Physicochemical properties, immunostimulatory and antioxidant activities of a novel polysaccharide isolated from Mirabilis himalaica (Edgew) Heim

The traditional use, structure, and immunostimulatory activity of bioactive polysaccharides from traditional Chinese root medicines: A review

As research on traditional Chinese medicine (TCM) has expanded, our understanding of the role it can have in controlling the immune system has increased. Polysaccharides from medicinal plants exhibit numerous beneficial therapeutic properties, presumably owing to their modulation of innate immunity and macrophage function. Numerous studies have demonstrated the multiple ways whereby certain polysaccharides can affect the immune system. In addition to stimulating immune cells, such as T cells, B lymphocytes, macrophages, and natural killer cells, polysaccharides stimulate complements and increase cytokine secretion. The biological functions of polysaccharides are directly correlated with their structures. This paper summarizes the sources, TCM uses, extraction and purification methods, structural characterization, in vitro and in vivo immune activities, and underlying molecular mechanisms of TCM root polysaccharides. Moreover, the structure-activity relationships of TCM root polysaccharides are emphasized and discussed. This review can provide a scientific basis for the research and industrial utilization of TCM root polysaccharides.

Oxybaphus himalaicus Mitigates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting TLR4/MD2 Complex Formation

Acute kidney injury (AKI) is described as the abrupt decrease in kidney function always accompanied by inflammation. The roots of Oxybaphus himalaicus Edgew. have long been used in Tibetan folk medicine for the treatment of nephritis. Nevertheless, modern pharmacological studies, especially about the underlying mechanism of O. himalaicus medications, are still lacking. Here, in lipopolysaccharide (LPS)-induced RAW264.7 macrophages, the O. himalaicus extract (OE) showed significant anti-inflammatory activity with the dose dependently reducing the LPS-stimulated release of nitric oxide and the mRNA level and protein expression of inflammatory cytokines and reversed the activation of nuclear factor kappa B (NF-κB). Co-immunoprecipitation assay indicated that OE inhibited Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD2) complex formation and further suppressed both myeloid differentiation factor 88 (MyD88)-dependent and TIR-domain-containing adapter-inducing interferon-β (TRIF)-dependent cascades activation. In addition, OE could restrain NADPH oxidase 2 (NOX2) endocytosis by blocking TLR4/MD2 complex formation to prevent reactive oxygen species production. In LPS-induced AKI mice, OE treatment mitigated renal injury and inflammatory infiltration by inhibiting TLR4/MD2 complex formation. UPLC-MS/MS analysis tentatively identified 41 components in OE. Our results indicated that OE presented significant anti-inflammatory activity by inhibiting TLR4/MD2 complex formation, which alleviated LPS-induced AKI in mice.