Effects of exercise and metformin on the prevention of glucose intolerance: a comparative study

We aimed to evaluate the effects of aerobic exercise training (4 days) and metformin exposure on acute glucose intolerance after dexamethasone treatment in rats. Forty-two adult male Wistar rats (8 weeks old) were divided randomly into four groups: sedentary control (SCT), sedentary dexamethasone-treated (SDX), training dexamethasone-treated (DPE), and dexamethasone and metformin treated group (DMT). Glucose tolerance tests and in situ liver perfusion were undertaken on fasting rats to obtain glucose profiles. The DPE group displayed a significant decrease in glucose values compared with the SDX group. Average glucose levels in the DPE group did not differ from those of the DMT group, so we suggest that exercise training corrects dexamethasone-induced glucose intolerance and improves glucose profiles in a similar manner to that observed with metformin. These data suggest that exercise may prevent the development of glucose intolerance induced by dexamethasone in rats to a similar magnitude to that observed after metformin treatment.

Effects of exercise and metformin on the prevention of glucose intolerance: a comparative study.

We aimed to evaluate the effects of aerobic exercise training (4 days) and metformin exposure on acute glucose intolerance after dexamethasone treatment in rats. Forty-two adult male Wistar rats (8 weeks old) were divided randomly into four groups: sedentary control (SCT), sedentary dexamethasone-treated (SDX), training dexamethasone-treated (DPE), and dexamethasone and metformin treated group (DMT). Glucose tolerance tests and in situ liver perfusion were undertaken on fasting rats to obtain glucose profiles. The DPE group displayed a significant decrease in glucose values compared with the SDX group. Average glucose levels in the DPE group did not differ from those of the DMT group, so we suggest that exercise training corrects dexamethasone-induced glucose intolerance and improves glucose profiles in a similar manner to that observed with metformin. These data suggest that exercise may prevent the development of glucose intolerance induced by dexamethasone in rats to a similar magnitude to that observed after metformin treatment.

Avaliação da atividade antiinflamatória do coentro (Coriandrum sativum L. ) em roedores / Evaluation of the anti-inflammatory activity of coriander (Coriandrum sativum L. ) in rodents

Coriandrum sativum L. (Umbelliferae), conhecido popularmente por coentro, é uma planta doméstica cultivada nas diversas partes do mundo, inclusive no Brasil. As folhas e frutos do coentro são utilizados como condimento em culinária e na medicina popular como analgésica, antirreumática, carminativa e colagoga. O objetivo deste estudo foi avaliar o efeito do tratamento com o óleo essencial (OEC) e o extrato hidroalcóolico (EHC) do coentro em modelos experimentais de inflamação em roedores. A atividade antiinflamatória do coentro foi avaliada por meio dos testes de pleurisia em ratos e formação do edema de orelha em camundongos. A pleurisia foi induzida pela carragenina em animais tratados ou não com EHC. O edema de orelha induzido pela aplicação tópica de óleo de cróton e a atividade da mieloperoxidase foi avaliada em camundongos tratados ou não com OEC ou EHC. No teste da pleurisia o tratamento com EHC promoveu significativa diminuição no edema pleural, mas não sobre a migração leucocitária. Além disso, diferentemente ao observado com o tratamento com OEC, o uso tópico de EHC diminui significativamente o edema de orelha e a migração celular induzidos pela aplicação do óleo de cróton. Os dados indicam que EHC apresenta atividade antiinflamatória quando administrado pelas via oral e tópica, enquanto que OEC não apresenta atividade antiinflamatória tópica.

