Interaction between human complement and a pectin type polysaccharide fraction, PMII, from the leaves of Plantago major L.
The interaction between a pectin type polysaccharide fraction, PMII, isolated from the leaves of Plantago major, and human complement was tested in two different hemolytic complement-fixation tests and in addition by two ELISA methods detecting complement-activation products. Sera were used as a complement source of 10 arbitrary human volunteers, individually and as a pool. The complement-fixation tests were designed to measure the concentration of the pectin necessary to inhibit 50% of the hemolysis (ICH(50)). The ELISA tests for complement-activation products were measured in AU/mg using a fully activated serum as a standard. We observed a more than 200-fold difference in ICH(50) activity of the PMII pectin in one of the hemolytic tests by varying the individual sera used as complement-source. On the other hand, the ELISA complement-activation tests showed no significant variation in activity of the PMII depending on the complement-serum used. The level of antibodies against PMII detected in the complement-sera did not correlate with the ICH(50) activity of PMII. The results show that PMII is a potent complement activator with an activity of the same order of magnitude on a weight basis as that of aggregated human immunoglobulin (Ig)G. This activation leads to a complement consumption probably explaining the PMII's effect in the complement-fixation tests. PMII seems to be an activator both on the classical and the alternative pathway of activation. The results might be related to the reported wound-healing effect of the leaves of Plantago major.
Michaelsen
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TE
Department of Vaccinology, National Institute of Public Health, Oslo, Norway. t.e.michaelsen@farmasi.uio.no
Gilje
A
A
Samuelsen
A B
AB
Høgåsen
K
K
Paulsen
B S
BS
D000328:Adult; D003167:Complement Activation; D003168:Complement Fixation Tests; D003170:Complement Pathway, Alternative; D003171:Complement Pathway, Classical; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D019684:Magnoliopsida / Q000737:chemistry; D008297:Male; D008519:Medicine, Traditional; D008875:Middle Aged; D010368:Pectins / Q000494:pharmacology*; D008517:Phytotherapy; D018515:Plant Leaves / Q000737:chemistry*; D010943:Plantago / Q000737:chemistry*; D010946:Plants, Medicinal
D010368:Pectins