/ml; 176.9+/-46 pg/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.

Simvastatin improves the healing of infected skin wounds of rats

Purpose: This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. Methods: Fourteen Wistar rats weighing 285±12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of sinvastatina microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFa and IL-1â by imunohistochemical technique, and histological analysis by HE stain were performed. Results: The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 ± 74.7 im 2 ) than in saline (2120.0 ± 327.1 im 2 ). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherchia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. Conclusion: In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising.PURPOSE This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. METHODS Fourteen Wistar rats weighing 285 +/- 12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of simvastatin microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFá and IL-1â by immunohistochemical technique, and histological analysis by HE stain were performed. RESULTS The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 +/- 74.7 ìm(2)) than in saline (2120.0 +/-327.1 ìm(2)). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherichia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. CONCLUSION In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising.

Efeitos da aplicação tópica do mel de Melipona subnitida em feridas infectadas de ratos

BACKGROUND: The current study investigated the antimicrobial, immunological and healing effects of Melipona subnitida honey on infected wounds of rat skin. METHOD: Wistar rats were anesthetized with sodium thiopental 20mg/Kg IP and ketamine 30 mg/kg IM. We evaluated the effects of honey using rats by generating 1 cm2 full-thickness skin wounds on the dorsum. The wounds of Group C rats (not infected) were treated daily with topic saline solution (0.9%) and in the Group HONEY (not infected) the wounds were treated with topic honey once a day. In the Groups C/I (infected) and HONEY/I (infected) the wounds were inoculated with polymicrobial solution, and tissue bacterial culture was performed 24 hours later. These wounds were treated with topic saline solution and honey, respectively. In the third day of treatment it was made a new bacterial culture. After epithelialization, wound tissue biopsies were used for cytokines dosage and histology. RESULTS: The HONEY/I wounds showed more rapid healing and re-epithelialization than in the other groups, and the difference was significant (p<0.05). It was observed that the density of collagen, fibroblasts, macrophages and the expression of TNF-a, IL1-â and Il-6 were higher on the HONEY/I wounds then in the other groups. After the treatment with honey, the amount of Gram-positive and Gram-negative bacteria in the infected wounds decreased significantly. CONCLUSION: The results may encourage the use of honey in skin infected wounds because it stimulated cytokine production, reduced the healing time and had antibacterial activity.

Influence of laparoscopy and laparotomy on gasometry, leukocytes and cytokines in a rat abdominal sepsis model

PURPOSE Laparoscopic surgery is associated with reduced surgical trauma, and less acute phase response, as compared with open surgery. Cytokines are important regulators of the biological response to surgical and anesthetic stress. The aim of this study was to determine if CO2 pneumoperitoneum would change cytokine expression, gas parameters and leukocyte count in septic rats. METHODS Wistar rats were randomly assigned to five groups: control (anesthesia only), laparotomy, CO2 pneumoperitoneum, cecum ligation and puncture by laparotomy, and laparoscopic cecum ligation and puncture. After 30 min of the procedures, arterial blood samples were obtained to determine leukocytes subpopulations by hemocytometer. TNFalpha, IL-1beta, IL-6 were determined in intraperitoneal fluid (by ELISA). Gas parameters were measured on arterial blood, intraperitoneal and subperitoneal exudates. RESULTS Peritoneal TNFalpha, IL-1beta and IL-6 concentrations were lower in pneumoperitoneum rats than in all other groups (p<0.05). TNFalpha, IL-1beta and IL-6 expression was lower in the laparoscopic than in laparotomic sepsis (p<0.05). Rats from laparoscopic cecum ligation and puncture group developed significant hypercarbic acidosis in blood and subperitoneal fluid when compared to open procedure group. Total white blood cells and lymphocytes were significantly lower in laparoscopic cecum ligation and puncture rats than in the laparotomic (p<0.01). Nevertheless, the laparotomic cecum ligation rats had a significant increase in blood neutrophils and eosinophils when compared with controls (p<0.05). CONCLUSIONS This study demonstrates that the CO2 pneumoperitoneum reduced the inflammatory response in an animal model of peritonitis with respect to intraperitoneal cytokines, white blood cell count and clinical correlates of sepsis. The pneumoperitoneum produced hypercarbic acidosis in septic animals.

