Betaine (BET) is a component of many food. It is an essential osmolyte and a source of methyl groups. BET consumed from food sources and through dietary supplements presents similar bioavailability. BET exerts an antioxidant activity and decreases inflammation states. Dietary supplement with BET are used in many inflammation-connected pathologies, although its mechanism of action is not fully understood. Recent studies have shown that BET stimulates muscle fibers differentiation via insulin like growth factor 1 (IGF-I). It is well known that IGF-I is one of the proliferating and differentiating factors affecting osteoblast activity. IGF-I and II are the most abundant growth factors produced by bone and stored in the bone matrix. On this basis, we evaluated the effect of BET on bone cells. Human osteoblasts (hOb) derived from trabecular bone waste material of orthopaedic surgery (Ethics Committee approved) were treated with 10 mM BET at 3, 6 and 24 h.
Real-time PCR results showed that BET induced a significant increase in IGF-I mRNA at 3 (P<0.05) and 6 h (P<0.01) after treatment. Immunofluorescence staining showed a significant increase of IGF-I protein at 6 and 24 h after BET treatment. Moreover, BET stimulated significantly (P<0.01) the expression of RUNX2, osterix, bone sialo protein and osteopontin. Western blotting results showed a significant (P<0.05) increase of osteopontin as well. BET was also able to increase the expression of SOD1 mRNA and SOD2 protein levels.
These preliminary results showed that BET has a stimulatory effect on osteogenic genes and on genes involved in antioxidant activity in hOb. Further studies are needed to fully characterize the mechanisms of action of BET in bone. However, considering that senile osteoporosis is frequently accompanied by enhanced inflammatory state, there might be a rationale in the use of BET as dietary supplement.
14 - 17 May 2016
European Calcified Tissue Society