FIGURE 1.

Dried plum polyphenolic fractions (1 and 10 µg/mL) alter osteoclast differentiation and activity in primary bone marrow–derived cultures. Multinucleated TRAP-positive osteoclasts are indicated in the representative micrographs with arrows (A) and were quantified per well (B). Resorption pit assays were used to assess osteoclast activity. The resorbed area was stained (see arrows) (C) and was then quantified (D). The relative mRNA abundance of Nfatc1, Traf6, and cFos (E) during osteoclast differentiation was evaluated after 1 h of treatment with DP-FrE and DP-FrF (10 μg/mL). The relative abundance of p-p38 and pErk1/2 to total p38 and Erk was evaluated via immunoblotting after 1 h of treatment with dried plum polyphenolic fractions (10 μg/mL) and expressed relative to the control. Representative immunoblots are shown (F), and immunoblots (n = 3 replicates/experiment × 3 experiments) were quantified (G). Values in panels B, D, E, and G are means ± SEs. Data were analyzed by using ANOVA followed by Fisher's least significant difference test. Bars without a common letter are significantly different from each other, P < 0.05. CON, control; DP-Fr, dried plum fraction; Erk, extracellular signal–regulated kinase; Nfatc1, nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1; p-, phosphorylated; RANKL, receptor activator of NF-κB ligand; Traf6, TNF receptor–associated factor 6; TRAP, tartrate-resistant acid phosphatase.