Abstract
Glyceollins, produced to induce disease resistance responses against specific species, such as an incompatible pathogen Phytophthora sojae in soybeans, have the potential to exhibit anti-inflammatory activity in RAW 264.7 cells. To investigate the anti-inflammatory effects of elicited glyceollins via a signaling pathway, we studied the glyceollin signaling pathway using several assays including RNA and protein expression levels. We found that soybean glyceollins significantly reduced LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the expression of inducible ΝΟ synthase (iNOS) and cyclooxygenase-2 (COX-2) via the suppression of NF-κB activation. Glyceollins also inhibited the phosphorylation of IκBα kinase (IKK), the degradation of IκBα, and the formation of NF-κB-DNA binding complex in a dose-dependent manner. Furthermore, they inhibited pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-18, but increased the generation of the anti-inflammatory cytokine IL-10. Collectively, the present data show that glyceollins elicit potential anti-inflammatory effects by suppressing the NF-κB signaling pathway in RAW 264.7 cells.