Tripeptide IRW (Ile-Arg-Trp) as a Potential Nutraceutical Intervention in Osteoporosis

Current Knowledge on Peptide Physiology (SY(T7)1)

Abstract

Bone health is an important medical concern in rapidly aging demographics worldwide. Excessive bone resorption, due to enhanced activity of osteoclasts, is a major underlying cause of bone disorders such as osteoporosis. Inflammation and oxidative stress are key factors contributing to increased osteoclastic activity. Like increased activity of osteoclasts, depletion of osteoblasts also contributes to weakened structural integrity of bone. Considering the epidemiology of bone disorders and aging demographics there is a substantial need for novel bone health therapeutics. IRW (Ile-Arg-Trp), an egg-derived tripeptide, exhibits a spectrum of pharmacological activity. In our recent work, we have shown that IRW inhibits osteoclastogenesis and promotes osteogenesis in the mouse macrophage RAW 264.7 and MC3T3-E1 cells. IRW treatment (25 and 50 μM) significantly inhibited osteoclastogenesis-associated factors [TRAF6 (TNF Receptor Associated Factor 6), Fos Proto-Oncogene (c-Fos), Nuclear Factor of Activated T Cells 1 (NFATc1), and cathepsin K] and upregulated osteogenesis-associated factors [RUNX2 (Runt-related transcription factor 2) and RANKL (Receptor activator of nuclear factor kappa-B ligand)] in the two cell lines. Currently, we are conducting studies to analyze the impact of IRW on Angiotensin II (Ang II)-induced stress in vitro and in vivo. In summary, our recent work presents the ability of IRW to prevent LPS-induced inflammatory bone resorption and activation of osteogenesis activity via multiple signaling pathways.