RESUMO
We tested whether chronic supplementation with soy isoflavones could modulate insulin secretion levels and subsequent recovery of pancreatic islet function as well as prevent metabolic dysfunction induced by early overfeeding in adult male rats. Wistar rats raised in small litters (SL, three pups/dam) and normal litters (NL, nine pups/dam) were used as models of early overfeeding and normal feeding, respectively. At 30 to 90 days old, animals in the SL and NL groups received either soy isoflavones extract (ISO) or water (W) gavage serving as controls. At 90 days old, body weight, visceral fat deposits, glycemia, insulinemia were evaluated. Glucose-insulin homeostasis and pancreatic-islet insulinotropic response were also determined. The early life overnutrition induced by small litter displayed metabolic dysfunction, glucose, and insulin homeostasis disruption in adult rats. However, adult SL rats treated with soy isoflavones showed improvement in glucose tolerance, insulin sensitivity, insulinemia, fat tissue accretion, and body weight gain, compared with the SL-W group. Pancreatic-islet response to cholinergic, adrenergic, and glucose stimuli was improved in both isoflavone-treated groups. In addition, different isoflavone concentrations increased glucose-stimulated insulin secretion in islets of all groups with higher magnitude in both NL and SL isoflavone-treated groups. These results indicate that long-term treatment with soy isoflavones inhibits early overfeeding-induced metabolic dysfunction in adult rats and modulated the process of insulin secretion in pancreatic islets.
Assuntos
Ilhotas Pancreáticas/efeitos dos fármacos , Isoflavonas/farmacologia , Doenças Metabólicas/prevenção & controle , Animais , Animais Recém-Nascidos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Insulina/metabolismo , Resistência à Insulina , Secreção de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/fisiologia , Isoflavonas/isolamento & purificação , Masculino , Doenças Metabólicas/etiologia , Doenças Metabólicas/patologia , Hipernutrição/complicações , Hipernutrição/metabolismo , Hipernutrição/patologia , Gravidez , Ratos , Ratos Wistar , Fatores Sexuais , Glycine max/químicaRESUMO
Metformin is an antidiabetic drug used for the treatment of diabetes and metabolic diseases. Imbalance in the autonomic nervous system (ANS) is associated with metabolic diseases. This study aimed to test whether metformin could improve ANS function in obese rats. Obesity was induced by neonatal treatment with monosodium L-glutamate (MSG). During 21-100 days of age, MSG-rats were treated with metformin 250 mg/kg body weight/day or saline solution. Rats were euthanized to evaluate biometric and biochemical parameters. ANS electrical activity was recorded and analyzed. Metformin normalized the hypervagal response in MSG-rats. Glucose-stimulated insulin secretion in isolated pancreatic islets increased in MSG-rats, while the cholinergic response decreased. Metformin treatment normalized the cholinergic response, which involved mostly the M3 muscarinic acetylcholine receptor (M3 mAChR) in pancreatic beta-cells. Protein expression of M3 mAChRs increased in MSG-obesity rats, while metformin treatment decreased the protein expression by 25%. In conclusion, chronic metformin treatment was effective in normalizing ANS activity and alleviating obesity in MSG-rats.
