Aging Reduces Insulin Clearance in Mice Marmentini, Carine; Soares, Gabriela M; Bronczek, Gabriela A ...
Frontiers in endocrinology (Lausanne),
05/2021, Letnik:
12
Journal Article
Recenzirano
Odprti dostop
Hyperinsulinemia is frequently associated with aging and may cause insulin resistance in elderly. Since insulin secretion and clearance decline with age, hyperinsulinemia seems to be maintained, ...primarily, due to a decrease in the insulin clearance. To investigate these aging effects, 3- and 18-month-old male C57BL/6 mice were subjected to intraperitoneal glucose and insulin tolerance tests (ipGTT and ipITT) and, during the ipGTT, plasma c-peptide and insulin were measure to evaluate
insulin clearance. Glucose-stimulated insulin secretion in isolated pancreatic islets was also assessed, and liver samples were collected for molecular analyses (western blot). Although insulin sensitivity was not altered in the old mice, glucose tolerance, paradoxically, seems to be increased, accompanied by higher plasma insulin, during ipGTT. While insulin secretion did not increase, insulin clearance was reduced in the old mice, as suggested by the lower c-peptide:insulin ratio, observed during ipGTT. Carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) and insulin-degrading enzyme (IDE), as well as the activity of this enzyme, were reduced in the liver of old mice, justifying the decreased insulin clearance observed in these mice. Therefore, loss of hepatic CEACAM1 and IDE function may be directly related to the decline in insulin clearance during aging.
A combination of resistance training and whey protein supplementation is a common practice among athletes and recreational exercisers to enhance muscle growth and strength. Although their safety as ...food additives is controversial, artificial sweeteners are present in whey protein supplements. Thus, natural sweeteners extracted from the leaves of
are a potential alternative, due to their safety and health benefits. Here, we investigated the effects of whey protein sweetened with
on physical performance and mitochondrial biogenesis markers in the skeletal muscle of resistance-trained rats.
Forty male Wistar rats were distributed into four groups: sedentary rats, trained rats, trained rats receiving whey protein and trained rats receiving whey protein sweetened with
leaf extracts. Resistance training was performed by climbing a ladder 5 days per week, during 8-weeks. The training sessions consisted of four climbs carrying a load of 50, 75, 90, and 100% of the maximum load-carrying capacity which we determined before by performing a maximum load-carrying test for each animal. After this period, we collected plasma and tissues samples to evaluate biochemical, histological and molecular (western blot) parameters in these rats.
Dietary supplementation with whey protein sweetened with
significantly enhanced the maximum load-carrying capacity of resistance-trained rats, compared with non-sweetened whey protein supplementation. This enhanced physical performance was accompanied by an increase in the weight of the gastrocnemius and soleus muscle pads. Although the muscle pad of the biceps brachii was not altered, we observed a significant increase in PGC-1α expression, which was followed by a similar pattern in TFAM protein expression, two important mitochondrial biogenesis markers. In addition, a higher level of AMPK phosphorylation was observed in these resistance-trained rats. Finally, supplementation with whey protein sweetened with
also induced a significant decrease in retroperitoneal adipocyte diameter and an increase in the weight of brown adipose tissue pads in resistance-trained rats.
The addition of
leaf extracts to whey protein appears to be a potential strategy for those who want to increase muscular mass and strength and also improve mitochondrial function. This strategy may be useful for both athletes and patients with metabolic disorders, such as obesity and type 2 diabetes.
The study aims to analyse the treatment of whey protein enriched with
Stevia rebaudiana
fraction in insulin secretion and its role mitigating streptozotocin-induced hyperglycemia in rats. Thus, ...diabetic animals were treated with whey protein enriched with
S. rebaudiana
fraction or with only the protein isolate or only the Stevia fraction. Insulin level in plasma was measured by radioimmunoassay and the viability of β cells was detected by immunohistochemistry. The results showed that diabetic animals treated with whey protein enriched with
S. rebaudiana
fraction had a greater recovery from insulinemia, with plasma levels similar to non-diabetic animals (~ 0.13 ng/mL). In addition, the same group showed a higher number of insulin-positive pancreatic B cells (~ 66%) in immunohistochemistry analysis, while the diabetic groups treated with only the fraction of stevia or whey protein showed 38 and 59% of positive cells, respectively. These results show that the treatment may have restored the viability of streptozotocin-injured pancreatic B cells, and consequently increased insulin secretion, suggesting whey protein enriched with
S. rebaudiana
fraction can be used an adjunct/supplement in diabetic treatment.
