Investigation of the effects of anthocyanins on rubratoxin B-treated HL60 cells

Abstract

The effects of anthocyanins on hepatotoxin rubratoxin B-treated HL60 cells were investigated. Anthocyanins are known to have an anti-oxidant activity and corresponding protective effects on hepatic injury. While cyanidin 3-O-β-_D-glucoside (Cy 3-glc) and peonidin 3-O-β-_D-glucoside (Pn 3-glc) slightly impaired the inhibitory effect of rubratoxin B on cell proliferation, their effects were not significant. In contrast, malvidin 3-O-β-_D-glucoside (Mv 3-glc) drastically strengthened the effect of rubratoxin B. Structural difference between Mv 3- glc and the others is the presence of an R group in the 5' position at the B ring, suggesting that the group in this position affected the proliferation of rubratoxin B-treated cells. The results for cytokine secretion were apparently different from those for cell proliferation. The effects of the three anthocyanins on rubratoxin B-induced secretion of interleukin-8 and tumor necrosis factor-α were not substantial. At 100 μM, all the anthocyanins markedly boosted the secretion of monocyte chemotactic protein (MCP)-1, indicating that the common structure shared by the three anthocyanins affected rubratoxin B-induced MCP-1 secretion. In this study, we thus found that anthocyanins exert their activities in ways that either do or do not depend on the identity of the R group in the 5' position at their B ring.