Lycium barbarum Polysaccharide Regulates Activation of RAW264.7 Macrophages Through MGL/TLR Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the mechanism of Lycium barbarum polysaccharides （LBP） in promoting the activation of RAW264.7 macrophages. MethodRAW264.7 macrophages were stimulated with LBP at different concentrations （50， 100， 200 mg·L-1）， and those stimulated with lipopolysaccharide （LPS） at 100 μg·L-1 and galactose （Gal） at 100 mg·L-1 as positive controls. After 24 h of LBP stimulation， the cell counting kit-8 （CCK-8） was used to detect the survival rate of RAW264.7 macrophages treated with LBP （0， 50， 100， 200， 400， 800 mg·L-1）. The levels of interleukin-6 （IL-6） and interleukin-12 （IL-12） in cell culture supernatant were detected by enzyme-linked immunosorbent assay （ELISA）. The protein and mRNA expression of p38 mitogen-activated protein kinase （MAPK）， extracellular signal-regulated kinase （ERK）， c-Jun N-terminal kinase （JNK）， and nuclear factor κB （NF-κB） in Toll-like receptor 4 （TLR4）/Toll-like receptor 2 （TLR2）/macrophage galactose-type lectin （MGL） pathway of RAW264.7 macrophages was detected by Real-time fluorescence-based quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultCCK-8 results showed that compared with the results in the blank group， the survival rate of RAW264.7 macrophages decreased in the 400， 800 mg·L-1 LBP groups （P<0.05）. ELISA results showed that compared with the blank group， 50 mg·L-1 LBP could promote the secretion of IL-12 in RAW264.7 macrophages （P<0.01）. Compared with the blank group， 100 mg·L-1 LBP and 200 mg·L-1 LBP could promote the secretion of IL-6 in RAW264.7 macrophages （P<0.05， P<0.01）. Western blot results showed that compared with the blank group， the LBP groups （50， 100， 200 mg·L-1） enhanced protein expression levels of MAPK key molecules （p-p38 MAPK， p-ERK， p-NF-κB， and p-JNK） in TLR4， TLR2， and MGL pathways （P<0.05， P<0.01）. Compared with the model group， the 200 mg·L-1 LBP group could promote the expression level of p-NF-κB protein in RAW264.7 macrophages （P<0.01）. Real-time PCR results showed that compared with the blank group， the LBP groups （50， 100， and 200 mg·L-1） enhanced the mRNA expression levels of MAPK key molecules （p38 MAPK， ERK， NF-κB， and JNK） in TLR4 and TLR2 pathways （P<0.05， P<0.01）. Compared with the model group， the 50 and 200 mg·L-1 LBP groups could promote the mRNA expression levels of JNK and ERK2 in RAW264.7 macrophages （P<0.05， P<0.01）. ConclusionLBP can regulate the activation of RAW264.7 macrophages and participate in the immune response through the TLR2/TLR4/MGL pathway.