Ziziphusjujuba "Huizao" Polysaccharides Exert Immunomodulatory Activity In Vitro and In Vivo by Modulating the...

Area of Science:

• Immunology
• Natural Products Chemistry
• Pharmacology

Background:

• Ziziphus jujuba polysaccharides are known for their immunomodulatory effects.
• Polysaccharides are key active compounds in Ziziphus jujuba for immune system support.

Purpose of the Study:

• To investigate the immunomodulatory effects of "Huizao" polysaccharides (HP2-1) from Ziziphus jujuba.
• To elucidate the molecular mechanisms underlying HP2-1's immune-enhancing properties.

Main Methods:

• In vitro assays using RAW264.7 cells to assess cell viability and phagocytic activity.
• In vivo studies in immunosuppressed mice to evaluate cytokine production, immunoglobulin levels, and oxidative stress markers.
• Analysis of the Toll-like receptor 4 (TLR4)/mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB) signaling pathway.

Main Results:

• HP2-1 significantly increased RAW264.7 cell viability and phagocytosis.
• HP2-1 promoted the secretion of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), nitric oxide (NO), and reactive oxygen species (ROS).
• In vivo, HP2-1 elevated immunoglobulin levels, enhanced antioxidant enzyme activity, and reduced malondialdehyde (MDA) levels in immunosuppressed mice.
• HP2-1 upregulated TLR4 expression, leading to the activation of ERK, JNK, and p38 MAPKs, and subsequent NF-κB activation and cytokine secretion.

Conclusions:

• "Huizao" polysaccharides (HP2-1) exhibit significant immunomodulatory and antioxidant effects.
• HP2-1 enhances immune responses through the TLR4/MAPK/NF-κB signaling pathway.
• Ziziphus jujuba polysaccharides represent a promising natural source for immune system enhancement.