An Acidic Polysaccharide with Anti-Inflammatory Effects from Blackened Jujube: Conformation and Rheological Properties

An acidic polysaccharide fraction (BJP-4) was isolated from blackened jujube, and its advanced structures and anti-inflammatory activity were investigated. X-ray diffraction showed that BJP-4 exhibits both crystalline and amorphous portions. Atomic force microscopy data suggested that it contains a large number of spherical lumps. Circular dichroism and Congo red experiments revealed that it has no triple-helix conformation. In steady shear flow results, the BJP-4 solution was a pseudoplastic non-Newtonian fluid with acid-base stability. BJP-4 (20 mg/mL) showed liquid-like properties (G '' > G'), while it performed weak gel-like behavior at a high concentration (40 mg/mL) (G' > G ''). The anti-inflammatory effects of BJP-4 were further evaluated through in vitro experiments. BJP-4 could down-regulate the over-secretion of inflammatory factors (NO, IL-6, IL-1 beta, TNF-alpha, iNOS and COX-2) in RAW264.7 cells due to LPS stimulation. Moreover, it demonstrated that BJP-4 restrained the NF-kappa B signal pathway by regulating TLR4 expression, reducing I kappa B alpha phosphorylation level and NF-kappa B p65 nuclear translocation. In summary, this present study contributes to the application of blackened jujube polysaccharides in the foods and medicine field.

Automated summary

This study isolated an acidic polysaccharide fraction (BJP-4) from blackened jujube and investigated its advanced structures and anti-inflammatory activity. The results showed that BJP-4 exhibited acid-base stability and had liquid-like properties as well as weak gel-like behavior. In vitro experiments demonstrated that BJP-4 could down-regulate the over-secretion of inflammatory factors and inhibit the NF-kappa B signal pathway. These findings contribute to the application of blackened jujube polysaccharides in the foods and medicine field.