Characterization of a polysaccharide from the medicinal lichen, Usnea longissima, and its immunostimulating effect in vivo

• DOI: 10.1016/j.ijbiomac.2021.03.183
• Publication Date: 2021-03-30T21:45:37Z
• Authors: Teng Wang; Chen Shen; Feng Guo; Yuqin Zhao; Jie Wang; Kunlai Sun; Bin Wang; Yan Chen; Yin Chen
• Keywords: Mice, Inbred ICR; 0303 health sciences; Lichens; Spectrophotometry, Infrared; Hydrolysis; Parmeliaceae; Proton Magnetic Resonance Spectroscopy; Monosaccharides; Thymus Gland; Methylation; Antioxidants; Gas Chromatography-Mass Spectrometry; 3. Good health; Intestines; 03 medical and health sciences; Liver; Polysaccharides; Animals; Cytokines; Female; Immunization; Carbon-13 Magnetic Resonance Spectroscopy; Spleen

A polysaccharide, CSL-0.1, was isolated from the medicinal lichen, Usnea longissima. CSL-0.1 was a neutral rhamnose-containing glucogalactomannan with a molecular weight of 7.86 × 104 Da. The polysaccharide had a core mannan structure with (1 → 6)-α-d-Manp units as the main chain and was substituted at the O-2 positions with side chains containing (1 → 2)-α-d-Manp residue, [3)-α-Glcp(1 → 4)-α-Glcp(1→] and 6-O-substituted β-d-Galf units. 2-O- and 2,3-di-O-substituted Rhap units. The effects of CSL-0.1 on intestinal immunity and antioxidant activity were evaluated. CSL-0.1 increased the spleen and thymus indices in a dose-dependent manner and conferred immunomodulation on reversing the Th1/Th2-related cytokine imbalance in cyclophosphamide (CP)-induced immunosuppressed mice. CSL-0.1 could also enhance the levels of secretory immunoglobulin A in CP-injected mice. Additionally, the antioxidant levels in the liver and intestine of the mice were increased 20%-50% after intragastric injection by CSL-0.1.