Biologically active polysaccharides as possible lead compounds

Various carbohydrate polymers have during the last decades been shown to be responsible for biological effects, either by exhibiting the effect themselves or by inducing effects via complex reaction cascades. These are e.g. anti-inflammatory, immunostimulating, complement activation, antithrombotic, antidiabetic and infection protectant. Modern pharmaceutical industry has extensive research programs where the aim is to obtain information on traditional use of medicinal plants still being in use, and perform screening of these for the claimed biological activity and follow the isolation of chemical compounds with the relevant activity tests, but few of the programs focus on polysaccharides. Various plants have been used for treating wounds of different types, both internally and externally and bioassay guided isolation of active compounds in these plants showed that in many cases, polysaccharides were responsible for the biological activity. Many of these polysaccharide fractions have been shown to activate complement. The active compounds studied are often of the pectic type, but acetylated glucomannans and glucans are also among those having the same kind of effect and certain structure/activity relationships of these polysaccharides is discussed.