Assuntos
Sistema Nervoso Autônomo/efeitos dos fármacos , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Obesidade/tratamento farmacológico , Acetilcolina/farmacologia , Animais , Glucose/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Neostigmina/farmacologia , Obesidade/induzido quimicamente , Obesidade/metabolismo , Obesidade/fisiopatologia , Ratos Wistar , Receptor Muscarínico M3/metabolismo , Glutamato de Sódio , Nervo Vago/efeitos dos fármacos , Nervo Vago/fisiologiaRESUMO
NEW FINDINGS: What is the central question of this study? Studies reported the efficacy of metformin as a promising drug for preventing or treating of metabolic diseases. Nutrient stresses during neonatal life increase long-term risk for cardiometabolic diseases. Can early metformin treatment prevent the malprogramming effects of early overfeeding? What is the main finding and its importance? Neonatal metformin treatment prevented early overfeeding-induced metabolic dysfunction in adult rats. Inhibition of early hyperinsulinaemia and adult hyperphagia might be associated with decreased metabolic disease risk in these animals. Therefore, interventions during infant development offer a key area for future research to identify potential strategies to prevent the long-term metabolic diseases. We suggest that metformin is a potential tool for intervention. ABSTRACT: Given the need for studies investigating the possible long-term effects of metformin use at crucial stages of development, and taking into account the concept of metabolic programming, the present work aimed to evaluate whether early metformin treatment might program rats to resist the development of adult metabolic dysfunctions caused by overnutrition during the neonatal suckling phase. Wistar rats raised in small litters (SLs, three pups per dam) and normal litters (NLs, nine pups per dam) were used as models of early overfeeding and normal feeding, respectively. During the first 12 days of suckling, animals from SL and NL groups received metformin, whereas the controls received saline injections. Food intake and body weight were monitored from weaning until 90 days of age, when biometric and biochemical parameters were assessed. The metformin treatment decreased insulin concentrations in pups from SL groups, and as adults, these animals showed improvements in glucose tolerance, insulin sensitivity, body weight gain, white fat pad stores and food intake. Low-glucose insulinotrophic effects were observed in pancreatic islets from both NL and SL groups. These results indicate that early postnatal treatment with metformin inhibits early overfeeding-induced metabolic dysfunctions in adult rats.
Assuntos
Ilhotas Pancreáticas/efeitos dos fármacos , Doenças Metabólicas/prevenção & controle , Metformina/farmacologia , Hipernutrição/tratamento farmacológico , Tecido Adiposo Branco/metabolismo , Animais , Animais Recém-Nascidos , Glicemia/efeitos dos fármacos , Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Feminino , Insulina/metabolismo , Resistência à Insulina/fisiologia , Ilhotas Pancreáticas/metabolismo , Leptina/metabolismo , Masculino , Doenças Metabólicas/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Hipernutrição/metabolismo , Ratos , Ratos Wistar , Aumento de Peso/efeitos dos fármacosRESUMO
Objectives: We aimed to assess the effects of a maternal protein-caloric restriction diet during late pregnancy on the metabolism of rat offspring fed a high-fat diet (HFD) during adulthood.Methods: During late pregnancy, rat dams received either a low-protein (4%; LP group) or normoprotein (23%; NP group) diet. After weaning, the offspring were fed a standard diet (Control; C). Male offspring (60 days old) from both groups were then fed either the C diet or HFD until they were 90 days old. The adult offspring and maternal metabolic parameters and autonomic nervous system (ANS) were then evaluated.Results: Dams exhibited low body weight gain and food intake during the LP diet consumption. At lactation, these dams showed high body weight gain, hypoinsulinemia and hyperglycemia. The maternal LP diet resulted in low body weights for the pups. There were also no differences in the metabolic parameters between the adult LP offspring that were fed the C diet and the NP group. Adults of both groups that were fed the HFD developed obesity associated with altered insulin/ glucose homeostasis and altered ANS activity; however, the magnitudes of these parameters were higher in the LP group than in the NP group.Conclusions: Maternal protein malnutrition during the last third of pregnancy malprograms the metabolism of rat offspring, resulting in increased vulnerability to HFD-induced obesity, and the correlated metabolic impairment might be associated with lower sympathetic nerve activity in adulthood.
