Aqueous extracts and polysaccharides from liquorice roots (Glycyrrhiza glabra L.) inhibit adhesion of Helicobacter pylori to human gastric mucosa.
OBJECTIVE
Aqueous extracts from the roots of Glycyrrhiza glabra L. (Fabaceae) are widely used for treatment of stomach ulcer. The clinical proven effects are related to the presence of anti-inflammatory 12-keto-triterpensaponins in the extracts. Apart from that the influence of Glycyrrhiza glabra extract on the bacterial adhesion of Helicobacter pylori to stomach tissue was to be investigated. Additionally the influence of Glycyrrhiza glabra secondary compounds on the bacterial adhesion of Porphyromonas gingivalis, a major pathogen for induction of periodontal inflammations was to be investigated.


METHODS
In vitro cytotoxicity against Helicobacter pylori was investigated by agar diffusion assay; antiadhesive properties of aqueous extract, raw polysaccharides and purified polysaccharide fractions was investigated by means of an in situ adhesion assay with FITC-labelled bacteria on tissue slides of human stomach resectates.


RESULTS
Aqueous extract (1mg/mL) of Glycyrrhiza glabra significantly inhibited the adhesion of Helicobacter pylori to human stomach tissue. This effect was related to the polysaccharides isolated from the extract, with one purified acidic fraction (0.25 SPB) as main active polymer. Purified polysaccharides did not exhibit direct cytotoxic effects against Helicobacter pylori and did not influence hemagglutination. Additionally raw polysaccharides from Glycyrrhiza glabra were shown to have strong antiadhesive effects against Porphyromonas gingivalis.


CONCLUSIONS
Aqueous extracts and polysaccharides from the roots of Glycyrrhiza glabra are strong antiadhesive systems, which may be used as potent tools for a further development of cytoprotective preparations with anti-infectious potential.
Wittschier
Nicole
N
University of Münster, Institute for Pharmaceutical Biology and Phytochemistry, Hittorfstrasse 56, D-48149 Münster, Germany.
Faller
Gerhard
G
Hensel
A
A
D000143:Acids / Q000302:isolation & purification / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D005753:Gastric Mucosa / Q000187:drug effects*; D006035:Glycyrrhiza / Q000737:chemistry; D016480:Helicobacter pylori / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology*; D016966:Porphyromonas gingivalis / Q000187:drug effects*
D000143:Acids; D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D011134:Polysaccharides