Inhibition of metastatic potential of B16-F10 melanoma cell line in vivo and in vitro by biflorin

Aim: The aim of this study was to determine the antimetastatic potential of biflorin using in vivo and in vitro approaches. Main methods: Biflorin was isolated from Capraria biflora collected in Fortaleza, Ceara, Brazil. Adhesion, migration and invasion assays were performed to avail of the antimetastatic potential of this quinone. Experimental metastasis was performed to avail of the antimetastatic potential of bilflorin using in vivo assay. Key findings: Treatment with biflorin (25 and 50 mg/kg/day) was shown to be effective in reducing B16-F10 melanoma metastasis in C57BL/6 mice. The administration of biflorin at 25 mg/kg/day intraperitoneally inhibited the formation of metastases by about 57% compared to untreated control animals. When the animals were treated with 50 mg/kg/day intraperitoneally, there was a 71% decrease in the number of lung metastases. Morphological assays showed the presence of hemosiderin and erythrocytes in the lung parenchyma, indicating the occurrence of hemorrhage, probably a side effect of biflorin. Biflorin at non-toxic concentrations (0.5, 1.0 and 1.5 g/mL) was tested directly on B16-F10 cells in vitro, and it inhibited cell adhesion to type I collagen and cell motility using the wound-healing assay. Significance: These data suggest that biflorin has a promising antimetastatic potential, as shown by its anti-adhesion, anti-migration and anti-invasion properties against a metastatic melanoma cell line. However, further studies are essential to elucidate its mechanism of action. (C) 2013 Elsevier Inc. All rights reserved.