Camila Aparecida Machado de Oliveira

Efeitos do treinamento físico de alta intensidade sobre os leucócitos de ratos diabéticos

Several studies have demonstrated that regular physical activity improves diabetes conditions, favoring the peripheral glucose uptake, glycogen and protein metabolism. However, the effects of high intensity physical training on the immune system of diabetic organisms are not totally clear. The aim of this study was to verify the effects of high intensity physical training on the total and differential leukocyte count of diabetic rats. Male young Wistar rats were distributed into four groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Diabetes was induced by alloxan (30 mg/kg body weight i.v.). During six weeks the animals of TC and TD groups followed a high intensity physical training protocol which consisted of four sets of 10 jumps/day (interrupted by one minute of rest interval) in a swimming pool, with the water level corresponding to 150% of the body length and overload equivalent to 50% of the body weight. At the end of the experimental period, blood samples were collected for total and differential leukocyte count. The results were analyzed by ANOVA at a significance level of 5%. Serum glucose was increased in diabetic groups while the insulin level was reduced in these groups. There were no significant differences in lymphocytes, neutrophils, and eosinophils, and in total leukocyte count when the groups were compared. Monocytes count was higher in both trained groups (SC = 10.0 ± 4.5, TC* = 25.4 ± 7.9, SD = 19.75 ± 7.4, TD* = 25.8 ± 4.4%). The relative weight of the thymus was reduced by diabetes and training (SC = 125.0 ± 37.7, TC* =74.6 ± 8.2, SD* = 47.5 ± 12.2, TD* = 40.1 ± 16.9). In conclusion, the high intensity physical training protocol did not change the general diabetes conditions, but improved relative monocytes. These results can represent a positive effect on the immune response.

The role of exercise on long-term effects of alloxan administered in neonatal rats

The present study was designed to analyse the effects of aerobic exercise on the metabolic effects of alloxan. Male Wistar newborn rats (2 days old) received alloxan (200 mg (kg body weight)−1) intraperitoneally (A rats). Vehicle‐injected rats were used as controls (C rats). At 28 days old, some of the A rats were subjected to swimming for 1 h day−1, 5 day week−1 (AT rats). At 28, 60 and 90 days old the animals were subjected to glucose (GTTo) and insulin (ITTsc) tolerance tests. All the animals were then killed by decapitation for blood and tissue evaluations. On the 60th day, there was a reduction in blood glucose level during the GTTo (mmol l−1 (90 min)−1) in the AT rats (7640.7 ± 694.0) with respect to C (7057.5 ± 776.9) and A (8555.6 ± 1096.7) rats. However on the 90th day, AT rats showed higher glucose levels (8004.6 ± 267.9) when compared to the other groups (C, 7305.5 ± 871.2; A, 7088.8 ± 536.9). The serum free fatty acid (FFA) concentration (μEq l−1) was higher in the alloxan‐treated animals (A, 231.1 ± 58.5; AT, 169.8 ± 20.1) than in controls (C, 101.4 ± 22.4). In conclusion, although the high blood glucose level is transitory in the A animals, some blood and tissue alterations remain and can be harmful to the maintenance of homeostasis. Physical exercise counteracted only partially these alterations. Furthermore, training worsened glucose tolerance at the 90th day, suggesting that exercise intensity should be adjusted to the diabetic condition.

Bioactive metabolites produced by Penicillium sp.1 and sp.2, two endophytes associated with Alibertia macrophylla (Rubiaceae).

In the course of our continuous search for bioactive metabolites from endophytic fungi living in plants from the Brazilian fl ora, leaves of Alibertia macrophylla (Rubiaceae) were submitted to isolation of endophytes, and two species of Penicillium were isolated. The acetonitrile fraction obtained in corn from a culture of Penicillium sp.1 afforded orcinol (1). On the other hand, Penicillium sp.1 cultivated in potato-dextrose-broth furnished two different compounds, cyclo-(L-Pro-L-Val) (2) and uracil (3). The chromatographic fractionation of the acetonitrile fraction obtained from Penicillium sp.2 led to three dihydroisocoumarins, 4-hydroxymellein (4), 8-methoxymellein (5) and 5-hydroxymellein (6). Compounds 5 and 6 were obtained from the Penicillium genus for the fi rst time. Additionally, metabolites 1 - 6 were evaluated for their antifungal and acetylcholinesterase (AChE) inhibitory activities. The most active compounds 1 and 4 exhibited detection limits of 5.00 and 10.0 μg against Cladosporium cladosporioides and C. sphaerospermum, respectively. Compound 2 showed a detection limit of 10.0 μg, displaying potent AChE inhibitory activity.

Effects of Exercise Training on Hippocampus Concentrations of Insulin and IGF-1 in Diabetic Rats

The present study investigated the role of swimming training on cerebral metabolism and hippocampus concentrations of insulin and IGF‐1 in diabetic rats. Wistar rats were divided in sedentary control (SC), trained control (TC), sedentary diabetic (SD), and trained diabetic (TD). Diabetes was induced by Alloxan (35 mg kg−1 b.w.). Training program consisted in swimming 5 days/week, 1 h/day, 8 weeks, supporting a load corresponding to 90% of maximal lactate steady state (MLSS). For MLSS determination, rats were submitted to three sessions of 25‐min supporting loads of 4, 5, or 6% of body wt, with intervals of 1 week. Blood samples were collected every 5 min for lactate determination. An acute exercise test (25 min to 90% of MLSS) was done in 7th week to confirm the efficacy of training. All dependent variables were analyzed by one‐way analysis of variance (ANOVA) and a significance level of P < 0.05 was used for all comparisons. The Bonferroni test was used for post hoc comparisons. At the end of the training period, rats were sacrificed and sample blood was collected for determinations of serum glucose, insulin, GH, and IGF‐1. Samples of gastrocnemius muscle and liver were removed to evaluate glycogen content. Hippocampus was extracted to determinate glycogen, insulin, and IGF‐1 contents. Diabetes decreased serum GH, IGF‐1, and liver glycogen stores in SD. Diabetes also increased hippocampus glycogen and reduced hippocampus IGF‐1 content. Physical training recovered liver and hippocampus glycogen stores and promoted increases in serum IGF‐1 in TD group. Physical training restored hippocampus IGF‐1 content in diabetic group. It was concluded that in diabetic rats, physical training induces important metabolic and hormonal alterations that areassociated with an improvement in glucose homeostasis and with an increased activity in the systemic and hippocampus IGF‐1 peptide.

