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Therapeutic Potential of Anthocyanin Against Diabetes
Published in Hafiz Ansar Rasul Suleria, Megh R. Goyal, Health Benefits of Secondary Phytocompounds from Plant and Marine Sources, 2021
Tawheed Amin, H. R. Naik, Bazila Naseer, Syed Zameer Hussain
Digestion of carbohydrates inside our body occurs in a successive way with α-amylase acting initially on starch trailed by α-glucosidase to produce dietary glucose. Once the food is ingested, starch is acted upon by α-amylases (both salivary and pancreatic) and four small intestinal mucosal α-glucosidase subunits [57], and at an inner α-1,4 glucosidic linkages via an endo mechanism thereby producing linear and branched maltooligosaccharides [55]. Maltase-glucoamylase and sucrose-isomaltase (the two membrane-bound protein complexes), and mucosal α-glucosidases are exo-type starch hydrolyzing enzymes [65, 68] that produce glucose by hydrolyzingα-1,4 glucosidic linkages opposite to the reducing end of dextrins already degraded by α-amylase [6, 27, 29]. Apart from illustrious maltase activity, the C-terminal subunit (maltase-glucoamylase) is named as isomaltase because of its action on long-chain oligomers [54] whereas the N-terminal subunit (sucrose isomaltase) is named as isomaltase because of its debranching activity [28].
Fetal and Postnatal Development of the Small and Large Intestine
Published in Jean Morisset, Travis E. Solomon, Growth of the Gastrointestinal Tract: Gastrointestinal Hormones and Growth Factors, 2017
Ménard Daniel, Calvert Raymond
The neonatal rodent small intestine is mainly characterized by the presence of high lactase activity and the absence of sucrase.8 Indeed, lactase, which hydrolyzes milk lactose and is already detectable in late fetal life, attains maximal activity during the first 2 weeks after birth and then declines, reaching adult values by the end of the fourth week. On the other hand, sucrase activity is undetectable during the first 2 weeks, but appears on approximately day 15 and rises rapidly, reaching adult levels by the end of the fourth week. Maltase, glucoamylase, and trehalase have low activities during the first 2 weeks, then undergo a substantial increase during the next 2 weeks. These enzymatic modifications are correlated with quantitative changes in the protein bands of brush border microvillus membranes as studied by gel electrophoresis.
Inhibiting the Absorption of Dietary Carbohydrates and Fats with Natural Products
Published in Christophe Wiart, Medicinal Plants in Asia for Metabolic Syndrome, 2017
Degradation products of starch are hydrolyzed in the jejunum into free absorbable glucose by 4 brush border α-glucosidases arranged into 2 enzymatic complexes termed as sucrase–isomaltase and maltase–glucoamylase.22 Members of the family Menispermaceae often accumulate isoquinoline alkaloids that hamper glucose absorption by inhibiting enterocyte membrane bound α-glucosidases. As an example, Tinospora crispa (L.) Hook. f. & Thomson synthetize palmatine, jatrorrhizine, and magnoflorine that inhibited the enzymatic activity of sucrase with IC50 of 36.2, 23.4, and 9.8 μg/mL, respectively.23 In the same experiment, palmatine, jatrorrhizine, and magnoflorine inhibited the enzymatic activity of maltase with IC50 values equal to 22, 38.4, and 7.6 μg/mL.23 Magnoflorine at a dose of 20 mg/kg mitigated the raise in glycaemia induced by oral administration of 2 g/kg of glucose to rodents.23 Magnoflorine is known to induce hypotension when parenterally administered and to be nontoxic in animals when given orally.24
Discovery of differentially expressed genes in the intestines of Pelteobagrus vachellii within a light/dark cycle
Published in Chronobiology International, 2020
Chuanjie Qin, Jiaxian Sun, Jun Wang, Yongwang Han, He Yang, Qingchao Shi, Yunyun Lv, Peng Hu
The rodent facilitated fructose transporters GLUT, GLUT2, and GLUT5, and the Na-glucose transporter SGLT1, display peak expression at night, and in clock mutant mice (Fatima et al. 2009), however, these nutrient transporters lost their circadian rhythms (Pan and Hussain 2009). Similarly, nile tilapia (Oreochromis niloticus) plasma glucose levels showed a daily rhythm, with the achrophase shifted by 12 h when fed once a day at 11:00 h and at 23:00 h (Guerra-Santos et al. 2016). In the gilthead seabream (Sparus aurata), increased amylase activity was observed a few hours before mealtime with periodic feeding (Montoya et al. 2010). These studies suggested that the transport of glucose in the intestines is regulated rhythmically. In the present study, the maltase-glucoamylase, sucrase-isomaltase, showed regulated expression during the night. Similarly, amylase activity also showed a daily rhythm in the mid-intestines of European sea bass (Dicentrarchus labrax) (del Pozo et al. 2012), and the amylase of tambaqui (Colossoma macropomum) showed a clear daily rhythm when fed at midday or midnight (Silva Reis et al. 2019); however, activity peaked at night. Moreover, similar to rodents, the genes encoding sodium/glucose cotransporters 1 and 4, facilitated glucose transporter member 6-like, and facilitated glucose transporter member 11 showed regulated expression at night. The upregulated expression of these genes suggested that more glucose might be transported from lumen into the blood at night.
