BACKGROUND

Artemisia princeps Pampanini (Asteraceae) is used as a traditional medicine to immune function-related diseases, such as dysmenorrhea, inflammation, cancer, and ulcers.

OBJECTIVE

The purpose of this study is to evaluate the immunostimulatory effects of the hot water extract from the leaves of Artemisia princeps Pampanini (WAPP) in recombinant interferon-γ (rIFN-γ)-primed RAW 264.7 macrophages and in cyclophosphamide (20mg/kg, i.p.)-induced immunosuppressed Sprague-Dawley rats.

METHODS

RAW 264.7 macrophages were treated with WAPP and production and expressions of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) via nuclear factor-κB (NF-κB) were detected by immunoassay, western blot, qRT-PCR and reporter gene assay. In addition, in vivo immunomodulatory activity was studied by cyclophosphamide-induced myelosuppression in rats.

RESULTS

In rIFN-γ-primed RAW 264.7 macrophages, pretreatment with WAPP increased the productions of nitric oxide (NO) and tumor necrosis factor-α (TNF-α),and increased the expressions of inducible nitric oxide synthase (iNOS) at the protein level and of iNOS and TNF-α at the mRNA level. Molecular data revealed that WAPP upregulated the transcriptional activity and translocation of nuclear factor-κB (NF-κB) by activating inhibitory kappa B-α (IκB-α) degradation and phosphorylation. Furthermore, WAPP upregulated the phosphorylations of p38 MAP kinase, c-Jun NH2-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2). In cycloheximide-induced immunosuppressed rats, pretreatment with WAPP (100, 200, or 400mg/kg, p.o.) increased the serum levels of albumin and globulin, and reduced immobility times.

CONCLUSIONS

Our results suggest that upregulations of the expressions of iNOS and TNF-α via the activations of NF-κB and MAPK are responsible for the immunostimulatory effects of WAPP.