Synergistic effects of combined therapy of curcumin and Fructus Ligustri Lucidi for treatment of osteoporosis: cellular and molecular evidence of enhanced bone formation.

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.