Transglycosylation catalysed by Caco-2 membrane disaccharidases: A new approach to understand carbohydrates digestibility.

Under appropriate experimental conditions, some glycoside hydrolases can catalyze transglycosylation reactions; a hypothesis associated with this is that the glycosidic linkages formed will be preferentially hydrolyzed under optimal conditions. Therefore, the hydrolytic and transglycosylation activities of isolated membranes from differentiated Caco-2 cells on sucrose, maltose and isomaltulose were evaluated. After the enzymatic reactions, the di- and trisaccharides obtained were identified by gas chromatography coupled to a mass spectrometer. Differentiated Caco-2 cell membranes exerted hydrolytic and transglycosylation activities towards the studied disaccharides. The obtained di- and trisaccharides were detected for the first time using human cell models. Due to the absence of maltase-glucoamylase complex (MGAM) in Caco-2 cells, and the known hydrolytic activity of sucrase-isomaltase (SI) towards sucrose, maltose and isomaltulose, it is plausible that the glycosidic linkages obtained after the transglycosylation reaction, mainly α-glucosyl-fructoses and α-glucosyl-glucoses, were carried out by SI complex. This approach can be used as a model to explain carbohydrate digestibility in the small intestine and as a tool to design new oligosaccharides with low intestinal digestibility.

Hydrolysis and transglycosylation activities of glycosidases from small intestine brush-border membrane vesicles.

In order to know the catalytic activities of the disaccharidases expressed in the mammalian small intestinal brush-border membrane vesicles (BBMV) high concentrated solutions of sucrose, maltose, isomaltulose, trehalose and the mixture sucrose:lactose were incubated with pig small intestine disaccharidases. The hydrolysis and transglycosylation reactions generated new di- and trisaccharides, characterized and quantified by GC-MS and NMR, except for trehalose where only hydrolysis was detected. In general, α-glucosyl-glucoses and α-glucosyl-fructoses were the most abundant structures, whereas no fructosyl-fructoses or fructosyl-glucoses were found. The in-depth structural characterization of the obtained carbohydrates represents a new alternative to understand the potential catalytic activities of pig small intestinal disaccharidases. The hypothesis that the oligosaccharides synthesized by glycoside hydrolases could be also hydrolysed by the same enzymes was confirmed. This information could be extremely useful in the design of new non-digestible or partially digestible oligosaccharides with potential prebiotic properties.

Antioxidant activity, antibacterial and inhibitory effect of intestinal disaccharidases of extracts obtained from Eugenia uniflora L. seeds / Atividade antioxidante, antibacteriana e efeito inibidor de dissacaridases intestinais de extratos obtidos das sementes de Eugenia uniflora L

The use of medicinal plants for disease prevention, treatment and cure is an ancient practice used by humanity, and many plants species are used in bioprospecting research. In this context, its stands out Eugenia uniflora L., populary known as pitangueira and belongs to the Myrtaceae family, with a wide geographic distribution and native of Brazil. In view of the therapeutic qualities of the plant and the lack of the studies on its seeds, the present study had as objective to evaluate the phytochemical profile of the extracts of Eugenia uniflora L. seeds, from different solvents, as well as their antibacterial activity, antioxidant and its inhibitory effect of intestinal disaccharidases. Results showed a high content of phenolic compounds and total flavonoids, thus characterizing antioxidant activity, also highlighting the best bacteriostatic action for the Gram positive strain of Staphylococcus aureus in the ethanolic fraction. Regarding the disaccharidases, a strong inhibitory action was observed for all concentrations, evidencing a antihyperglycemic potential. The present research allowed to concluded that Eugenia uniflora L. seeds have promising biological activities for the industrial sector, but a more detailed investigation is needed regarding their bioactive compounds.

