Role of the Antioxidant Lycopene in Bone Health: Emphasis on the RANKL/RANK/OPG Signaling Pathway.

Bone health is maintained by a balance between bone formation and bone resorption. Lycopene, a lipophilic carotenoid and an acyclic isomer of beta-carotene, functions as an antioxidant and may improve bone health via multiple pathways, including the suppression of inflammatory cytokines, stimulation of osteoblast activity, regulation of the wingless-related integration site (Wnt)/β-catenin pathway, and modulation of the receptor activator of nuclear factor-kB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) pathway. Our understanding of the mechanisms involved in bone remodeling has improved with the discovery of the RANK/RANKL/OPG pathway. Elevated RANKL/RANK signaling promotes osteoclastogenesis and consequently bone resorption, while inhibition of this pathway may prevent bone resorption. This review summarizes current evidence on the impact of lycopene on bone health via the RANK/RANKL/OPG signaling pathway, a key regulator of bone remodeling.