Roberto Marinho Maciel

Antioxidant and anti-inflammatory effects of quercetin in functional and morphological alterations in streptozotocin-induced diabetic rats

The aim of this study was to investigate functional and morphological alterations caused by oxidative stress in streptozotocin (STZ)-induced diabetic rats and to evaluate the antioxidant effect of quercetin (QUE) in this disease. One hundred and thirty male Wistar rats, it were randomly distributed in 10 different experimental groups, with ten animals per group: Control Saline (CS), Control Ethanol (CE), Control QUE 5mg/kg (CQ5), Control QUE 25mg/kg (CQ25), Control QUE 50mg/kg (CQ50), Diabetic Saline (DS), Diabetic Ethanol (DE), Diabetic QUE 5mg/kg (DQ5), Diabetic QUE25 mg/kg (DQ25), Diabetic QUE 50mg/kg (DQ50). Therefore, hyperglycemia is directly involved in oxidative stress production, as well as in functional and morphological alterations caused by the excess of free radicals. QUE, specially at the dosage of 50mg/kg, can act as an antioxidant and anti-inflammatory agent, becoming a promising adjuvant in the treatment of diabetes mellitus.

Neuroprotective effects of quercetin on memory and anxiogenic-like behavior in diabetic rats: Role of ectonucleotidases and acetylcholinesterase activities

The present study investigated the protective effect of quercetin (Querc) on memory, anxiety-like behavior and impairment of ectonucleotidases and acetylcholinesterase (AChE) activities in brain of streptozotocin-induced diabetic rats (STZ-diabetes). The type 1 diabetes mellitus was induced by an intraperitoneal injection of 70mg/kg of streptozotocin (STZ), diluted in 0.1M sodium-citrate buffer (pH 4.5). Querc was dissolved in 25% ethanol and administered by gavage at the doses of 5, 25 and 50mg/kg once a day during 40days. The animals were distributed in eight groups of ten animals as follows: vehicle, Querc 5mg/kg, Querc 25mg/kg, Querc 50mg/kg, diabetes, diabetes plus Querc 5mg/kg, diabetes plus Querc 25mg/kg and diabetes plus Querc 50mg/kg. Querc was able to prevent the impairment of memory and the anxiogenic-like behavior induced by STZ-diabetes. In addition, Querc prevents the decrease in the NTPDase and increase in the adenosine deaminase (ADA) activities in SN from cerebral cortex of STZ-diabetes. STZ-diabetes increased the AChE activity in SN from cerebral cortex and hippocampus. Querc 50mg/kg was more effective to prevent the increase in AChE activity in the brain of STZ-diabetes. Querc also prevented an increase in the malondialdehyde levels in all the brain structures. In conclusion, the present findings showed that Querc could prevent the impairment of the enzymes that regulate the purinergic and cholinergic extracellular signaling and improve the memory and anxiety-like behavior induced by STZ-diabetes.

Concentrações séricas de minerais e funções hepática e renal de frangos intoxicados com aflatoxina e tratados com montmorilonita sódica

The objective of this work was to evaluate the seric mineral concentrations and the hepatic and renal functions of broiler chicken, experimentally intoxicated with 3 ppm of aflatoxin, and submitted to different concentrations of sodic montmorillonite in the diet. In this study 720 Cobbs male broiler chickens were used, which were divided in six treatments: T1, normal diet; T2, diet with aflatoxin (3 ppm); T3, diet with sodic montmorillonite (0.25%); T4, diet with aflatoxin (3 ppm) + sodic montmorillonite (0.25%); T5, diet with sodic montmorillonite (0.50%); T6, diet with aflatoxin (3 ppm) + sodic montmorillonite (0.5%); with six repetitions of each treatment. The diet with 3 ppm of aflatoxin resulted in a significant decrease in serum concentrations of total protein, albumin, globulins and aspartate aminotransferase; there was significant decrease of seric concentration of uric acid in the diet with aflatoxin (3 ppm) + 0.25% sodic montmorillonite; in the diet with aflatoxin + 0.5% sodic montmorillonite there was significant decrease in seric concentrations of phosphorus. Aflatoxin in the diet (3 ppm) causes change in the hepatic function of broiler chickens. The use of 0.5% sodic montmorillonite is effective in preventing the toxic effects of aflatoxins, but causes decrease in phosphorus seric levels.