Commonly known as coriander, Coriandrum sativum L. (Umbelliferae) is a home plant grown in several parts of the world, including Brazil. Its leaves and fruits have been used as condiment in cooking and in folk medicine as analgesic, antirheumatic, carminative and cholagogue. The aim of this study was to evaluate the effect of essential oil (EO) and hydroalcoholic extract (HE) from coriander on experimental inflammation models in rodents. Coriander anti-inflammatory activity was evaluated by pleurisy tests in rats and ear edema formation in mice. Pleurisy was induced by carrageenan in HE-treated or non-treated animals. The ear edema was induced by topical application of croton oil and the myeloperoxidase activity was evaluated in EO-treated and HE-treated or non-treated mice. In the pleurisy test, HE treatment significantly decreased pleural edema but not the leukocyte migration. Furthermore, differently from EO, the topical use of HE significantly decreased ear edema and cell migration induced by croton oil application. The results indicate that HE had anti-inflammatory activity when orally and topically administered, whereas EO did not present topical anti-inflammatory activity.

Avaliação dos efeitos da suplementação com farinha de linhaça (Linum usitatissimum L. ) marrom e dourada sobre o perfil lipídico e a evolução ponderal em ratos Wistar / Evaluation of the effects of supplementation with brown and golden flax (Linum usitatissimum L. ) flour on lipid profile and weight gain in Wistar rats

Neste trabalho foram comparados os efeitos da farinha de linhaça dourada e farinha de linhaça marrom sobre o perfil lipídico e evolução ponderal em ratos Wistar. Os animais foram divididos aleatoriamente em três grupos, Grupo Controle (GC); Grupo suplementado com Farinha de Linhaça Marrom (LM) e Grupo Suplementado com Farinha de Linhaça Dourada (LD). Os animais foram submetidos à avaliação ponderal em dias alternados até o dia do sacrifício, no 36º dia, quando amostras de sangue foram coletadas para avaliação do perfil lipídico. O uso da farinha de linhaça como suplemento dietético de ratos Wistar, no período de 35 dias, promoveu redução significativa dos níveis de triglicérides séricos e da razão CT/HDL-c, com concomitante aumento dos níveis séricos de HDL-c, demonstrando assim efeito cardioprotetor. Os efeitos sobre o incremento de massa corporal dos animais durante o período do experimento sugerem importante ação preventiva no desenvolvimento da obesidade para a farinha de linhaça.

In this work, the effects of brown and golden flax flour were compared based on lipid profile and weight gain in Wistar rats. The animals were randomly divided into three groups: control group (CG); group supplemented with brown flax flour (BF); and group supplemented with golden flax flour (GF). The animals were subjected to weight assessment on alternate days until sacrifice at the 36th day, when blood samples were collected for lipid profile evaluation. The use of flax flour as dietary supplement to Wistar rats, in a 35-day period, led to a significant decrease in the serum levels of triglycerides and TC:HDL-C ratio, with concomitant increase in HDL-C serum levels, demonstrating thus a cardioprotective effect. The effects on rat weight gain over the experimental period suggest an important preventive action of flax flour on the obesity development.

Anti-inflammatory and antinociceptive effects of Rosmarinus officinalis L. essential oil in experimental animal models.

Rosmarinus officinalis L. (Family Lamiaceae), popularly named rosemary, is a common household plant grown in many parts of the world, including Brazil. Rosemary leaves are used for food flavoring and have been used in folk medicine for many conditions; they have antispasmodic, analgesic, antirheumatic, carminative, cholagogue, diuretic, expectorant, and antiepileptic effects. The objective of this study was to evaluate the effects of rosemary essential oil (REO) on experimental models of nociception and inflammation in animals. The anti-inflammatory effect of REO was evaluated by inflammatory exudate volume and leukocyte migration in carrageenan-induced pleurisy and carrageenan-induced paw edema tests in rats. Antinociception was evaluated using the acetic acid-induced writhing and hot plate tests in mice. REO (500 mg/kg) significantly reduced the volume of pleural exudate and slightly decreased the number of cells that had migrated compared with the control animals. At doses of 250, 500, and 750 mg/kg, REO significantly inhibited carrageenan-induced edema 1-4 hours after injection of the phlogistic agent. In the hot plate test, REO administration (125, 250, and 500 mg/kg) showed unremarkable effects on response latency, whereas control injection of meperidine induced significant antinociceptive effects. REO at doses of 70, 125, and 250 mg/kg had a significant antinociceptive effect in the acetic acid-induced abdominal writhing test compared with control animals. These data suggest that REO possesses anti-inflammatory and peripheral antinociceptive activity.

