An acidic glycoconjugate from Lythrum salicaria L. with controversial effects on haemostasis

Aim of the studyLythrum salicaria L. belongs to the small Lythraceae family of 22 genera, which range in habit from herbs to shrubs and trees found with worldwide distribution ( Heywood, 1993). The generic name of Lythrum derived from Greek “luthron”—blood, possibly referring to the color of the flowers or to the one of its herbal use as an astringent to stop bleeding ( Thompson et al., 1987, Mountain, 1994 and Pawlaczyk and Pacula, 2002). The flowering parts and the flowering branch tips are used in traditional medicine and pharmaceuticals internally in a form of decoctions or as extracts for treatment of diarrhea, chronic intestinal catarrhs, hemorrhoids and eczema, or externally to treat varicose veins, venous insufficiency and gums ( Mantle et al., 2000 and Rauha et al., 2000). The aim of this study was to isolate the plant glycoconjugate from flowering parts of Lythrum salicaria, and to verify its influence on blood coagulation process.Materials and methodsFrom the air-dried flowering parts of this plant a water-soluble glycoconjugate has been isolated by hot alkaline extraction followed by neutralization and purification by multi-steps extraction with organic solvents, dialysis and concentration. The plant isolate was tested in vitro on anticoagulant activity on human plasma, and on Wistar rats blood system in vivo as well as ex vivo.ResultsA dark brown isolate was obtained in the yield of 8% of starting material (w/w) as a macromolecular compound with Mw ∼ 12,500. Chemical analysis revealed the presence of carbohydrates (30%), phenolics (1 g contained 1.2 mM of gallic acid equivalent) and proteins (0.8%). The result of compositional analyses of carbohydrate part revealed the predominance of uronic acids (∼66%), galactose (∼12%), rhamnose (∼10%) and arabinose (∼9%) residues indicating thus the presence of pectic type of polymers, i.e. galacturonan and/or rhamnogalacturonan associated with arabinogalactan in Lythrum glycoconjugate. In vitro and ex vivo experiments showed complete inhibition of plasma clot formation, however, the application of Lythrum glycoconjugate in vivo showed controversial effect on animal blood system in comparison with in vitro ones, i.e. pro-coagulant activity.ConclusionThe in vivo results give a scientific explanation for the traditional use of Lythrum salicaria as a styptic agent. It seems that pro-coagulant activity of this complex could be probably connected with the other factors in blood circulation system, like platelets.

The generic name of Lythrum derived from Greek “luthron”—blood, possibly referring to the color of flowers or to its herbal use as an astringent to stop bleeding. The polyphenolic glycoconjugate from Lythrum salicaria showed controversial effects on coagulation process.Figure optionsDownload as PowerPoint slide