Role of acute phase proteins in the immune response of rabbits infected with Trypanosoma evansi.

The aim of this study was to characterize the response of acute phase proteins (APP) in rabbits experimentally infected with Trypanosoma evansi (T. evansi), and to relate the findings with serum immunoglobulins levels, in order to verify the relation between APP and the immune response of rabbits. A total of 12 animals were used in this experiment and divided into 2 groups, control and infected, of six rabbits each. The experimental period was 118 days, and blood was collected on days 0, 5, 20, 35, 65, 95 and 118 post-infection (PI). The infection with T. evansi stimulated APP and immunoglobulins production, once the infected animals showed an increase in C-reactive protein, haptoglobin, alpha 2-macroglobulin and IgM levels. The elevation in IgM levels observed in this study, when related to the increase in C-reactive protein and haptoglobin levels, suggests the involvement of these proteins in host defense against flagellated protozoa, with possible participation in the control of the parasitemia in rabbits infected with T. evansi.

Perfil eletroforético das proteínas séricas de frangos de corte alimentados com dietas contendo aflatoxinas e/ou argila clinoptilolita natural

This study was aimed at evaluating the electrophoresis profile of serum protein in broilers fed with diets containing aflatoxins and natural clinoptilolite clay. Five hundred and twenty eight male broilers Ross were distributed in six treatments and each one with 4 replications: T1 – control (without aflatoxins or clinoptilolite), T2 –5ppm of aflatoxins, T3 –0.25% of clinoptilolite, T4 –5ppm of aflatoxins and 0.25% of clinoptilolite, T5 –0.5% of clinoptilolite and T6 – 5ppm of aflatoxins and 0.5% of clinoptilolite. The broilers were allocated in 24 boxes and submitted to a treatments for 42 days, when they were slaughtered. Total proteins, albumin fractions, alpha 1, alpha 2, beta and gamma were analyzed. Except gamma fraction the Tukey test showed differences (P<0.05) on serum total proteins and proteins fractions in all treatments which aflatoxin was present. The clinoptilolite did not modify (P<0.05) the serum proteins. The control broilers fed with diets containing aflatoxins and clinoptilolite presented low levels (P<0.05) of total protein, albumin, and globulins (alpha and beta fractions). In conclusion, aflatoxins change the electrophoresis profile and clinoptilolite is not able to protect avoid these changes.

Reticulócitos e hematócrito de cães pré e pós esplenectomia parcial

ABSTRACT The reticulocytes are erythroid cells that exhibitresidual RNA, being released from bone marrow byerythropoietin stimulus in response to tissue hypoxia. After itsrelease from bone marrow, they are temporarily sequestred inthe spleen, where they acquire form of mature erythrocytes.Besides, the spleen is also responsible for storage of the bloodand their elements. The splenectomy is indicated in cases ofsplenic torsion or rupture, symptomatic splenomegaly, andsplenic masses. This study aimed to evaluate the response ofreticulocytes and of hematocrit in dogs submitted to partialsplenectomy. Nine mongrel males and female dogs were used.The samples were obtained one hour before the surgery and48, 96, 144 and 168 hours after this procedure. The findingsdemonstrated that the hematocrit decreases significantly afterthe partial splenectomy. Highest values reticulocytes werereached 96 h after the surgery, followed by a decline in number,nevertheless, the counting was higher than moments before ofthe partial splenectomy.