Chlorpropamide treatment restores the reduced carrageenan-induced paw edema and pleural exudate volume in diabetic rats.

OBJECTIVE AND DESIGN: Knowing that hyperglycemia is a hallmark of vascular dysfunction in diabetes and that neonatal streptozotocin-induced diabetic rats (n-STZ) present reduced inflammatory response, we decided to evaluate the effect of chlorpropamide-lowered blood glucose levels on carrageenan-induced rat paw edema and pleural exudate in n-STZ. MATERIALS: Diabetes was induced by STZ injection (160 mg/kg, ip) in neonates (2-day-old) Wistar rats. TREATMENT: n-STZ diabetic rats were treated with chlorpropamide (200mg/kg, 15d, by gavage) 8 weeks after STZ injection. METHODS: Carrageenan-induced paw edema and pleural exudate volumes were assessed concomitantly with peripheral and exudate leukocyte count. We also evaluated the expression of inducible nitric oxide synthase (iNOS) in lungs of all experimental groups. RESULTS: Chlorpropamide treatment improved glucose tolerance, beta-cell function (assessed by HOMA-beta), corrected paw edema, and pleural exudate volume in n-STZ. Neither leukocyte count nor iNOS expression were affected by diabetes or by chlorpropamide treatment. CONCLUSION: Chlorpropamide treatment by restoring beta-cell function, reducing blood sugar levels, and improving glucose tolerance might be contributing to the correction of the reduced inflammatory response tested as paw edema and pleural exudate in n-STZ diabetic rats.

Anti-inflammatory activity of the extract, fractions and amides from the leaves of Piper ovatum Vahl (Piperaceae).

Leaves of Piper ovatum are known in folk medicine as "joão burandi" or "anestésica" and in traditional Brazilian medicine are used to treat inflammatory disease. The hydroalcoholic extract, fractions, and a mixture of piperovatine (1) and piperlonguminine (2) in a proportion of 2:3 obtained from Piper ovatum were assayed for anti-inflammatory activity by means of carrageenan-induced pleurisy in rats and croton oil-induced ear edema in mice. The hydroalcoholic extract was analyzed by high-performance liquid chromatography. Fraction constituents were evaluated by phytochemical screening, and the mixture of amides (1 and 2) was identified by analyses of spectral data of (1)H and (13)C nuclear magnetic resonance. Acute toxicity of the extract also was evaluated. At 500mg/kg, the hydroalcoholic extract of Piper ovatum leaves did not reduce the volume of inflammatory pleural exudates compared with control animals. However, the hydroalcoholic extract and fractions F1-F3 at doses of 5.0mg/ear and a mixture of piperovatine (1) and piperlonguminine (2) at doses of 2.5, 1.25, and 0.625mg/ear significantly reduced the degree of ear edema. Taken together, the results indicate that the amide fractions piperovatine and piperlonguminine showed the greatest inhibitory activity of topical inflammation induced by croton oil.

Acute immune and non-immune inflammatory response in spontaneously hypertensive rats and normotensive rats. Role of endogenous nitric oxide.

UNLABELLED: The present study investigated the acute inflammatory response (increase in vascular permeability and leukocytes migration) in the pleura of spontaneously hypertensive rats (SHR) and normotensive rats (NTR), using two different stimulus: carrageenan and active anaphylaxis. In addition, the role of endogenous nitric oxide in these responses was investigated. RESULTS: The inflammatory response induced by intrapleural carrageenan injection in SHR developed similarly to that in NTR. Treatment with L-NAME, reduced the intensity of this response in both groups of rats. The inflammatory response induced by active anaphylaxis in SHR and NTR was different. The increase in vascular permeability occurred later in the SHR compared to NTR. The number of leukocyte present in inflammatory exudates was increased at 4 h in both groups of rats. L-NAME treatment did not inhibit exudation at the intervals under analysis, however, reduced the number of mononuclear cells in the inflammatory exudate of SHR. CONCLUSION: The development of the inflammatory response in SHR differs from that in NTR, depending on the nature of the inflammatory stimulus. Endogenous NO plays a clear role in carrageenan-induced inflamma-tion, but not in immunologically mediated inflammation in the analyzed period.