A utilização de plantas com fins medicinais para prevenção, tratamento e cura de doenças é uma prática antiga utilizada pela humanidade, sendo que muitas espécies vegetais são usadas para a pesquisa da bioprospecção. Neste contexto, destaca-se a Eugenia uniflora L., conhecida popularmente como pitangueira e pertencente à família Myrtaceae, com ampla distribuição geográfica e nativa do Brasil. Diante das qualidades terapêuticas da planta e a falta de estudos sobre suas sementes, o presente trabalho teve como objetivo avaliar o perfil fitoquímico dos extratos das sementes de Eugenia uniflora L. a partir de diferentes solventes, bem como sua atividade antibacteriana, antioxidante e seu efeito inibidor de dissacaridases intestinais. Os resultados mostraram um alto teor de compostos fenólicos e flavonóides totais, caracterizando a atividade antioxidante, destacando também a melhor ação bacteriostática para a cepa Gram positiva de Staphylococcus aureus na fração etanólica. Em relação às dissacaridases, uma forte ação inibitória foi observada para todas as concentrações, evidenciando um potencial anti-hiperglicêmico. A presente pesquisa permitiu concluir que as sementes de Eugenia uniflora L. apresentam atividades biológicas promissoras para o setor industrial, mas é necessária uma investigação mais detalhada de seus compostos bioativos.

A retrospective study on the association of gastrointestinal symptoms in children with low lactase activity and low activity of other disaccharidases.

BACKGROUND: Disaccharides such as lactose and sucrose are sugars commonly found in human diet. They are broken down by mucosal disaccharidases in the duodenum. Previous small studies found no associations between gastrointestinal (GI) symptoms and combined low disaccharidase activity. We aim to explore the associations of low activity of disaccharidase and combinations of low activity of different disaccharidases with general GI symptom presentations in a large cohort of pediatric patients. METHODS: We examined a cohort (0-21 yrs.) who have undergone esophagogastroduodenoscopy and received disaccharidase activity assay from duodenal biopsy in the time period 2010 to 2012. Disaccharidase assays tested for activity of lactase, sucrase, maltase, and palatinase. GI symptoms were grouped into four categories, abdominal pain, diarrhea, weight loss, and gastroesophageal reflux. RESULTS: Of the 347 subjects, we found an association between low lactase activity and abdominal pain (OR = 1.78; 95% CI = 1.07-2.97; p < 0.05). Subjects with a lactase/sucrase ratio < 0.2 were found to be associated with abdominal pain (OR = 2.25; 95% CI = 1.25-4.04; p < 0.05), Subjects with low pandisaccharidase may be correlated with abdominal pain and have a unique frequency of GI symptoms due to low frequency of diarrhea and weight loss, but they were not statistically significant. CONCLUSIONS: Low activities of certain disaccharidase combinations may be associated with GI symptoms in subjects; a prospective study may be needed to investigate further.

The role of disaccharidases in the digestion - diagnosis and significance of their deficiency in children and adults.

Disaccharidases are a group of enzymes of the small intestinal brush border, that are essential for degradation of disaccharides (sucrose, lactose, maltose, isomaltose, trehalose) into monosaccharides, which are then absorbed from the gastrointestinal tract. Their deficiency may occur at any stage of human life and have a genetic basis or be a secondary to ongoing gastrointestinal disease. Disaccharidase deficiencies cause disorders of digestion and absorption leading to occurrence of clinical symptoms such as abdominal pain, flatulence, diarrhea. For more than fifty years disaccharidase activity (DA) measurements in the small intestine biopsy samples are still considered the "gold standard" in the diagnostics for disaccharide deficiency. The aim of this review was to emphasize the role of disaccharidases in the digestion. Moreover, the significance of their deficiency in children and adults based on the current knowledge was described. It was showed that deficiency or inactivity of disaccharidases may lead to gastrointestinal intolerance symptoms. Early diagnostics allows the initiation of appropriate treatment, which contribute to reduction or complete resolution of clinical symptoms.

Associations of mucosal disaccharidase kinetics and expression in the jejunum of steers with divergent average daily gain.