Assuntos
Desnutrição/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Complicações na Gravidez/metabolismo , Sistema Nervoso Simpático/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Feminino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Ratos WistarRESUMO
Bendamustine, an anticancer drug with alkylating properties, is widely used to treat hematological malignancies. Since the nitrogen mustard family alkylators induce DNA damages and have been associated with an elevated risk of second malignancy, current study evaluates the cytotoxic, mutagenic, and recombinogenic effects of bendamustine by using, respectively the mitotic index assay, the in vitro mammalian cell micronucleus test (Mnvit) and the chromosome aberration (CA) test in human peripheral lymphocytes, and the in vivo homozygotization assay in Aspergillus nidulans, which detects the loss of heterozygosity (LOH) due to somatic recombination. Bendamustine (6.0 µg/ml, 9.0 µg/ml, and 12.0 µg/ml) induced a statistically significant concentration-related increase in the frequencies of micronuclei and a significant reduction in the cytokinesis block proliferation index (CBPI) rates when compared to negative control. In the CA test, bendamustine significantly increased the frequencies of structural aberrations at the three tested concentrations when compared to the negative control. Aspergillus nidulans diploids, obtained after bendamustine treatment (6.0 µg/ml, 12.0 µg/ml, and 24.0 µg/ml), produced, after haploidization, homozygotization index (HI) rates higher than 2.0 and significantly different from the negative control. Since bendamustine showed genotoxic effects in all tested concentrations, two of them corresponding to the peak plasma concentrations observed in cancer patients treated with bendamustine, data provided in the current research work may be useful to identify the most appropriate dosage regimen to achieve the efficacy and safety of this anticancer medication.
Assuntos
Antineoplásicos Alquilantes/toxicidade , Aspergillus nidulans/efeitos dos fármacos , Cloridrato de Bendamustina/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Perda de Heterozigosidade/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Adolescente , Adulto , Aspergillus nidulans/genética , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Linfócitos/patologia , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Adulto JovemRESUMO
We examined the long-term effects of protein restriction during puberty on the function of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes in male rats. Male Wistar rats from the age of 30 to 60 days were fed a low-protein diet (4%, LP). A normal-protein diet (20.5%) was reintroduced to rats from the age of 60 to 120 days. Control rats were fed a normal-protein diet throughout life (NP). Rats of 60 or 120 days old were killed. Food consumption, body weight, visceral fat deposits, lipid profile, glycemia, insulinemia, corticosteronemia, adrenocorticotropic hormone (ACTH), testosteronemia and leptinemia were evaluated. Glucose-insulin homeostasis, pancreatic-islet insulinotropic response, testosterone production and hypothalamic protein expression of the androgen receptor (AR), glucocorticoid receptor (GR) and leptin signaling pathway were also determined. LP rats were hypophagic, leaner, hypoglycemic, hypoinsulinemic and hypoleptinemic at the age of 60 days (P < 0.05). These rats exhibited hyperactivity of the HPA axis, hypoactivity of the HPG axis and a weak insulinotropic response (P < 0.01). LP rats at the age of 120 days were hyperphagic and exhibited higher visceral fat accumulation, hyperleptinemia and dyslipidemia; lower blood ACTH, testosterone and testosterone release; and reduced hypothalamic expression of AR, GR and SOCS3, with a higher pSTAT3/STAT3 ratio (P < 0.05). Glucose-insulin homeostasis was disrupted and associated with hyperglycemia, hyperinsulinemia and increased insulinotropic response of the pancreatic islets. The cholinergic and glucose pancreatic-islet responses were small in 60-day-old LP rats but increased in 120-day-old LP rats. The hyperactivity of the HPA axis and the suppression of the HPG axis caused by protein restriction at puberty contributed to energy and metabolic disorders as long-term consequences.
