Tea flavonoids stimulate mineralization in osteoblast‐like cells (259.7)

Abstract

Epidemiological studies suggest that habitual tea consumption is associated with higher bone mineral density. Rooibos tea, in particular, is a rich source of flavonoids, including rutin, orientin, hyperoside, and luteolin, that may favorably modulate cellular processes such as hydroxyapatite production. The study objective was to determine if individual flavonoids (0.001µM‐100µM) promoted mineralization in Saos2 cells. Mineralization was quantified by alizarin red staining at day 21, while alkaline phosphatase activity, a marker of osteoblast cell activity, was determined at days 3, 7 and 10. Rutin (25µM), orientin (0.01µM), hyperoside (5µM) and luteolin (5µM) resulted in higher (p<0.05) mineral production than control. Higher mineral production was associated with higher alkaline phosphatase activity (p<0.05) for rutin (25µM), orientin (0.1µM), hyperoside (1µM) and luteolin (1µM) as early as 3 days into the mineralization process. Maximum enzyme activity was dependent on the flavonoid. Mitochondrial activity, a marker of cellular proliferation, reflected the mineralization data. In conclusion, flavonoids can positively influence mineral production in osteoblasts and this is, in part, due to higher osteoblast activity. Thus, tea flavonoids are a promising area for future research investigating dietary approaches for bone health.Grant Funding Source: Supported by a NSERC Discovery Grant for W. Ward