Astragalus Polysaccharide Protects Astrocytes from Being Infected by HSV‐1 through TLR3/NF‐κB Signaling Pathway

Abstract

Astragalus polysaccharide (APS) is the most immunoreactive substance in Astragalus. APS can regulate the body's immunity and is widely used in many immune related diseases. However, till now, there is little information about its contribution to the protection of astrocytes infected by virus. Toll-like receptor 3 (TLR3) is a key component of the innate immune system and has the ability to detect virus infection and trigger host defence responses. This study was undertaken to elucidate the protective effect of APS on herpes simplex virus (HSV-1) infected astrocytes and the underlying mechanisms. The results showed that APS protected the astrocytes from HSV-1 induced proliferation inhibition along with increasing expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) markedly. Moreover, APS significantly promoted the expression of Toll-like receptor 3 (TLR3) and the activation of nuclear factor-κB (NF-κB) in astrocytes. In addition, while astrocytes were pretreated with TLR3 antibody before adding HSV-1 and APS, the expression of TLR3, TNF-α, and IL-6 and the activation of NF-κB decreased sharply. These results indicate that APS can protect astrocytes by promoting immunological function provoked by HSV-1 through TLR3/NF-κB pathway.

Astragalus polysaccharides inhibits PCV2 replication by inhibiting oxidative stress and blocking NF-κB pathway

“…The results pretreatment with BAY 11-7082 could increase the inhibition effects of APS on PCV2 replication by suppressing NF-B signaling pathway on the other hand. From two sides what has been discussed above, our study has showed that pre-treatment with APS inhibited PCV2 replication by suppressing NF-B signaling pathway, which was consistent with its anti-viral activity and anti-inflammation activity shown by blocking NF-B pathway [40,41]. Therefore, APS inhibit PCV2 replication by inhibiting oxidative stress and suppressing the NF-B signaling pathway.…”

chTLR4 pathway activation by Astragalus polysaccharide in bursa of Fabricius

“…3a ). We assumed that this might be related with the non-unique activation of TLR4 molecules in the presence of APS [ 1 ]. Also, chMyD88-dependent pathway could be stimulated by all TLRs.…”

“…Astragalus polysaccharide (APS), a medicinal herb, has been used for thousands years in China. Numerous studies have demonstrated that APS has a wide range of antiviral, antioxidant, anti-inflammatory, and immunoregulatory properties in mammals [ 1 – 4 ]. Shao et al demonstrated for the first time that APS directly interacted with Toll-like receptor 4 (TLR4) molecule [ 2 ].…”

Traditional Chinese Medicine as a Potential Source for HSV-1 Therapy by Acting on Virus or the Susceptibility of Host

“…Lately, the antiviral effect of APS was detected in astrocytes infected by HSV-1. Research uncovered that APS could not inhibit the virus directly, but instead it protected astrocytes by promoting immunological function, such as markedly increasing the expression of tumor necrosis factor-α (TNF-α), interleukin6 (IL-6), Toll-like receptor (TLR3), and nuclear factor-κB (NF-κB) provoked by HSV-1 [ 60 ].…”

“…Dpo ( 32 ) also improves the organism’s immunity against HSV-1 in a STING-dependent manner, hence contributing to a sustained and significant increase in IRF7 (interferon regulatory factor 7) [ 59 ]. Similarly, APS ( 33 ) (astragalus polysaccharide) promots immunological function by markedly increasing the expression of TNF-α (tumor necrosis factor-α), IL-6 (interleukin-6), TLR3 (toll-like receptor 3), and NF-κB provoked by HSV-1 [ 60 ]. From another perspective, IRF3 (interferon regulatory factor 3) can also be phosphorylated, and phosphorylated IRF3 activated type I interferon expression by binding to ISRE (interferon-stimulated response element) [ 76 ].…”