Assuntos
Dieta com Restrição de Proteínas/efeitos adversos , Metabolismo Energético , Maturidade Sexual , Testosterona/metabolismo , Animais , Células Cultivadas , Proteínas Alimentares/farmacologia , Metabolismo Energético/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/metabolismo , Ratos , Ratos Wistar , Maturidade Sexual/efeitos dos fármacosRESUMO
PURPOSE: Environmental and nutritional disorders during perinatal period cause metabolic dysfunction in the progeny and impair human health. Advanced glycation end products (AGEs) are primarily produced during metabolism of excess blood glucose, which is observed in diabetes. Methylglyoxal (MG) is a precursor for the generation of endogenous AGEs, which disturbs the metabolism. This work aimed to investigate whether the maternal MG treatment during lactation programs the progeny to metabolic dysfunction later in life. METHODS: Female Wistar rats were divided into two groups: control group (C) treated with saline and MG group treated with MG (60 mg/kg/day) by gavage throughout the lactation period. Both mothers and offspring were fed a standard chow. At weaning, breast milk composition was analyzed and mothers euthanized for blood and tissue sample collections. At 90 days of age, offspring were submitted to glucose tolerance test (ivGTT) and euthanized for blood and tissue samples collection. RESULTS: MG mothers showed increase in glucose and fructosamine levels; however, they showed low insulin levels and failure in ß-cell function (p < 0.05). MG mothers also showed dyslipidemia (p < 0.05). Moreover, breast milk had elevated levels of glucose, triglycerides, cholesterol and fructosamine and low insulin (p < 0.05). Interestingly, MG offspring had increased body weight and adipose tissue at adulthood, and they also showed glucose intolerance and failure in ß-cell function (p < 0.05). Besides, MG offspring showed dyslipidemia (p < 0.05) increasing cardiovascular diseases risk. CONCLUSIONS: Maternal MG treatment negatively affects the male rat offspring, leading to type 2 diabetes and dyslipidemia in later life, possibly by changes in breast milk composition.
Assuntos
Diabetes Mellitus Tipo 2/induzido quimicamente , Dislipidemias/induzido quimicamente , Poluentes Ambientais/toxicidade , Lactação/efeitos dos fármacos , Exposição Materna/efeitos adversos , Obesidade/induzido quimicamente , Aldeído Pirúvico/toxicidade , Adiposidade/efeitos dos fármacos , Administração Oral , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Dislipidemias/sangue , Dislipidemias/metabolismo , Dislipidemias/patologia , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/análise , Feminino , Insulina/análise , Insulina/sangue , Insulina/metabolismo , Resistência à Insulina , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Gordura Intra-Abdominal/efeitos dos fármacos , Gordura Intra-Abdominal/metabolismo , Gordura Intra-Abdominal/patologia , Lactação/metabolismo , Masculino , Leite/química , Obesidade/sangue , Obesidade/metabolismo , Obesidade/patologia , Gravidez , Aldeído Pirúvico/administração & dosagem , Aldeído Pirúvico/análise , Distribuição Aleatória , Ratos Sprague-Dawley , Toxicocinética , Aumento de Peso/efeitos dos fármacosRESUMO
Acephate has been used extensively as an insecticide in agriculture. Its downstream sequelae are associated with hyperglycemia, lipid metabolism dysfunction, DNA damage, and cancer, which are rapidly growing epidemics and which lead to increased morbidity and mortality rates and soaring health-care costs. Developing interventions will require a comprehensive understanding of which excess insecticides during perinatal life can cause insulin resistance and type 2 diabetes. A Wistar rat animal model suggests that acephate exposure during pregnancy and lactation causes alterations in maternal glucose metabolism and programs the offspring to be susceptible to type 2 diabetes at adulthood. Therapeutic approaches based on preventive actions to food contaminated with insecticides during pregnancy and lactation could prevent new cases of type 2 diabetes.
Assuntos
Diabetes Mellitus Tipo 2/induzido quimicamente , Inseticidas/toxicidade , Compostos Organotiofosforados/toxicidade , Fosforamidas/toxicidade , Animais , Animais Recém-Nascidos , Diabetes Mellitus Tipo 2/patologia , Feminino , Humanos , Lactação , Gravidez , Ratos , Ratos WistarRESUMO
We tested whether treatment with a cholinergic antagonist could reduce insulin levels in early postnatal life and attenuate metabolic dysfunctions induced by early overfeeding in adult male rats. Wistar rats raised in small litters (SLs, 3 pups/dam) and normal litters (NLs, 9 pups/dam) were used in models of early overfeeding and normal feeding, respectively. During the first 12 days of lactation, animals in the SL and NL groups received scopolamine butylbromide (B), while the controls received saline (S) injections. The drug treatment decreased insulin levels in pups from both groups, and as adults, these animals showed improvements in glucose tolerance, insulin sensitivity, vagus nerve activity, fat tissue accretion, insulinemia, leptinemia, body weight gain and food intake. Low glucose and cholinergic insulinotropic effects were observed in pancreatic islets from both groups. Low protein expression was observed for the muscarinic M3 acetylcholine receptor subtype (M3mAChR), although M2mAChR subtype expression was increased in SL-B islets. In addition, beta-cell density was reduced in drug-treated rats. These results indicate that early postnatal scopolamine butylbromide treatment inhibits early overfeeding-induced metabolic dysfunctions in adult rats, which might be caused by insulin decreases during lactation, associated with reduced parasympathetic activity and expression of M3mAChR in pancreatic islets.