The objective of this study was to quantify the differences in the activity of jejunal maltase and isomaltase between two groups of steers with average dry matter intake (DMI) and differing average daily gain (ADG). DMI and ADG were measured in crossbred steers (n = 69; initial body weight = 456 ± 5.0 kg) consuming a finishing diet containing 67.8% dry-rolled corn, 20.0% wet distillers grains with solubles, 8.0% alfalfa hay, and 4.2% vitamin/mineral supplement on a dry matter basis for 84 d. Jejunal mucosal samples were collected from eight steers with the greatest (high) or least (low) ADG and average DMI (± 0.55 standard deviation). Homogenates of jejunal mucosa were incubated with increasing amounts of maltose and isomaltose to determine the disaccharidase kinetics. Total mucosal protein concentration (mg protein/g tissue; P = 0.45) of the mucosa and small intestinal weights (P = 0.69) did not differ between the groups. Neither the Michaelis-Menten constant (Km) of isomaltase (P = 0.15) nor maltase (P = 0.21) differed between groups. The isomaltase maximum velocity (Vmax) expressed per gram of protein tended to differ (P = 0.10) between groups of steers but did not differ (P = 0.13) when expressed on a tissue basis. Similarly, neither the maltase Vmax expressed per gram of protein (P = 0.31) nor tissue (P = 0.32) differed between groups. While previous studies have indicated that disaccharidase expression is associated with differences in ADG, data presented here indicate that differences in enzyme activity at the end of the finishing period are minimal.

Hypoglycemic activity of extracts of Chamaecyparis obtusa var. formosana leaf in rats with hyperglycemia induced by high-fat diets and streptozotocin.

Chamaecyparis obtusa var. formosana is a species indigenous to Taiwan and has been used as a medicinal plant. It has been claimed that the hot water extracts of C. obtusa var. formosana leaves (CoLE) with flavonoids and proanthocyanidins have anti-oxidant and anti-hyperglycemic activities in vitro. This study further examines the anti-hyperglycemic activity of CoLE and its possible mechanisms in hyperglycemic rats. Hyperglycemia of rats was induced by streptozotocin (STZ) and high-fat diets (HFD). Hyperglycemic rats treated orally with 30 and 150 mg/kg CoLE were classified into LCO and HCO groups, respectively. After three-month treatment, both LCO and HCO groups showed improved glucose metabolism in oral glucose tolerance and postprandial blood glucose tests. Decrease in HOMA-IR, leptin and adiponectin levels of the HCO group revealed amelioration of insulin and leptin resistance. Obesity and accumulation of visceral fats induced by STZ and HFD could be alleviated in both HCO and LCO groups. These anti-diabetic effects might be contributed by inhibition of intestinal digested enzymes and protein tyrosine phosphatases (PTPases). Although other studies are necessary, these findings suggest that CoLE could be potentially used as a health complement for treating diabetes without significant toxicity.

[Pharmacological and clinical feature of rebamipide: new therapeutic targets].

Rebamipide is a cytoprotector developed in Japan where it has been successfully used for the treatment of stomach diseases for 30 years. Initially discovered effects of the drug included the induction of prostaglandins and the elimination of free oxygen radicals. Recent studies discovered new therapeutic targets of the drug, its new forms that made possible using rebamipid for the treatment of such diseases as NSAID enteropathy, ulcerative colitis, radiation colitis, pouchitis, enteropathy with impaired membrane digestion. It is used in endoscopy, ophthalmology, chemotherapy, rheumatology. The aim of this review is to present current information about the pharmacological and clinical feature of rebamipide and to study its therapeutic potential.

Effects of Bidens gardneri Baker leaves aqueous extract in glucose homeostasis of rats.

