Effects of anti-TNF-α in experimental diversion colitis

Abstract Purpose: To evaluate the effects of infliximab on the inflammation of the colonic mucosa devoid from fecal stream. Methods: Twenty-four rats were submitted to a Hartmann's procedure. They remained for 12 weeks with the fecal derivation to development of diversion colitis on excluded colorectal stump. After this period, they were divided into 3 groups: one group received intervention with saline (2.0 mL / week), other group infliximab at doses of 5 mg/kg/week and the other 10 mg/kg/week for five consecutively weeks. Concluded the intervention period, the animals were euthanized to remove colon segments with and without fecal stream. Colitis was diagnosed by histological analysis and the degree of inflammation by validated score. The neutrophilic infiltrate was evaluated by tissue expression of myeloperoxidase identified by immunohistochemical. The tissue content of myeloperoxidase was measured by computer-assisted image analysis. Results: The inflammatory score was high in colonic segments without fecal stream. The intervention with infliximab reduced the inflammatory score in excluded colonic segments. The content of myeloperoxidase was reduced in colonic segments of animals treated with infliximab mainly in high concentrations. Conclusion: Intervention with infliximab reduced the inflammation and the neutrophil infiltrate in colonic segments devoid of the fecal stream.

Up-regulation of Hsp72 and keratin16 mediates wound healing in streptozotocin diabetic rats

BACKGROUND: Impaired wound healing is a complication of diabetes and a serious problem in clinical practice. We previously found that whey protein (WP) was able to regulate wound healing normally in streptozotocin (STZ)-dia-betic models. This subsequent study was designed to assess the effect of WP on heat shock protein-72 (Hsp72) and keratin16 (Krt16) expression during wound healing in diabetic rats. METHODS: WP at a dosage of 100 mg/kg of body weight was orally administered daily to wounded normal and STZ-diabetic rats for 8 days. RESULTS: At day 4, the WP-treated diabetic wound was significantly reduced compared to that in the corresponding control. Diabetic wounded rats developed severe inflammatory infiltration and moderate capillary dilatation and regeneration. Treated rats had mild necrotic formation, moderate infiltration, moderate to severe capillary dilatation and regeneration, in addition to moderate epidermal formation. Hsp72 and Krt16 densities showed low and dense activity in diabetic wounded and diabetic wounded treated groups, respectively. At day 8, WP-treatment of diabetic wounded animals revealed great amelioration with complete recovery and closure of the wound. Reactivity of Hsp72 and Krt16 was reversed, showing dense and low, or medium and low, activity in the diabetic wounded and diabetic wounded treated groups, respectively. Hsp72 expression in the pancreas was found to show dense reactivity with WP-treated diabetic wound rats. CONCLUSION: This data provides evidence for the potential impact of WP in the up-regulation of Hsp72 and Krt16 in T1D, resulting in an improved wound healing process in diabetic models.

Oral administration of curcumin (Curcuma longa) can attenuate the neutrophil inflammatory response in zymosan-induced arthritis in rats

PURPOSE: To evaluate the effect of curcumin in the acute phase of zymosan-induced arthritis. METHODS: Twenty-eight male rats were subjected to intra-articular infiltration of zymosan of both knees and, in four the infiltration was made with saline. The animals were divided into five groups second received every six hours by gavage: corn oil by (positive and negative control); curcumin (100 mg/kg); prednisone 1 mg/kg/day; prednisone 8 mg/kg. All animals were sacrificed after six, 12, 24 and 48 hours of the infiltration. The knees were removed for evaluation of neutrophil infiltration. The number of neutrophils was counted by computer-assisted analysis of the images. The neutrophil infiltrate was stratified into four grades: 0 = normal; + = mild; ++/+++ = moderate; > ++++ = severe. The results were compared using the Mann-Whitney test and the variance by Kruskal-Wallis test adopting a significance level of 5% (p<0.05). RESULTS: Curcumin reduces inflammatory activity in the first six hours after zymosan-induced arthritis when compared to saline (p<0.01). This was also observed in animals subjected to administration of prednisone (1 mg/kg) and those treated with prednisone (8 mg/kg). Curcumin was more effective than lower doses of prednisone in the first six hours after induction of the arthritis. After 12, 24 and 48 hours, curcumin does not have the same anti-inflammatory effects when compared to prednisone. After 48 hours, prednisone is more effective than curcumin in reducing the inflammatory infiltrate regardless of the dose of prednisone used. CONCLUSION: Oral administration of curcumin reduces inflammation in the first six hours after experimentally zymosan-induced arthritis. .

