Immunostimulatory activities of β-d-glucan from Ganoderma Lucidum

A water-insoluble β-(1→3)-d-glucan (GLPs) with few branches at C-6 and C-2 positions was extracted from the fruit body of Ganoderma Lucidum by 1 M NaOH at 40 °C. By the striking inhibition of NO and TNF-α production, GLPs showed significant anti-inflammation activity against LPS induced Raw 264.7 cells. Results of RT-PCR revealed the down regulation of iNOS and TNF-α mRNA gene expression. GLPs severely inhibited the phosphorylation of IκBα and JNK1/2, while the ERK1/2 and p38 were not apparently affected by GLPs. The neutralizing antibodies against dectin-1 and TLR-4, respectively, did not affect GLPs-mediated inhibition of NO production. But neutralizing of TLR2 affected the inhibition of NO. All of these results revealed that GLPs can inhibit the inflammation of Raw 264.7 cell induced by LPS at least partially attributed to the blocking of NF-κB and JNK MAPK, and TLR2 plays a major role in GLPs anti-inflammation activity.