Combined Effects of Soy Isoflavones and β-Carotene on Osteoblast Differentiation
AbstractSoy isoflavones, genistein, daidzein and its metabolite equol, as well as β-carotene have been reported to be effective for maintaining bone health. However, it remains to be elucidated whether combining soy isoflavones with β-carotene is beneficial to bone formation. This study investigated the combined effect of soy isoflavones and β-carotene on the differentiation of MC3T3-E1 preosteoblastic cells. Daidzein and genistein alone did not affect cell growth but increased alkaline phosphatase (ALP) activity. Beta-carotene alone inhibited cell growth and markedly enhanced ALP activity. Soy isoflavones combined with β-carotene resulted in higher ALP activity than treatment with isoflavones or β-carotene alone. We observed significant main effects of β-carotene on the enhanced expression of Runx2, ALP, and ostepontin mRNA, whereas there was a significant main effect of soy isoflavones on the expression of osterix mRNA. To investigate how β-carotene affected osteoblast differentiation, MC3T3-E1 cells were treated with retinoic acid receptor (RAR) pan-antagonist combined with β-carotene. Osteopontin and ALP mRNA expression levels, which were increased following treatment with β-carotene, were significantly suppressed by the RAR pan-antagonist. This suggests treatment with β-carotene enhanced early osteoblastic differentiation, at least in part via RAR signaling. These results indicate that a combination of isoflavones and β-carotene may be useful for maintaining a positive balance of bone turnover by inducing osteoblast differentiation. View Full-Text
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Nishide, Y.; Tousen, Y.; Tadaishi, M.; Inada, M.; Miyaura, C.; Kruger, M.C.; Ishimi, Y. Combined Effects of Soy Isoflavones and β-Carotene on Osteoblast Differentiation. Int. J. Environ. Res. Public Health 2015, 12, 13750-13761.
Nishide Y, Tousen Y, Tadaishi M, Inada M, Miyaura C, Kruger MC, Ishimi Y. Combined Effects of Soy Isoflavones and β-Carotene on Osteoblast Differentiation. International Journal of Environmental Research and Public Health. 2015; 12(11):13750-13761.Chicago/Turabian Style
Nishide, Yoriko; Tousen, Yuko; Tadaishi, Miki; Inada, Masaki; Miyaura, Chisato; Kruger, Marlena C.; Ishimi, Yoshiko. 2015. "Combined Effects of Soy Isoflavones and β-Carotene on Osteoblast Differentiation." Int. J. Environ. Res. Public Health 12, no. 11: 13750-13761.