Analysis of Toxicity and Hemostatic Properties of Polysaccharides from Plants

Abstract

Plants are commonly used throughout the world, most particularly in Africa for different purposes including use as drugs, food and cosmetics. Polysaccharides were extracted from the cell walls of seven plants endemic to Gabon, <em>Uvaria klainei</em>, <em>Petersianthus macrocarpus</em>, <em>Trichoscypha addonii</em>, <em>Aphanocalyx microphyllus</em>, <em>Librevillea kleaneana</em>, <em>Neochevalierodendron stephanii</em> and <em>Scorodophloeus zenkeri</em>. Pectins and hemicelluloses from these plants were extracted using ammonium oxalate and potassium hydroxide and their sugar compositions were determined using gas chromatography. These fractions were used to test their toxicity compared to standard products such as mercuric chloride (HgCl₂), 4-Nitro-quinoloine (4-NOQ), 2-Amino-Anthracene (2AA) and ivermectin. Their anticoagulant capacity was tested by measuring Activated Partial Thromboplastin Time (APTT), prothrombin time (PT/QT) compared to snake venom and the heparin response. The results showed that these extracts had no cytotoxicity since the IC₅₀ of polysaccharide extracts and ivermectin varied from 456.62 to 892.42 &mug/mL compared to standard toxic HgCl, 4-NOQ, 2AA: 1.8-22 &mug/mL. No genotoxicity or pro-genotoxicity was found: the SOS test Inhibiting Factor (IF) from pectins and hemicelluloses varied from 0.4 to 1.2 compared to the standard genotoxic 4-NOQ, with an IF of 9.33. Acute toxicity was not observed, as indicated by the minimum inhibition at 20% (MIC₂₀) that varied from 25.45 to 65.85 for polysaccharides, while the standard toxic level was at a MIC₂₀ of 0.0284. However, <em>in vitro</em> anticoagulant activities were detected. De-esterification and enzyme degradation of the homogalacturonan pectin chains did not change the hemostatic trend of pectic fractions.