Anti-hyperglycemic and genotoxic studies of 1-O-methyl chrysophanol, a new anthraquinone isolated from Amycolatopsis thermoflava strain SFMA-103
Published in Drug and Chemical Toxicology, 2021
Cheemalamarri Chandrasekhar, Hemshikha Rajpurohit, Kalpana Javaji, Madhusudana Kuncha, Aravind Setti, A. Zehra Ali, Ashok K. Tiwari, Sunil Misra, C. Ganesh Kumar
Post-prandial hyperglycemia could be cured by decreasing glucose levels in the blood. Enzymes including α-amylase and α-glucosidase which helps in stimulating the breakdown of carbohydrate dietary substrates and lowering the intestinal absorption of glucose. α-amylase present in saliva and pancreas helps in hydrolyzing α-1→4 linkages present in starch into various oligosaccharides such as maltose, maltotriose, and α-dextrins. These products are converted by a combination of different exohydrolases: maltase-glucoamylase and sucrose-isomaltase present in the intestinal brush border (Dhital et al.2017). α-glucosidases (glucoamylase, dextrinase, maltase, and sucrase) present on the brush border of intestines acts at the terminal end of oligosaccharides to release glucose which further gets absorbed into intestine elevating the blood glucose levels. Dihydroxyanthraquinones were earlier reported to form hydrogen bonds with amino acid residues present in quinone binding site of maltase-glucoamylase enzyme which is one of the prominent intestinal brush border enzymes (Arvindekar et al.2015). In the present study, OMC which is structurally similar to chrysophanol was evaluated for its anti-hyperglycemic activity. Initially, in silico studies were carried out to understand the amino acid residue interactions of both α-amylase and α-glucosidase with OMC and establish the binding energy values in comparison with acarbose as standard. OMC exhibited relatively high binding energy and less stable interaction when compared to acarbose. In fact, acarbose (645.6 g/mol) contains 9 torsional bonds and is a highly polar molecule; while OMC (268.26 g/mol) contains only one torsional bond and is a moderately polar molecule. Since, the molecular weight, torsions, and presence of polar groups are deemed less in OMC, it produced high binding energy as revealed through docking experiments. In addition, both acarbose and OMC interacted efficiently with α-amylase because of the higher number of hydrogen bonds or contribution due to steric interaction in the active site of the protein-ligand complex. Based on promising molecular docking results, enzyme inhibition assays were performed with OMC where the results showed moderate inhibition of OMC against both α-amylase and α-glucosidase. Considering this fact, starch tolerance test was performed in Wistar rats with acarbose as standard. Glucose lowering efficacy of OMC exhibited 100 mg/kg as compared to starch control (Figure 3). These results corroborated with the reports on glucose transport assay conducted in L6 rat myoblasts (CRL-1458TM) by chrysophanol that showed mild anti-diabetic effect (Lee and Sohn 2008).