Bidens gardneri Baker, popularly known as "picão-vermelho", has been used, traditionally, as a medicinal plant for the treatment of Diabetes mellitus. This study aimed to evaluate antidiabetic effect of leaves from B. gardneri aqueous extract (BGAE). We also evaluated in vitro anti-glycation potential. Chemical composition was analyzed based on a colorimetrics and HPLC methods. The oral glucose tolerance test (OGTT), was performed in rats with different doses (30, 100 and 300 mg/kg). Alloxan-induced diabetic and hypercaloric diet-fed rats were treated with 300 mg/kg of BGAE, orally, for 10 days and then 10 weeks, respectively. The activity of intestinal disaccharidases (maltase, sucrase and lactase) and quantification of muscle and liver glycogen content were also evaluated. On chemical analysis, the extract showed high phenolics content and the chromatogram showed 4-O-caffeoylquinic acid as the major component. The extract presented inhibition in the formation of advanced glycation end products (AGEs) and disaccharidases activity. In OGTT the dose of 300 mg/kg significantly decreased the blood glucose. In diabetic animals, BGAE significantly decreased blood glucose levels, preventing weight loss. In addition, in hypercaloric diet-fed rats, the extract prevented hyperglycemia. Our results suggest that, aqueous extract of B. gardneri has a potential for therapeutic intervention of diabetes.

Efecto de los residuos fibrosos de avena ( Avena sativa ) y caraotas ( Phaseolus vulgaris ) sobre la actividad in vitro de las disacaridasas intestinales en ratas / Effect of the Fibrous Residues of Avena (Avena sativa) and Black Beans (Phaseolus vulgaris) on the in vitro Activity of Intestinal Disacaridases in Rats

Resumen Antecedentes: las disacaridasas intestinales pueden ser inhibidas o estimuladas parcialmente en presencia de fibra. Objetivo: evaluar el efecto de los residuos fibrosos de avena (Avena sativa) y caraotas (Phaseolus vulgaris) sobre la actividad in vitro de las disacaridasas intestinales. Materiales y métodos: 15 ratas Sprague Dawley se dividieron en tres grupos: un grupo control, un grupo alimentado con harina de caraota y un grupo alimentado con harina de avena, durante 21 días. Se obtuvo un homogeneizado de la mucosa intestinal que fue utilizado para la determinación de la actividad de las disacaridasas por un método enzimático, en presencia de sustrato natural y con la adición de residuos fibrosos de harina de avena y caraotas en concentración de 2,5 % (P/V). Resultados: la mayor actividad enzimática se registró en la región intestinal media para cada enzima (p<0,05). El orden de actividad enzimática en mg glucosa/mg proteína/min fue maltasa (0,149) sacarasa (0,096) y lactasa (0,014) (p<0,05). La maltasa fue inhibida en mayor medida por el residuo de caraota; la sacarasa, por el residuo de avena; y la lactasa, por ambos. Conclusiones: la adición de fibra purificada de avena y caraota produjo una disminución significativa de la actividad in vitro de las disacaridasas intestinales, especialmente en presencia del residuo de caraota.

Abstract Background: Intestinal disaccharidases can be partially inhibited or stimulated in the presence of fiber. Objective: To evaluate the effect of fibrous residues of oats (Avena sativa) and black beans (Phaseolus vulgaris) on the "in vitro" activity of the intestinal disaccharidases. Materials and Methods: 15 Sprague Dawley rats, were divided into three groups: control, fed with bean flour, and fed with oatmeal flour for 21 days. Homogenate was obtained by scraping the mucosa. The determination of enzymatic activity of the disaccharidases was measured by the enzymatic method, in the presence of its natural substrate and with addition of the fibrous residues obtained from the oatmeal and black beans, in concentration of 2.5 % (W/V). Results: The highest enzymatic activity was recorded in the middle intestinal region for each enzyme (p <0.05). The order of enzymatic activity in mg glucose / mg protein / min was maltase (0.149) sucrase (0.096) and lactase (0.014) (p<0.05). Maltase was inhibited to a greater extent by bean residue; sucrase by oat residue and lactase by both. Conclusion: The addition of purified fiber of oats and bean produced a significant decrease in the in vitro activity of the intestinal disaccharidases, especially in the presence of the bean residue.

Antihyperglycemic activities of twig extract of indigenous cinnamon (Cinnamomum osmophloeum) on high-fat diet and streptozotocin-induced hyperglycemic rats.

