Screening of an Armillaria gallica strain for Gastrodia elata cultivation / 中国中药杂志

This study aims to screen a strain from Armillaria for the cultivation of Gastrodia elata. Specifically, Armillaria strains were isolated from different producing areas of G. elata and identified. Based on the growth characteristics of the strains and the experiment on the cultivation of G. elata, an optimal A. gallica strain was screened out. The specific process is as follows. The fungus-gro-wing materials of G. elata were collected from four producing areas and the Armillaria strains were isolated(G,Y,S,H). The strains were then identified based on morphological observation and phylogeny analysis and the commonly used strains were determined. The sucrase genotypes of the strains were identified according to our previous research findings, and the growth characteristics of the strains, such as growth rate, diameter, dry weight, and polysaccharide content of the rhizomorphs, were measured. According to the biological characteristics and sucrase genotypes, two strains were selected for the cultivation of G. elata. The tuber yield and the content of gastrodin and p-hydroxybenzyl alcohol in the tuber of G. elata were measured to select the optimal strain. The results showed that the four strains were all A. gallica. The rhizomorphs of strains G and H of the same sucrase genotype had larger/higher length, growth rate, diameter, branch number, dry weight, and polysaccharide content than those of strains S and Y of the same sucrase genotype. The tuber yield and the total content of gastrodin and p-hydroxybenzyl alcohol in tuber of G. elata cultivated with strain H were 6.528 kg·m~(-2) and 0.566%, respectively, which were 4.58 and 1.30 folds those of G. elata cultivated with strain S. Strains H and S were screened out from four strains of A. gallica based on the growth characteristics and sucrase genotype. According to the tuber yield and content of total gastrodin and p-hydroxybenzyl alcohol in the tuber of G. elata, strain H was identified as the optimal one. The findings in this study are expected to lay a basis for cultivating G. elata with high yield and quality of tubers.

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.

Preparation,stability and in vitro activity of egg yolk immunoglobulin Y against human Sucrase / 中国免疫学杂志

Objective:To prepare the egg yolk immunoglobulin Y ( IgY) against human Sucrase and study its stability,in vitro activity. Methods:Hy-line laying hens were immunized with human Sucrase protein,IgY was isolated and purified from egg yolks of im-munized hens using water dilution and salting out method. Indirect ELISA was used to evaluate the titer and stability of IgY. The purity and specificity of IgY were analysed by SDS-PAGE and Western blot respectively. The inhibitory effects of IgY on α-glucosidase was studied by PNPG method. Results:Indirect ELISA results showed IgY could be detected on the tenth day after the first immunization, and the peak titer of IgY was 1:12 800 after the 40th day of immunization. SDS-PAGE showed that the heavy chain and light chain of IgY were 65 kD and 25 kD respectively, and the IgY against human Sucrase could specifically recognize the protein of human Sucrase. The IgY maintained primary titer when it was kept between 29-69℃ for 15 min,and pH 4-7,37℃,4 h. The titer of IgY was maintained 50% after digestion by pepsin and trypsin respectively for 2 hours. IgY had a higher resistence to pepsin than trypsin after longer digestion time. IgY showed an inhibitory effect on α-glucosidase in concentration dependent manner. The half inhibitory concentration (IC50) was 0. 540 mg/ml. Conclusion:The IgY against human Sucrase has been successfully obtained,which established foundations for its study of Type 2 diabetes mellitus rat models in vivo.

Coconut-derived D-xylose affects postprandial glucose and insulin responses in healthy individuals

Metabolic alterations including postprandial hyperglycemia have been implicated in the development of obesity-related diseases. Xylose is a sucrase inhibitor suggested to suppress the postprandial glucose surge. The objectives of this study were to assess the inhibitory effects of two different concentrations of xylose on postprandial glucose and insulin responses and to evaluate its efficacy in the presence of other macronutrients. Randomized double-blind cross-over studies were conducted to examine the effect of D-xylose on postprandial glucose and insulin response following the oral glucose tolerance test (OGTT). In study 1, the overnight-fasted study subjects (n = 49) consumed a test sucrose solution (50 g sucrose in 130 ml water) containing 0, 5, or 7.5 g D-xylose powder. In study 2, the overnight-fasted study subjects (n = 50) consumed a test meal (50 g sucrose in a 60 g muffin and 200 ml sucrose-containing solution). The control meal provided 64.5 g of carbohydrates, 4.5 g of fat, and 10 g of protein. The xylose meal was identical to the control meal except 5 g of xylose was added to the muffin mix. In study 1, the 5 g xylose-containing solutions exhibited significantly lower area under the glucose curve (AUCg) and area under the insulin curve (AUCi) values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P < 0.0001), 0-60 min (P < 0.0001, P < 0.0001), 0-90 min (P < 0.0001, P < 0.0001) and 0-120 min (P = 0.0071, P = 0.0016). In study 2, the test meal exhibited significantly lower AUCg and AUCi values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P = 0.0005), 0-60 min (P = 0.0002, P = 0.0025), and 0-90 min (P = 0.0396, P = 0.0246). In conclusion, xylose showed an acute suppressive effect on the postprandial glucose and insulin surges.

Triple sugar screen breath hydrogen test for sugar intolerance in children with functional abdominal symptoms.

Background Sugar intolerance and functional gastrointestinal disorders are both common in school age children. Both may present with similar complaints such as abdominal pain, diarrhea and bloating. Lactose, fructose and sucrose hydrogen breath tests are widely used to detect sugar malabsorption. Aim To determine the proportion of children with symptoms of functional gastrointestinal disorders (FGID) that have sugar intolerance as determined by using a breath hydrogen test. Methods We prospectively enrolled subjects with chronic abdominal pain, bloating and/or chronic diarrhea. All subjects underwent triple sugar screen hydrogen breath test (TSST) using the combined sugar solution. Breath hydrogen concentration ≥20 ppm above baseline was interpreted a positive test for sugar malabsorption. Results A positive hydrogen breath test consistent with sugar malabsorption was found in 5 out of 31 (16%) subjects. Three of these subjects were confirmed to have lactose malabsorption based on small bowel lactase enzyme analysis or subsequent lactose hydrogen breath test. One subject with positive TSST was diagnosed with fructose malabsorption based on dietary history; he improved on a limited fructose diet, and one was diagnosed to have gastric Crohn’s disease. Conclusion Approximately one in six children with symptoms of FGID had sugar intolerance as determined by the TSST.

Antidiabetic activity and mechanisms of acarbose in KKAy mice

To elucidate antidiabetic effect and mechanism(s) of acarbose in a polygenic spontaneous hyperglycemic and hyperinsulinemic diabetic animal model, KKAy mice, acarbose was administered orally for 4 weeks and effects on body weight, plasma glucose and insulin levels, genetic expressions of intestinal sucrase-isomaltase (SI), sodium-glucose cotransporter (sGLT1) and glucose transporter in quadriceps muscle (GLUT4) were examined in this study. Although no differences in body weight were detected between control and acarbose-treated groups, plasma glucose level in acarbose-treated group was markedly reduced as compared to the control. In the mechanism study, acarbose downregulated the SI and SGLT1 gene expressions, and upregulated the GLUT4 mRNA and protein expressions when compared to the control group. In conclusion, the data obtained strongly implicate that acarbose can prevent the hyperglycemia in KKAy mice possibly through blocking intestinal glucose absorption by downregulations of SI and sGLT1 mRNA expressions, and upregulation of skeletal muscle GLUT4 mRNA and protein expressions.