Biodistribution of the radiophamarceutical sodium pertechnetate (Na99mTcO4) after massive small bowel resection in rats

PURPOSE To evaluate the biodistribution of sodium pertecnetate (Na(99m)TcO(4)) in organs and tissues, the morphometry of remnant intestinal mucosa and ponderal evolution in rats subjected to massive resection of the small intestine. METHODS Twenty-one Wistar rats were randomly divided into three groups of 7 animals each. The short bowel (SB) group was subjected to massive resection of the small intestine; the control group (C) rats were not operated on, and soft intestinal handling was performed in sham rats. The animals were weighed weekly. On the 30th postoperative day, 0.l mL of Na(99m)TcO(4), with mean activity of 0.66 MBq was injected intravenously into the orbital plexus. After 30 minutes, the rats were killed with an overdose of anesthetic, and fragments of the liver, spleen, pancreas, stomach, duodenum, small intestine, thyroid, lung, heart, kidney, bladder, muscle, femur and brain were harvested. The biopsies were washed with 0.9% NaCl.,The radioactivity was counted using Gama Counter Wizard 1470, PerkinElmer. The percentage of radioactivity per gram of tissue (%ATI/g) was calculated. Biopsies of the remaining jejunum were analysed by HE staining to obtain mucosal thickness. Analysis of variance (ANOVA) and the Tukey test for multiple comparisons were used, considering p<0.05 as significant. RESULTS There were no significant differences in %ATI/g of the Na(99m)TcO(4) in the organs of the groups studied (p>0.05). An increase in the weight of the SB rats was observed after the second postoperative week. The jejunal mucosal thickness of the SB rats was significantly greater than that of C and sham rats (p<0.05). CONCLUSION In rats with experimentally-produced short bowel syndrome, an adaptive response by the intestinal mucosa reduced weight loss. The biodistribution of Na(99m)TcO(4) was not affected by massive intestinal resection, suggesting that short bowel syndrome is not the cause of misleading interpretation, if an examination using this radiopharmaceutical is indicated.

Biodistribution of the radiopharmaceutical sodium pertechnetate after biliopancreatic bypass with a duodenal switch

Study with the purpose to examine the effects of duodenal switch (DS), regularly performed in morbidly obese patients, on biodistribution of sodium pertechnetate in several organs of rats. There was no early or late mortality in either rats groups. The values of percent radioactivity per gram of tissue (%ATI/g), showed no significant difference in liver, stomach, small bowel, duodenum, kidney, heart, bladder, bone and brain, when compared the DS rats with sham and controls rats. A postoperative significant increase (p<0.05) in mean %ATI/g levels was observed in spleen, pancreas and muscle in group DS rats, as compared to group S and C rats. In the lung there was an increase and in thyroid a decrease in mean %ATI/g of DS rats, when compared to sham rats (p<0.05). In conclusion, the biliopancreatic diversion with duodenal switch in rats modified the biodistribution of sodium pertechnetate in thyroid, lung, pancreas, spleen and muscle.

Efeito da sinvastatina na sepse abdominal de ratos diabéticos

OBJECTIVE: Infection and sepsis are major causes of morbidity and mortality after surgery of diabetic patients. Statins have been shown to exhibit anti-inflammatory and immunomodulatory (pleiotropic) effects, independent of lipid lowering. This study aimed to observe whether the pretreatment with simvastatin in a cecal ligation and perforation model of sepsis is beneficial in diabetic rats. METHODS: Fifty six Wistar rats were randomly assigned to non-diabetic group (n=28), and streptozotocin-induced diabetic group (n=28). Abdominal sepsis was induced in 14 diabetic and in 14 non diabetic rats and the other 28 rats were allocated on sham group. Sepsis rats and sham rats (each with 7 animals) were treated with oral simvastatin (20 mg kg-1 day-1) or normal saline solution 0.9%. Peripheral blood TNFα, IL-1β, IL-6, C-reactive protein, procalcitonin, leukocytes and neutrophils were tested in all the animals. Statistical analysis was done by ANOVA and Tukey test, with p<0.05. RESULTS: Simvastatin reduced mortality in diabetic rats. Peripheral blood TNFα, IL-1β, IL-6, C-reactive protein, procalcitonin, leukocytes and neutrophils were lower in diabetic and non diabetics septic rats treated with simvastatin, than after saline treatment. CONCLUSION: Simvastatin showed anti-inflammatory effect, which could play some protection against the progress of sepsis in diabetic rats.