BACKGROUND: Cinnamomum osmophloeum (indigenous cinnamon) is an endemic species in Taiwan and its twigs contain abundant A-type proanthocyanidins. C. osmophloeum twig extracts (CoTEs) were found to have α-glucosidase and α-amylase inhibitory activities in vitro. The aim of this study is to further investigate the antihyperglycemic activity of CoTEs in hyperglycemic rats. RESULTS: Hyperglycemic rats were divided into three groups and were treated orally with high-dosage CoTEs (HCO, 150 mg kg-1 ), low-dosage CoTEs (LCO, 30 mg kg-1 ) and positive control (PC, 30 mg kg-1 pioglitazone). The HCO group showed improved glucose tolerance in an oral glucose tolerance test after 1 month of treatment, contributed by the inhibition of intestinal disaccharidases, amylase, and lipase. Compared with the PC group, both the HCO and LCO groups had decreased weight of visceral fats and lower atherogenic index; while their low-density lipoprotein-cholesterol, food intake, feed efficiency, and biochemical parameters remained unchanged compared with the NC group. Furthermore, the HCO group had decreased weight gain and the LCO group had decreased serum leptin level. CONCLUSION: These results suggest that CoTE has potential antihyperglycemic activities for treating hyperglycemia without weight gain. © 2018 Society of Chemical Industry.

Mechanism of action of camphoryl-benzene sulfonamide derivative on glucose uptake in adipose tissue.

The aim of the present study was to investigate the mechanism of action of a sulfonamide derivative on glucose uptake in adipose tissue, as well as to characterize the effects of this compound on intestinal disaccharidases and advanced glycation end-products (AGEs) formation. Camphoryl-benzene sulfonamide (CS) was able to stimulate glucose uptake in isolated adipocytes, adipose tissue, and in soleus muscle. The stimulatory effect of the compound (10 µM) on glucose uptake on adipose tissue was blocked by diazoxide, wortmannin, U73122, colchicine, and N-ethylmaleimide. On the other hand, the effects of CS were not blocked by glibenclamide, an inhibitor of the K+ -ATP channel, or even by the inhibitor of protein p38 MAPK, SB 203580. In vivo, this compound reduced intestinal disaccharidase activity, while, in vitro, CS reduced the formation of AGEs at 7, 14, and 28 days of incubation. The stimulatory effect of CS on glucose uptake requires the activation of the K+ -ATP channel, translocation, and fusion of GLUT4 vesicles to the plasma membrane on adipocytes for glucose homeostasis. In addition, the inhibition of disaccharidase activity contributes to the glucose homeostasis in a short-term as well as the remarkable reduction in AGE formation indicates that the CS may prevent of complications of late diabetes.

Characterization of Mucosal Disaccharidases from Human Intestine.

In this study, we used a brush border membrane (BBM) preparation from human small intestine to analyze the proportion and the activity of major intestinal disaccharidases, including sucrase-isomaltase (SI), maltase-glucoamylase (MGAM) and lactase-phlorizin hydrolase (LPH). SI, MGAM and LPH respectively constituted 8.2%, 2.7% and 1.4% of total BBM protein. The activity of SI and LPH decreased threefold after purification from the brush border membrane, which highlights the effect of membrane microdomains on the functional capacity of these enzymes. All of the disaccharidases showed optimal activity at pH 6, over 50% residual activity between pH 5 to pH 7, and increasing activity with rising temperatures up to 45 °C, along with a stable functional structure. Therefore the enzymes can withstand mild intraluminal pH alterations with adequate function, and are able to increase their activity with elevated core body temperature. Our data provide a functional measure for characterization of intestinal disaccharidases under different physiological and pathological conditions.

Modulatory effects of Caralluma fimbriata extract against high-fat diet induced abnormalities in carbohydrate metabolism in Wistar rats.