The role of adrenal corticosteroids in the anti-inflammatory effect of the whole extract of Harpagophytum procumbens in rats.

This study was carried out to evaluate whether the anti-inflammatory response in rats to the whole extract of Harpagophytum procumbens is a consequence of adrenal corticosteroid release. Carrageenan-induced inflammatory responses in the hindpaws were evaluated in control, sham-operated and adrenalectomized rats. The extract was administered orally (by gavage) or intraperitoneally, 30min prior to injury stimulus. Blood samples were then collected, and the number of circulating leukocytes was estimated. Pretreatment with the whole extract of H. procumbens reduced the intensity of inflammatory response in normal, sham-operated and adrenalectomized animals. When administered orally, the extract was ineffective. The reduced number of circulating leukocytes observed following intraperitoneal injection of the extract characterized adrenal hyperactivity. The inhibitory effect of the whole extract of H. procumbens on acute inflammatory response in the rat, when administered intraperitoneally, does not depend on the release of adrenal corticosteroids.

Immunomodulatory effect of Canova medication on experimental Leishmania amazonensis infection.

This study investigates the action of Canova medication (CM) on experimental infection by Leishmania (Leishmania) amazonensis, utilizing in vitro and in vivo assays. For the in vitro tests, Balb/c mouse peritoneal macrophages (5x10(5) cells in 500 microl of culture medium, supplemented with 10% fetal calf serum, penicillin (100 U/ml) and streptomycin (0.1 mg/ml) (were distributed in 24-well plates and CM was added at concentrations of 20 or 40%. Twenty-four hours later, the macrophages were infected with Leishmania amastigotes in culture medium. The effect of CM on macrophages leishmanicidal activity in 24 and 48 h cultures was evaluated by determining infection index and measuring nitric oxide (NO) production. The in vivo tests were performed in mice infected with 10(7)L. (L.) amazonensis promastigotes injected in to the right hind footpad (25 microl in phosphate buffered saline). The progression of the lesions was examined over a 9-week period by measuring footpad swelling, and the parasite load in regional lymph nodes and spleen. The in vitro results showed that at 40% CM reduced the infection index, and induced NO production in the elicited macrophages, which suggests that the inhibitory effect on infection index may be mediated by NO. In the in vivo infection, when administered, orally or subcutaneously in mice, CM reduced infection by L. (L.) amazonensis in the paws, resulting in smaller lesions. CM treatment also decreased parasite load in the regional popliteal lymph nodes and in the spleen. These results suggest that CM modulates experimental infection by L. (L.) amazonensis, controlling infection progression and limiting dissemination.

Efficiency of combined methotrexate/chloroquine therapy in adjuvant-induced arthritis.

The present study evaluates the effects of methotrexate (MTX) and chloroquine (CQ), and of combined MTX + CQ treatment, on the inflammatory response and on plasma and liver phosphatase and transaminase activities, employing an adjuvant-induced arthritis model in rats. Arthritis was induced by the intradermal injection of a suspension of Mycobacterium tuberculosis in mineral oil into the plantar surface of the hind paws. Development of the inflammatory response was assessed over a 21-day period. Animal groups received either: (i) MTX, administered i.p., weekly, in 0.15, 1.5, 3, 6 or 12 mg/kg doses; (ii) CQ, given intragastrically, in daily 25 or 50 mg/kg doses; or (iii) MTX + CQ, administered in two combinations (MTX1.5 mg/kg + CQ50 mg/kg, or MTX6 mg/kg + CQ50 mg/kg). At the end of the experimental period, the animals were anesthetized and killed, blood and liver samples were collected and prepared for measurement of acid and alkaline phosphatase (AP, ALP), and aspartate (AST) and alanine aminotransferase (ALT) activities. MTX at 6 and 12 mg/kg reduced the inflammatory response while CQ had no effect. MTX6 mg/kg + CQ50 mg/kg reduced the inflammatory response similar to MTX12 mg/kg, without affecting the bone marrow. Plasma AP and liver ALP activities were very elevated in the arthritic rats. While MTX treatment partially reduced both plasma AP and liver ALP activities at all doses used in the arthritic rats, CQ treatment reduced plasma AP, but increased liver AP activity. MTX + CQ treatment decreased plasma AP and liver ALP activities in the arthritic rats to control values. Plasma and liver AST activities were unaltered in the arthritic rats, and were unaffected by treatment. However, plasma and liver ALT activities were significantly reduced in the arthritic rats. While MTX or CQ treatment did not alter plasma transaminase activity in the arthritic rats, after MTX + CQ treatment, plasma ALT activity returned to normal values. In conclusion, the present data suggest that MTX + CQ treatment provides more effective anti-inflammatory protection against adjuvant-induced arthritis than does MTX alone, reverting the alterations in enzyme activities induced by this inflammatory disease in rats.