Assuntos
Brometo de Butilescopolamônio/farmacologia , Doenças Metabólicas , Obesidade , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Feminino , Masculino , Doenças Metabólicas/metabolismo , Doenças Metabólicas/patologia , Doenças Metabólicas/prevenção & controle , Obesidade/metabolismo , Obesidade/patologia , Obesidade/prevenção & controle , Ratos , Ratos WistarRESUMO
Metabolic malprogramming has been associated with low birth weight; however, the interplay between insulin secretion disruption and adrenal function upon lipid metabolism is unclear in adult offspring from protein-malnourished mothers during the last third of gestation. Thus, we aimed to study the effects of a maternal low-protein diet during the last third of pregnancy on adult offspring metabolism, including pancreatic islet function and morphophysiological aspects of the liver, adrenal gland, white adipose tissue, and pancreas. Virgin female Wistar rats (age 70 d) were mated and fed a protein-restricted diet (4%, intrauterine protein restricted [IUPR]) from day 14 of pregnancy until delivery, whereas control dams were fed a 20.5% protein diet. At age 91 d, their body composition, glucose-insulin homeostasis, ACTH, corticosterone, leptin, adiponectin, lipid profile, pancreatic islet function and liver, adrenal gland, and pancreas morphology were assessed. The birth weights of the IUPR rats were 20% lower than the control rats (P < .001). Adult IUPR rats were heavier, hyperphagic, hyperglycemic, hyperinsulinemic, hyperleptinemic, and hypercorticosteronemic (P < .05) with higher low-density lipoprotein cholesterol and lower high-density lipoprotein cholesterol, adiponectin, ACTH, and insulin sensitivity index levels (P < .01). The insulinotropic action of glucose and acetylcholine as well as muscarinic and adrenergic receptor function were impaired in the IUPR rats (P < .05). Maternal undernutrition during the last third of gestation disrupts the pancreatic islet insulinotropic response and induces obesity-associated complications. Such alterations lead to a high risk of metabolic syndrome, characterized by insulin resistance, visceral obesity, and lower high-density lipoprotein cholesterol.
Assuntos
Dieta com Restrição de Proteínas , Resistência à Insulina/fisiologia , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Síndrome Metabólica/etiologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Animais , Glicemia/metabolismo , Peso Corporal/fisiologia , Colesterol/sangue , Ingestão de Alimentos/fisiologia , Feminino , Insulina/sangue , Leptina/sangue , Masculino , Síndrome Metabólica/metabolismo , Pâncreas/metabolismo , Pâncreas/patologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos WistarRESUMO
Pioglitazone (PTZ) is an oral antidiabetic agent whose anti-cancer properties have been described recently. Since PTZ increases the production of reactive oxygen species in mammalian cells, the aim of current study was to evaluate the cytotoxic, mutagenic and recombinogenic effects of PTZ using respectively the in vitro mitotic index assay and the in vitro mammalian cell micronucleus test in human peripheral lymphocytes, and the in vivo homozygotization assay in Aspergillus nidulans, which detects the loss of heterozygosity due to somatic recombination. Although the lowest PTZ concentrations (4-36 µM) did not show any significant rise in the micronucleus production, the higher PTZ concentration (108 µM) produced a statistically higher number of micronuclei than the negative control and significantly altered the cell-proliferation kinetics, demonstrating the mutagenic and antiproliferative effects of PTZ, respectively. The recombinogenic activity of PTZ, demonstrated here for the first time, was observed at the highest tested concentration (400 µM) through the homozygotization index rates significantly different from the negative control. Taken together, our results show that PTZ is genotoxic at a concentration higher than the therapeutic plasma concentration. This PTZ genotoxicity may be a potential benefit to its previously described antitumour activity.