The present study was aimed to evaluate the modulatory effects of hydroalcoholic extract of Caralluma fimbriata (CFE) by assaying the activities of key enzymes of carbohydrate metabolism and changes in glycogen content (liver and muscle) in high-fat (HF) diet-induced diabetic rats. In vitro glucose uptake studies were carried out in both psoas muscle and adipose tissue. The inhibitory effect of the extract on α-amylase was determined in in vitro studies. Male Wistar rats of body weight around 180g were divided into five groups (n=8), two of these groups were fed with standard pellet diet and the other three groups were fed with HF- (60%) diet. CFE (200mg/kg body weight/day) was administered through oral route to each group of standard pellet diet rats and HF-fed rats and Metformin (Met) (20mg/kg body weight/day) was administered through oral route to HFD+Met group for 90 days. At the end of the experimental period, biochemical parameters related to glycogen content in liver and muscle, and intestinal disaccharidases like maltase, sucrase and lactase were assayed. Alterations in the activities of enzymes of glucose metabolism (hexokinase, phosphorfructoki nase, pyruvate kinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and glucose-6-phosphate dehydrogenase), intestinal disaccharidases and glycogen content as observed in the high fat diet-fed rats were prevented with CFE/Met administration. From this study, we observed that CFE/Met could significantly restore the levels of glycogen in liver and muscle and key enzymes of carbohydrate metabolism to near normal in groups-HFD+CFE and HFD+Met. The skeletal muscle of HF-diet fed rats showed degenerative changes of muscle myofibers with fat deposition. These changes were attenuated in the HFD group treated with CFE/Met and retained their normal structure appearance. It can be concluded from these results that CFE might be of value in reducing the alterations related to carbohydrate metabolism under high calorie diet consumption.

Disaccharidase Deficiencies in Children With Chronic Abdominal Pain.

OBJECTIVES: Carbohydrate intolerance or malabsorption has been suggested as a cause of chronic abdominal pain (CAP) in a subset of patients. We aimed to evaluate disaccharidase deficiencies in children with functional CAP and to correlate deficiencies with clinical features. METHOD: Patients presenting to the gastroenterology clinic at Children's Hospital of Wisconsin with abdominal pain prospectively completed a detailed demographic, history, and symptom questionnaire. The CAP cohort included those with at least 1 month of symptoms. Data on disaccharidase activity and histology of endoscopic biopsies were collected retrospectively. Only patients with normal histology were included in the study. The association between groups with low disaccharidases and clinical features was examined. RESULTS: A total of 203 pediatric patients with CAP were included. The mean (SD) age was 11.5 (3.1) years, and 32.5% were male. The percentages of abnormally low disaccharidase levels using the standard laboratory cutoffs were lactase, 37%; sucrase, 21%; glucoamylase, 25%; and palatinase, 8%. Thirty-nine percent of the patients with low lactase also had low sucrase, and 67% of the patients with low sucrase had low lactase. There was no significant difference in the activities of any of the disaccharidases or sucrase/lactase ratio in relation to age. Also, no association was found between stool consistency, stool frequency, or location of pain and low disaccharidase activity. CONCLUSIONS: A large proportion of patients with CAP have deficiencies in disaccharidases. Bowel frequency, vomiting, or location of pain was no different between groups, suggesting that these clinical features cannot be used to predict disaccharidase deficiencies.

Antioxidant activity, antibacterial and inhibitory effect of intestinal disaccharidases of extracts obtained from Eugenia uniflora L. Seeds

Abstract The use of medicinal plants for disease prevention, treatment and cure is an ancient practice used by humanity, and many plants species are used in bioprospecting research. In this context, its stands out Eugenia uniflora L., populary known as pitangueira and belongs to the Myrtaceae family, with a wide geographic distribution and native of Brazil. In view of the therapeutic qualities of the plant and the lack of the studies on its seeds, the present study had as objective to evaluate the phytochemical profile of the extracts of Eugenia uniflora L. seeds, from different solvents, as well as their antibacterial activity, antioxidant and its inhibitory effect of intestinal disaccharidases. Results showed a high content of phenolic compounds and total flavonoids, thus characterizing antioxidant activity, also highlighting the best bacteriostatic action for the Gram positive strain of Staphylococcus aureus in the ethanolic fraction. Regarding the disaccharidases, a strong inhibitory action was observed for all concentrations, evidencing a antihyperglycemic potential. The present research allowed to concluded that Eugenia uniflora L. seeds have promising biological activities for the industrial sector, but a more detailed investigation is needed regarding their bioactive compounds.

