Effect of berberrubine on interleukin-8 and monocyte chemotactic protein-1 expression in human retinal pigment epithelial cell line

We examined the effects of berberrubine, a protoberberine alkaloid, on interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) expression in a human retinal pigment epithelial cell line (ARPE-19) stimulated with interleukin-1β (IL-1β) or tumor necrosis factor α (TNF-α). ARPE-19 cells were cultured to confluence. Berberrubine and IL-1β or TNF-α were added to the medium. IL-8 and MCP-1 protein concentrations were measured using enzyme-linked immunosorbent assay. IL-8 and MCP-1 mRNA were measured by real time polymerase chain reaction. Nuclear factor κB (NF-κB) translocation was examined by immunofluorescent staining/microscopy. Berberrubine dose-dependently inhibited IL-8 and MCP-1 protein levels in the media and mRNA expression of the cells stimulated with IL-1β or TNF-α. Immunofluorescent staining/microscopy of NF-κB in the nucleus of unstimulated cells was faint (51 ± 14 arbitrary units). Fluorescein was dense (215 ± 42 or 170 ± 24 arbitrary units, respectively) 30 min after stimulation with IL-1β or TNF-α and was decreased to 62 ± 18 or 47 ± 16 arbitrary units, respectively, by berberrubine. Berberrubine dose-dependently inhibited IL-8 and MCP-1 expression and protein secretion induced by IL-1β or TNF-α. Possibly, the effect on chemotactic factors may be via suppression of NF-κB translocation.