Amitriptyline, clomipramine, and maprotiline attenuate the inflammatory response by inhibiting neutrophil migration and mast cell degranulation

Objective: Despite the recognized anti-inflammatory potential of heterocyclic antidepressants, the mechanisms concerning their modulating effects are not completely known. Thus, we evaluated the anti-inflammatory effect of amitriptyline, clomipramine, and maprotiline and the possible modulating properties of these drugs on neutrophil migration and mast cell degranulation. Methods: The hind paw edema and air-pouch models of inflammation were used. Male Wistar rats were treated with saline, amitriptyline, clomipramine or maprotiline (10, 30, or 90 mg/kg, per os [p.o.]) 1 h before the injection of carrageenan (300 μg/0.1 mL/paw) or dextran (500 μg/0.1 mL/paw). Then, edema formation was measured hourly. Neutrophil migration to carrageenan (500 μg/pouch) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) (10-6 M/mL/pouch) was also investigated in 6-day-old air-pouch cavities. Compound 48/80-induced mast cell degranulation was assessed in the mesenteric tissues of antidepressant-treated rats. Results: All tested antidepressants prevented both carrageenan- and dextran-induced edema. The anti-inflammatory effect of these drugs partially depends on the modulation of neutrophil migration, since they significantly counteracted the chemotactic response of both carrageenan and fMLP (p < 0.01). Furthermore, amitriptyline, clomipramine and maprotiline inhibited compound 48/80-induced mast cell degranulation (p < 0.001). Conclusions: These results suggest an important anti-inflammatory role of heterocyclic antidepressants, which is dependent on the modulation of neutrophil migration and mast cell stabilization. .

Simvastatin attenuates neutrophil recruitment in one-lung ventilation model in rats

PURPOSE: To investigate the anti-inflammatory effects of simvastatin in rats undergoing one-lung ventilation (OLV) followed by lung re-expansion. METHODS: Male Wistar rats (n=30) were submitted to 1-h OLV followed by 1-h lung re-expansion. Treated group received simvastatin (40 mg/kg for 21 days) previous to OLV protocol. Control group received no treatment or surgical/ventilation interventions. Measurements of pulmonary myeloperoxidase (MPO) activity, pulmonary protein extravasation, and serum levels of cytokines and C-reactive protein (CRP) were performed. RESULTS: OLV significantly increased the MPO activity in the collapsed and continuously ventilated lungs (31% and 52% increase, respectively) compared with control (p<0.05). Treatment with simvastatin significantly reduced the MPO activity in the continuously ventilated lung but had no effect on lung edema after OLV. The serum IL-6 and CRP levels were markedly higher in OLV group, but simvastatin treatment failed to affect the production of these inflammatory markers. Serum levels of IL-1β, TNF-α and IL-10 remained below the detection limit in all groups. CONCLUSIONS: In an experimental one-lung ventilation model pre-operative treatment with simvastatin reduces remote neutrophil infiltration in the continuously ventilated lung. Our findings suggest that simvastatin may be of therapeutic value in OLV-induced pulmonary inflammation deserving clinical investigations.

Protective perioperative strategy using a third generation hydroxyethyl starch during surgery in a murine model of liver reperfusion injury / Estratégia protetora perioperatória usando um hidroxietilamido de terceira geração para expansão volêmica durante a cirurgia em modelo murino de lesão de reperfusão hepática

PURPOSE: To investigate whether a third generation colloid, hydroxyethyl starch (HES 130/0.4), used for perioperative fluid therapy, protects the rat liver against the late-phase response of ischemia/reperfusion injury (IRI) and if inhibition of neutrophil hepatic infiltration plays a part in this mechanism. METHODS: Wistar rats were used (8 in each group). Three groups had IRI induced by lobar vascular occlusion (60 minutes) and reperfusion (24 hours) and received HES (13 mL/kg iv), 7.5 percent saline (HS) (13 mL/kg iv) or no fluid. Three other groups were sham-operated and received the same fluid as the test groups. After 24 hours of reperfusion, blood was drawn for alanine aminotransferase (ALT) quantification and ischemic liver samples were taken for histological study (hematoxylin and eosin and chloroacetate staining of neutrophils). RESULTS: HES treatment attenuated the elevation in serum ALT (P=0.001) and reduced the extent of hepatocellular necrosis (P<0.01) compared with the IRI controls. HES-mediated cytoprotection was associated with a decrease of infiltration of neutrophils in the necrotic areas (P<0.05) compared with the untreated IRI rats, but not with the volume control IRI rats (P>0.05). CONCLUSION: Hydroxyethyl starch suppresses inflammatory response and ameliorates the late-phase response of hepatic ischemia/reperfusion injury.

