Objective
The present study explored the effects of the combined herbal therapy consisting of curcumin (CUR) and Fructus Ligustri Lucidi (FLL) on aspects of bone regeneration.
Methods
Prior to analyzing the ability of this novel combined herbal therapy to promote aspects of bone regeneration, its cytotoxicity was determined using MC3T3-E1 cells (pre-osteoblast model). Cell proliferation was evaluated using phase-contrast microscopy and cell differentiation was estimated using alkaline phosphatase activity. The effect of the combined herbal therapy (CUR?+?FLL) was also assessed in terms of mineralization in the extracellular matrix (ECM) of cultured cells. Further, to explore the molecular mechanisms of bone formation, time-dependent expression of bone-regulating protein biomarkers was also evaluated.
Results
Combined herbal therapy (CUR?+?FLL) significantly upregulated the viability, proliferation and differentiation of MC3T3-E1 cells compared to the monotherapy of CUR or FLL. The magnitude of ECM mineralization (calcium deposition) was also higher in MC3T3-E1 cells treated with combined therapy. The time-dependent expression of bone-forming protein biomarkers revealed that the tendency of expression of these bone-regulating proteins was remarkably higher in cells treated with combined therapy.
Conclusion
The co-administration of CUR and FLL had superior promotion of elements of bone regeneration in cultured cells, thus could be a promising alternative herbal therapy for the management of bone erosive disorders such as osteoporosis.

Key words: Osteoporosis, Curcumin, Fructus Ligustri Lucidi, Combined herbal therapy, Cell proliferation, Cell differentiation, Bone formation