Comparison of Carbohydrate Structures and Immunomodulating Properties of Extracts from Berries and Flowers of Sambucus nigra L.

Abstract

Aims: To investigate if the immunomodulating activity of compounds present in berries and flowers of S. nigra were of the same order, or different, and also if the most active components were of high or low molecular weight nature. Methodology: Defatted material of berries and flowers of S. nigra were extracted with 50% ethanol and with water of 50ºC and 100ºC. High molecular weight fractions were obtained after gel filtration on BioGelP6DG. The different fractions were investigated for their monosaccharide contents and carbohydrate structures. The immunomodulating effects were investigated using a complement fixing assay as well as a system for measuring the production of NO after stimulation of macrophages with the different fractions. Results: All fractions contained substantial amounts of carbohydrates. Removal of low molecular weight material revealed polysaccharide fractions containing monosaccharides typical for pectins and showed enhanced bioactivity. Conclusion: High molecular weight fractions from elderflowers showed higher bioactivity than the equally extracted fractions from elderberries. The 100ºC water flower fraction gave after gel filtration the fraction with the highest activity and with the longest backbone of rhamnogalacturonan I. Based on this; one should encourage the drinking of juice made form flowers in the same way as has been done for the juice made from berries, since both may have a beneficial heath effect.