OBJETIVO: Investigar se um colóide de terceira geração (HES 130/0.4), utilizado para fluidoterapia perioperatória, protege o fígado de rato contra a resposta da fase tardia de isquemia/reperfusão e se a inibição da infiltração hepática de neutrófilos desempenha um papel neste mecanismo. MÉTODOS: Foram utilizados ratos Wistar (8 em cada grupo). Três grupos tiveram lesão de isquemia/reperfusão (IRI) induzida por oclusão vascular lobar (60 minutos) e reperfusão (24 horas) e receberam HES (13 ml / kg iv), soro fisiológico a 7,5 por cento (HS) (13 ml / kg iv) ou nenhum fluido. Três outros grupos foram sham-operados e receberam o mesmo tipo de fluido dos grupos de teste. Após 24 horas de reperfusão, o sangue foi retirado para quantificação da alanina aminotransferase (ALT) e amostras de fígado isquêmico foram retiradas para estudo histológico (hematoxilina e eosina e coloração cloroacetato para neutrófilos). RESULTADOS: O tratamento com HES atenuou a elevação da ALT sérica (P = 0,001) e reduziu a extensão da necrose hepatocelular (P<0,01) em comparação com os controles da IRI. A citoproteção mediada por HES foi associada a uma diminuição da infiltração de neutrófilos nas áreas de necrose (P<0,05) em comparação com os ratos não tratados IRI, mas não com os ratos controlo IRI (P> 0,05). CONCLUSÃO: HES suprime a resposta inflamatória e melhora a resposta na fase tardia da isquemia/reperfusão hepática.

Anti-inflammatory effect of the epigallocatechin gallate following spinal cord trauma in rat

Spinal cord injury [SCI] stimulates an inflammatory reaction that causes substantial secondary damage inside the injured spinal tissue. The purpose of this study was to determine the anti-inflammatory effects of epigallocatechin gallate [EGCG] on traumatized spinal cord. Methods: Rats were randomly divided into four groups of 12 rats each as follow: sham-operated group, trauma group, and EGCG-treatment groups [50 mg/kg, i.p., immediately and 1 hour after SCI]. Spinal cord samples were taken 24 hours after injury and studied for determination of myeloperoxidase [MPO] activity, histopathological assessment and immunohistochemistry of tumor necrosis factor-a [TNF-alpha], interleukin-1 beta [IL-1beta], Nitrotyrosine, inducible nitric oxide synthase [iNOS], cyclooxygenase-2 [COX-2], and poly [ADP-ribose] polymerase [PARP]. The results showed that MPO activity was significantly decreased in EGCG-treatment groups. Attenuated TNF-alpha, IL-1beta, Nitrotyrosine, iNOS, COX-2, and PARP expression could be detected in the EGCG treated rats. Also, EGCG attenuated myelin degradation. On the basis of these findings, we propose that EGCG may be effective in protecting rat spinal cord from secondary damage by modulating the inflammatory reactions

Induction of inflammatory cell accumulation using human mast cell tryptases.

The aim of this study was to investigate the effects of human tryptases on inflammatory cell accumulation in vivo. Various concentrations of purified lung or skin tryptases were injected into the peritoneum of BALB/c mouse. At 6 hours or 16 hours following injection, cells from the peritoneal lavage were collected and stained with modified Wright's stain. Differential cell counts were performed and results were expressed as absolute numbers of each cell type per mouse peritoneum. The results showed a dose-dependent infiltration of neutrophils with a maximal increase of up to 32 fold or 43 fold in numbers at 16 hours following an injection of skin and lung tryptases, respectively. Skin tryptase was able to attract more eosinophils than lung tryptase. Significant increases in lymphocyte and macrophage numbers were also observed. In conclusion, both skin and lung tryptases are able to induce nucleated cell accumulation in the peritoneum of mice with similar specificity and potency.