An effect of apiogalacturonanic
pectin of duckweed Lemna minor L. (
lemnan LM) was studied on the inflammatory response to
ovalbumin injected intradermally into the footpad of control and
ovalbumin-fed mice.
Lemnan LM (1-2 mg per mouse) was found to enhance by as much as 50-60% the footpad swelling in control mice.
Oral administration of
ovalbumin was shown to result in sensitization that increased
inflammation.
Ovalbumin admixed with
lemnan was found to increase by two-fold footpad
edema in comparison with the mice receiving
ovalbumin alone. Apple
pectin used as a reference compound failed to influence the inflammatory reaction. Degradation of
lemnan was performed to elucidate the active region of the
polysaccharide macromolecule. The apiogalacturonanic fragment (LMP) obtained using a digestion of
lemnan LM with
pectinase was shown to increase the footpad response in both control and
ovalbumin-fed mice. Fragment LMPH deprived of some terminal
apiose residues as a result of partial acidic hydrolysis failed to have an effect on the inflammatory response.Thus, the data obtained reveal an enhancement by
lemnan of the inflammatory response. The ramified apiogalacturonan seemed to be the active region of the
lemnan macromolecule.