Effect of Vigna angularis on toll-like receptor activation and pro-inflammatory cytokine production = 적소두 추출물이 톨유사수용체 활성 및 염증유발 사이토카인의 생성에 미치는 영향

Abstract

The mechanisms of Toll-like receptor (TLR) signaling have been the focus of extensive studies because TLRs are the target of therapeutic intervention on multiple diseases. In this study, we investigated the inhibitory potential of Vigna angularis (azuki bean) on the TLR signaling. The effect of Vigna angularis extract (JSD) on TLR activation was investigated by assessing NF-<TEX>${\kappa}B$</TEX> and AP-1 inducible secreted embryonic alkaline phosphatase (SEAP) activity. JSD significantly inhibited SEAP activity induced by poly I:C (TLR3 ligand) and poly I (TLR7 ligand) in a dose-dependent manner at concentration below 100 <TEX>${\mu}g/ml$</TEX> with no sign of cytotoxicity. Pretreatment of JSD markedly suppressed mRNA expressions of pro-inflammatory cytokines and adhesive molecules such as TNF-<TEX>${\alpha}$</TEX>, IL-6, RANTES, MCP-1 and ICAM-1 induced by TLR ligands. It also diminished the phosphorylation of <TEX>$I{\kappa}B$</TEX> kinase and <TEX>$I{\kappa}B$</TEX>, and followed by <TEX>$I{\kappa}B$</TEX>-mediated nuclear translocation of p50, p65, and phosphorylation of p38, JNK, and IRF signaling pathway. In conclusion, our results suggest that Vigna angularis has inhibitory activity on TLR-3 and -7 signaling and it can be further developed as a remedy in curing TLR-related multiple diseases.