Immune And Anti-inflammatory Effects Of Magnolol And Its Mechanisms

Magnolol is the main active constituents of traditional Chinese medicine Magnolia officinalis. Preliminary study showed that magnolol has pharmacological action on anti-inflammatory, anti-bacterial, anti-viral, anti-tumor, anti-asthma, anti-oxidant, cardiovascular protection, anti-ulcer, analgesia, hormone regulation, etc. Currently, there was achieved a certain achievements on immunological activity and anti-inflammatory activity of magnolol, but the mechanism remains need to further expand and study.Objective: This paper was designed to study the effect of magnolol on human immune cells and the influence of the phagocytosis and anti-inflammatory activities is researched by U937 cell model and the mechanism will be looked for. Our research was to provide experimental data and theory basis for research on anti-inflammatory drug related with Magnolol.Methods: MTT is used to make sure the non-toxic concentrations.on U937 cell and L0-2 cell, FCM and Confocal is used to test the influence of Magnolol on phagocytosis. Griess reagent is used to examined the effect of NO release of magnolol on LPS-induced U937 cell. CCK-8 is used to assay the effect of magnolol on PBMC and T cells. Real-time PCR is used to further investigated the effect of magnolol on mRNA expression of IL-1β and TNF-α and protein released by ELISA. The signaling pathways as MAPK and NF-κB were assayed by Western blotting.Result: Magnolol has little toxicity to U937 cells when the dose less than 40μM, and has a dose-dependent effect on autophagy when dose between 10 to 40μM, and the autophagy can be nearly increase about 50% when dose is 40μM. It make a inhibition of cells survival on PBMC in 1-20μM and promotes T cell proliferation in 10-20μM but Inhibits in 1μM. In the concentration range 1-40μM, the affection of LPS inducing NO release can be inhibited significantly; the mRNA of IL-1β and TNF-α expression can be inhibited in a dose-dependent manner, and has the most obviously effect in the 40μM dose. It has few effect on ERK1/2 of MAPK paths way, but has effect on decreasing the phosphorylate level of JNK and p38. The phosphorylate IκBα and p65 in NF-κB paths way can be inhibited in a dose-dependent manner. The IL-1β secretion of U937 cell can also be inhibited in a dose-dependent manner and has a significance effect in high dose of 40μM. magnolol has little effect on TNF-α secretion when in a low dose of 10 or 20 μM, and has an obvious effect in high dose of 40 μM.Conclusion: Magnolol can increase the autophagy function of U973 cells in vitro; it can inhibit PBMC cells survival and promotes T cell proliferation in high concentration but Inhibits in low. It has anti-inflammatory by down-regulation the JNK and p38 phosphorylate level of MAPK paths way and IκBα and p65 of NF-κB paths way.