Pectic polysaccharide from roots of Glycyrrhiza uralensis: Possible contribution of neutral oligosaccharide in the galacturonase-resistant region to anti-complementary and mitogenic activities

Two anti-complementary polysaccharide fractions (GR-2IIa and GR-2IIb), isolated from the roots of Glycyrrhiza uralensis Fisch et D.C., each gave five anti-complementary polysaccharides (GR-2IIa-1-5 and GR-2IIb-1-5) on h.p.l.c.; likewise, GR-2IIc gave two anti-complementary and mitogenic polysaccharides (GR-2IIc-1-2A and -2IIc-2) by gel filtration and h.p.l.c. GR-2IIc-1-2A showed the most potent anti-complementary activity. GR-2IIa-1-5 and GR-2IIb-1-5 contained 40-85% and 50-90% of GalA, respectively, in addition to Rha, Ara, and Gal. GR-2IIc-1-2A and -2IIc-2 mainly comprised Glc, Gal, GalA, and GlcA in addition to Rha, Fuc, Xyl, Ara, and Man. Methylation analysis and digestion with endo-alpha-(1----4)-polygalacturonase indicated that all of the polysaccharides contained polygalacturonan regions which were frequently methyl-esterified. GR-2II-a, -2IIb, and -2IIc gave enzyme-resistant fractions of large and intermediate sizes, in addition to oligogalacturonides. Each large fraction from GR-2IIa and -2IIb consisted mainly of Ara, Gal, and GalA, whereas the intermediate fractions were composed of small proportions of 2-Me-Fuc, 2-Me-Xyl, and apiose (Api), in addition to Rha, Ara, Gal, and GalA. The large fraction from GR-2IIc mainly contained Rha, Man, Gal, and GalA in addition to Fuc, Ara, Xyl, and Glc, whereas the intermediate fraction consisted of 2-Me-Fuc, 2-Me-Xyl, and Api, in addition to Rha, Ara, GalA, Fuc, Xyl, Man, Gal, and Glc. Base-catalysed beta-elimination followed by ethylation indicated that all the polysaccharides except GR-2IIc-2 contained a 4-linked uronic acid attached to position 2 of 2,4-linked Rha. Single radial gel diffusion, using the beta-D-glucosyl-Yariv antigen, indicated that GR-2IIa-1 and GR-2IIc-2 contained relatively large proportions of (1----3,6)-beta-D-galactan moieties. The anti-complementary activities of GR-2IIa-3, GR-2IIa-4, and GR-2IIb-4 decreased after de-esterification followed by digestion with endo-alpha-(1----4)-polygalacturonase. The large fractions from GR-2IIa-2IIc showed more potent anti-complementary activities than the original polysaccharide fractions, whereas the intermediate fractions and oligogalacturonides were inactive. The large fraction from GR-2IIc had more potent mitogenic activity than GR-2IIc, whereas the intermediate fraction and oligogalacturonides from GR-2IIc were inactive.

A dried decoction of a kampo (Japanese herbal) medicine, Juzen-Taiho-To (TJ-48), has been fractionated into five fractions and tested for their effects on antibody response of mice. An intraperitoneal injection (300 mg/kg) of TJ-48 stimulated anti-sheep red blood cell (SRBC) antibody response of normal Balb/c mice, but only the polysaccharide fraction (F-5, 300 mg/kg) enhanced the antibody response among the fractions from TJ-48. When F-5 (0.5 or 1.0 g/kg/day) was orally administered to normal Balb/c mice (7-weeks-old) from 7 days before to 4 days after immunization with SRBC, the number of anti-SRBC-IgM-PFC in spleen and the titer of anti-SRBC-IgM in plasma were increased significantly. However, a lower dose (0.1 g/kg/day) of F-5 did not show a significant stimulative activity on the anti-SRBC-response. Although aged Balb/c mice (6-months-old) produced a lower level of anti-SRBC-IgG in comparison with young Balb/c mice (8-weeks-old), the anti-SRBC-IgG response of the aged mice was stimulated significantly when F-5 (0.13 g/kg/day) or TJ-48 (1.0 g/kg/day) was orally administered to the aged mice from 6 days before immunization. Intraperitoneal injections of i-carrageenan (2.5 mg/kg/day) at 3 and 1 days before the immunization with SRBC increased the level of anti-SRBC antibody response compared with normal mice. Oral administrations of TJ-48 (1.0 g/kg/day) or F-5 (0.5 g/kg/day) to the i-carageenan-treated mice reduced the level of the anti-SRBC-antibody response near to that of normal mice.(ABSTRACT TRUNCATED AT 250 WORDS)

The Kampo (Japanese herbal) medicine "Juzen-Taiho-To" (TJ-48), which was prepared by decocting a concoction (formula), contains ten kinds of herbs and has several immunostimulating activities. In order to determine the contribution of each herbal component, the complement-activating and mitogenic activities of the hot water extract as well as the polysaccharide fraction from each herb were tested. Hot water extracts of Glycyrrhizae radix, Astragali radix, and Atractylodes lanceae rhizoma showed significant mitogenic activity whereas that of Cinnamomi cortex showed potent complement-activating activity. However, the exclusion of any single component herb whether active or not on its own did not result in a loss or an increase of the overall activity of TJ-48. The polysaccharide fraction from Glycyrrhizae radix showed the most potent of both activities among the same fractions from the other nine herbs, and reduced both activities after periodate oxidation, thus indicating that the carbohydrate moiety may contribute to both activities.