Assuntos
Dano ao DNA , Linfócitos/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , PPAR gama/agonistas , Tiazolidinedionas/efeitos adversos , Aspergillus nidulans/efeitos dos fármacos , Aspergillus nidulans/genética , Células Cultivadas , DNA/efeitos dos fármacos , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/uso terapêutico , Hipoglicemiantes/toxicidade , Perda de Heterozigosidade , Testes de Mutagenicidade , Estresse Oxidativo/efeitos dos fármacos , Pioglitazona , Tiazolidinedionas/uso terapêutico , Tiazolidinedionas/toxicidadeRESUMO
Essential polyunsaturated fatty acids (PUFAs) prevent cardiometabolic diseases. We aimed to study whether a diet supplemented with a mixture of n-6/n-3 PUFAs, during perinatal life, attenuates outcomes of long-term metabolic dysfunction in prediabetic and obese mice. Seventy-day-old virgin female mice were mated. From the conception day, dams were fed a diet supplemented with sunflower oil and flaxseed powder (containing an n-6/n-3 PUFAs ratio of 1.2 : 1.0) throughout pregnancy and lactation, while control dams received a commercial diet. Newborn mice were treated with monosodium L-glutamate (MSG, 4 mg g-1 body weight per day) for the first 5 days of age. A batch of weaned pups was sacrificed to quantify the brain and pancreas total lipids; another batch were fed a commercial diet until 90 days of age, where glucose homeostasis and glucose-induced insulin secretion (GIIS) as well as retroperitoneal fat and Lee index were assessed. MSG-treated mice developed obesity, glucose intolerance, insulin resistance, pancreatic islet dysfunction, and higher fat stores. Maternal flaxseed diet-supplementation decreased n-6/n-3 PUFAs ratio in the brain and pancreas and blocked glucose intolerance, insulin resistance, GIIS impairment, and obesity development. The n-6/n-3 essential PUFAs in a ratio of 1.2 : 1.0 supplemented in maternal diet during pregnancy and lactation prevent metabolic dysfunction in MSG-obesity model.
RESUMO
Glibenclamide is an oral hypoglycemic drug commonly prescribed for the treatment of type 2 diabetes mellitus, whose anti-tumor activity has been recently described in several human cancer cells. The mutagenic potential of such an antidiabetic drug and its recombinogenic activity in eukaryotic cells were evaluated, the latter for the first time. The mutagenic potential of glibenclamide in therapeutically plasma (0.6 µM) and higher concentrations (10 µM, 100 µM, 240 µM and 480 µM) was assessed by the in vitro mammalian cell micronucleus test in human lymphocytes. Since the loss of heterozygosity arising from allelic recombination is an important biologically significant consequence of oxidative damage, the glibenclamide recombinogenic activity at 1 µM, 10 µM and 100 µM concentrations was evaluated by the in vivo homozygotization assay. Glibenclamide failed to alter the frequency of micronuclei between 0.6 µM and 480 µM concentrations and the cytokinesis block proliferation index between 0.6 µM and 240 µM concentrations. On the other hand, glibenclamide changed the cell-proliferation kinetics when used at 480 µM. In the homozygotization assay, the homozygotization indices for the analyzed markers were lower than 2.0 and demonstrated the lack of recombinogenic activity of glibenclamide. Data in the current study demonstrate that glibenclamide, in current experimental conditions, is devoid of significant genotoxic effects. This fact encourages further investigations on the use of this antidiabetic agent as a chemotherapeutic drug.