Participation of endogenous corticosteroids in inflammatory response in type 2 streptozotocin diabetic rats.

The inflammatory response is decreased in diabetic animals. After adrenals removal this impaired response in type 2 diabetic rats evaluated by pleurisy and vascular permeability tests was restored. Our studies demonstrate that endogenous corticosteroids play a partial role in the impaired inflammatory response in type 2 streptozotocin diabetic rats.

Influence of type 2 diabetes on the inflammatory response in rats.

OBJECTIVES AND DESIGN: To verify whether the inflammatory responses in animals with type 2 diabetes are altered to an extent similar to that in type 1 diabetes. MATERIALS: Male newborn (2 days old) Wistar rats were made diabetic by streptozotocin (160 mg/kg, i.p.) and used 8-10 weeks later (10 rats/group). METHODS: The inflammatory responses were evaluated using paw edema (induced by local injection of carrageenan or dextran), pleurisy (by pleural injection of carrageenan), increases in vascular permeability (induced by intradermal injection of histamine, serotonin and bradykinin) and leukocyte counts in peripheral blood and pleural exudate. RESULTS: Diabetic animals showed reduced inflammatory responses to carrageenan but not to dextran. The increase in vascular permeability induced by serotonin and bradykinin was reduced whereas that to histamine was not altered in diabetic compared to control rats. Although the pleural exudate was reduced, leukocyte counts were similar in diabetic and control rats. Insulin (2 IU, 4 h before), though effective in reducing blood sugar levels, did not restore the altered responses in diabetic rats. In contrast to that in rats with type 1 diabetes, in rats with type 2 diabetes, removal of the adrenal glands restored the reduced inflammatory responses. CONCLUSIONS: Insulin resistance in type 2 diabetic rats led to reduced inflammatory responses, which were partially corrected by adrenalectomy.

The uncoupling effect of the nonsteroidal anti-inflammatory drug nimesulide in liver mitochondria from adjuvant-induced arthritic rats.

The aim of the present study was to evaluate the changes caused by adjuvant-induced arthritis in liver mitochondria and to investigate the effects of the nonsteroidal anti-inflammatory drug nimesulide. The main alterations observed in liver mitochondria from arthritic rats were: higher rates of state IV and state III respiration with beta-hydroxybutyrate as substrate; reduced respiratory control ratio and impaired capacity for swelling dependent on beta-hydroxybutyrate oxidation. No alterations were found in the activities of NADH oxidase and ATPase. Nimesulide produced: (1) stimulation of state IV respiration; (2) decrease in the ADP/O ratio and in the respiratory control ratio; (3) stimulation of ATPase activity of intact mitochondria; (4) inhibition of swelling driven by the oxidation of beta-hydroxybutyrate; (5) induction of passive swelling due to NH(3)/NH(4)+ redistribution. The activity of NADH oxidase was insensitive to nimesulide. Mitochondria from arthritic rats showed higher sensitivity to nimesulide regarding respiratory activity. The results of this work allow us to conclude that adjuvant-induced arthritis leads to quantitative changes in some mitochondrial functions and in the sensitivity to nimesulide. Direct evidence that nimesulide acts as an uncoupler was also presented. Since nimesulide was active in liver mitochondria at therapeutic levels, the impairment of energy metabolism could lead to disturbances in the liver responses to inflammation, a fact that should be considered in therapeutic intervention.

