Polysaccharides from green and black teas and their protective effect against murine sepsis

Abstract

Polysaccharides from green and black teas were obtained via hot aqueous extraction, and after fractionation, chemical analysis showed that they consisted mainly of a rhamnogalacturonan containing a long sequence of →4)-6-O-Me-α-d-GalpA-(1→, interrupted by α-l-Rhap residues, which were substituted by type II arabinogalactan chains. The polysaccharides were similar, except that black tea contained lesser galacturonic acid residues (35%), when compared with green tea (65%). Starch was present in both teas. The polysaccharides were tested, via oral administration in mice against induced-polymicrobial sepsis, at doses of 30, 50 and 100mg/kg. Green and black tea polysaccharides were capable of reducing mortality rate by 40% and 25% respectively, compared to sham-controls. The influx of neutrophils was also affected, decreasing its accumulation in lungs and tissue injury. The difference between the green and black tea polysaccharides seems to result from the processing that the leaves have undergone and the different abilities to prevent mice death can be related to the different uronic acid contents.