Assuntos
Glibureto/toxicidade , Hipoglicemiantes/toxicidade , Linfócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Adulto , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Linfócitos/citologia , Linfócitos/metabolismo , Testes para Micronúcleos , Adulto JovemRESUMO
BACKGROUND/AIMS: The objective of the current work was to test the effect of metformin on the tumor growth in rats with metabolic syndrome. METHODS: We obtained pre-diabetic hyperinsulinemic rats by neonatal treatment with monosodium L-glutamate (MSG), which were chronically treated every day, from weaning to 100 day old, with dose of metformin (250 mg/kg body weight). After the end of metformin treatment, the control and MSG rats, treated or untreated with metformin, were grafted with Walker 256 carcinoma cells. Tumor weight was evaluated 14 days after cancer cell inoculation. The blood insulin, glucose levels and glucose-induced insulin secretion were evaluated. RESULTS: Chronic metformin treatment improved the glycemic homeostasis in pre-diabetic MSG-rats, glucose intolerance, tissue insulin resistance, hyperinsulinemia and decreased the fat tissue accretion. Meanwhile, the metformin treatment did not interfere with the glucose insulinotropic effect on isolated pancreatic islets. Chronic treatment with metformin was able to decrease the Walker 256 tumor weight by 37% in control and MSG rats. The data demonstrated that the anticancer effect of metformin is not related to its role in correcting metabolism imbalances, such as hyperinsulinemia. However, in morphological assay to apoptosis, metformin treatment increased programmed cell death. CONCLUSION: Metformin may have a direct effect on cancer growth, and it may programs the rat organism to attenuate the growth of Walker 256 carcinoma.
Assuntos
Carcinoma 256 de Walker/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Metformina/administração & dosagem , Neoplasias/tratamento farmacológico , Animais , Glicemia , Carcinoma 256 de Walker/metabolismo , Carcinoma 256 de Walker/patologia , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/patologia , Intolerância à Glucose/tratamento farmacológico , Intolerância à Glucose/patologia , Hipoglicemiantes/administração & dosagem , Insulina/metabolismo , Resistência à Insulina/genética , Ilhotas Pancreáticas/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Ratos , Glutamato de Sódio/toxicidadeRESUMO
Nutritional insults during developmental plasticity have been linked with metabolic diseases such as diabetes in adulthood. We aimed to investigate whether a low-protein (LP) diet at the beginning of adulthood is able to program metabolic disruptions in rats. While control rats ate a normal-protein (23%; NP group) diet, treated rats were fed a LP (4%; LP group) diet from 60 to 90 days of age, after which an NP diet was supplied until they were 150 days old. Plasma levels of glucose and insulin, autonomous nervous system (ANS), and pancreatic islet function were then evaluated. Compared with the NP group, LP rats exhibited unchanged body weight and reduced food intake throughout the period of protein restriction; however, after the switch to the NP diet, hyperphagia of 10% (P<0.05), and catch-up growth of 113% (P<0.0001) were found. The LP rats showed hyperglycemia, insulin resistance, and higher fat accretion than the NP rats. While the sympathetic tonus from LP rats reduced by 28%, the vagus tonus increased by 21% (P<0.05). Compared with the islets from NP rats, the glucose insulinotropic effect as well as cholinergic and adrenergic actions was unaltered in the islets from LP rats. Protein restriction at the beginning of adulthood induced unbalanced ANS activity and fat tissue accretion later in life, even without functional disturbances in the pancreatic islets.
Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Dieta com Restrição de Proteínas/efeitos adversos , Ilhotas Pancreáticas/inervação , Ilhotas Pancreáticas/metabolismo , Animais , Peso ao Nascer/efeitos dos fármacos , Peso ao Nascer/fisiologia , Glicemia/metabolismo , Células Cultivadas , Proteínas Alimentares/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Similar to gestation/lactation, puberty is also a critical phase in which neuronal connections are still being produced and during which metabolic changes may occur if nutrition is disturbed. In the present study we aimed to determine whether peripubertal protein restriction induces metabolic programming. Thirty-day-old male rats were fed either a low protein (LP group) diet (4% w/w protein) or a normal protein (NP group) diet (23%) until 60 days of age, when they received the NP diet until they were 120 days old. Body weight (BW), food intake, fat tissue accumulation, glucose tolerance, and insulin secretion were evaluated. The nerve electrical activity was recorded to evaluate autonomous nervous system (ANS) function. Adolescent LP rats presented hypophagia and lower BW gain during the LP diet treatment (P<0.001). However, the food intake and BW gain by the LP rats were increased (P<0.001) after the NP diet was resumed. The LP rats presented mild hyperglycemia, hyperinsulinemia, severe hyperleptinemia upon fasting, peripheral insulin resistance and increased fat tissue accumulation and vagus nerve activity (P<0.05). Glucose-induced insulin secretion was greater in the LP islets than in the NP islets; however, the cholinergic response was decreased (P<0.05). Compared with the islets from the NP rats, the LP islets showed changes in the activity of muscarinic receptors (P<0.05); in addition, the inhibition of glucose-induced insulin secretion by epinephrine was attenuated (P<0.001). Protein restriction during adolescence caused high-fat tissue accumulation in adult rats. Islet dysfunction could be related to an ANS imbalance.