COVID-19 During Development: A Matter of Concern Saavedra, Lucas Paulo Jacinto; Prates, Kelly Valério; Gonçalves, Gessica Dutra ...
Frontiers in cell and developmental biology,
04/2021, Letnik:
9
Journal Article
Recenzirano
Odprti dostop
A new infectious disease, COVID-19, has spread around the world. The most common symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are cough and fever, but severe ...cases can develop acute respiratory distress syndrome. The main receptor for SARS-CoV-2 in human tissue is angiotensin-converting enzyme 2, and the lungs, heart, and kidneys are the most affected organs. Besides the inflammatory process and tissue damage, the presence of a cytokine "storm" has been related to a higher mortality rate. Other infectious viral diseases, such as Zika, chikungunya, and influenza, were associated with complications in pregnant women, such as growth restriction, malformation, preterm birth, low birth weight, miscarriage, and death, although they can also cause developmental disorders in infants and adolescents. Evidence points out that stressors during pregnancy and infancy may lead to the development of obesity, diabetes, and cardiovascular disease. Therefore, we hypothesize that COVID-19 infection during the critical phases of development can program the individual to chronic diseases in adulthood. It is important that COVID-19 patients receive proper monitoring as a way to avoid expensive costs to public health in the future.
Stevia rebaudiana (Bert.) Bertoni besides being a source of noncaloric sweeteners is also an important source of bioactive molecules. Many plant extracts, mostly obtained with ethyl acetate solvent, ...are rich in polyphenol compounds that present insulinotropic effects. To investigate whether the nonsweetener fraction, which is rich in phenolic compounds isolated from Stevia rebaudiana with the solvent ethyl acetate (EAF), has an insulinotropic effect, including interference at the terminals of the autonomic nervous system of the pancreatic islets of rats. Pancreatic islets were isolated from Wistar rats and incubated with EAF and inhibitory or stimulatory substances of insulin secretion, including cholinergic and adrenergic agonists and antagonists. EAF potentiates glucose-stimulated insulin secretion (GSIS) only in the presence of high glucose and calcium-dependent concentrations. EAF increased muscarinic insulinotropic effects in pancreatic islets, interfering with the muscarinic receptor subfamily M3. Adrenergic inhibitory effects on GSIS were attenuated in the presence of EAF, which interfered with the adrenergic α2 receptor. Results suggest that EAF isolated from stevia leaves is a potential therapy for treating type 2 diabetes mellitus by stimulating insulin secretion only in high glucose concentrations, enhancing parasympathetic signal transduction and inhibiting sympathetic signal transduction in beta cells.
This work aimed to formulate and perform physicochemical and functional characterization of maltodextrin microcapsules containing ethanolic extract of stevia, rich in antioxidant compounds, ...encapsulated by a spray‐drying process with two maltodextrins (DE10 and DE19). The powders were named M10 and M19, respectively. We analyzed the physicochemical parameters, antidiabetic activity, cytotoxicity, bioaccessibility of the compounds by in vitro digestion, as well as the structure of the microcapsules by scanning electron microscopy. Microcapsules showed higher solubility (∼35%), lower moisture content (∼29%), and the maltodextrin DE10 had higher efficiency as an encapsulating agent (87%) when compared to DE19 (76%) and showed well‐defined spherical structures. The microencapsulation preserved the content of phenolic compounds and antioxidant activity present in the extract (7.2% and 87.5%, respectively). The bioaccessibility of these microencapsulated compounds and antioxidant activity were higher under different conditions of in vitro digestion (mouth, gastric, and intestinal conditions) and showed no cytotoxic effects. We identified 41 compounds (by UHPLC‐MS/MS‐Qtof) related to the nutritional benefits offered by stevia and the microencapsulation technique can be recommended to preserve bioactive compounds.
Practical Application
Ethanol extract from stevia leaves contains antioxidant phytochemicals related to the nutritional benefits of stevia. However, this extract presents low solubility and consequently low bioaccessibility under in vitro digestion. The microencapsulation process protects the bioactive compounds of the different pH from digestion and improves the physical‐chemical parameters of the extract, increasing its applicability as a possible food additive.
Several epidemiological, clinical and experimental studies in recent decades have shown the relationship between exposure to stressors during development and health outcomes later in life. The ...characterization of these susceptible phases, such as preconception, gestation, lactation and adolescence, and the understanding of factors that influence the risk of an adult individual for developing obesity, metabolic and cardiovascular diseases, is the focus of the DOHaD (Developmental Origins of Health and Disease) research line. In this sense, advancements in molecular biology techniques have contributed significantly to the understanding of the mechanisms underlying the observed phenotypes, their morphological and physiological alterations, having as a main driving factor the epigenetic modifications and their consequent modulation of gene expression. The present narrative review aimed to characterize the different susceptible phases of development and associated epigenetic modifications, and their implication in the development of non-communicable diseases. Additionally, we provide useful insights into interventions during development to counteract or prevent long-term programming for disease susceptibility.
