[Objective]To evaluate the effect of polysaccharide from Polygonatum sibiricum on Toll-like receptor 4(TLR4)activation and clarify its antigen specific response-enhancing effect on mice.[Methods]The HEK-BlueTM hTLR4 cell line which was stably transfected with genes of human TLR4 and secreted embryonic alkaline phosphatase(SEAP)was used to quickly evaluate the activation of four different types of polysaccharide from Polygonatum sibiricum,including Polygonatum kingianum NP H2O(PKNH),Polygonatum kingianum AP H2O(PKAH),Polygonatum kingianum NP 5%EtOH(PKNEt)and Polygonatum kingianum AP 5%EtOH(PKAEt)on TLR4.C57BL/10ScNJ(TLR4-/-)mice were used to determine the relationship between the drug effect and TLR4.Ovalbumin(OVA)immunized mouse model was used to evaluate the enhancement of drug on specific immune response.The serum immunoglobulin G1(IgG1)and the cytokines related to the TLR4 signaling pathways such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interferon-γ inducible protein-10(IP-10)levels were detected by enzyme-linked immunosorbent assay(ELISA),and lymphocyte proliferation was evaluated by 5-[3-(Aarboxymethoxy)phenyl]-3-(4,5-dimethyl-2-thiazolyl)-2-(4-sulfophenyl)-2H-tetrazolium innersalt(MTS)assay.The mRNA expression levels of cytokines related to the TLR4 signaling pathways was determined by reverse transcription-polymerase chain reaction(RT-PCR).[Results]TLR4 was activated most strongly by treatment of neutral polysaccharides from PKNH for 24 h(P<0.001).Compared with wild type,the cell proliferation and the expressions of TNF-α,IL-6 and IP-10 were significantly decreased in PKNH treated splenic lymphocyte from C57BL/10 ScNJ mice(P<0.001).Intragastric administration of PKNH significantly increased serum IgG1 level(P<0.01)and promoted splenic lymphocyte proliferation in OVA immunized mice(P<0.05).[Conclusion]The polysaccharide from Polygonatum sibiricum PKNH enhances the antigen specific immune response through activation of TLR4.

[Objective]To evaluate the effect of polysaccharide from Polygonatum sibiricum on Toll-like receptor 4(TLR4)activation and clarify its antigen specific response-enhancing effect on mice.[Methods]The HEK-BlueTM hTLR4 cell line which was stably transfected with genes of human TLR4 and secreted embryonic alkaline phosphatase(SEAP)was used to quickly evaluate the activation of four different types of polysaccharide from Polygonatum sibiricum,including Polygonatum kingianum NP H2O(PKNH),Polygonatum kingianum AP H2O(PKAH),Polygonatum kingianum NP 5%EtOH(PKNEt)and Polygonatum kingianum AP 5%EtOH(PKAEt)on TLR4.C57BL/10ScNJ(TLR4-/-)mice were used to determine the relationship between the drug effect and TLR4.Ovalbumin(OVA)immunized mouse model was used to evaluate the enhancement of drug on specific immune response.The serum immunoglobulin G1(IgG1)and the cytokines related to the TLR4 signaling pathways such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interferon-γ inducible protein-10(IP-10)levels were detected by enzyme-linked immunosorbent assay(ELISA),and lymphocyte proliferation was evaluated by 5-[3-(Aarboxymethoxy)phenyl]-3-(4,5-dimethyl-2-thiazolyl)-2-(4-sulfophenyl)-2H-tetrazolium innersalt(MTS)assay.The mRNA expression levels of cytokines related to the TLR4 signaling pathways was determined by reverse transcription-polymerase chain reaction(RT-PCR).[Results]TLR4 was activated most strongly by treatment of neutral polysaccharides from PKNH for 24 h(P<0.001).Compared with wild type,the cell proliferation and the expressions of TNF-α,IL-6 and IP-10 were significantly decreased in PKNH treated splenic lymphocyte from C57BL/10 ScNJ mice(P<0.001).Intragastric administration of PKNH significantly increased serum IgG1 level(P<0.01)and promoted splenic lymphocyte proliferation in OVA immunized mice(P<0.05).[Conclusion]The polysaccharide from Polygonatum sibiricum PKNH enhances the antigen specific immune response through activation of TLR4.