Assuntos
Dieta com Restrição de Proteínas/efeitos adversos , Ilhotas Pancreáticas/metabolismo , Puberdade/metabolismo , Animais , Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Glucose/farmacologia , Hiperglicemia/metabolismo , Hiperinsulinismo/metabolismo , Insulina/metabolismo , Masculino , RatosRESUMO
The essential oil of Achillea millefolium is commonly used in folk medicine for the treatment of several diseases and has been demonstrated previously to exert an in vitro antimicrobial activity against human pathogens. Current study investigates the genotoxic activity of A. millefolium oil. The oil's major constituents are: chamazulene (42.15%), sabinene (19.72%), terpin-4-ol (5.22%), beta-caryophyllene (4.44%) and eucalyptol (3.10%), comprising 74.63% of the total. The oil's genotoxic evaluation was performed at concentrations of 0.13 microL/mL, 0.19 microL/mL and 0.25 microL/mL with a heterozygous diploid strain of Aspergillus nidulans, named A757//UT448, with green conidia. A statistically significant increasing number of yellow and white mitotic recombinants, per colony, of the diploid strain was reported after oil treatment with 0.19 microL/mL and 0.25 microL/mL concentrations. The genotoxicity of the oil was associated with the induction of mitotic non-disjunction or crossing-over by oil.
Assuntos
Achillea/química , Aspergillus nidulans/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Aspergillus nidulans/genética , Troca Genética/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Medicina Tradicional , Testes de Mutagenicidade , Não Disjunção Genética/efeitos dos fármacosRESUMO
Sulindac sulfide is a non-steroidal anti-inflammatory drug (NSAID) with chemopreventive effect on human cancer cells. Due to the involvement of the somatic recombination in the carcinogenic process, sulindac sulfide's recombinogenic potential was evaluated by the Homozygotization Index (HI) in the filamentous fungus Aspergillus nidulans. The drug's recombinogenic potential was evaluated by its capacity to induce homozygosis of recessive genes from heterozygous diploid cells. Sulindac sulfide at 175 and 350 æM concentrations induced mitotic recombination in A. nidulans diploid cells, with HI values for genetic markers higher than 2.0, and significantly different from control HI values. The recombinogenic effect of NSAID was related to the induction of DNA strand breaks and cell cycle alterations. Sulindac sulfide's carcinogenic potential was also discussed.
Sulfeto de sulindaco é um antiinflamatório não-esteroidal com efeitos quimiopreventivos em cânceres humanos. O presente estudo teve como objetivo avaliar o potencial recombinagênico do sulfeto de sulindaco em células diplóides de Aspergillus nidulans. O efeito recombinagênico da droga foi demonstrado através da homozigotização de genes recessivos, previamente presentes em heterozigose. Os valores de HI (índice de Homozigotização) para diferentes marcadores genéticos apresentaram-se maiores do que 2,0 e significativamente diferentes dos valores obtidos em sulfeto de sulindaco ausência da droga (controle). O potencial recombinagênico do sulfeto de sulindaco foi associado à indução de quebras na molécula do DNA e a alterações no ciclo celular. O potencial carcinogênico do sulfeto de sulindaco foi discutido no presente trabalho.