Document Detail


Glycosylated compounds from okra inhibit adhesion of Helicobacter pylori to human gastric mucosa.
MedLine Citation:
PMID:  15030201     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In Asian medicine the fruit of the okra plant, Abelmoschus esculentus (L.) Moench., is used as a mucilaginous food additive against gastric irritative and inflammative diseases. To find a rational basis for its use against these diseases, several crude and purified carbohydrate-containing fractions from immature okra fruits were isolated and analyzed, and their effects against Helicobacter pylori in an in situ adhesion model on sections of human gastric mucosa were determined. Pretreatment of the bacteria with a fresh juice preparation inhibited the bacterial adhesion almost completely. Lyophilization and reconstitution of an extract solution led to a reduction of this effect. A crude polysaccharide (RPS) isolated from the fresh juice by ethanolic precipitation showed strong inhibitory effects. Further fractionation of RPS revealed a purified, highly acidic subfraction (AF III) with high antiadhesive qualities. Carbohydrate analysis revealed the presence of rhamnogalacturonans with a considerable amount of glucuronic acid, whereas other inactive subfractions contained little glucuronic acid or were glucuronic acid-free. After heat denaturation of the fresh juice or protein precipitation with 5% TCA the antiadhesive activity of the fresh extract was reduced, indicating that besides polysaccharides, protein fractions also exhibited antiadhesive properties. SDS-PAGE analysis of the precipitate revealed several bands of glycosylated proteins between 25 and 37 kDa that were almost diminished in the nonactive supernatant. Preincubations of gastric tissue with any of the active fractions did not lead to reduced bacterial binding. The antiadhesive activity is therefore due to the blocking capacity of specific Helicobacter surface receptors that coordinate the interaction between host and bacterium. Neither of the active fractions showed inhibitory effects on bacterial growth in vitro. The antiadhesive qualities of okra were assumed to be due to a combination of glycoproteins and highly acidic sugar compounds making up a complex three-dimensional structure that is fully developed only in the fresh juice of the fruit.
Authors:
Christian Lengsfeld; Fritz Titgemeyer; Gerhard Faller; Andreas Hensel
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of agricultural and food chemistry     Volume:  52     ISSN:  0021-8561     ISO Abbreviation:  J. Agric. Food Chem.     Publication Date:  2004 Mar 
Date Detail:
Created Date:  2004-03-19     Completed Date:  2004-05-07     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  0374755     Medline TA:  J Agric Food Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1495-503     Citation Subset:  IM    
Affiliation:
Hochschule Wädenswil, Pharmaceutical Biotechnology, Glycopharmacy Research Group, University of Applied Sciences, Box 335, Grüntal, CH-8820 Wädenswil, Switzerland.
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MeSH Terms
Descriptor/Qualifier:
Abelmoschus / chemistry*
Bacterial Adhesion / drug effects*
Carbohydrate Conformation
Carbohydrate Sequence
Carbohydrates / chemistry,  isolation & purification,  pharmacology*
Gastric Mucosa / microbiology*
Glucuronic Acid / analysis
Glycoproteins / analysis,  pharmacology
Glycosylation
Helicobacter pylori / physiology*
Humans
Microscopy, Fluorescence
Molecular Sequence Data
Polysaccharides / analysis,  chemistry
Chemical
Reg. No./Substance:
0/Carbohydrates; 0/Glycoproteins; 0/Polysaccharides; 576-37-4/Glucuronic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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