Antiulcer effectiveness of Maytenus aquifolium spray dried extract.

The antiulcer activity of Maytenus aquifolium spray dried extract was studied in rats. Ulcers were induced by means of three experimental models: acidified-ethanol, indomethacin and acute stress. The extract was found to have significant antiulcer activity against all the models studied. These results show that preparation of the extract by means of the spray dried technique does not alter the biological activity of Maytenus aquifolium.

Effect of Maytenus aquifolium extract on the pharmacokinetic and antiinflammatory effectiveness of piroxicam in rats.

This study explored the interference by Maytenus aquifolium leaves hydroalcoholic (MALHE) extract, administered orally, on the pharmacokinetic and antiinflammatory activity of piroxicam in rats. The results showed no significant difference in piroxicam bioavailability with simultaneous application of MALHE. MALHE also had no effect on the inhibitory effect of piroxicam on inflammatory processes induced by carrageenan and complete Freund adjuvant.

Gastric antiulcerogenic effects of Stryphnodendron adstringens in rats.

The antiulcer activity of the total extract and the fractions of Stryphnodendron adstringens was studied in rats and compared with that of cimetidine. Ulcers were induced in rats by means of three experimental models: acute stress, acidified-ethanol and indomethacin. The total extract and the fractions were found to have significant antiulcer activity in the case of the acute stress and acidified-ethanol models. These findings support the use of S. adstringens extracts in the treatment of gastric lesions.

Effects of the nonsteroidal anti-inflammatory drug nimesulide on energy metabolism in livers from adjuvant-induced arthritic rats.

The effects of nimesulide on energy metabolism and the hepatic metabolic alterations produced by adjuvant-induced arthritis were investigated in the perfused rat liver an in isolated liver mitochondria. Nimesulide, at therapeutic levels (20-50 microM), produced: (1) stimulation of oxygen consumption in the perfused rat liver and in isolated mitochondria, (2) inhibition of gluconeogenesis; (3) reduction of ADP/O ratio and the respiratory control ratio and stimulation of glycogenolysis in the livers from healthy rats, but not in livers from arthritic rats. These results indicate that nimesulide acts as a mitochondrial uncoupler. The main alterations produced by adjuvant-induced arthritis were: higher rates of oxygen consumption in both perfused livers and isolated mitochondria, with no decrease in the efficiency of mitochondrial energy transduction; (2) decreased gluconeogenesis and lack of glycogenolytic response to uncouplers, but not to alpha 1-agonists. These data allow to conclude that nimesulide-induced impairment of energy metabolism should worsen the hepatic disturbances that are already associated with the adjuvant disease.

Intradermal irritation of dental bleaching agents in rats.

AIM: To evaluate the irritative potential of three dental bleaching agents (hydrogen oxide, carbopol, and carbamide peroxide). METHODS: In rats, Evans blue (2.5%, 1 mL.L-1) was injected i.v. and later each test solution was injected intradermally on the back. After the concentration of the dye in the stained skin area was determined by spectrophotometric analysis. RESULTS: All the dental bleaching agents caused increase of vascular permeability and the intensity varied with the time. CONCLUSION: Dental bleach agents had a great potential for irritating soft tissues.

Pharmacokinetic profile of piroxicam beta-cyclodextrin, in rat plasma and lymph.

1. The absorption of piroxicam into the blood of rats is significantly slower after oral administration of piroxicam beta-cyclodextrin than of free piroxicam. 2. The pharmacokinetic profiles of piroxicam in rat lymph were very similar in both groups. 3. Bioavailability of piroxicam in plasma is higher after treatment with the inclusion product than with free piroxicam. On the other hand, bioavailability in lymph is higher when free piroxicam is administered.