Resumo A utilização de plantas com fins medicinais para prevenção, tratamento e cura de doenças é uma prática antiga utilizada pela humanidade, sendo que muitas espécies vegetais são usadas para a pesquisa da bioprospecção. Neste contexto, destaca-se a Eugenia uniflora L., conhecida popularmente como pitangueira e pertencente à família Myrtaceae, com ampla distribuição geográfica e nativa do Brasil. Diante das qualidades terapêuticas da planta e a falta de estudos sobre suas sementes, o presente trabalho teve como objetivo avaliar o perfil fitoquímico dos extratos das sementes de Eugenia uniflora L. a partir de diferentes solventes, bem como sua atividade antibacteriana, antioxidante e seu efeito inibidor de dissacaridases intestinais. Os resultados mostraram um alto teor de compostos fenólicos e flavonóides totais, caracterizando a atividade antioxidante, destacando também a melhor ação bacteriostática para a cepa Gram positiva de Staphylococcus aureus na fração etanólica. Em relação às dissacaridases, uma forte ação inibitória foi observada para todas as concentrações, evidenciando um potencial anti-hiperglicêmico. A presente pesquisa permitiu concluir que as sementes de Eugenia uniflora L. apresentam atividades biológicas promissoras para o setor industrial, mas é necessária uma investigação mais detalhada de seus compostos bioativos.

Acetonic Extract from the Feijoa sellowiana Berg. Fruit Exerts Antioxidant Properties and Modulates Disaccharidases Activities in Human Intestinal Epithelial Cells.

Feijoa sellowiana fruit has been shown to possess various biological activities, such as anti-bacterial and anti-cancer properties, in a variety of cellular models, but its activity on human intestinal epithelial cells has never been tested. The purpose of this study was to investigate the effects of the acetonic extract of F. sellowiana fruits on the viability, membrane peroxidation, disaccharidases activities and proliferation of in vitro models of human intestinal epithelial cells. To obtain this goal, Caco-2 and HT-29 cells were exposed to the acetonic extract for 24 h. Cell proliferation, viability, lactase and sucrase-isomaltase activity and H2 O2 -induced membrane lipid peroxidation were tested. We found that, compared to control conditions, the acetonic extract significantly increased lactase and sucrase-isomaltase activity in Caco-2, but not HT-29, cells, decreased proliferation, had no effects on viability and restored lipid peroxidation in both cell models. This study suggests that the acetonic extract improves lactase and sucrase-isomaltase activity, inhibits cell proliferation, have no cytotoxic effects and prevent lipid peroxidation of intestinal epithelial cells. These effects may be exploited in case of disaccharidases deficit and also as an adjuvant treatment of diseases related to oxidative stress. Copyright © 2016 John Wiley & Sons, Ltd.

Incretinomimetic and Insulinomimetic Effect of (2E)-N'-(1'-Naphthyl)-3,4,5-Trimethoxybenzohydrazide for Glycemic Homeostasis.

To characterize the role and the mechanism of action of (2E)-N'-(1'-naphthyl)-3,4,5-trimethoxybenzohydrazide (BZD) on incretin secretion, glucose uptake in skeletal muscle and α-glucosidase activity on intestine, targets for glucose homeostasis. It was assayed on glucose tolerance test (GTT) to analyze GLP-1 secretion and the activity of DPP-4 enzyme in vitro. In skeletal muscle, mechanism of action on glucose uptake was carried out by in vitro experiments. The activity of intestinal disaccharidases was performed after in vivo and in vitro experiments. The compound improved the glucose tolerance around 30%, 25%, and 20% at 15, 30, and 60 min, respectively and potentiated the sitagliptin effect, an inhibitor of the enzyme that removes GLP-1, about 50, 45, and 54% at 15, 30, and 60 min, respectively. Additionally, BZD did not modify the activity of DPP-4 enzyme. The acute effect of BZD on glucose uptake is mediated by increasing GLUT4 expression (around 140%) and its translocation to the plasma membrane in soleus muscle. The genomic effect as well as GLUT4 translocation involve the activation of PI-3K and MAPK pathways and require the microtubules integrity to the complete stimulatory effect of this compound on glucose uptake. Beyond, BZD acts in an alternative target to ameliorate glycaemia, intestinal disaccharidases. In a whole, these data point an incretino- and insulinomimetic effect of the compound for glycemic control.