Exercise at anaerobic threshold intensity and insulin secretion by isolated pancreatic islets of rats

To evaluate the effect of acute exercise and exercise training at the anaerobic threshold (AT) intensity on aerobic conditioning and insulin secretion by pancreatic islets, adult male Wistar rats were submitted to the lactate minimum test (LMT) for AT determination. Half of the animals were submitted to swimming exercise training (trained), 1 h/day, 5 days/week during 8 weeks, with an overload equivalent to the AT. The other half was kept sedentary (sedentary). At the end of the experimental period, the rats were submitted to an oral glucose tolerance test and to another LMT. Then, the animals were sacrificed at rest or immediately after 20 minutes of swimming exercise at the AT intensity for pancreatic islets isolation. At the end of the experiment mean workload (% bw) at AT was higher and blood lactate concentration (mmol/L) was lower in the trained than in the control group. Rats trained at the AT intensity showed no alteration in the areas under blood glucose and insulin during OGTT test. Islet insulin content of trained rats was higher than in the sedentary rats while islet glucose uptake did not differ among the groups. The static insulin secretion in response to the high glucose concentration (16.7 mM) of the sedentary group at rest was lower than the sedentary group submitted to the acute exercise and the inverse was observed in relation to the trained groups. Physical training at the AT intensity improved the aerobic condition and altered insulin secretory pattern by pancreatic islets.

Biologically Active Eremophilane-Type Sesquiterpenes from Camarops sp., an Endophytic Fungus Isolated from Alibertia macrophylla

Two new eremophilane-type sesquiterpenes, xylarenones F (3) and G (4), have been isolated from solid substrate cultures of a Camarops sp. endophytic fungus isolated from Alibertia macrophylla, together with the known compounds xylarenones C (1) and D (2). The structures and relative configurations of 1-4 were elucidated by extensive NMR and HRESIMS spectroscopic analysis. Due to their effects on the respiratory burst of neutrophils, which included inhibition of the reactive oxygen species production, these sesquiterpenes exhibited potential anti-inflammatory and antioxidant properties.

Citocalasinas produzidas por Xylaria sp., um fungo endofítico de Piper aduncum (piperaceae)

A chemical study on the EtOAc extract produced by Xylaria sp., an endophytic fungus from Piper aduncum, resulted in the isolation of a new cytochalasin 1, along with five known 19,20-epoxycytochalasin D (2), C (3), N (4), Q (5), and R (6). The 1-6 were evaluated against the fungi C. cladosporioides and C. sphaerospermum and only 5 showed weak activity. The cytotoxicity in vitro against HeLA and CHO cells lines were investigated and the cytochalasins 2-4, and 6 showed a strong activity against HeLA. The DNAdamaging activity of 1-6 were also investigated against mutant strains of S. cerevisiae.

Exercise test and glucose homeostasis in rats treated with alloxan during the neonatal period or fed a high calorie diet.

Background:  Animal models appear well‐suited for studies into the role of exercise in the prevention of non‐insulin‐dependent diabetes mellitus (NIDDM). The aim of the present study was to analyze glucose homeostasis and blood lactate during an exercise swimming test in rats treated with alloxan during the neonatal period and/or fed a high calorie diet from weaning onwards.

Influence of spirulina intake on metabolism of exercised rats

In this study we compared the metabolic response to acute exercise among rats fed on a standard diet or on a spirulina diet. Young Wistar rats were divided into two groups according to diet: control (C) (standard diet) and spirulina (S) (spirulina diet). At the end of experimental period (5 weeks) rats were submitted to an acute exercise session of swimming (20 minutes, supporting a load corresponding to 5% of body weight) to determine blood lactate and serum glucose, insulin, proteins, albumin and fatty free acids (FFA). Gastrocnemius and liver samples were used to determine glycogen and lipids tenors. Both C and S groups showed increase in serum glucose and FFA, a drop in serum insulin and a decrease of muscle and liver glycogen contents after acute exercise. Blood lactate during exercise was higher in S than C rats. It was concluded that the response pattern to acute exercise was similar for C and S rats. However, diet protein seemed to influence aspects of glucose metabolism.

Influência da ingestão de espirulina sobre o metabolismo de ratos exercitados

In this study we compared the metabolic response to acute exercise among rats fed on a standard diet or on a spirulina diet. Young Wistar rats were divided into two groups according to diet: control (C) (standard diet) and spirulina (S) (spirulina diet). At the end of experimental period (5 weeks) rats were submitted to an acute exercise session of swimming (20 minutes, supporting a load corresponding to 5% of body weight) to determine blood lactate and serum glucose, insulin, proteins, albumin and fatty free acids (FFA). Gastrocnemius and liver samples were used to determine glycogen and lipids tenors. Both C and S groups showed increase in serum glucose and FFA, a drop in serum insulin and a decrease of muscle and liver glycogen contents after acute exercise. Blood lactate during exercise was higher in S than C rats. It was concluded that the response pattern to acute exercise was similar for C and S rats. However, diet protein seemed to influence aspects of glucose metabolism.