Comparisons of Chemical Characteristics, Antioxidant, Immunomodulatory, and Lipid-Lowering Activities of Polysaccharides of Hemerocallis citrina from Different Producing Areas

Hemerocallis citrina (H. citrina) is not only consumed as a vegetable, but also utilized as a medicinal plant. Polysaccharides are major components of H. citrina, which possess a variety of biological activities. The present study was conducted to perform preliminary comparisons of chemical characteristics, antioxidant, immunomodulatory, and lipid-lowering activities of the polysaccharides in H. citrina from five major producing areas of China (e.g., Qidong, Huaiyang, Qingyang, Datong, and Dali). The results showed that these H. citrina polysaccharides (HCPQD, HCPHY, HCPQY, HCPDT, and HCPDL) exhibited different chemical characteristics, of which HCPQD and HCPHY had higher uronic acid content. Regarding monosaccharide composition, these H. citrina polysaccharides were mainly composed of Man, Glc, and Gal, especially HCPQD had higher Man, GlcA, and GalA contents, HCPHY had higher Gal and GalA contents. The in vitro assay showed that these H. citrina polysaccharides had potent antioxidant, immunomodulatory, and lipid-lowering activities, of which HCPQD had stronger antioxidant and immunomodulatory activities, and HCPHY had stronger lipid-lowering activity. In conclusion, this is the first study to report on the variations in H. citrina polysaccharides from the primary production regions, which will help to enhance the bioactivity-based quality control of H. citrina polysaccharides for consumers and processors.