Nanotechnology in Phytotherapy: Antiinflammatory Effect of a Nanostructured Thymol Gel from Lippia sidoides in Acute Periodontitis in Rats

Lippia sidoides Cham (Verbenaceae) is largely distributed in the northeastern region of Brazil. It is popularly known as ‘Alecrim‐pimenta’. Recent studies have shown that some species of Lippia have interesting pharmacological activities. This study aimed to evaluate the effect of a nanostructured thymol gel (TG) 1.2 mg/g on acute phase of ligature‐induced periodontitis model [acute periodontal disease (APD)] in rats. APD was induced in 24 Wistar rats subjected to ligature placement on left molars in maxillae. Animals were treated with TG, immediately after APD induction. Saline‐based gel was utilized as negative control and diethylammonium diclofenac gel 10 mg/g was used as positive control. Animals were randomly assigned into the groups. The periodontium and the surrounding gingiva were examined at histopathology, as well as the neutrophil influx into the gingiva was assayed using myeloperoxidase activity levels by ELISA method. TG treatment reduced tissue lesion at histopathology coupled to decreased myeloperoxidase activity production in gingival tissue when compared with the saline gel control group (p < 0.05). The TG gel was able to provide a significant myeloperoxidase decreasing in gingiva tissue confirming to be effective in reducing gingival inflammation in this model. Copyright

Biodistribution of the radiopharmaceutical technetium-99m-sodium phytate in rats after splenectomy

Drugs and surgery can interfere with the biodistribution of radiopharmaceuticals and data about the effect of splenectomy on the metabolism of phytate-Tc-99m are scarce. This study aimed at evaluating the interference of splenectomy on phytate-Tc-99m biodistribution and liver function in rats. The SP group rats (n=6) underwent splenectomy. In group C (control) the animals were not operated on. After 15 days, all rats were injected with 0.1mL of Tc-99m-phytate via orbital plexus (0.66MBq). After 30 minutes, liver samples were harvested, weighed and the percentage of radioactivity per gram (%ATI/g) was determined by a Wizard Perkin-Elme gama counter. The ATI%/g in splenectomized rats (0.99±0.02) was significantly higher than in controls (0.4±0.02), (p=0.034). ALT, AST and HDL were significantly lower in SP rats (p= 0.001) and leukocytosis was observed in SP rats. In conclusion, splenectomy in rats changed the hepatic biodistribution of Tc-99m-phytate and liver enzimatic activity.

Metabolism and gastric remnant changes after Roux-en-Y gastric bypass in rats.

ABSTRACT Background: The Roux-en-Y gastric bypass (RYGB) may affect metabolism, microbiology, and histology of gastric remnant. Therefore, this study aimed to investigate these issues in rats. Methods: Twelve rats were randomly allocated to a RYGB group (n = 6) and nonoperated normal rats group (n = 6). After 30 postoperative days, all rats were injected with 0.1ml of Na99mTc− i.v. (radioactivity 0.66 MBq). After 30 min, liver, stomach, thyroid, heart, lung, kidney, and femur samples were harvested and weighed. Percentage radioactivity per gram of organ (%ATI/g) was determined using a Perkin-Elmer gamma counter. Serum albumin, calcium, aminotransferases (ALT, AST), T3, T4, and PTH were determined. Samples of the excluded stomach mucosa were harvested for bacterial and fungal count such as colony-forming units/g and histology. Results: A significant reduction (t test) in %ATI/g was observed in the liver, stomach, and femur in the RYGB rats, compared with normal rats (p < .05). A significant reduction in serum albumin and calcium in RYGB rats was detected, compared with normal rats (p < .05). ALT and AST were significantly different between the two groups. T3 and T4 levels were significantly lower in RYGB rats than in normal rats (p < .05); PTH levels were higher in RYGB rats than in controls (p = .009). The gastric remnant mucosa of RYGB rats showed higher bacterial and fungal count, atrophy, intestinal metaplasia, and neutrophilic polymorphonuclear inflammation than in normal rats. Conclusions: This investigation demonstrated that a model of murine RYGB significantly modified metabolic parameters and the microbiology/histology of the remnant stomach.