Low concentrations of caffeic acid phenethyl ester stimulate osteogenesis in vitro

The aim of this study was to evaluate the effects of caffeic acid phenethyl ester (CAPE) on osteoblast-like cell cultures (SAOS-2).

SAOS-2 were exposed to CAPE at 1 nM, 10 nM, 100 nM, 1 μM, and 10 μM. Non-exposed cultures were used as control. The following parameters were assayed: 1) cell viability at 1, 3, and 7 days; 2) alkaline phosphatase (ALP) activity at 5 and 10 days; 3) matrix mineralization at 14 days; and 4) Runt-related transcription factor 2 (RUNX2), ALP, osteopontin (SPP1), and osteocalcin (BGLAP) gene expression at 5 and 10 days. The data were analyzed by ANOVA two-way or Kruskal-Wallis (α = 5%).

At day 1, cell viability was similar among all groups (p > 0.05). At days 3 and 7, cultures exposed to CAPE at 10 μM exhibited a significant reduction in cell viability compared with the others groups (p < 0.05). At day 5, ALP activity was similar among all experimental groups; at day 10, however, the stain intensity was higher in cultures exposed to CAPE at 100 nM and 10 nM in comparison with the other groups (p < 0.05). At days 5 and 10, RUNX2, ALP, SPP1, and BGLAP gene expression was greater in cultures exposed to CAPE in comparison with the control (p < 0.05). At day 14, matrix mineralization was similar in cultures exposed to CAPE at 1 nM and 10 nM (p > 0.05), but superior to those ones observed in the other experimental groups (p < 0.05).

CAPE at low concentrations can positively module the osteogenesis in vitro.