Chu‑Yen Chenga, Chia‑Chou Yeha,b*
aDepartment of Chinese Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chia-Yi, Taiwan, bSchool of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien, Taiwan
Open Access funded by Buddhist Compassion Relief Tzu Chi Foundation
Abstract
Objective: To investigate the mechanism of the adaptive effect of two compounds in Lonicerae japonica flos (LJF), luteolin (LUT) and chlorogenic acid (CGA), on the expression of interleukin (IL) IL‑10 and IL‑6. Materials and Methods: RAW264.7 cells receiving lipopolysaccharide (LPS) were pretreated with CGA and LJF. The expression of pro‑inflammatory cytokines and IL‑10 was evaluated by reverse transcription‑polymerase chain reaction. Moreover, the concentrations of IL‑10 and IL‑6 were measured by enzyme‑linked immunosorbent assay in the culture medium obtained 24 h after LPS treatment. Nuclear extracts of RAW264.7 cells, pretreated with CGA or LUT and LPS, were prepared after 6 h, and C/EBPβ and C/EBPδ were measured by Western blotting. Nuclear factor‑κB (NF‑κB) activity was measured by electrophoretic mobility shift assay. The phosphorylated form of IκB, ERK1/2, p38, JNK, and IκB, ERK2, p38, or JNK were also measured by Western blotting. Results: CGA enhanced the LPS-induced expression of IL-10 and IL-6, and increased NF-κB, Sp1, C/EBPβ and δ. The effect of CGA is interfered with Lut by suppressing the phosphorylation of IκB and p38, and NF-κB activity. In the event, IL-6 was suppressed and IL-10 was not influenced. Conclusion: LUT and CGA, which are abundant in LJF that is one of the ingredients in Gingyo‑san, have adaptive immunoregulative effect on the expression of IL‑10.
Keywords: Chlorogenic acid, Interleukin‑10, Lonicerae japonica flos, Luteolin