Decanoato de nandrolona no hemograma e nas células mononucleares da medula óssea de ratos Wistar hígidos

O decanoato de nandrolona (DN), um estimulante do sistema hematopoetico, caracteriza-se por ser um medicamento acessivel aos proprietarios de animais com escassos recursos economicos. Assim, este estudo objetivou avaliar o efeito de diferentes doses do DN no hemograma e na quantificacao e a viabilidade das celulas mononucleares (CM) da medula ossea (MO), juntamente com a marcacao das celulas hematopoeticas CD34+ de ratos Wistar saudaveis. Para isso, 48 animais foram separados em seis tratamentos, de forma aleatoria, com oito animais cada. Os grupos foram constituidos por: G1 - controle (solucao fisiologica); G2 - controle diluente (somente veiculo oleoso de origem vegetal); G3 - 0,42mg kg-1 de DN; G4 - 1,8mg kg-1 de DN; G5 - 4,6mg kg-1 de DN; e G6 - 10,0mg kg-1 de DN. O farmaco foi aplicado semanalmente por tres semanas. Os parâmetros hematologicos e medulares avaliados nao tiveram diferenca significativa entre os grupos, o que pode ter sido influenciado pela condicao da MO ou pelo intervalo entre as doses. De acordo com os resultados obtidos e nas condicoes em que esta pesquisa foi desenvolvida, pode-se concluir que o DN nao altera o hemograma, a quantificacao e a viabilidade das CM e a marcacao de CD34+ em ratos wistar saudaveis.

Role of the adjunctive antimicrobial photodynamic therapy to periodontal treatment at plasmatic oxidative stress and vascular behavior

BACKGROUND To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model. METHODS Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis. RESULTS PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels. CONCLUSION In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment.

Complete blood count and acetylcholinesterase activity of lymphocytes of demyelinated and ovariectomized rats treated with resveratrol

Resveratrol is a phytoestrogen that has many beneficial actions. This study aimed to evaluate the effect of resveratrol on the complete blood count (CBC) and the acetylcholinesterase (AChE) activity of lymphocytes of ovariectomized rats experimentally demyelinated by ethidium bromide (EB). Forty adult female Wistar rats (60 days, 200–220 g) were divided randomly into five groups (n = 4) to evaluate the demyelination phase and five groups (n = 4) to evaluate the remyelination phase. In each phase, the groups consisted of sham rats–G1; ovariectomized rats, not demyelinated, treated only with vehicle (ethanol 25%)–G2; demyelinated ovariectomized rats treated only with vehicle–G3; ovariectomized rats, not demyelinated, treated with resveratrol–G4; and demyelinated ovariectomized rats treated with resveratrol–G5. Only during the remyelination phase, CBC showed a significant difference (p < 0.05) in the number of monocytes between G2 and G5 groups. In the demyelination phase, there was a significant decrease (p < 0.05) in the AChE activity in the G4 group, while the G5 group was statistically similar to the G1, G2 and G4 groups. In the remyelination phase, there were no significant differences in the AChE activity among the groups. The treatment for 7 days with resveratrol with or without the experimental demyelization with EB appears to influence the AChE activity of lymphocytes, without changing the number of these cells in the circulation. However, in the remyelination phase, there seems to be stabilization in its effect on the lymphocyte AChE activity.

Antimicrobial photodynamic therapy with photosensitizer in ethanol improves oxidative status and gingival collagen in a short-term in periodontitis

BACKGROUND This study evaluated the antimicrobial photodynamic therapy (aPDT) effects using the methylene blue (MB) in ethanol 20% on systemic oxidative status and collagen content from gingiva of rats with periodontitis. METHODS Rats were divided into five experimental groups: NC (negative control; no periodontitis); PC (positive control; periodontitis without any treatment); SRP (periodontitis and scaling and root planing), aPDT I (periodontitis and SRP+aPDT+MB solubilized in water), and aPDT II (periodontitis and SRP+aPDT+MB solubilized in ethanol 20%). After 7days of removal of the ligature, the periodontal treatments were performed. At 7/15/30days, gingival tissue was removed for morphometric analysis. The erythrocytes were used to evaluate systemic oxidative status. RESULTS PC group showed higher lipoperoxidation levels at 7/15/30days. aPDT indicated a protective influence in erythrocytes at 15days observed by the elevation in levels of systemic antioxidant defense. aPDT II group was the only one that restored the total collagen area in 15days, and recovered the type I collagen area at the same time point. CONCLUSIONS aPDT as an adjunct to the SRP can induce the systemic protective response against oxidative stress periodontitis-induced and recover the gingival collagen, thus promoting the healing periodontal, particularly when the MB is dissolved in ethanol 20%.