Multitargeted combination effects of a triherbal formulation containing ELP against osteoporosis: in vitro evidence.

ABSTRACT

OBJECTIVES: An anti-osteoporotic herbal formula ELP containing Epimedii Herba (E), Ligustri Lucidi Fructus (L) and Psoraleae Fructus (P) was studied to investigate the herb-herb interaction (or the possible synergistic effect) among each component and to identify the principal herbs in different modes of action. METHODS: Rat osteoblast-like UMR-106 cells proliferation, rat MSCs-derived osteoblastogenesis and RANKL-induced RAW 264.7 osteoclastogenesis were adopted to investigate the bone-forming activity and bone-degrading activity of the herbal extracts. In the statistical aspect, a modified Tallarida's approach was employed to assess the synergistic effects in herbal combinations. KEY FINDINGS: Psoraleae Fructus is the active herb for stimulating osteoblast proliferation, and mild synergy was detected in the pairwise combinations EL, LP and formula ELP. In osteoblastogenesis assay, E and L are the principal herbs for promoting osteoblast differentiation and significant synergy was detected in the pairwise combination EL. For inhibiting osteoclast formation, L is the active herb and significant synergy was detected in the 3-way combination ELP. CONCLUSIONS: The presence of E, L and P is essential for ELP formula as a whole to act against osteoporosis via enhancing bone formation and reducing bone reabsorption. An optimal dosage at 150 µg/ml was proposed for ELP based on our findings.