Chebulagic acid, isolated form Terminalia chebula Retz, proved to be a reversible and non-competitive inhibitor of maltase with a K(i) value of 6.6 muM. The inhibitory influence of chebulagic acid on the maltase-glucoamylase complex was more potent than on the sucrase-isomaltase complex. The magnitude of alpha-glucosidase inhibition by chebulagic acid was greatly affected by its origin. These results show a use for chebulagic acid in managing type-2 diabetes.
Journal of Enzyme Inhibition and Medicinal Chemistry
Terminalia chebula fruit extracts were prepared sequentially with hexane, ethyl acetate, methanol and methanol-water (70:30) and tested for their ?-glucosidase inhibitory and antioxidant potential. The study resulted in the formulation of an extract with high ?-glucosidase inhibitory potential (IC(50) 0.19 ± 0.03 µg mL(-1)) enriched with hydrolysable tannins.
Nine hydrolyzable tannins, including three previously unknown and six artifacts, were isolated, together with thirty-nine known ones, from the fruits of Terminalia chebula Retz. (Combretaceae). They were identified as 1,2,3-tri-O-galloyl-6-O-cinnamoyl-?-d-glucose, 1,2,3,6-tetra-O-galloyl-4-O-cinnamoyl-?-d-glucose, 4-O-(2?,4?-di-O-galloyl-?-l-rhamnosyl)ellagic acid, 1'-O-methyl neochebulanin, dimethyl neochebulinate, 6'-O-methyl neochebulagate, dimethyl neochebulagate, dimethyl 4'-epi-neochebulagate, and methyl chebulagate by the spectroscopic interpretation.
A potent natural alpha-glucosidase inhibitor called kotalanol has been isolated from an antidiabetic traditional Ayurvedic medicine, the roots and stems of Salacia reticulata Wight, through bioassay-guided separation. The structure of kotalanol was elucidated on the basis of chemical and physicochemical evidence to be the inner salt comprised of 1-deoxyheptosyl-3-sulfate anion and 1-deoxy-4-thio-D-arabinofuranosyl sulfonium cation. Kotalanol was found to show more potent inhibitory activity against sucrase than salacinol and acarbose.
Hydnocarpus wightiana is advocated in traditional Indian medicine to possess strong antidiabetic activity. In the course of identifying bioactive fractions from Indian medicinal plants we observed that acetone extract of the seed hulls of H. wightiana possess strong free radicals (DPPH and ABTS) scavenging, alpha-glucosidase and moderate N-acetyl-beta-D-glucosaminidase inhibitory activities. Further fractionation of the extract led to the isolation of hydnocarpin, luteolin and isohydnocarpin in substantial yields. All the compounds showed strong ABTS scavenging property.
Formulations of traditional medicines are usually made up of complex mixture of herbs. However, effective quality control methods in order to select right quality materials are lacking. Though Piper longum is a widely used herb in several Ayurvedic formulations prescribed for various diseases, there is no analytical method in the literature so far which can help in selecting the right quality material with proper proportions of the active ingredients (alpha-glucosidase-I enzyme inhibitory principles).
Food and Chemical Toxicology: An International Journal Published for the British Industrial Biological Research Association
Salacia oblonga has been used for thousands of years in Ayurvedic medicine for the oral treatment of diabetes. The root extract has been shown to inhibit the activity of intestinal alpha-glucosidases, therefore S. oblonga holds potential as a natural method to mitigate the blood glucose response for people with diabetes. As part of a safety evaluation of novel ingredients for use in blood glucose control, the potential genotoxicity of a S.