Exacerbation of intestinal brush border enzyme activities and oxidative stress in streptozotocin-induced diabetic rats by monocrotophos.

The present study was undertaken to investigate the potential of monocrotophos (MCP), one of the widely used broad spectrum systemic organophosphorus insecticides (OPI) in India, to alter small intestinal structure and function. Further, its potential to exacerbate diabetes induced alterations in intestinal structure and function was also studied in experimentally induced diabetic rats. Rats were rendered diabetic with an acute dose of streptozotocin (60 mg/kg b.w.). MCP was orally administered at a sublethal dose (1/20 LD50 i.e. 0.9 mg/kg b.w./d) for 15 days to both normal and diabetic rats. MCP significantly increased unit weight of intestine in diabetic rats. MCP alone increased (up to 57%) the activities of intestinal brush border disaccharidases in normal rats and further augmented the enzyme activities in diabetic rats. Similar results were found with intestinal alkaline phosphatase activity. In addition, Na(+)/K(+)-ATPase activity was found to be aggravated in diabetic rats by MCP treatment. Oxidative stress markers showed similar degree of change in both MCP and diabetic rats while MCP aggravated oxidative stress condition in diabetic rats. Scanning electron microscopy and histological analysis of the small intestine revealed increased length of villi, congestion, goblet cell hyperplasia and infiltration of inflammatory cells in MCP and diabetic rats while MCP also induced necrotic lesions in diabetic rats. Collectively, our findings provide evidence that multiple doses of MCP has the propensity to augment diabetes associated intestinal dysfunctions in rats.

Effect of dietary supplementation with an ethanolic extract of propolis on broiler intestinal morphology and digestive enzyme activity.

The present study aimed to evaluate the effect of different levels of an ethanolic extract of propolis (EEP) on broiler performance, carcass characteristics, weight of gastrointestinal organs, intestinal morphometry and digestive enzyme activity. 1020 male broiler chicks were assigned in a completely randomised experimental design to six treatments (EEP supplement levels of 0, 1000, 2000, 3000, 4000 and 5000 ppm) and five replications, and 34 birds per experimental unit. The experimental diets were administered from 1 to 21 days of age, and the birds were subsequently provided a ration based on corn and soybean meal. EEP supplementation from 1 to 7 days negatively affected (p < 0.05) the weight gain and feed intake. The proventriculus weight at 7 days exhibited a quadratic response (p < 0.05), which predicted a lower weight at a dose of 2865 ppm of the EEP. For the duodenum at 21 days of age, the response pattern (p < 0.05) predicted that birds that were fed 2943 and 3047 ppm of the EEP would exhibit an improved crypt depth and villus-to-crypt ratio respectively. The villus height, crypt depth and villus-to-crypt ratio in the jejunum and the ileum were not affected (p > 0.05). With increased EEP doses, the duodenal sucrase activity linearly decreased at 7 days of age and linearly increased in the jejunum at 21 days of age (p < 0.05), while pancreatic enzyme activity was unaffected (p > 0.05). Although the carcass and cut yields did not improve, the percentage of abdominal fat decreased (p < 0.05). The supplementation of the broiler pre-starter diet with 1000-5000 ppm of the EEP impaired performance at this stage, most likely due to the decreased sucrase activity. However, the EEP supplementation from 3000 ppm improved intestinal morphophysiology at 21 days of age and did not affect the performance or carcass yield at 42 days of age.