Effects of baicalin, baicalein, and wogonin on interleukin-6 and interleukin-8 expression, and nuclear factor-κb binding activities induced by interleukin-1β in human retinal pigment epithelial cell line

• Published in: Experimental eye research Vol. 77; no. 2; pp. 195 - 202
• Main Authors: Nakamura, Nobuo, Hayasaka, Seiji, Zhang, Xue-Yun, Nagaki, Yasunori, Matsumoto, Masayuki, Hayasaka, Yoriko, Terasawa, Katsutoshi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2003
• Subjects: anti-inflammatory agent; baicalein; baicalin; cytokine; gene expression; interleukin; plant flavonoids; retinal pigment epithelium; wogonin; cytokine; baicalin; plant flavonoids; baicalein; retinal pigment epithelium; interleukin; wogonin; gene expression; anti-inflammatory agent
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/S0014-4835(03)00116-7

The objective of the study was to investigate the effects of baicalin, baicalein, and wogonin (plant flavonoids) on interleukin-6 (IL-6) and interleukin-8 (IL-8) protein production, mRNA expression, and nuclear factor-κB (NF-κB) binding activities induced by interleukin-1β (IL-1β) in human retinal pigment epithelial cell line (ARPE-19) cells. To induce IL-6 and IL-8 mRNA expression and protein levels, IL-1β was added to serum-free medium of ARPE-19 cells and incubated. The flavonoids were added to the medium. IL-6 and IL-8 in the media were measured using enzyme-linked immunosorbent assay. Both IL-6 and IL-8 mRNA were measured by semiquantitative reverse transcription polymerase chain reaction. The binding activities of the transcription factor NF-κB complexes to IL-6 and IL-8 were measured by electrophoretic mobility shift assay. IL-6 and IL-8 in the culture media of ARPE-19 cells were increased by IL-1β in a dose-dependent manner. Baicalin did not suppress IL-1β-induced IL-6 and IL-8 production, but dexamethasone, baicalein, and wogonin, significantly suppressed IL-6 and IL-8 production. Elevation of IL-6 and IL-8 mRNA was not suppressed by baicalin but was significantly suppressed by dexamethasone, baicalein, and wogonin. NF-κB binding activities were not suppressed by baicalin and baicalein, but was suppressed by wogonin. Wogonin and baicalein inhibited IL-1β-induced IL-6 and IL-8 mRNA and protein production in ARPE-19 cells. The data suggest that wogonin may inhibit IL-6 and IL-8 mRNA expression via the suppression of NF-κB binding activities.