Cannabidiol (CBD), a compound obtained from Cannabis sativa, has wide range of therapeutic properties, including mitigation of diabetes and neurodegeneration. Cerebral ischemia and consequent ...learning disabilities are aggravated in elderly diabetic subjects. However, there are no studies showing the effect of CBD treatment in elderly diabetes patients suffering cerebral ischemia. The present work tested the hypothesis that CBD treatment improves metabolic dysfunctions in middle-aged diabetic rats submitted to chronic cerebral hypoperfusion. In this work, 350-day-old male Wistar streptozotocin-induced diabetic rats were used. To induce cerebral ischemia was used a chronic cerebral hypoperfusion (CCH), surgically, via the four-vessel occlusion/internal carotid artery (4-VO/ICA). Four diabetic groups were established: Non-CCH Treated Diabetic (DNT), CCH Treated Diabetic (DCT), Non-CCH Vehicle Diabetic (DNV), and CCH Vehicle Diabetic (DCV). Vehicle groups were not treated with CBD. The animals were treated during 30 days with 10 mg CBD/Kg bw/day. After treatment, the animals were euthanized, and blood levels of glucose, insulin, total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, fructosamine, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were evaluated. DCT group presented reduction of hyperglycemia and an increase of insulinemia. Also was observed lower fructosamine, LDL, HDL, triglycerides and total cholesterol levels. AST and ALT concentration were reduced in CBD treated groups. CBD may be used as therapeutic tool to protect metabolism against injuries from diabetes aggravated by cerebral ischemia.
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•CBD reduced hyperglycemia of middle-aged diabetic rats with CCH.•CBD increased insulin secretion and decreased AGEs levels.•CBD reduced fructosamine, LDL, HDL, triglycerides and total cholesterol levels.•CBD presented hepatoprotective effect.•CBD could mitigate neurodegeneration caused by DM associated to cerebral ischemia.
Purpose
In this study, we investigated the effects of the supplementation with whey protein sweetened with
Stevia
upon insulin clearance markers in the liver and skeletal muscle of resistance-trained ...rats.
Methods
Male Wistar rats were assigned to four groups: sedentary (SC), trained (TC), trained receiving whey protein (TW), and trained receiving whey protein sweetened with
Stevia
(TWS). Resistance training consisted of four climbs on a leader, carrying a load of 50, 75, 90, and 100% of the maximum load capacity, 5 days per week. After an 8-week training, an insulin tolerance test (ITT) was performed to evaluate insulin sensitivity. Also, liver and skeletal muscle samples were collected to determine the content of specific proteins (Western blot).
Results
Insulin sensitivity increased in TC rats, but this effect was attenuated in TW and TWS groups. The expression of the major enzyme responsible for insulin degradation, insulin-degrading enzyme (IDE), increased in the liver, but not in the skeletal muscle from TWS compared to TC rats. However, the expression of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), a critical mediator for hepatic insulin clearance, was not altered, suggesting that this process was not modulated in the TWS rats.
Conclusion
Our results suggested that the supplementation with whey protein sweetened with
Stevia
does not change insulin clearance in resistance-trained rats. Also, our results show that it is important to be aware of a possible deleterious effect on insulin sensitivity induced by this supplementation, since the increased insulin sensitivity, induced by resistance training, was attenuated in TWS rats.
A stevia fraction (ASF) free of steviol glycosides was extracted from
Stevia rebaudiana
leaves (Stevia UEM-13). ASF essentially constitutes phenolic compounds (52.42%), which were identified by ...liquid chromatography tandem mass spectrometry (LC–MS/MS) as caffeic acid, quercetin-3-
o
-glycoside, cyanidin-3-glucoside, kaempferol, quercetin, apigenin, rozmarinic acid, chlorogenic acid and dicaffeoylquinic acid. ASF was used as a multi-functional source of phenolic compounds to fortify the whey protein isolate (WPI) obtained by membrane separation. WPI fortified with 0.2% ASF showed an 80% increase in its antioxidant activity and more pronounced antidiabetic effects than the unfortified WPI, mainly in the glycemic control of diabetic animals induced by streptozotocin. The in vitro and in vivo antioxidant effects of ASF may enhance the effects of WPI. Indeed, this pioneering study revealed that ASF can be used to enrich the antioxidant and antidiabetic properties of WPI.
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