Abstract
Rhododendron principis leaves have been used as “Dama”, a Traditional Tibetan Medicine for treating inflammatory
diseases. R. principis crude polysaccharides with
anticomplementary activity demonstrated promising anti-inflammatory effects on acute
lung injury induced by lipopolysaccharide. R. principis crude polysaccharides significantly
decreased the levels of TNF-α and interleukin-6 in both serum and blood and bronchoalveolar lavage fluid in lipopolysaccharide-induced
acute lung injury mice by intragastric
administration (100 mg/kg). A heteropolysaccharide, ZNDHP, was obtained from R. principis crude polysaccharides with successive anticomplementary activity-guided separation.
ZNDHP was
characterized as a branched neutral polysaccharide with a backbone composed of → 2)-β-Glcp-(1→, → 2,6)-α-Glcp-(1→, → 6,3)-β-Galp-(1→,
→ 2,6)-α-Galp-(1→, → 6,2)-β-Glcp-(1→, → 4)-α-Glcp-(1→, → 5)-β-Araf-(1→, → 3,5)-α-Araf-(1→, and
→ 4,6)-β-Manp-(1→, and the backbone structure was further confirmed by partial acid hydrolysis.
In addition to anticomplementary and antioxidant activities, ZNDHP exhibited
potent anti-inflammatory activity by significantly inhibiting the secretion of nitric
oxide, TNF-α, interleukin-6, and interleukin-1β of lipopolysaccharide-treated RAW 264.7
cells. However, all of these activities decreased greatly after partially hydrolyzing,
indicating the importance of the multibranched structure for its bioactivity. Therefore,
ZNDHP might be
an important component of R. principis for treating inflammation.
Key words
Ericaceae -
Rhododendron principis
- polysaccharide - anti-inflammatory - anticomplementary - structure characterization
