Xinjiang herbal tea exerts immunomodulatory activity via TLR2/4-mediated MAPK signaling pathways in RAW264.7 cells and prevents cyclophosphamide-induced immunosuppression in mice

These results indicated that XMT-WE at 50 µg/ml exerts immunomodulatory activity via TLR2/4-mediated MAPK signaling pathways in RAW 264.7 cells. Furthermore, in vivo experiments revealed that XMT-WE at the dose of 50 and 100 mg/kg strongly stimulated inflammatory cytokines.

RAW 264.7 cells were treated with various concentrations of XMT-WE. Nitric oxide (NO) levels were determined using Griess reagents, and pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α were investigated with a cytometric bead array kit. The effects on mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α were investigated. Furthermore, activation of nuclear factor (NF)-κB and AP-1 mitogen-activated protein kinase (MAPK) signaling pathways was investigated.

Pre-treatment with XMT-WE significantly increased secretion of NO, IL-6, and TNF-α. In addition, XMT-WE markedly increased expression of iNOS, COX-2, and TNF-α as well as AP-1 and NF-κB translocation from the cytoplasm into the nucleus, which was associated with an increase of phosphorylated ERK, JNK, and p38 as well as membrane receptors such as toll-like receptor (TLR) 2 and TLR4. Moreover, XMT-WE promoted the secretion of interleukin-2 (IL-2) and interferon-γ (IFN-γ) in cyclophosphamide (CTX)-induced immunosuppressive mice.